U.S. patent application number 10/396881 was filed with the patent office on 2003-11-27 for radar warning receiver with position and velocity sensitive functions.
This patent application is currently assigned to Escort Inc.. Invention is credited to Orr, Steven K..
Application Number | 20030218562 10/396881 |
Document ID | / |
Family ID | 26836859 |
Filed Date | 2003-11-27 |
United States Patent
Application |
20030218562 |
Kind Code |
A1 |
Orr, Steven K. |
November 27, 2003 |
Radar warning receiver with position and velocity sensitive
functions
Abstract
A GPS enabled radar detector (20) that aids in the management of
unrelated or otherwise unimportant sources (16), permitting the
detector to dynamically improve its handling of such sources based
upon previously-stored geographically-referenced information on
such sources. The detector includes technology (30, 32) for
determining the location of the detector, and comparing this
location to the locations of known stationary sources, to improve
the handling of such detections. The detector may ignore detections
received in an area known to contain a stationary source, or may
only ignore specific frequencies or may handle frequencies
differently based upon historic trends of spurious police radar
signals at each frequency. A Global Positioning Satellite System
(GPS) receiver (30, 32) is used to establish current physical
coordinates. The detector maintains a list (50, 82) of the
coordinates of the known stationary source "offenders" in
nonvolatile memory. Each time a microwave or laser source is
detected, it will compare its current coordinates to this list.
Notification of the driver will take on a variety of forms
depending on the stored information and current operating
modes.
Inventors: |
Orr, Steven K.; (Cincinnati,
OH) |
Correspondence
Address: |
WOOD, HERRON & EVANS, L.L.P.
2700 Carew Tower
441 Vine St.
Cincinnati
OH
45202
US
|
Assignee: |
Escort Inc.
West Chester
OH
|
Family ID: |
26836859 |
Appl. No.: |
10/396881 |
Filed: |
March 25, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10396881 |
Mar 25, 2003 |
|
|
|
09889656 |
Mar 15, 2002 |
|
|
|
09889656 |
Mar 15, 2002 |
|
|
|
PCT/US00/16410 |
Jun 14, 2000 |
|
|
|
60139097 |
Jun 14, 1999 |
|
|
|
60145394 |
Jul 23, 1999 |
|
|
|
Current U.S.
Class: |
342/20 |
Current CPC
Class: |
G01S 7/04 20130101; G01S
19/41 20130101; G01S 7/4806 20130101; G01S 19/42 20130101; G01S
7/022 20130101 |
Class at
Publication: |
342/20 |
International
Class: |
G01S 007/40 |
Claims
What is claimed is:
1. A police warning receiver comprising: a receiver section adapted
to receive electromagnetic signals indicative of police activity;
an alert section responsive to the receiver section and adapted to
provide an alert if a received electromagnetic signal correlates to
a police signal; and a position determining circuit generating a
location signal; wherein the alert section is further responsive to
the location signal and adapted to alter or not provide the alert
if the location signal correlates to a location of a rejectable
signal.
2. The police warning receiver of claim 1, wherein said
electromagnetic signals include radar signals in a radar band.
3. The police warning receiver of claim 1, wherein said
electromagnetic signals are carried in the visible or infrared
spectrum.
4. The police warning receiver of claim 1, wherein the alert
section further correlates said rejectable signal to said received
electromagnetic signal, and alters the alert based upon the result
of the correlation.
5. The police warning receiver of claim 1 wherein said rejectable
signal is correlated to said received electromagnetic signal by
comparing frequencies of said rejectable signal to frequencies of
said received signal.
6. The police warning receiver of claim 5 further comprising
storage for signal information associated with geographic
locations, said signal information identifying rejectable signals
at each geographic location.
7. The police warning receiver of claim 6 wherein said storage for
signal information includes a signal incidence counter identifying
a number of times a signal has been received by said receiver.
8. The police warning receiver of claim 7 wherein said storage for
signal information includes a plurality of signal incidence
counters, each associated with a frequency block and identifying a
number of times a signal within the associated frequency block has
been received by said receiver.
9. The police warning receiver of claim 8 wherein frequencies of
said received signal are compared to frequencies in said signal
information database to identify frequencies of said received
signal having low valued signal incidence counters.
10. The police warning receiver of claim 9 wherein, upon
identification of a frequency of said received signal having a low
valued signal incidence counter in said signal information
database, an alert signal is provided.
11. The police warning receiver of claim 1 further comprising
storage for flags associated with geographic locations, said flags
identifying rejectable signals at each geographic location.
12. The police warning receiver of claim 11 wherein said flags
include a flag associated with each of a plurality of frequencies
identified by said receiver, and indicating whether received
signals of the associated frequency are rejectable; and said
received electromagnetic signal is correlated to rejectable signals
by comparing frequencies of said received signal to rejectable
signal frequencies identified by said flags.
13. The police warning receiver of claim 11 wherein said flags
include a flag associated with a geographic location indicating
that all signals received at said geographic location are
rejectable; and said alert section is adapted to alter or not
provide the alert if a flag associated with the location signal
indicates that all signals received at said geographic location are
rejectable.
14. The police warning receiver of claim 11 wherein said flags
include a flag associated with a geographic location indicating
that all signals received at said geographic location are
rejectable and should be minimally visually identified; and said
alert section is adapted to provide a minimal visual alert if a
flag associated with the location signal indicates that all signals
received at said geographic location are rejectable and should be
minimally identified.
15. The police warning receiver of claim 1 further comprising
storage for signal information associated with geographic
locations, said signal information identifying rejectable signals
at each geographic location.
16. The police warning receiver of claim 15 further comprising an
interface connector, wherein signal information is stored in said
storage via said interface connector.
17. The police warning receiver of claim 1 adapted to access signal
information associated with geographic locations, said signal
information identifying rejectable signals at each geographic
location.
18. The police warning receiver of claim 17 further comprising
communication circuitry for obtaining said signal information from
an Internet resource.
19. The police warning receiver of claim 17 further comprising
communication circuitry for obtaining said signal information from
a general purpose computer.
20. The police warning receiver of claim 17 further comprising
communication circuitry for obtaining said signal information from
another police warning receiver.
21. The police warning receiver of claim 16 wherein said interface
connector complies with one of a universal serial bus standard, an
automotive wiring standard, the J1854, CAN, BH12 and LIN
standards.
22. The police warning receiver of claim 15 wherein said receiver
has a training mode in which said signal information is modified
based upon electromagnetic signals received by the police warning
receiver.
23. The police warning receiver of claim 22 wherein said signal
information comprises a signal incidence counter associated with a
geographic location, said signal incidence counter is incremented
upon reception of an electromagnetic signal at said geographic
location, and said signal incidence counter is decremented upon
failure to receive an electromagnetic signal at said geographic
location.
24. The police warning receiver of claim 23 wherein said signal
information comprises a plurality of signal incidence counters each
associated with a geographic location and a frequency block, a
signal incidence counter is incremented upon reception of an
electromagnetic signal in an associated frequency block at an
associated geographic location, and a signal incidence counter is
decremented upon failure to receive an electromagnetic signal in an
associated frequency block at an associated geographic
location.
25. The police warning receiver of claim 24 wherein said frequency
blocks are associated with frequencies of radar-band
electromagnetic signals, and said signal incidence counters are
incremented and decremented upon reception or failure to receive a
radar-band electromagnetic signal.
26. The police warning receiver of claim 1 further comprising
storage for vehicle history information identifying vehicle
activities including geographic locations entered by a vehicle
carrying said receiver.
27. The police warning receiver of claim 26 wherein said vehicle
history information comprises geographic locations entered by a
vehicle carrying said receiver and velocities of said vehicle at
said locations.
28. The police warning receiver of claim 1 wherein said receiver is
responsive to a user input confirming police activity, to identify
one or more geographic locations in which electromagnetic signals
are not rejectable.
29. The police warning receiver of claim 1 further comprising
storage for route information identifying geographic locations
relevant to a route traveled by a vehicle carrying said
receiver.
30. The police warning receiver of claim 29 further comprising
storage for signal information associated with geographic locations
of said route, said signal information identifying rejectable
signals at each geographic location of said route, wherein said
receiver detects transit of said vehicle along said route and in
response accesses said signal information to identify rejectable
signals.
31. The police warning receiver of claim 30 wherein said receiver
modifies said signal information based upon electromagnetic signals
received by the police warning receiver while traveling said
route.
32. The police warning receiver of claim 31 wherein said signal
information comprises a signal incidence counter associated with a
geographic location, said signal incidence counter is incremented
upon reception of an electromagnetic signal at said geographic
location, and said signal incidence counter is decremented upon
failure to receive an electromagnetic signal at said geographic
location.
33. The police warning receiver of claim 32 wherein said signal
information comprises a plurality of signal incidence counters each
associated with a geographic location and a frequency block, a
signal incidence counter is incremented upon reception of an
electromagnetic signal in an associated frequency block at an
associated geographic location, and a signal incidence counter is
decremented upon failure to receive an electromagnetic signal in an
associated frequency block at an associated geographic
location.
34. The police warning receiver of claim 1 wherein said receiver
tracks geographic locations in which electromagnetic signals are
continuously received.
35. The police warning receiver of claim 34 wherein said receiver
is responsive to a police confirmation by a user thereof to
identify tracked geographic locations in which electromagnetic
signals have been continuously received, as not rejectable.
36. The police warning receiver of claim 34 wherein said receiver
is responsive to a location lockout by a user thereof to identify
tracked geographic locations in which electromagnetic signals have
been continuously received, as not rejectable.
37. The police warning receiver of claim 34 wherein said receiver
tracks geographic locations in which electromagnetic signals of
each of a plurality of frequencies are continuously received.
38. The police warning receiver of claim 37 wherein said receiver
is responsive to a frequency lockout by a user thereof to identify
tracked geographic locations and frequencies in which
electromagnetic signals have been continuously received, as not
rejectable.
39. The police warning receiver of claim 15 wherein said receiver
stores signal information for geographic locations for which no
signal information has previously been stored.
40. The police warning receiver of claim 39 wherein said receiver
has a data overwrite mode in which signal information is erased to
provide room to store signal information for geographic locations
for which no signal information has previously been stored, and a
mode in which erasure of signal information is prevented.
41. The police warning receiver of claim 1 wherein said receiver
has a warning suppression mode in which the alert section is
adapted to alter or not provide an alert.
42. The police warning receiver of claim 1 wherein said receiver
has an expert meter mode in which the alert section is adapted to
display detailed information on said received signal.
43. A police warning receiver comprising: a receiver section
adapted to receive electromagnetic signals indicative of police
activity; an alert section responsive to the receiver section and
adapted to provide an alert if a received electromagnetic signal
correlates to a police signal; and a position determining circuit
generating a location signal; storage for vehicle history
information identifying vehicle activities including geographic
locations entered by a vehicle carrying said receiver.
44. The police warning receiver of claim 43 wherein said vehicle
history information comprises geographic locations entered by a
vehicle carrying said receiver and velocities of said vehicle at
said locations.
45. The police warning receiver of claim 43, wherein said
electromagnetic signals include radar signals in a radar band.
46. The police warning receiver of claim 43, wherein said
electromagnetic signals are carried in the visible or infrared
spectrum.
47. The police warning receiver of claim 43 wherein said storage
further stores signal information associated with geographic
locations, said signal information identifying rejectable signals
at geographic locations, said receiver correlating a received
electromagnetic signal to rejectable signals at a geographic
location corresponding to said location signal, and altering or not
providing an alert if the rejectable signals correlate to the
received electromagnetic signal.
48. The police warning receiver of claim 43 adapted to access
signal information associated with geographic locations, said
signal information identifying rejectable signals at each
geographic location.
49. The police warning receiver of claim 48 further comprising
communication circuitry for obtaining said signal information from
an Internet resource.
50. The police warning receiver of claim 48 further comprising
communication circuitry for obtaining said signal information from
a general purpose computer.
51. The police warning receiver of claim 48 further comprising
communication circuitry for obtaining said signal information from
another police warning receiver.
52. The police warning receiver of claim 43 further comprising an
interface connector, wherein vehicle history information may be
retrieved from said storage via said interface connector.
53. The police warning receiver of claim 52 wherein said interface
connector complies with one of a universal serial bus standard, an
automotive wiring standard, the J1858, CAN, BH12 and LIN
standards.
54. A police warning receiver comprising: a receiver section
adapted to receive electromagnetic signals indicative of police
activity; an alert section responsive to the receiver section and
adapted to provide an alert if a received electromagnetic signal
correlates to a police signal; and a dynamically allocatable
storage device storing information accessible to said receiver or
alert sections, and storing information usable by said receiver or
alert sections in receiving or correlating electromagnetic
signals.
55. The police warning receiver of claim 54, wherein said
electromagnetic signals include radar signals in a radar band.
56. The police warning receiver of claim 54, wherein said
electromagnetic signals are carried in the visible or infrared
spectrum.
57. The police warning receiver of claim 54, wherein said storage
device stores information on rejectable signals, and the alert
section further correlates a rejectable signal to said received
electromagnetic signal, and alters the alert based upon the result
of the correlation.
58. The police warning receiver of claim 54 wherein said rejectable
signal is correlated to said received electromagnetic signal by
comparing frequencies of said rejectable signal to frequencies of
said received signal.
59. The police warning receiver of claim 58 further comprising a
position determining circuit generating a location signal, wherein
said storage device stores signal information associated with
geographic locations, said signal information identifying
rejectable signals at each geographic location, and wherein said
alert section correlates a rejectable signal for a location
corresponding to said location signal, to said received
electromagnetic signal, and alters the alert based upon the result
of the correlation.
60. The police warning receiver of claim 59 adapted to access and
store said signal information associated with geographic locations
from external sources.
61. The police warning receiver of claim 60 further comprising
communication circuitry for obtaining said signal information from
an Internet resource.
62. The police warning receiver of claim 60 further comprising
communication circuitry for obtaining said signal information from
a general purpose computer.
63. The police warning receiver of claim 60 further comprising
communication circuitry for obtaining said signal information from
another police warning receiver.
64. The police warning receiver of claim 54 wherein said mass
storage device stores vehicle history information identifying
vehicle activities including velocities of a vehicle carrying said
receiver.
65. The police warning receiver of claim 64 further comprising a
position determining circuit generating a location signal, wherein
said vehicle history information comprises geographic locations
entered by a vehicle carrying said receiver and velocities of said
vehicle at said locations.
66. The police warning receiver of claim 54 further comprising an
interface connector, wherein information is stored in said storage
device via said interface connector.
67. The police warning receiver of claim 66 wherein said interface
connector complies with one of a universal serial bus standard, an
automotive wiring standard, the J1862, CAN, BH12 and LIN
standards.
68. A police warning receiver comprising: a receiver section
adapted to receive electromagnetic signals indicative of police
activity; an alert section responsive to the receiver section and
adapted to provide an alert if a received electromagnetic signal
correlates to a police signal; a display for displaying information
to a user; a position determining circuit generating a location
signal; and storage for information relating to prior encounters of
electromagnetic signals by the police warning receiver at
geographic locations; wherein information presented on said display
is derived from information relating to a prior encounter of an
electromagnetic signal at a geographic location corresponding to
the location signal.
69. The police warning receiver of claim 68, wherein said
electromagnetic signals include radar signals in a radar band.
70. The police warning receiver of claim 68, wherein said
electromagnetic signals are carried in the visible or infrared
spectrum.
71. The police warning receiver of claim 68, wherein the alert
section correlates information relating to a prior encounter of an
electromagnetic signal to said received electromagnetic signal, and
alters the alert based upon the result of the correlation.
72. The police warning receiver of claim 68 wherein said
information relating to prior encounters of electromagnetic signals
comprises signal information identifying signals received at each
geographic location.
73. The police warning receiver of claim 72 wherein said signal
information includes a signal incidence counter identifying a
number of times a signal has been received by said receiver at each
geographic location.
74. The police warning receiver of claim 68 wherein said
information relating to prior encounters of electromagnetic signals
comprises flags associated with geographic locations, said flags
identifying rejectable signals at each geographic location.
75. The police warning receiver of claim 68 further comprising an
interface connector, wherein information relating to prior
encounters of electromagnetic signals is stored in said storage via
said interface connector.
76. The police warning receiver of claim 75 wherein said interface
connector complies with one of a universal serial bus standard, an
automotive wiring standard, the J1862, CAN, BH12 and LIN
standards.
77. The police warning receiver of claim 68 adapted to access and
store said information relating to prior encounters from external
sources.
78. The police warning receiver of claim 77 further comprising
communication circuitry for obtaining said signal information from
an Internet resource.
79. The police warning receiver of claim 77 further comprising
communication circuitry for obtaining said signal information from
a general purpose computer.
80. The police warning receiver of claim 77 further comprising
communication circuitry for obtaining said signal information from
another police warning receiver.
81. A police warning receiver comprising: a receiver section
adapted to receive electromagnetic signals indicative of police
activity; an alert section responsive to the receiver section and
adapted to provide an alert if a received electromagnetic signal
correlates to a police signal; and a digital interface connector,
wherein said police warning receiver is configurable in response to
digital signals received via said digital interface connector.
82. The police warning receiver of claim 81, wherein said
electromagnetic signals include radar signals in a radar band.
83. The police warning receiver of claim 81, wherein said
electromagnetic signals are carried in the visible or infrared
spectrum.
84. The police warning receiver of claim 81 wherein said interface
connector complies with one of a universal serial bus standard, an
automotive wiring standard, the J1866, CAN, BH12 and LIN
standards.
85. The police warning receiver of claim 81 wherein said interface
connector is connectable to a digital computer for configuration of
said receiver.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a United States continuation-in-part of
U.S. Provisional Patent Application serial No. 60/139,097, filed
Jun. 14, 1999, and a United States continuation-in-part of U.S.
Provisional Patent Application serial No. 60/145,394, filed Jul.
23, 1999, both of which are hereby incorporated herein in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to radar warning
receivers.
BACKGROUND OF THE INVENTION
[0003] Radar detectors warn drivers of the use of police radar, and
the potential for traffic citations if the driver exceeds the speed
limit. The FCC has allocated several regions of the electromagnetic
spectrum for police radar use. The bands used by police radar are
generally as the X, K and Ka bands. Each relates to a different
part of the spectrum. The X and K bands are relatively narrow
frequency ranges, whereas the Ka band is a relatively wide range of
frequencies. By the early 1990's, police radar evolved to the point
that it could operate almost anywhere in the 1600-megahertz wide Ka
band. During that time radar detectors kept pace with models that
included descriptive names like "Ultra Wide" and "Super Wide." More
recently, police have begun to use laser (optical) systems for
detecting speed. This technology was termed LIDAR for "Light
Detection and Ranging."
[0004] Radar detectors typically comprise a microwave receiver and
detection circuitry that is typically realized with a
microprocessor or digital signal processor (DSP). Microwave
receivers are generally capable of detecting microwave components
in the X, K, and very broad Ka band. In various solutions, either a
microprocessor or DSP is used to make decisions about the signal
content from the microwave receiver. Systems including a digital
signal processor have been shown to provide superior performance
over solutions based on conventional microprocessors due to the
DSP's ability to find and distinguish signals that are buried in
noise. Various methods of applying DSP's were disclosed in U.S.
Pat. Nos. 4,954,828, 5,079,553, 5,049,885, and 5,134,406, each of
which is hereby incorporated by reference herein.
[0005] Police use of laser has also been countered with laser
detectors, such as described in U.S. Pat. Nos. 5,206,500, 5,347,120
and 5,365,055, each of which is incorporated herein by reference.
Products are now available that combined laser detection into a
single product with a microwave receiver, to provide comprehensive
protection.
[0006] The DSP or microprocessor in a modern radar detector is
programmable. Accordingly, they can be instructed to manage all of
the user interface features such as input switches, lights, sounds,
as well as generate control and timing signals for the microwave
receiver and/or laser detector. Early in the evolution of the radar
detector, consumers sought products that offered a better way to
manage the audible volume and duration of warning signals. Good
examples of these solutions are found in U.S. Pat. Nos. 4,631,542,
5,164,729, 5,250,951, and 5,300,932, each of which is hereby
incorporated by reference, which provide methods for conditioning
the response generated by the radar detector.
[0007] Methods for conditioning detector response are gaining
importance, because there is an increasing number of signals
present in the X, K, and Ka bands from products that are completely
unrelated to police radar. These products share the same regions of
the spectrum and are also licensed by the FCC. The growing number
of such signals is rapidly undermining the credibility of radar
detector performance. Radar detectors cannot tell the difference
between emissions from many of these devices and true police radar
systems. As a result, radar detectors are increasingly generating
false alarms, effectively "crying wolf", reducing the significance
of warnings from radar detectors.
[0008] One of the earliest and most prevalent unrelated Microwave
sources is the automatic door system used in many commercial
buildings such as supermarkets, malls, restaurants and shopping
centers. The majority of these operate in the X-Band and produce
signals virtually indistinguishable from conventional X-Band Police
Radar. Other than the fact that door opening systems are vertically
polarized, vs circular polarization for police radar, there is no
distinction between the two that could be analyzed and used bv a
receiver design.
[0009] Until recently, virtually all of the door opening systems
were designed to operate in the X-Band. As a result, radar
detectors generally announced X-Band alerts far more often than
K-Band. As these X-Band `polluters` grew in numbers, ultimately 99%
of X-Band alerts were from irrelevant sources. X-Band alerts became
meaningless. The only benefit that these sources offered the user
was some assurance that the detector was actually capable of
detecting radar. It also gave the user some intuition into the
product's detection range. To minimize the annoyance to users, most
radar detector manufacturers added a filter-like behavior that was
biased against X-Band sources. Many also added "Band priority" that
was biased against X and in favor of bands that were less likely to
contain irrelevant sources such as K, Ka, and Laser. If signals in
both X and K Bands were detected, band prioritization would
announce K, since it was more likely be a threat to the driver. In
the last few years, K-Band door opening systems have also grown in
number. This has reduced the significance of the K-Band warning and
further undercut the overall benefit to the user of a radar
detector.
[0010] Another unrelated microwave signal is generated by traffic
management systems such as the ARTIMIS manufactured by TRW, used in
Cincinnati, Ohio. ARTIMIS Stands for "Advanced Regional Traffic
Interactive Management and Information System", and reports traffic
flow information back to a central control center. Traffic
congestion and other factors are analyzed by the control center.
Control center employees use this information to formulate routing
suggestions and other emergency information, which they transmit to
a large distribution of overhead and roadside signs. In order to
collect information on vehicle traffic, a roadside ARTIMIS station
transmits an X-Band signal toward cars as they drive by. The
ARTIMIS source, unlike the X-Band door opener systems, is
distinguishable from police radar as it is not transmitted at a
single fixed frequency. As a result, it is possible to
differentiate police radar signals from sources such as ARTIMIS,
and ignore ARTIMIS sources in newer detectors. Older detectors,
however, do not incorporate this feature and could be obsolete in
areas where ARTIMIS is in use.
[0011] Unrelated Microwave signals are also transmitted by a system
called the RASHID VRSS. Rashid is an acronym for Radar Safety Brake
Collision Warning System. This electronic device warns heavy trucks
and ambulances of hazards in their path. A small number of these
RASHID VRSS units have been deployed. They are categorized as a
member of the `non-stationary` set of unrelated sources. As in the
ARTIMIS example, detection of RASHID can be prevented.
[0012] Perhaps the biggest source of non-stationary unrelated
sources is from other radar detectors. These are sometimes referred
to as "polluting radar detectors," and present a serious threat to
some detector products. An early example of this occurred in the
mid 1980's when radar detectors using superhomodyne circuitry
became popular. Such detectors leak energy in the X-Band and
K-bands and appeared as police radar to other detectors. A solution
to this problem is described in U.S. Pat. No. 4,581,769, which is
hereby incorporated by reference in its entirety. A similar problem
occurred in the early 1990's when the Ka band was widened. An
unexpected result was that the wider Ka band then also detected
harmonics of.signals generated by local oscillators within many
existing radar detectors. U.S. Pat. No. 5,305,007, which is hereby
incorporated by reference in its entirety, describes a method for
ignoring these polluting detectors.
[0013] At this time, there are very few signal sources that can
cause false laser detections in comparison to the substantial list
of false microwave signals just described. However there are
certain types of equipment that can cause the amplifiers and
detection circuitry used in a laser detector to generate a "false"
detect. In particular, certain locations near airports have been
demonstrated to cause such problems for various laser detector
products. As a result, selected airport environments are examples
of stationary signals that produce false laser detections.
[0014] As can be appreciated from the foregoing example, as sources
of unrelated signals continue to propagate, radar detectors must
continually increase in sophistication to filter unrelated sources
and accurately identify police radar. Each of these changes and
enhancements has the potential effect of obsoleting existing
detectors that do not include appropriate countermeasures.
Furthermore. some sources. particularly stationary door opener
sources, at this time cannot be filtered economically, and thus
threaten the usefulness of even the most sophisticated modern radar
detector.
[0015] During the 1980's, the functionality of radar detectors
expanded into other classes of driver notification. A system was
developed that required a special transmitter be placed on
emergency vehicles, trains, and other driving hazards. The term
`emergency radar` was coined, and a variety of products were
introduced that could detect these transmitters. One such solution
was disclosed in U.S. Pat. No. 5,559,508, which is hereby
incorporated by reference herein in its entirety. Another system
was later introduced offering a larger class of `hazard categories`
called the SWS system. Both emergency radar and SWS involve the
transmission of microwave signals in the `K` band. Such signals are
considered to be a part of the group of signal types that are
intended to be detected by radar detectors.
[0016] A drawback of these warning systems is that stationary
transmitters of these signals send the same message to drivers
constantly, and become a nuisance during daily commute. This is
beneficial to `new` drivers receiving the message for the first
time. However these messages become an annoyance to drivers who
follow the same path to work everyday.
[0017] Thus, radar detector manufacturers are continually
confronted with new problems to solve, due to the variety of
different types of unrelated sources and their sheer numbers. The
rate at which new or upgraded radar detector models are introduced
continues to increase as manufacturers try to evolve their products
to manage the growing number of unrelated sources. Meanwhile, the
market for radar detectors is shrinking because consumers are no
longer interested in buying products that so quickly become
obsolete.
SUMMARY OF THE INVENTION
[0018] The present invention overcomes these difficulties bv
providing a method of operating a radar detector that aids in the
management of unrelated sources, and permitting the detector to
dynamically improve its handling of unrelated sources. As noted
above, many non-stationary sources can be identified and ignored
using existing technology. However, many stationary sources cannot,
as yet be effectively filtered economically with existing
technology. Accordingly, the invention provides a radar detector
that includes technology for determining the location of the
detector, and comparing this location to the locations of known
stationary sources, to improve the handling of such detections.
[0019] In one embodiment, a radar detector may ignore detections
received in an area known to contain a stationary source. In the
specific embodiment described below, substantially more
sophisticated processing is performed to determine whether and what
actions to take in response to a detection.
[0020] The Global Positioning Satellite System (GPS) offers an
electronic method for establishing current physical coordinates
very accurately. In the detailed embodiment described below, a
radar detector utilizes a GPS system to determine its current
position. The detector also maintain a list of the coordinates of
the known stationary source "offenders" in nonvolatile memory. Each
time a microwave or laser source is detected, it will compare its
current coordinates to this list. Notification of the driver will
take on a variety of forms depending on the setup
configuration.
[0021] By adding GPS conditioning capabilities to a radar detector,
the combination becomes a new product category that is capable of
rejecting signals from any given location no matter what the nature
of the microwave/laser signals might be from that location. This
will have a dramatic effect on the usable life of the product and
subsequent value to its owner.
[0022] The above and other objects and advantages of the present
invention shall be made apparent from the accompanying drawings and
the description thereof.
BRIEF DESCRIPTION OF THE DRAWING
[0023] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and, together with a general description of the
invention given above, and the detailed description of the
embodiments given below, serve to explain the principles of the
invention.
[0024] FIG. 1 is an illustration of a vehicle receiving radar
signals from police radar and from a number of unrelated sources,
and further receiving global positioning signals from a global
positioning satellite;
[0025] FIG. 2 is an electrical block diagram of a radar detection
circuit in accordance with principles of the present invention;
[0026] FIG. 3 is a illustration of a database structure used by the
radar detection circuit of FIG. 2, for storing information radar
signals received or receivable from unrelated sources at a number
of locations, as identified by cell coordinates;
[0027] FIG. 4 is an illustration of a database structure used for
storing historic information on the locations of a vehicle carrying
the radar detection circuit of FIG. 2, as identified by cell
coordinates;
[0028] FIG. 5 is an illustration of a database structure used for
storing flags identifying various conditions at a number of
locations, as identified by cell coordinates;
[0029] FIG. 6A is a flow chart of the operations of the CPU of the
radar detector of FIG. 2, carrying out principles of the present
invention;
[0030] FIG. 6B is a flow chart of operations of the CPU of FIG. 2
in processing GPS information when GPS signals are being
received;
[0031] FIG. 6C is a flow chart of operations of the CPU of FIG. 2
in updating stored information when a radar signal is being
received; FIG. 6D is a flow chart of operations of the CPU of FIG.
2 in updating stored information when a radar signal is not being
received;
[0032] FIG. 6E is a flow chart of operations of the CPU of Fig.2 in
responding to keypad activity to change operative mode of the GPS
enabled radar detector; and
[0033] FIG. 6F is a flow chart of operations of the CPU of FIG. 2
in generating audible and visible responses based upon operating
modes of the radar detector and the presence or absence of radar
signals and stored information.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0034] To provide background for the present invention, a summary
of GPS (Global Positioning System) technology will now be provided.
GPS is a mature technology that provides a method for a GPS
receiver to determine its relative location and velocity at any
time. The (GPS) system is a worldwide constellation of 24
satellites and their ground stations. GPS receivers on earth use
`line of sight` information from these satellites as reference
points to calculate positions accurate to a matter of meters.
Advanced forms of GPS actually enable measurements to within a
centimeter. The Global Positioning System consists of three
segments: a space segment of 24 orbiting satellites, a control
segment that includes a control center and access to overseas
command stations, and a user segment, consisting of GPS receivers
and associated equipment. Over time GPS receivers have been
miniaturized to just a few integrated circuits and have become very
economical.
[0035] An unfortunate side effect of the GPS system is that it can
be used by enemy forces, as GPS signals can be picked up by any
receiver including both domestic and foreign. When the United
States Department of Defense devised the GPS system they
incorporated a feature that prevents high precision measurements
unless the receiver is equipped with special military `keys.` This
is accomplished with the intentional introduction of "noise" into
the satellite's clock data which adds noise (or inaccuracy) into
position calculations. The DOD sometimes also sends slightly
erroneous orbital data to the satellites, which is transmitted back
to receivers on the ground. This intentional degradation is
referred to as "Selective Availability" or "SA" error. Military
receivers use a decryption key to remove the SA errors. As a result
of the SA error, there are two classes of GPS service, "Standard
Positioning Service (SPS) and "Precise Positioning System" (PPS.).
These classes are realized by having GPS satellites transmit two
different signals: the Precision or P-code and the Coarse
Acquisition or C/A-code. The P-code is designed for authorized
military users and provides PPS service. To ensure that
unauthorized users do not acquire the P-code, the DOD can engage an
encryption segment on the P-code called anti-spoofing (AS). The
C/A-code is designed for use by nonmilitary users and provides SPS
service. The C/A-code is less accurate and easier to jam than the
P-code. It is also easier to acquire, so military receivers first
track the C/A-code and then transfer to the P-code. Selective
availability is achieved by degrading the accuracy of the
C/A-code.
[0036] The precision of SPS is stated as providing 100-meter
horizontal and 156 meter vertical accuracy "95% of the time." PPS
is only available for the U.S. and allied military, certain U.S.
Government agencies, and selected civil users specifically approved
by the U.S. Government. PPS provides 22 meters horizontal and 22.7
meters vertical accuracy 95% of the time.
[0037] Other than intentional errors inserted by the DOD, there are
a variety of other error sources that vary with terrain and other
factors. GPS satellite signals are blocked by most materials. GPS
signals will not pass through buildings, metal, mountains, or
trees. Leaves and jungle canopy can attenuate GPS signals so that
they become unusable. In locations where at least four satellite
signals with good geometry cannot be tracked with sufficient
accuracy, GPS is unusable.
[0038] The "Differential GPS" system was developed in order to
compensate for the inaccuracy of GPS readings. A high-performance
GPS receiver (known as a reference station or beacon) is placed at
a specific location; the information it receives is then compared
to the receiver's location and corrects the SA satellite signal
errors. The error data is then formatted into a correction message
and transmitted to GPS users on a specific frequency (300 kHz). A
true or arbitrary set of coordinates are assigned to the position
occupied by a reference GPS receiver. The difference between these
and the coordinates received via GPS at the reference is a very
close approximation to the SA error at nearby sites. This error is
nearly identical to the error calculated by any nearby GPS
receiver. The reference site is sometimes referred to as a
`beacon,` as it constantly transmits these difference coordinates.
A DPGS receiver is designed to receive both the GPS information and
the beacon information. It generates a far more accurate estimate
of its coordinates by applying the difference information to the
GPS coordinates. The drawback to this is that the remote and
reference receivers may not be using the same set of satellites in
their computations. If this is the case, and the remote receiver
incorporates the corrections, it may be accounting for satellite
errors that are not included in its own measurement data. These
corrections can make the differential solution worse than the
uncorrected GPS position. To prevent this error, an improved form
of differential GPS involves the derivation of the corrections to
the actual measurements made at the reference receiver to each
satellite. By receiving all of the corrections independently, the
remote receiver can pick and choose which are appropriate to its
own observations. This method of DGPS is most widely used.
Typically, the DGPS correction signal loses approximately 1 m of
accuracy for ever 150 km of distance from the reference
station.
[0039] The availability of Beacons for DGPS systems elevate the
very threat that the SA error was intended to reduce. In the
presence of such networks, potentially hostile weapons systems
using DGPS could be developed relatively rapidly. For this reason
and others, the SA error has diminished in military significance.
The White House has Directed that the S/A error be "Set to Zero" by
the year 2006.
[0040] In the United States, the US Coast Guard (USCG) and Army
Corps of Engineers (ACE) have constructed a network of Beacon
stations that service the majority of the eastern United States,
the entire length of both coastlines, and the Great Lakes. Further
plans exist to increase the density of this network to provide dual
redundant coverage throughout the continental US by the end of the
year 2000 for a variety of applications including intelligent
transportation system, infrastructure management, and public
safety.
[0041] The Canadian Coast Guard (CCG) provides coverage in Canada
for the St. Lawrence River, throughout the Great Lakes, and both
coastlines. In total, there are over 160 stations operational
worldwide with over 140 sites proposed to come online within the
next two years. Coverage currently exists in many other regions of
the world including Europe, Asia, Australia, Africa, and South
America.
[0042] The beacons perform the differential calculation and
broadcasts this information by modulating the data onto a 300 kHz
signal transmitted by the established network of Radiobeacons. The
advantages of using the Beacon DGPS network include: (1) Free
access to differential correction information; (2) Long range
signal which penetrates into valleys, and travels around obstacles;
(3) High quality differential corrections which are continuously
monitored for integrity; and (4) Inexpensive user equipment.
[0043] The range of the 300 kHz signal is dependent upon a number
of factors which include transmission power and conductivity of the
surface over which the transmission is propagating. The Beacons
within the global network broadcast at varying power. Typical
broadcasting ranges for radiobeacons vary from as little as 35
nautical miles to as much as 300 nautical miles. Signals broadcast
by DGPS radiobeacons are integrity monitored by remote stations for
quality of beacon transmission, differential corrections, and GPS
positional information. In addition, government agencies concerned
with public safety have made it their mandate to ensure that beacon
DGPS services are available 24 hours a day, 365 days a year.
Performance requirements for marine applications dictate that an
availability of 99% or greater is required if a particular system
is to be used as a sole means of navigation. The US Coast Guard and
Army Corps of Engineers Beacon Network, for example, offer this
high level of availability free of charge to all civilian
users.
[0044] There are other navigation systems in place, in addition to
GPS, that merit review. LORAN-C is a ground-based radio navigation
system. It operates on a frequency band of 90 kHz to 110 kHz (LF).
It has an approximate range of hundreds to thousands of miles, and
an accuracy of 0.25 nautical miles repeatable to 18-90 meters, with
95% confidence. Loran-C is a pulsed hyperbolic system that provides
0.25 nm predictable accuracy, 18-90 m repeatable accuracy, 95%
confidence and 99.7% availability. Loran-C provides coverage for
the continental U.S. and its coastal waters, the Great Lakes, and
most of Alaska. Many other countries are also involved in the
providing of Loran-C (or Loran-like) services, or are in
negotiations with their neighbors to expand coverage. These
countries include India, Norway,France, Ireland, Germany, Spain,
Italy, Russia, China, Japan, the Philippines and others.
[0045] Omega is a low frequency band system with accuracy of 2 to 4
nautical miles with 95% confidence level. Developed by the United
States, it is operated in conjunction with six other nations. OMEGA
is a very low frequency, phase comparison, worldwide
radionavigation system
[0046] Tacan operates in the U.S. in a frequency band of 960
MHz-1215 MHz (UHF). It has a range of approximately 200 miles at
high altitudes. TACAN is primarily used by U.S. and other military
aircraft. TACAN radio stations are often co-located with civilian
VOR systems allowing military aircraft to operate in civil
airspace. The system provides the pilot with relative bearing and
distance to the radio beacon.
[0047] VOR operates in a frequency band of 108.0 MHz-117.95 MHz
(VHF). It has an approximate range of 250 miles, but accuracy as
poor as 20 miles. VOR is a beacon-based navigation system operated
in the U.S. by the Federal Aviation Administration (FAA) for civil
aircraft navigation. When used by itself, the system allows users
to determine their azimuth from the VOR station without using any
directional equipment. VOR stations are radio beacons that transmit
two signals. The first, called the reference signal, is transmitted
with constant phase all around the transmitter. The second signal
is phase shifted from the first depending on the compass direction
of the user from the station. A simple, inexpensive receiver in the
aircraft is used to determine the received phase difference of the
two signals, and from that information the direction of the
aircraft from the transmitter. By using two VOR stations, a
specific location may be determined.
[0048] Of all the navigation systems mentioned, GPS offers better
service, more accuracy, and more serviceable regions than any other
approach. There are various classes of GPS service that improve
accuracy at higher costs. These include the following categories:
(1) Low-cost, single receiver SPS projects (100 meter accuracy);
(2) Medium-cost. differential SPS code Positioning (1-10 meter
accuracy); (3) High-cost, single receiver PPS projects (20 meter
accuracy); (4) High-cost, differential carrier phase surveys (1 mm
to 1 cm accuracy); and (5) High-cost, Real-Time-Kinematic (1 cm)
with real time accuracy indications.
[0049] Referring now to FIG. 1, a vehicle 10 is illustrated in
operation on a roadway, under exposure to radio frequency signals
from a variety of sources. These include the GPS satellite system,
LORAN or OMEGA radio towers, non-police sources of interference
such as restaurant 16, and police radar signals from a radar gun
18. In accordance with principles of the present invention, vehicle
10 is equipped with a radar detector able to identify the present
coordinates and/or velocity of the vehicle, e.g. using an
associated GPS receiver or alternatively a receiver of land-based
signals such as LORAN. The radar detector is able to use this
information to enhance its decision-making abilities.
[0050] Referring now to FIG. 2, the radar detector 20 in accordance
with principles of the present invention includes a fusion
processor 22 for controlling all functions of the unit. Fusion
processor receives information on radar signals from a conventional
microwave receiver 24, coupled to processor 22 via a digital signal
processor (DSP) 26. Microwave receiver 24 and DSP 26 may utilize
any of the techniques described above and in the above-referenced
patents, for rejecting noise and increasing discrimination between
actual and spurious police radar signals. Further, receiver 24 and
DSP 26 may be controlled by an optional second CPU 25, which can
enable additional signal evaluation beyond that which is possible
using a DSP.
[0051] Processor 22 is further connected to a laser detector 28 for
detecting police LIDAR signals. Processor 22 is further connected
to a GPS receiver 32 and a separate differential GPS (DGPS)
receiver 30, such that differential GPS methodologies may be used
where beacon signals are available. Since the radar detector
application described in this patent is not a candidate for
military class service, it is not able to access the more accurate
PPS. However it is considered a "civil user" and can use the SPS
without restriction.
[0052] Processor 22 executes a stored program, found in an
electrically erasable programmable read only memory (EEPROM) 34,
flash memory, or masked read only memory (ROM). The processor is
programmed to manage and report detected signals in various ways
depending on its stored program. This programming includes
functions for "detector response conditioning," as elaborated
below, e.g., with reference to FIGS. 6A through 6D.
[0053] The radar detector further incorporates a user input keypad
or switches 36. Operational commands are conveyed by the user to
processor 22 via the keypad. Processor 22 is further connected to a
display 38, which may comprise one or more light emitting diodes
for indicating various status conditions, or in a more feature-rich
device, may include an alphanumeric or graphical display for
providing detailed information to a user. A speaker 40 is also
provided to enable processor 22 to deliver audible feedback to a
user under various alert conditions, as is elaborated below.
[0054] Processor 22 may further include an interface 44, such as an
ODB II compliant interface, for connection to vehicle electronic
systems 42 that are built into the vehicle 10. Modern vehicles are
being equipped with standardized information systems using the
so-called OBD II standard interface. This standard interface is
described in an article entitled ODB II Diagnostics, by Larry
Carley, from Import Car, Jan. 1997, which is hereby incorporated
herein by reference. Processor 22, using the OBD II standard
interface 44, can obtain vehicle speed and other vehicle status
information directly from the vehicle, and then may use this
information appropriately as described in more detail below.
[0055] Processor 22 is further coupled to a Universal Serial Bus
(USB) interface 46 that provides a means for uploading and
downloading information to and from processor 22. Specifically, USB
interface 46 may be used to automate the assimilation of coordinate
information into data structures in EEPROM 34, as described below
with reference to FIGS. 3 through 5. USB interface 46 may also be
used to interface the detector to a separate host computer or
product application containing a larger storage capacity than
available from internal memory. Remote storage devices may include
any form of dynamically allocatable storage device (DASD) such as a
hard disk drive, removable or fixed magnetic, optical or
magneto-optical disk drive, or removable or fixed memory card, or
any device including a dynamic directory structure or table of
contents included in the storage format to permit dynamic storage
allocation. The host computer or other connected device need not be
visible to the driver and may be in any convenient location, such
as under the vehicle dash.
[0056] Coordinate information can be stored, e.g., on a hard drive
organized with an indexed database structure to facilitate rapid
retrieval, and the hard drive may include a special purpose
processor to facilitate rapid retrieval of this information.
[0057] Where a general purpose host computer is connected via the
USB interface, it will likely be based on a higher scale CPU chip
and thus be able to efficiently carry out complex coordinate
comparison tasks such as are described below, and such tasks may be
delegated to the host CPU rather than carried out in fusion
processor 22. The host CPU can also anticipate the need for
information about particular coordinates based upon vehicle
movements, and respond by retrieving records within proximity of
the current location for ready deliver, to fusion processor 22. The
host computer can also provide navigational functions to the
driver, potentially using stored signal information and flag bits
to provide the user with location-specific information about
driving hazards and potential police stakeout locations.
[0058] Signal information may also be downloaded from other hosts,
for example, a connection may be established directly via the USB
interface to an Internet site carrying signal information, as is
now done in a text form at the Internet site speedtrap.com. An
indirect Internet connection may also be established via a host
computer. Furthermore, connections may be established between two
receivers, e.g. a trained receiver having extensive signal
information, and a receiver having less extensive information, to
transfer signal information between the receivers so that either or
both has a more complete set of signal information.
[0059] Generally speaking, processor 22 compares the radar
detector's immediate coordinates with a stored list of the
coordinates of unwanted stationary sources. If the radar detector
receives a microwave/laser signal within a certain distance of one
of these pre-designated sources, processor 22 applies additional
constraints to the detection criterion before alerting the user.
Since stationary radar sources make up the bulk of the unwanted
sources, there is a significant benefit resulting from these
functions. Further details on these operations are provided below
with reference to FIGS. 6A through 6D.
[0060] FIG. 3 illustrates data structures 50 stored in EEPROM 34
and used for managing information utilized in accordance with
principles of the present invention. As seen in FIG. 3, these data
structures include a plurality of main entries 52, each including a
field 54 for a coordinate, a field 56 for identifying the date and
time data was collected, and three fields 58, 60 and 62 providing
information on the source.
[0061] Field 54 provides the coordinate of a "cell" of space. As
will be elaborated below, coordinates provided by GPS receiver 32
are reduced in resolution to arrive at a "cell" coordinate, which
indicates that the current location of the receiver is within a
relatively large (e.g., 1/8 or 1/4 mile square) block of space on
the Earth's surface. This approach reduces the storage requirements
for information stored by the radar detector to a manageable level.
The sizes of the cells can be variably adjusted based upon the
available memory and the desired precision. In the present example,
128 bits are allocated to storing cell coordinates, so the cell
coordinates can only have as much precision as can be provided in
128 bits, a cell, e.g., by discarding the least significant bits of
the coordinates. In other applications, different bit sizes and
resolutions could be utilized. It will also be noted that the
storage requirements can be reduced by designing the receiver for
operation only in a specified part of the Earth, eg., only in
Europe, Japan or North America. By so doing, part of the
coordinates for a cell will not need to be stored because they will
be the same for all stored cells. In such an embodiment, whenever
the coordinates provided by the GPS receiver fall outside of the
pre-established region, the receiver will either disable all
storage of information (if approved via operational input from the
user), or establish a new region of interest and discard all data
from previously identified regions. Alternatively, the operator may
set the device in either a "precision" (high coordinate resolution)
or "wide area" (low coordinate resolution) mode, based upon the
driving habits of the driver. In "wide area" mode, the reduced
resolution used for each cell coordinate permits a greater number
of coordinates to be stored, albeit with reduced precision as to
each coordinate. Rural drivers and others that often follow common
paths, would be best suited to "precision" mode, whereas urban
drivers would be better suited to "wide area" mode. As a further
alternative, the detector may automatically select a mode based
upon the memory consumption or the time lapse before the memory of
the detector becomes full; if the memory fills rapidly, the unit
would automatically switch to a "wide area" mode using low
precision coordinates, whereas if the memory never fills or fills
only slowly, the unit will remain in its "precision" mode.
[0062] The date and time information in field 56 is useful when
selecting least recently used (oldest) entries in storage for
replacement, as is described further below.
[0063] Fields 58, 60 and 62 store source incidence counters, one
for each of a plurality of frequency blocks. Field 58 stores
counter(s) for block(s) in the X band. Field 60 stores counter(s)
for block(s) in the K band. Field 62 stores counter(s) for block(s)
in the Ka band. The number of blocks in each band can vary in
different embodiments of the present invention, and is a function
of the signal frequency content details provided by the detector 24
and DSP 26. As one example, the X, K and Ka bands are divided into
a total of 32 frequency blocks. Each block is provided a 4-bit
counter in fields 58, 60 and 62. The counters have a minimum value
of 0 and a maximum value of 15, and are a measure of the number of
times a signal in the associated frequency block has been detected
at that location. As will be described below in greater detail, the
"source incidence" counters are used in identifying geographic
locations that appear to have spurious sources of police radar
signals, due to repeated detection of such signals without
confirmation of police activity.
[0064] In the data structures shown in FIG. 3, to save space, main
entries 52 are interleaved with a greater number of differential
entries 64, each of which stores information for a cell. A first
field in a differential entry 64 is an index pointer 66 to a main
entry 52, e.g. an index to a storage location at which the main
entry is stored. A second field is a differential field 68 that
identifies the difference between the coordinate of the
differential entry 64 and the coordinate stored in the main entry
52. The index and differential can be stored in substantially fewer
than 128 bits, so that a differential entry 64 is substantially
smaller than a main entry, thus saving storage space. Differential
entries further include a date and time field 56 and fields 58, 60
and 62 for storing counters for X, K or Ka frequencies, as
described above.
[0065] FIG. 4 illustrates data structures 70 used to store vehicle
motion history records or trip records in EEPROM 34. These data
structures include main entries 72 which include field 74 storing a
128 bit cell coordinate, followed by a speed field 76 which can be,
for example, 7 bits in length. Differential entries 78 associated
with each main entry include a differential coordinate field 80
indicating the difference in the cell coordinate from the
associated main entry 72, and a speed field 76 indicating a speed
recorded at the cell. Because motion history records or trip
records are stored sequentially during motion of the detector,
differential entries 78 are stored after and adjacent to the
associated main entry 72. Accordingly, differential entries 78 do
not require an index field to associate the differential entry 78
with a main entry 72, because the association is implied from the
location of the differential entry 78 in memory after its
associated main entry 72.
[0066] History entries may be used for a number of purposes. For
example, in the following description, history entries are accessed
as part of defining an "everyday route" taken by the detector at
the operator's identification. History entries may also be used for
driver monitoring: they may be downloaded to a host PC via USB
interface 46, and evaluated to determine whether the vehicle has
taken abrupt turns, show excessive speed, or entered undesired
locations, all of which may be useful in monitoring the activity,
e.g., of teenage drivers. History entries may also be uploaded to
PC to provide evidence of the driving history of the vehicle before
and at the time of a police citation for speeding. If a driver has
been unfairly cited for speeding, history records from the detector
can provide compelling evidence to court that the citation is in
error. For the purpose of enabling these uses, history entries
stored by fusion processor 22 are encrypted when stored and cannot
be modified by fusion processor 22 or any PC software supplied for
viewing those entries.
[0067] FIG. 5 illustrates data structures 82 that can be used to
store hazard information and other flag bits related to cells.
These data structures 82 include main entries 84 which include a
full 128 bit cell coordinate in field 88, followed by a date and
time field 90 and flag bits 92 indicating the hazard or condition
associated with the identified location. The differential entries
86 include an index field 94 pointing to one of the main entries, a
differential coordinate field 96 indicating the difference in the
cell coordinate from the associated main entry 84, a date and time
field 98, and a set of flag bits 92 indicating the hazard or
condition associated with the identified location. The flag bits
may identify various hazard conditions. For example, in the
specific embodiment described below, there is an "always warn" flag
bit that indicates that police activity has previously been
confirmed at the location, and therefore the user should be warned
of all apparent police radar signals at the location. Further,
there is a "location lockout" flag that indicates that broadband
sources of spurious police radar signals have been experienced at
the location, and therefore in the future warnings of police radar
signals should be suppressed at the location. Similarly, a "minimal
visual lockout" flag indicates that, due to the unwanted
distraction of spurious police radar warnings at a location, only a
minimal visual warning should be made of police radar signals
identified at the location. The flag bits further include
"frequency lockout" bits, one for each frequency block identified
by the radar receiver. These bits identify frequencies at the
location in which spurious police radar signals have previously
been encountered, so that in the future apparent police radar
signals at the same frequencies are ignored. The flag bits may also
include additional flags to warn of other conditions, such as that
there was construction at the identified location, or that some
other cause for traffic slowdowns were seen at the identified
location, to aid in vehicle navigation.
[0068] The information contained in the databases of FIGS. 3 and 5
may be assimilated by the detector through operation, as is
described below. Alternatively. this information may be
pre-installed in the detector, e.g. via an upload from a host PC
via the USB port 46. There would be substantial benefits to
pre-training a detector in this way for a particular geographic
area. By pre-training the detector, the driver would not have to
enure the audible alerts that would naturally occur before it is
trained for each source of spurious police radar signals. In a give
area, the ideal training profile would not vary much from one
detector to the next, since all detectors should reject the same
sources in the same areas. As a result, there are few issues that
would have to be resolved in order to transfer training information
from one radar detector.
[0069] The Internet provides a convenient means for storing and
accessing repositories of information. Web sites will be
established and devoted to this task. They will provide several
convenient types of training information. One will be a training
file containing the coordinate information from the online "Speed
Trap Registry" at the internet site www.speedtrap.com. This
information would be usable to set "always warn" bits at the
locales of known speed traps. A second type of training information
would be training files submitted by individuals for use in
particular areas, and the third type of information would be
aggregate training files created by integrating
individually-submitted information into single files organized by
region. Aggregate training files would be managed and updated by
the web site administrator.
[0070] Training files would have low value if they could not be
readily used by other detectors. The transferability of training
files from one detector to another will depend on the differences
in how real world signals are perceived by their embedded
processors. In large part, these differences are a direct result of
manufacturing and component variations. During the manufacturing
process, a detector goes through a set of calibration steps in
order to guarantee that the unit meets specifications for Spectral
Band Coverage and Sensitivity. These calibration steps reduce the
cost of designing the product since lower cost, poorer tolerance
components can be used on the assumption that a final manufacturing
calibration procedure will eventually compensate for the lower
tolerance. Once calibrated, an acceptable product must also be able
to perform over a predefined temperature range.
[0071] Component tolerance, manufacturing calibration, and
operating temperature are key factors that determine how the
spectrum of microwave signals are `viewed` by the embedded
Microprocessor or DSP. Radar products convert the spectral band
such as X-Band into an array of values that are proportional to the
signal energy in consecutive slots or bins of the spectrum. In
order for the product to be `in tolerance` these slot positions
must be adjusted so they precisely cover the full range of X, K,
and the Ka bands
[0072] The calibration procedure is only concerned with
guaranteeing that the slots provide adequate coverage of each band.
It is less concerned as to whether any one of these slots falls on
a precise physical frequency. Therefore the first frequency block
in one detector will not necessary be perceived at the same
frequency as the first slot in another detector.
[0073] If training data is to be shared between various detectors,
it will be necessary for supporting software to compensate for
these variations. When new pre-trained data is supplied, the
detector will undergo an authentication procedure in order to
determine the relationships between the pre-train data and its own
receiver configuration. This will be based on comparing the
frequencies of newly encountered sources to those of the pre-train
data at matching coordinates. By comparing the observed frequencies
to those in the training set, a "correction profile" will be
constructed, that represents the change between the pre-train data
and the output of the local microwave receiver. At the end of the
authentication procedure, the entire pre-training file will be
incorporated into the active train data. During the authentication
procedure, the user will be exposed to unconditioned detector
responses. This authentication procedure will be substantially
shorter than the training period of a virgin detector. Once
authentication is complete, the user will receive a notification
indicating that the product is switching from authentication over
to normal operation. If the training mode is engaged, the
authenticated data will continue to be massaged by new driving
encounters, as detailed below.
[0074] Referring now to FIG. 6A, operations of the fusion processor
22 to carry out principles of the present invention can be
described in greater detail. Fusion processor 22 performs a main
loop of steps during regular operation of GPS enabled radar
detection. This main loop of steps is illustrated in FIG. 6A and is
detailed in FIGS. 6B through 6F.
[0075] When fusion processor 22 is initialized, i.e., when power to
the GPS enabled radar detector is turned on, the device is
initialized in step 100. This initialization step includes
performing diagnostic checks on the various circuitry illustrated
in FIG. 2 to insure its proper operation, as well as initialization
of the GPS receiver 32 to insure GPS signals can be received
accurately by fusion processor 22. In addition, various internal
variables, such as a variable for identifying a current position,
are initialized. The initial values are chosen to insure proper
operation; for example, the current position variable is
initialized to a value that will cause the first pass through the
main loop FIG. 6A to include processing of a current location in
steps 110 and 112 in accordance with FIGS. 6B-6E, as discussed
below.
[0076] The first step in the main loop performed by fusion
processor 22, is step 102, in which radar detection circuitry 24
and 26 is accessed to obtain information on police radar signals
currently being received by the GPS enabled radar detector. In a
subsequent step 104, fusion processor 22 communicates with GPS
receiver 32 to request a current location and a current vehicle
speed from the GPS receiver 32. This information can then be
utilized in performing GPS related operations described in the
following steps. As noted above, vehicle speed may also be obtained
from the vehicle itself via an OBDII interface 44 if the vehicle in
which the GPS enabled radar detector is installed has a suitable
OBD connector for delivering vehicle speed information. It will be
appreciated further that vehicle location information might also be
obtained via an OBDII connector from a GPS receiver that may be
built into the vehicle within which the GPS enabled radar detector
is installed. When the vehicle in which the GPS enabled radar
detector is installed has both vehicle speed and vehicle position
information available via an OBDII connector, the GPS receiver 32
may not be used at all, or may not even be included in the GPS
enabled radar detector, to facilitate cost reduction for the GPS
enabled radar detector.
[0077] Following steps 102 and 104 in which current police radar
and GPS related information is obtained, different actions are
taken based upon whether GPS information is available.
Specifically, in step 106 it is determined whether a GPS signal has
been received. If a GPS signal is available, then all GPS enhanced
functions of the radar detector may be performed. If no GPS signal
has been received, then the radar detector will revert to
processing police radar signals at a manner analogous to
conventional non-GPS enabled radar detectors.
[0078] Assuming for the moment that a GPS signal is available in
step 106, and therefore a current position for the vehicle is
known, then in step 108 a sequence of steps is preformed to process
the GPS signal, as is further detailed below with reference to FIG.
6B, 6C and 6D. This processing can include retrieval and/or
updating of stored police radar information and the signal
information database illustrated in FIG. 3, the vehicle history
database illustrated in FIG. 4, and/or the flag database
illustrated in FIG. 5.
[0079] After processing the GPS signal, in step 110 keypad activity
on keypad 36 is detected and processed to alter operating modes of
the GPS enabled radar detector, as described below in further
detail with reference to FIG. 6E. The operative modes controllable
through the keypad include:
[0080] a "warning suppression" mode in which warnings, particularly
audible warnings, produced by the GPS enabled radar detector are
suppressed so that they are not disturbing to the operator of the
vehicle.
[0081] an "expert meter" mode in which detailed information
regarding received warning signals are displayed on display 38 of
the GPS enabled radar detector, as described in U.S. Pat. No.
5,668,554, which is hereby incorporated by reference herein in its
entirety.
[0082] a "data overwrite" mode in which the GPS enabled radar
detector saves, into the signal information database of FIG. 3,
data regarding any location not previously stored in the database,
even when this signal information database is full, by overwriting
the oldest data in the signal information database when necessary.
When the "data overwrite" mode is disabled, then the signal
information database will not be overwritten once it becomes
full.
[0083] a "frequency lockout" mode, in which police radar
frequencies detected by the receiver are taken to be from
non-police sources, and appropriate flags are set in the flag
database illustrated in FIG. 5. The "frequency lockout" mode is
engaged by the vehicle operator when non-police radar signals are
being received and the operator wishes to suppress future warning
signals caused by the same sources at the same geographic
locations. As noted below, "frequency lockout" mode can only be
engaged while the GPS enabled radar detector is detecting an
apparent police radar signal and will be automatically disengaged
when this signal is no longer being received.
[0084] a "location lockout" mode, in which the flag database of
FIG. 5 is updated to suppress all audible warnings of radar signals
at the current location of the vehicle. As is the case with the
"frequency lockout" mode, the "location lockout" mode will be
enabled by a vehicle operator when the vehicle is near to a known
source of spurious police radar signals of a broadband character.
The "location lockout" mode can only be engaged while the GPS
enabled radar detector is detecting an apparent police radar
signal, and will be automatically disengaged whenever a police
radar signal is no longer being received from the GPS enabled radar
detector.
[0085] a "minimal visual lockout" mode, in which the flag database
of FIG. 5 is updated to suppress most or all visual warnings of
radar signals at the current location of the vehicle. The "location
lockout" mode will be enabled by a vehicle operator when the
vehicle is near to a known source of spurious police radar signals
of a broadband character, and at that location does not wish to be
disturbed by even a visual radar signal warning. The "location
lockout" mode can only be engaged while the GPS enabled radar
detector is detecting an apparent police radar signal, and will be
automatically disengaged whenever a police radar signal is no
longer being received from the GPS enabled radar detector.
[0086] a "police confirmation" mode, in which flags in the flag
database of FIG. 5 will be set to insure a warning signal is always
delivered for any police radar signal received at the current
vehicle location. The "police confirmation" mode will be activated
by a vehicle operator upon sighting a police stakeout.
[0087] a "training" mode, in which the GPS enabled radar detector
will store signal information for all geographic locations that the
GPS enabled radar detector reaches or passes during operation. When
"training" mode is disabled, the signal incidence counters found in
the signal information database of FIG. 3, will not be modified by
the GPS enabled radar detector during its normal operation.
[0088] a "route identification" mode in which the route currently
traveled by the vehicle is memorized by the GPS enabled radar
detector to be subsequently referenced in performing radar
detection. Using "route identification" mode, a user may establish
one or more everyday routes traveled by the vehicle, and cause the
GPS enabled radar detector to continuously update its signal
incidence information in the signal information database of FIG. 3
whenever one of these routes are traversed. Routes are identified
by an operator by entering the "route identification" mode at the
beginning a route, and then exiting the "route identification" at
the end of the route.
[0089] After selecting appropriate modes based upon keypad
activity, in step 112, an appropriate audible or visible response
is produced by the GPS enabled radar detector based upon it current
operating mode and the presence or absence of radar detector signal
received in step 102. Details of this operation are described below
with reference to FIG. 6F. After step 112, processing returns to
step 102 to obtain a new radar detector signal output and a new
current location and speed and then perform additional analysis of
that data as described above.
[0090] As noted above, in some circumstances a GPS signal will not
be available during operation of the GPS enabled radar detector. In
this case, processing continues from step 106 to step 114 in which
any non-GPS related operational modes may be activated based upon
the activity at keypad 35. GPS enabled modes are unavailable so
long as no GPS signal has been obtained, so the processing in step
114 eliminates those modes which cannot be activated in the absence
of a GPS signal. After step 114, processing continues to step 112
in which an appropriate audible or visible response is generated
based upon the current operating mode and the radar detected signal
received in step 102.
[0091] Referring now to FIG. 6B, the processing performed on a GPS
signal in step 108 of FIG. 6A can be described in greater detail.
As a first step 120, GPS coordinates received from the GPS receiver
32 are modified by reducing their accuracy. This process is known
as "gridding" the coordinates and involves truncating that part of
the coordinate of greater accuracy than the defined grid. As a
consequence of this modification, the GPS coordinate is mapped into
a cell number; every location on the globe falls within a cell of
the grid, and has a particular cell number derived from the most
significant bits of the GPS coordinates measured within the cell.
Cells may be relatively small, i.e., one-eighth of a mile square,
or may be relatively large, i.e., one mile square.
[0092] After a current cell number is generated from GPS
coordinates, then actions are taken based upon whether the vehicle
is transitioning from one cell to another, and further based upon
current operational modes of the GPS enabled grid are detected. In
the first of these steps 122, it is determined whether the current
cell obtained from the GPS receiver is the same a stored prior cell
obtained from the GPS receiver during the previous pass through the
processing of FIG. 6B. If so, the vehicle is in the same cell as
has been previously processed, and then no further processing for
the current cell is required, and the process of FIG. 6B
returns.
[0093] If, however, the vehicle has moved to a new cell, then in
step 124, the cell number for this new current cell is stored as
the prior cell, so that in subsequent passes through the process of
FIG. 6B. it will be known whether or not the vehicle has moved to
another cell.
[0094] After step 124, steps are taken to manage "everyday route"
modes of the GPS enabled radar detector. As noted above, the user
of the GPS enabled radar detector may establish one or more
everyday routes traveled by the vehicle and cause the GPS enabled
radar detector to, along those routes continuously update its
signal incidence information in the signal information database of
FIG. 3. Accordingly, when the GPS enabled radar detector detects
that it is following one of these everyday routes, then it will
automatically enter its everyday route mode, and subsequently
perform different processing (as further described below in
connection with FIGS. 6C and 6D). As seen in FIG. 6B, each time the
GPS enabled radar detector determines in step 122 that it has
passed from one cell to another, then (a.) if the detector has been
following an everyday route, an evaluation is made whether the GPS
enabled radar detector is continuing to follow the previously
defined everyday route, or (b.) if the detector has not been
following an everyday route, a determination is made whether the
GPS enabled radar detector has started following a previously
defined everyday route.
[0095] In the first step of this process, in step 126 it is
determined whether the GPS enabled radar detector is already in its
"everyday route" mode. If the radar detector is not currently not
in its "everyday route" mode, then it is determined whether the
radar detector is entering an everyday route; specifically, in step
128, it is determined whether the current cell coordinate is on any
of the pre-stored everyday routes. If the current cell is on one of
the everyday routes, then the GPS enabled radar detector will
determine that the vehicle carrying the detector is beginning or
joining one of these pre-stored routes. In such a case, in step 130
the GPS enabled radar detector will enter its "everyday route" mode
for the stored route containing the current cell coordinate. If the
current coordinate is not on any stored route, step 130 is
bypassed.
[0096] Returning to step 126, if the GPS enabled radar detector is
already in its "everyday route" mode, then it is determined whether
the detector is continuing to follow this route. In this case,
processing proceeds from step 126 to step 132 to determine whether
the everyday route is being followed. Specifically, in step 132 it
is determined whether the current coordinate is on the current
everyday route. If not, then in step 134 the GPS enabled radar
detector exits it "everyday route" mode, indicating that the
vehicle is no longer on the previously stored everyday route.
Otherwise, step 134 is bypassed, and the detector remains in its
"everyday route" mode.
[0097] Following step 134 or immediately following step 130,
additional steps are performed to determine whether and how to
update previously stored signal incidence information in the signal
information database of FIG. 3. Processing also proceeds to step
140 from steps 132 or directly from step 128 based upon conditions
described above.
[0098] In step 140 it is determined whether a radar signal is being
received by the GPS enabled radar detector. If so, then in step 142
the procedure described below with reference to FIG. 6C is
performed to update, as needed, the signal information database of
FIG. 3. If no radar signal is being currently detected, then in
step 144 the process described below with reference to FIG. 6D is
performed to update, as needed, the signal information database of
FIG. 3. After step 142 or 144, in step 146 the history database of
FIG. 4 is updated by removing the oldest history entry from that
database (if necessary to make room), and creating a new history
entry for the current cell. The new history entry will include the
cell coordinate or a differential coordinate as discussed above
with reference to FIG. 4, and would also include a vehicle speed as
obtained in step 104 from the GPS receiver or alternatively from an
OBD II interface to the vehicle. Following step 146, the processing
of the GPS signal is complete.
[0099] Referring to FIG. 6C, updating of the signal information
database of FIG. 3 in the presence of a police radar signal can be
elaborated. In the first step 150 it is determined whether the GPS
enabled radar detector is in its "signal tracking" mode. The
"signal tracking" mode is entered whenever the GPS enabled radar
detector is receiving an apparent police radar signal as the
detector is passing through space. So long as an apparent police
radar signal is being continuously detected, the detector will
remain in signal tracking mode in order to associate that police
radar signal with all of the geographic locations in which it was
detected. It will be appreciated that the process of FIG. 6C will
not commence unless there is a police radar signal being detected;
therefore, the first step 150 is to determine whether the detector
is in its signal tracking mode, and if not, in step 152 to enter
the signal tracking mode to thereby begin tracking the police radar
signal that had not previously been detected.
[0100] After step 152 or after step 150 if the detector is already
in its signal tracking mode, in step 154 the current cell
coordinate and the frequency data for the current cell is stored in
a special tracking storage area accessible to fusion processor 22
in EEPROM 34. The frequency data and cell information stored in
this tracking storage can be used subsequently to identify the
source of the tracked police radar signal more accurately.
[0101] After step 154, different actions are taken based upon
whether the signal information database of FIG. 3 already contains
signal information for the detector's current cell coordinate. If
there is no matching cells in the signal information database of
FIG. 3, then processing continues to step 158 in which it is
determined whether the signal information database of FIG. 3 is
full, i.e., all the storage space allocated to this database in
EEPROM 34 has been consumed. If all the space has been consumed,
then in step 160 it is determined whether the GPS enabled radar
detector is in its "data overwrite" mode. If so, then the user has
identified that current information should be stored for each cell
encountered by the vehicle, even when doing so requires the
elimination of older stored data. Accordingly, in data overwrite
mode, processing proceeds from step 160 to step 162 in which the
oldest signal and flag entries in the databases of FIGS. 3 and 5
are removed, and then to step 164 in which new signal and flag
entries are created for the current cell so that signal information
and flag information can be stored. If, however, the detector is
not in its "data overwrite" mode in step 160, then a warning is
delivered to the user that storage of information is being
prevented due to the database being full (step 166).
[0102] After step 166 or 164, or immediately after step 156 if
there is already data stored for the current cell, in step 168 it
is determined whether the GPS enabled radar detector is in its
"training" or "everyday route" mode. As noted above, in these
modes, signal information stored in the database of FIG. 3 is
continuously updated each time a cell is encountered. Accordingly,
if the detector is in either its "training" or "everyday route"
mode, then in step 170 the unwanted source incidence counter for
each frequency block identified by the radar receiver 24 as
containing signal, is incremented, preventing an overflow.
Subsequently, in step 172 the unwanted source incidence counter for
each frequency block identified by the radar receiver 24 as not
having signal, is decremented, preventing an underflow. This thus
updates the source incidence counters for each frequency block for
the current cell. After this processing, or immediately after step
168 if the GPS enabled radar detector is not in the "training" or
"everyday route" mode, updating in step 142 is complete.
[0103] Referring now to FIG. 6D, processing in step 144, to update
various databases when no signal is detected, can be explained. As
will be elaborated below, when no police radar signal is being
received by the GPS enabled radar detector, this indicates that
many of the modes described above for tracking and identifying
sources of police radar signal should be terminated.
[0104] Specifically, in step 180 it is determined whether the GPS
enabled radar detector is in "signal tracking" mode. As discussed
above, the "signal tracking" mode signifies that the GPS enabled
radar detector is currently tracking the cell locations and
frequencies of an apparent police radar signal detected by the GPS
enabled radar detector. As discussed above with reference to FIG.
6C, step 152, the GPS enabled radar detector will enter "signal
tracking" whenever an apparent police radar signal is received. So
long as the signal is continuously received, processing of the GPS
signal will pass through step 140 of FIG. 6B to FIG. 6C, and
"signal tracking" mode will remain engaged. If, however, no police
radar signal is being received when processing of the GPS signal
passes through step 140 of FIG. 6B, then processing will pass to
FIG. 6D and thus to step 180 of FIG. 6D. In the first pass through
FIG. 6B after a police radar signal has faded, e.g., due to motion
of the vehicle past the source of that signal, "signal tracking"
mode will still be engaged as a consequence of prior passes through
FIGS. 6B and 6C. Thus, if in step 180 of FIG. 6D, if "signal
tracking" mode is engaged, but no police radar signal is currently
being received, this indicates that the previously detected signal
has just faded. In such a situation, a complete record has been
made of the locations in which the source was received by the GPS
enabled radar detector. This record can be used to characterize the
source as to location and frequency, by analyzing the cells in
which the signal was tracked, and the frequencies in which the
signal was tracked. Thus, if in step 144, the GPS enabled radar
detector is "signal tracking" mode, in step 182 the detector exits
its "signal tracking" mode. Subsequently, steps are taken to store
relevant information collected for the tracked signal.
[0105] In a first step 184, it is determined whether the GPS
enabled radar detector is in "police confirmation" mode. If so,
then the vehicle operator has pressed a key on the keypad of the
GPS enabled radar detector indicating that a police stakeout was
sighted, during the tracking of apparent police radar signals. In
such a case, in step 186 the "always warn" flag bit is set for all
or the centralmost cells in the tracked sequence of cells
identified while in "signal tracking" mode. Thus, the likely
locations of the source of the tracked signal are identified and
the flag bits are set so that any apparent police radar signal
found in those cells will always cause the user to be warned of
police radar.
[0106] If the GPS enabled radar detector is not in "police
confirmation" mode, in step 188 it is determined whether the GPS
enabled radar detector is in "frequency lockout" mode. As described
above, the detector will be in "frequency lockout" mode if the
vehicle operator has used the keypad to indicate that any apparent
police radar signals that were tracked in the preceding and current
cell, are from spurious sources, and that the frequencies in which
those spurious signals appeared should be ignored in subsequent
passes through the same cell location. Accordingly, if the detector
is in "frequency lockout" mode in step 188, processing continues to
step 190 in which the lockout bits, in the flag bits 92, are set
for all or central cells of the tracked path taken by the vehicle,
for those frequencies that were identified during the "signal
tracking" mode.
[0107] After step 190, or immediately after step 188 if the
detector is not in "frequency lockout" mode, it is determined
whether the receiver is in "location lockout" mode in step 192. It
is noted above, "location lockout" mode is engaged by the vehicle
operator when broadband sources of spurious produced radar signals
are experienced at a geographic location, and the operator wishes
to lockout all frequencies at that location. In such a case, in
step 194 all of the frequency lockout bits for all or the
centralmost cells in the tracked path of the vehicle are set.
[0108] After step 194, or immediately after step 192 if the
detector is not in "location lockout" mode, in step 196 it is
determined whether the detector is in "minimal visual" mode. As
noted below, the detector will be placed in "minimal visual" mode
by the operator when the operator wishes to minimize the
indications of police radar signals produced when passing through a
geographic region. In such a case, processing continues from step
196 to step 198 in which a minimal visual (MV) flag bit is set in
the flag database of FIG. 5 for all or the centralmost cells in the
tracked path of the vehicle.
[0109] After step 198, or immediately after step 196 if the
detector is not in "minimal visual" mode, or immediately after step
186 if the GPS enabled radar detector is in "police confirmation"
mode, in step 200 it is determined whether the signal information
database of FIG. 3 includes data for matching or neighboring cells
to those cells in the tracked path of the vehicle. If such a match
is found, then in step 202 it is determined whether the detector is
in its "training" or "everyday route" mode. If so, then the
detector should update the stored signal information for the
current cell. Specifically, to update signal information, in step
204 all of the unwanted source incidence counters for frequency
blocks identified by the receiver are decremented, preventing
underflow.
[0110] Following step 204, or immediately following step 200 if
there is no matching signal information or step 202 if the detector
is not in its "training" or "everyday route" mode, in step 206 the
"frequency lockout", "location lockout", "minimal visual" and
"police confirmation" modes are cleared, because the tracking of a
police radar signal has ended, and these modes are therefore no
longer relevant to the current location of the vehicle.
[0111] Referring now to FIG. 6E, the processing of keypad activity
to enter and exit the various modes described throughout can be
explained. As noted with reference to FIG. 6A, various modes are
available only if a GPS signal has been obtained from the GPS
receiver. If a GPS signal has been obtained then modes are selected
from the keypad beginning at step 110. If a GPS signal has not been
obtained then modes are selected from the keypad beginning at step
114, and a substantial number of modes are disabled and cannot be
selected in this circumstance.
[0112] The keypad activity to select and deselect a mode may vary
based upon the application and style of the GPS enabled radar
detector. The display and keypad 38 and 36 may interact to produce
a menu system for selecting particular modes and displaying
associated information. Alternatively, individual keys of keypad 36
may be utilized to directly activate certain modes. Furthermore,
display 38 may include icons or other indicators to identify
currently activated modes.
[0113] A first collection of modes that may be activated via the
keypad 36, are the "frequency lockout", "location lockout", and
"minimal visual lockout" modes. Through interactions with the
keypad in step 210, the user may initiate or terminate these modes.
As described above, when initiated, these modes cause lockout
information to be stored into flags of the flag database of FIG. 5
upon termination of tracking an apparent police radar signal. If
these modes are not engaged at the time that the police radar
signal fades from reception, then no action will be taken to set
lockout bits in the flag database of FIG. 5. This approach permits
a vehicle operator to initiate a lockout mode and then cancel the
lockout mode, for example if the operator initially believes a
radar signal to be spurious, but then determines that it is in fact
being generated by a police source. It will also be noted that, by
the operations of FIG. 6D, the "police confirmation" mode will
override the "lockout" modes, in that if the "police confirmation"
mode is engaged when a police radar signal fades from reception,
any "lockout" modes that are engaged will be ignored. The user is
not, however, prevented from engaging both modes simultaneously.
For example, the user may receive a signal believed to be spurious,
and engage a "lockout" mode. The user may then sight a police
vehicle and, believing the signal is not spurious, engage "police
confirmation" mode. The user may later, however, confirm that the
police vehicle is not engaged in a speed trap, and consequently
disengage "police confirmation" mode. If the received signal then
fades from view, the "lockout" mode will be active and accordingly
lockout bits will be set as described above with reference to FIG.
6D.
[0114] In step 212 the vehicle operator may enter or exit the
"training mode", which as described above causes the GPS enabled
radar detector to collect signal information for all cells that the
vehicle traverses.
[0115] A third activity that may be undertaken with the keypad, in
step 214, is to request to clear all lockouts for the current
vehicle location. This step may be taken where the GPS enabled
radar detector has previously been programmed to lockout a
frequency or location and subsequently the vehicle operator sights
a police source at that location, and wishes to terminate the
lockout at that location. When the vehicle operator requests to
clear all existing lockouts, in step 216 the grid coordinates of
the vehicle location are compared to all existing members of the
flag database of FIG. 5, and all matching and/or neighboring cells
are selected and all lockout bits in those cells are cleared.
[0116] The vehicle operator may also enter or exit a "warning
suppression" mode in step 218, in which a warning for a currently
tracked police radar signal is suppressed, i.e., so that the
detector does not continue to issue warning signals for the same
radar signal received. An operator may also enter or exit an
"expert meter" mode in step 220, requesting that enhanced
information on police radar signals received and/or GPS related
lockout information or signal incidence information be displayed on
display 38 of the detector. An operator may also enter a "data
override" mode in step 222, thus requesting that signal information
for new locations visited by the vehicle not found in the database
be stored, even at the expense of overriding the oldest previously
stored data of this kind. It is also possible, as shown in FIG. 6E,
that there may be no keypad activity at the time that operation of
the detector passes through step 110. In this circumstance, step
224, no further processing is performed.
[0117] A further action that a vehicle operator may take is to
confirm of a police sighting in step 226. This step causes the
detector to enter "police confirmation" mode, so that the detector
will ensure that police radar signals at the identified stakeout
location is handled with particular urgency. Accordingly, when the
user enters a police confirmation in step 226, then action is taken
to set one for more "always warn" flag bits of the flag database of
FIG. 5.
[0118] If at the time that the operator presses the police
confirmation, no apparent police radar signal is currently being
tracked, then in step 228 the receiver will not be in "signal
tracking" mode. In such a circumstance, processing will continue
from step 228 to step 232 in which the "always warn" flag bit is
set for the current and neighboring cells of the current location
of the vehicle. This step ensures that in future times when a
police radar signal is detected in these locations, a warning will
be delivered to the vehicle operator regardless of other conditions
applicable at the time. If a signal is being tracked at the time
that the vehicle operator enters a police confirmation, then a
slightly different activity is undertaken. Specifically, in this
case processing continues from step 228 to step 230 in which the
"police confirmation" mode is entered. As noted above with respect
to FIG. 6D, once the receiver is in police confirmation mode, upon
termination of signal tracking, central or all cells along the
tracked path of the vehicle when the police radar signal was
detected, will be marked as "always warn" in the flag database of
FIG. 5.
[0119] A further activity that may be undertaken by a vehicle
operator is to indicate that the vehicle is at the beginning of an
everyday route, in step 240. Doing so causes the GPS enabled radar
detector to begin to collect information on the everyday route, for
the purpose of ultimately storing a definition of an everyday route
to be evaluated in connection with the processing described in
connection with FIG. 6B, step 128. When the user indicates that the
vehicle is at the beginning of an everyday route, in step 242 the
current cell coordinate and the current entry in the vehicle
history database of FIG. 4 are stored for later reference. Then in
step 244 the detector enters a "route identification" mode, used
later in establishing that a route has been identified and is being
tracked. When the user wishes to complete an everyday route or
wishes to clear everyday route processing for the current vehicle
location, the user engages an end or clear operation in step 246.
When this step is taken by the user, an initial determination is
made in step 248 whether the detector is currently in its "route
identification" mode. If so, then the user has identified the end
of the everyday route that was previously identified in step 240.
Thus, in step 250 it is determined whether the history entry
identified and marked in step 242 continues to store the location
of the route start that was stored in step 242. If so, then all of
the cells accumulated in the vehicle history following the history
entry identified in step 242, describe the route taken by the
vehicle along the path selected by the user. In this case, all
cells accumulated in the history database of FIG. 4 are copied to a
special "everyday route" storage area so that all of these cells
are available for analysis in connection with the processing of
FIG. 6B, step 128. After storing the accumulated history entry
cells, in step 252, processing is completed. After step 252, in
step 253 the "route identification" mode is exited.
[0120] If in step 250, it is determined that the vehicle history
database of FIG. 4 is no longer storing the start of the everyday
route defined by the user, then the everyday route defined by the
user was too lengthy to be processed by the GPS enabled radar
detector. In such a situation, in step 254 the stored route start
information is cleared and the "route identification" mode is
exited.
[0121] If in step 248, the GPS enabled radar detector is not in
"route identification" mode at the time that the vehicle operator
requests the end of everyday route in step 246, then the vehicle
operator may wish to delete any everyday route that includes or
passes through the current cell. Thus, in step 258, a display is
generated to the operator requesting confirmation that any everyday
route including the current cell should be cleared. If a
confirmation is received in step 258, then in step 260 all everyday
routes including the current cell are erased from the everyday
route storage of the GPS enabled radar detector. If the vehicle
operator does not confirm erasure of everyday route information,
then processing completes without erasing any everyday route
information.
[0122] In step 114 of FIG. 6A, non GPS modes of the GPS enabled
radar detector may be activated utilizing keypad activity. This
step may be taken if no GPS signal is available at some point
during operation of the GPS enabled radar detector. In such a
circumstance, in step 262 all GPS related modes of the GPS enabled
radar detector are cleared. These include the frequency location
and minimal visual lockout modes, the route identification mode,
the police confirmation mode, the training mode and the everyday
route mode (step 262). After clearing these modes, non GPS related
modes of the GPS enabled radar detector can be initiated. These
modes include the "warning suppression" mode (step 218), the
"expert meter" (step 220), and the "data override" mode (step 222).
Other modes that the operator may attempt to select will be ignored
so long as no GPS signal is being received.
[0123] Referring now to FIG. 6F, operations performed in connection
with generating audible and visible responses to police radar
signals can be explained. In a first step 270, it is determined
whether any of a number of lockout or other flags in the flag
database of FIG. 5 are applicable to the current cell. In this step
270, the flag database is evaluated to see if there is an entry for
the current cell, and if so whether the location lockout, minimal
visual lockout or always warn flags in that entry are set. If none
of these flags are set, then processing of police radar signals at
the current location proceeds based upon information in the signal
information database of FIG. 3, or based upon defaults if there is
no previously stored information. Accordingly, if none of the flags
identified in step 270 are set, then in step 272 it is determined
whether there is a cell match in the signal information database of
FIG. 3. If there is such a cell match, the frequencies identified
by the radar receiver are compared to the signal information in the
entry in the database of FIG. 3.
[0124] In the first step of this process, the first frequency block
identified by the receiver is selected (step 274). Then, in step
276, it is determined whether the selected frequency block in the
signal information database has a source incidence counter greater
than a predetermined "ignore" threshold. If radar signals have been
frequently detected in the selected frequency block, but there has
never been a police sighting there (and thus the "always warn" flag
has never been set), this is strongly indicative of a false source
at that location. Accordingly, if the source incidence counter for
a frequency block exceeds the "ignore" threshold, then any police
radar signals identified in that frequency block are ignored. If,
however, the selected frequency block does not have a source
incidence counter greater than this threshold, then in step 278 it
is determined whether the frequency block has a lockout flag bit
set in the flag database of FIG. 5. Only if the frequency lockout
bit for the selected frequency is not set, will processing continue
to step 280. In step 280 it is determined whether the selected
frequency block has a source incidence counter greater than a
"silent" threshold. If the source incidence counter exceeds this
threshold, then it is likely that there is a false source radar
signals at the location, and as a result in step 282 a visual-only
response is generated for the frequency band including the selected
frequency block. If, however, the selected frequency block does not
have a source incidence counter greater than the silent threshold,
then an audible and visual response can be generated. In step 284
it is determined whether the receiver is in "warning suppression"
mode. If not in this mode, then an audible and visual response is
generated for the band of signals including the selected frequency
block. Visual response may be a normal response or may be an
"expert meter" response depending upon the status of the "expert
meter" mode of the receiver.
[0125] After steps 282 or 284, or immediately after steps 276 or
278 if a frequency block is to be ignored or has been locked out,
in step 285 it is determined whether there are additional frequency
blocks to be evaluated. If so, then in step 286 the next frequency
block is selected and processing returns to step 276. After all
frequency blocks have been evaluated, processing ends at step 285,
and the generation of audible and visual responses is
completed.
[0126] Returning to step 270, if one of the location lockout,
minimal visual lockout or always warn flags are set for the current
cell, then in step 290 and in step 292 it is determined which of
these flags is set. If the "always warn" flag is set for the
current cell, then in step 288 an audible and visual response is
generated for all frequencies identified by the received, unless
suppressed by "warning suppression mode". Step 288 is also
performed following step 272 if there is no match for the current
cell in the signal information database.
[0127] If the "minimal visual" flag is set for a current cell, but
the "always warn" flag is not, processing proceeds from step 290 to
step 292 and then to step 294 in which a minimal visual response is
generated for all frequencies identified by the receiver, such as a
small blinking flag on the display of the detector.
[0128] If the "always warn" and "minimal visual" flags are not set,
but the "location lockout" flag is set for the current cell, then
processing continues from step 270 through steps 290 and 292 to
step 296, in which a visual-only response is generated for all
frequencies identified by the receiver, which may include expert
meter information or other details available from the detector.
[0129] After step 288, 294 or 296 processing to generate an audible
and/or visual response is completed.
[0130] While the present invention has been illustrated by a
description of various embodiments and while these embodiments have
been described in considerable detail, it is not the intention of
the applicants to restrict or in any way limit the scope of the
appended claims to such detail. Additional advantages and
modifications will readily appear to those skilled in the art.
[0131] For example, it will be appreciated that principles of the
present invention may also be applied to systems that do not
include a GPS receiver. For example, in a simplified embodiment of
the present invention, the radar warning receiver may automatically
enter its "warning suppression" mode based upon the speed of the
vehicle. The speed of the vehicle may, of course, be obtained from
a GPS receiver, but if a GPS receiver is not available and/or
unnecessarily expensive to include in the receiver, the receiver
could obtain vehicle speed information directly from the vehicle's
on-board information processing system via the ODB II interface
discussed above. A threshold speed of 15 MPH could be used as a
default, with "warning suppression" mode automatically engaged at
speeds below this threshold. This threshold may be user-adjustable,
e.g., within a range such as 5 to 50 MPH.
[0132] The interface connector used by the receiver may take other
forms than the known USB standard. It may use any computer
interface standard (e.g., IEEE 488), or an automotive wiring
standard, the J1854, CAN, BH12 and LIN standards, or others.
[0133] In a more refined embodiment, a "everyday route" mode could
be included, in which the operator can perform "everyday route
velocity" training. In this "everyday route velocity" training
mode, the vehicle speed at each point along the "everyday route"
would be stored along with the cell locations along the route.
Subsequently, when the detector determines that it is on a
previously defined everyday route, it will enter "warning
suppression" mode whenever the vehicle speed is within a tolerance
of, or below, the velocity recorded when in "everyday route
velocity" training mode. Thus, no warning signals will be generated
so long as the vehicle is not traveling faster than the threshold
speed identified by the operator during "everyday route velocity"
training of the detector.
[0134] It will be further appreciated that the "signal tracking"
mode described herein may operate upon each frequency band
independently, so that the "signal tracking" mode may be engaged
for one band while disengaged for others, and so that the fade-out
of a tracked signal at one frequency will cause flag bits to be set
for that frequency while other frequencies continue to be
tracked.
[0135] It will be further appreciated that the determination of
whether to generate an audible or visual response, or both, may be
based on information in addition to the flags applicable to the
current cell of the vehicle. For example, the flags in cells
recently traversed by the vehicle may also be consulted to
determine whether audible or visual signals should be suppressed at
a current cell. Thus, for example, if the detector passes through a
cell that has been marked for "minimal visual" lockout, warnings
will be suppressed for subsequent cells entered by the vehicle
while the same signal is being tracked, regardless of whether flag
bits in those cells call for a lockout.
[0136] The invention in its broader aspects is therefore not
limited to the specific details, representative apparatus and
method, and illustrative example shown and described. Accordingly,
departures may be made from such details without departing from the
spirit or scope of applicant's general inventive concept.
* * * * *
References