U.S. patent application number 11/097076 was filed with the patent office on 2005-08-04 for system and method for warning of potential collisions.
This patent application is currently assigned to Altra Technologies Incorporated. Invention is credited to Gunderson, Richard A..
Application Number | 20050168331 11/097076 |
Document ID | / |
Family ID | 34576191 |
Filed Date | 2005-08-04 |
United States Patent
Application |
20050168331 |
Kind Code |
A1 |
Gunderson, Richard A. |
August 4, 2005 |
System and method for warning of potential collisions
Abstract
A collision avoidance system for a vehicle. The collision
avoidance system includes one or more transmitting devices, one or
more receiving devices, a control module and a mirror. The
receiving devices receive return signals and send information
regarding the return signals to the control module. The control
module detects a hazard based on the information received from one
or more receiving devices. The mirror includes visual indicators
for warning a driver of the hazard detected by the control
module.
Inventors: |
Gunderson, Richard A.; (Eden
Prairie, MN) |
Correspondence
Address: |
SCHWEGMAN, LUNDBERG, WOESSNER & KLUTH, P.A.
P.O. BOX 2938
MINNEAPOLIS
MN
55402-0938
US
|
Assignee: |
Altra Technologies
Incorporated
|
Family ID: |
34576191 |
Appl. No.: |
11/097076 |
Filed: |
April 1, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11097076 |
Apr 1, 2005 |
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09621748 |
Jul 21, 2000 |
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6894608 |
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60145156 |
Jul 22, 1999 |
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Current U.S.
Class: |
340/468 |
Current CPC
Class: |
G01S 2013/932 20200101;
G01S 2013/93272 20200101; G01S 2015/938 20130101; G01S 7/04
20130101; G01S 15/931 20130101; G01S 2013/93274 20200101; G01S
2013/93271 20200101; B60Q 9/008 20130101; B60Q 9/006 20130101; B60Q
9/007 20130101; B60Q 1/525 20130101; G01S 13/931 20130101; G01S
2013/9317 20130101; B60Q 2900/30 20130101 |
Class at
Publication: |
340/468 |
International
Class: |
B60Q 001/26 |
Claims
What is claimed is:
1. A collision avoidance system for a vehicle, comprising: one or
more transmitting devices; one or more receiving devices, wherein
the receiving devices receive return signals; a control module
connected to the transmitting devices and the receiving devices,
wherein the control module detects a hazard based on information on
the return signals received from the one or more receiving devices;
and a mirror, wherein the mirror includes visual indicators for
warning a driver of the hazard detected by the control module.
Description
RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/621,748, filed Jul. 21, 2000, which claimed
priority under 35 U.S.C. 119(e) of U.S. Provisional Application
Ser. No. 60/145,156, filed Jul. 22, 1999, which applications are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to sensor-based
systems, and more particularly to a vehicle-mounted collision
avoidance system which warns drivers of potential collisions.
[0004] 2. Background Information
[0005] The roads are becoming more and more congested with
vehicular traffic. As traffic congestion has increased, the number
of accidents has also increased. Some of these accidents can be
traced to driver inattentiveness or to the failure of the driver or
of other drivers to see and react to surrounding vehicles.
[0006] Muth Mirror Systems of Sheboygan, Wis. manufactures a side
view mirror with a built-in turn signal display (a "chevron"). The
side view mirror can be mounted on both the passenger and driver
sides of the vehicle and includes light emitting diodes (LEDs)
which blink in time to the turn signal. The chevron is designed to
be clearly visible to drivers in the lane adjacent to the host
vehicle.
[0007] Such a display is good for warning drivers of adjacent
vehicles. It does little, however, to warn the driver of the host
vehicle of potential collisions.
[0008] Systems for warning drivers of objects external to their
vehicle have been around for a long time. Mirrors, and sometimes
combinations of mirrors, are being used to reveal locations hidden
to the driver's view (i.e. "blind spots"). Mirrors, however, have a
deficiency in that the driver can only look in one spot at any one
time, and no one mirror can provide a complete view of all the
possible blind spots. If they look in one mirror, see that the way
is clear, start looking elsewhere and then a vehicle pulls into the
area they thought was clear, they won't see it and may run into the
vehicle. For example, if the driver looks at the lane adjacent to
the vehicle, sees that the way is clear, starts looking elsewhere
and then a vehicle pulls along side, the driver won't see it and
may clip the vehicle while changing lanes.
[0009] In addition, mirrors don't work well in changing lanes,
particularly in tractor-trailer rigs. One reason is that a side
view mirror only looks in the lane adjacent to the vehicle and to
the rear of the side view mirror. Vehicles forward of the side view
mirror or more than one lane away from the vehicle may be missed.
In addition, as soon as the rig begins to turn, the mirror that
looked down along the side of the vehicle is directed into the side
of the trailer and the driver is blinded to activity on that side
of his truck.
[0010] Sensor-based warning systems have also been proposed. For
instance, Sonar Safety Systems of Santa Fe Springs, Calif. has a
rear-mounted sensor system based on a single sensor which detects
objects in three distance zones from the rear of the vehicle. The
system provides alarms and audible feedback that inform the driver
whether the obstacle is close (Zone III), out a little farther
(Zone II), or even farther out yet (Zone I).
[0011] What is needed is a system and method for automatically
warning the driver of potential collisions at the front, to the
sides and behind a vehicle.
SUMMARY OF THE INVENTION
[0012] According to one aspect of the present invention, a
collision avoidance system for a vehicle includes one or more
transmitting devices, one or more receiving devices, a control
module and a mirror. The receiving devices receive return signals
and send information regarding the return signals to the control
module. The control module detects a hazard based on the
information received from the one or more receiving devices. The
mirror includes visual indicators for warning a driver of the
hazard detected by the control module.
[0013] According to another aspect of the present invention, a
method of alerting a driver of potential hazards is described. A
potential collision event is detected and a symbol is displayed
within a mirror indicating that the potential collision event has
been detected.
[0014] According to yet another aspect of the present invention, a
collision avoidance system includes a plurality of transmitting
devices, a plurality of receiving devices, a control module
connected to the plurality of transmitting devices and the
plurality of receiving devices and a side view mirror. The
plurality of transmitting devices include a first and a second
transmitting device, wherein the first and second transmitting
devices transmit a first signal and a second signal, respectively.
The plurality of receiving devices include a first and a second
receiving device, wherein the first receiving device receives a
return representative of the signal transmitted from the first
transmitting device and transmits a first return signal
representative of the first return and wherein the second receiving
device receives a return of the signal transmitted from the second
transmitting device and a second return signal representative of
the return. The control module receives the first and second return
signals and detects potential hazards as a function of the first
and second control signals. The side view mirror includes visual
indicators for warning a driver of potential hazards detected by
the control module.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a collision avoidance system;
[0016] FIG. 2 shows a more complex embodiment of the collision
avoidance system shown in FIG. 1;
[0017] FIG. 3 is a system block diagram of a collision avoidance
system according to FIG. 2;
[0018] FIGS. 4a and 4b show side view mirror displays which can be
used with the control modules of FIGS. 1 and 3;
[0019] FIGS. 5a-c show the operation of two rear-mounted sensors
according to the present invention;
[0020] FIGS. 6a-c show one embodiment of an operator interface
units which can be used with the control modules of FIGS. 1 and
3;
[0021] FIG. 7 illustrates a backup warning system;
[0022] FIGS. 8 and 9 show wireless portable transducer systems;
[0023] FIG. 10 illustrates a side display module;
[0024] FIG. 11 illustrates an alternate embodiment of a collision
avoidance system;
[0025] FIG. 12 illustrates a mirror-mounted display; and
[0026] FIGS. 13 and 14 illustrate a side-mounted display.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In the following detailed description of the preferred
embodiments, reference is made to the accompanying drawings which
form a part hereof, and in which is shown by way of illustration
specific embodiments in which the invention may be practiced. It is
to be understood that other embodiments may be utilized and
structural changes may be made without departing from the scope of
the present invention.
[0028] Some portions of the detailed descriptions which follow are
presented in terms of algorithms and symbolic representations of
operations on data bits within a computer memory. These algorithmic
descriptions and representations are the ways used by those skilled
in the data processing arts to most effectively convey the
substance of their work to others skilled in the art. An algorithm
is here, and generally, conceived to be a self-consistent sequence
of steps leading to a desired result. The steps are those requiring
physical manipulations of physical quantities. Usually, though not
necessarily, these quantities take the form of electrical or
magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It has proven convenient at
times, principally for reasons of common usage, to refer to these
signals as bits, values, elements, symbols, characters, terms,
numbers, or the like. It should be borne in mind, however, that all
of these and similar terms are to be associated with the
appropriate physical quantities and are merely convenient labels
applied to these quantities. Unless specifically stated otherwise
as apparent from the following discussions, terms such as
"processing" or "computing" or "calculating" or "determining" or
"displaying" or the like, refer to the action and processes of a
computer system, or similar computing device, that manipulates and
transforms data represented as physical (e.g., electronic)
quantities within the computer system's registers and memories into
other data similarly represented as physical quantities within the
computer system memories or registers or other such information
storage, transmission or display devices.
[0029] FIG. 1 shows a collision avoidance system 10 according to
the present invention. System 10 includes a control module 12 and
two sensors 14. Each sensor 14 includes a transmitter 16 and a
receiver 18. In one embodiment, transmitter 16 and receiver 18 are
mounted together in a single sensor housing. In another embodiment,
transmitter 16 and receiver 18 are mounted in separate
housings.
[0030] In one embodiment, sensors 14 include separate acoustic
transducers for each of transmitter 16 and receiver 18. In another
embodiment, a single acoustic transducer is used for both
transmitting a signal and receiving its echo. Some transducers
which would operate in such a system 10 are the 9000 Series Piezo
Transducers available from Polaroid OEM Components Group and the
KSN 6530 45 KHz transducer available from Motorola. In addition,
the KSN 6529 45 KHz transducer available from Motorola could be
used for receiver 18.
[0031] In another embodiment, sensors 14 are micropower impulse
radar (MIR) devices. In one embodiment, MIR devices such as those
described in the white paper entitled "Microwave Impulse Radar
(MIR) Technology Overview", available from Lawrence Livermore
National Laboratory, are used. The advantage of such devices are
that they are low power and fairly inexpensive. In addition, a
single device can be used as both transmitter 16 and receiver
18.
[0032] In yet another embodiment, sensors 14 are microwave or
millimeter wave transceiver devices. In one such embodiment, each
transceiver includes a small integrated antenna and electronic
interface board. In another embodiment, sensors 14 include both
proximity detectors 14.1 and longer range detectors 14.2. The
longer range detectors incorporate a larger antenna to operate as a
Doppler Radar Forward Looking Detector. An example of one such
transducer is the model DRO3000 Microwave Transceiver Module
available from Advanced Frequency Products of Andover, Mass.
[0033] In one embodiment, such as is shown in FIG. 2, a collision
avoidance system 30 includes up to seventeen sensors 14 mounted
around the periphery of a vehicle.
[0034] A variety of collision avoidance systems are described in
"System and Method of Avoiding Collisions," U.S. patent application
Ser. No. 09/130,279, filed Aug. 6, 1998 and assigned to the
assignee of the present invention, the descriptions of which are
hereby incorporated by reference.
[0035] In one embodiment, sensors 14 of system 30 are grouped in
detector subsystems. The output from each detector subsystem is fed
into control module 12, as is shown in FIG. 3. As shown in FIG. 3,
system 30 includes a control module 12, an operator interface 32, a
proximity detector subsystem 34 and a rear guard subsystem 36. Each
subsystem includes one or more sensors 14. System 30 may also
include a forward-looking detector subsystem 33 (with two or more
sensors).
[0036] In one embodiment, each sensor 14 is a stand alone smart
sensor as is described in "System and Method of Providing Scalable
Sensor Systems Based on Stand Alone Sensor Modules," U.S. patent
application Ser. No. 09/505,418, filed Feb. 16, 2000 and assigned
to the present assignee. The description of the sensors and of
systems of such sensors is incorporated herein by reference.
[0037] In one embodiment, proximity detector subsystem 34 includes
up to 15 sensors and rear-guard subsystem 36 includes up to 7
sensors. The output of each sensor in each detection subsystem is
fed into control module 12, as shown in FIG. 3.
[0038] In one embodiment, system 30 includes side displays 35, side
warning lights 37 and rear warning lights 39. In one embodiment,
control module 12 includes a vehicle inputs module 38 for receiving
signals from other vehicle sensors. In addition, control module 12
may communicate with an on-board computer 31.
[0039] In one embodiment, side displays 35 and side warning lights
37 are integrated into the side view mirror of the vehicle. One
such embodiment is shown in FIG. 4a, where a left side view mirror
40 includes a chevron 42, a slash 44 and a backup indicator 46. A
similar embodiment is shown in FIG. 4b, where right side view
mirror 41 includes a chevron 42, a slash 44 and a backup indicator
46. A numeric range indicator, such as indicator 35 shown in FIG.
10 could also be included.
[0040] Chevron 42 is a arrow-shaped set of LEDs which flash in time
to the turn signal. The arrow-shaped chevron is visible by drivers
of vehicles in the adjacent lane as a warning to them that the host
vehicle is about to turn or change lanes. In another embodiment, a
flashing amber light or other such visual warning can be directed
at vehicles in adjacent lanes.
[0041] Slash 44 is a diagonal line of LEDs which flash to indicate
that there is a potential hazard in the adjacent lane which would
make a lane change or turn unwise. For example, if the left turn
signal is activated indicating the driver's intent to change lanes
to the left, or to make a left turn, slash 44 will flash in side
view mirror 40 if an object is detected within a specified range of
the left side of the vehicle. The same is true for the right side
mirror if the right turn signal is active and an object is detected
on the right hand side of the vehicle.
[0042] In one embodiment, slash 44 is a diagonal series of LEDs
that cross mirrors 40 and 41 between two opposite corners. A more
reduced line of LEDs could also be used.
[0043] In one embodiment, slash 44 is a steady-state indicator
which remains on as long as the turn signal is on and the potential
hazard is detected. In another embodiment, slash 44 pulses on and
off at a rate of 4 Hz to catch the driver's attention. Other
flashing sequences could also be used.
[0044] Backup indicator 46 is a series of LED symbols used to help
the driver avoid objects while backing up the vehicle. In one
embodiment, the LEDs are arranged in a horizontal row along the top
or bottom of each side view mirror. In one embodiment, backup
indicator 46 is incorporated in only one of the side view mirrors
40 or 41.
[0045] In one embodiment, triangle 48 is displayed when the
transmission is in reverse and an object is detected within a
predefined distance (e.g., 25 feet) of the rear of the vehicle. In
one such embodiment, triangle 48 is a cluster of three LEDs such as
is shown in FIGS. 4a and 4b.
[0046] In one embodiment both triangle 48 and the remaining four
LEDs are displayed when the transmission is in reverse and an
object is detected within a predefined distance (e.g., 25 feet) of
the rear of the vehicle. In one such embodiment, the four LEDs are
turned off one at a time moving closer to triangle 48 as the
vehicle moves closer to the object behind the truck. When the
vehicle is at close range to the object behind the truck, the four
LEDs and the triangle flash (e.g., at 4 Hz) to alert the driver to
stop the vehicle.
[0047] In one embodiment, the remaining four LEDs turn on one at a
time moving closer to the triangle as the vehicle moves closer to
the object behind the truck. When the truck is within a second
predefined distance (e.g., three feet) of the object, all four LEDs
flash (e.g., at 4 Hz) to alert the driver to stop the vehicle. The
LEDs remain flashing until the transmission is shifted out of
reverse.
[0048] In another embodiment, the LED furthest from triangle 48
(LED 4) lights when the distance is less than 25 feet but greater
than 12 feet. The next LED (LED 3) lights when the distance is less
than 25 feet but greater than 8 feet. The next LED (LED 2) lights
when the distance is less than 25 feet but greater than 5 feet and
the final LED (LED 1) lights when the distance is less than 25 feet
but greater than 3 feet. As in above, when the truck is within 3
feet of the object, all four LEDs flash to alert the driver to stop
the vehicle, and remain flashing until the transmission is shifted
out of reverse.
[0049] An alternative to the sequencing of LEDs 46 described above
is to incorporate a numeric range indicator 35 such as is shown in
FIG. 10.
[0050] Such an approach integrates a lot of information into the
side view mirrors. Since the side view mirrors have to be viewed as
part of a turn, lane change or when backing the vehicle, such an
approach provides a lot of information with minimal impact on the
driver.
[0051] Other symbols can also be used. For example, slash 44 can be
replaced with a different symbol. Also, the triangle and series of
LEDs of backup indicator 46 can be replaced with another form of
distance-related information.
[0052] In one embodiment, separate nine wire cables run from
control module 12 to each of side mirrors 40 and 41. Each wire is
at least 18-gauge stranded wire. The cables are connected to
control module 12 with nine pin D subminiature connectors.
[0053] In another embodiment, a two-wire data communication cable
is run from a stand-alone smart sensor to a display processor in
the manner described in "System and Method of Providing Scalable
Sensor Systems Based on Stand Alone Sensor Modules," described
above, the description of which is incorporated herein by
reference. The hazard information is sent from the stand-alone
smart sensor over the data communications cable to the display
processor which, in turn, drives the visual indicators in side view
mirrors 40 and 41.
[0054] In one embodiment, a digital I/O board within control module
12 drives LEDs within each of side mirrors 40 and 41. A control
register within the digital I/O board contains eight left side
mirror bits and eight right side mirror bits. In one embodiment,
each bit is associated with a particular function. For instance, in
one embodiment, each set of bits includes one bit for each of the
individual LEDs 1-4 on its respective side mirror, a bit for
triangle 48 and a bit for slash 44. In addition, a bit can be used
to place side mirror 40 in a flash mode which overrides the
individual bits to place LEDs 1-4 and triangle 48 in a flashing
status during which LEDs 1-4 and triangle 48 flash at a
predetermined frequency (e.g., 4 Hz).
[0055] In another embodiment, control circuitry is placed in
proximity to mirrors 40 and 41 and control module 12 writes
commands to the control circuitry to cause the appropriate signals
to light or flash. Such an approach reduces the amount of wiring
needed to put system 30 in place.
[0056] In one embodiment, a single bit is used to turn on triangles
48 in mirrors 40 and 41. This reflects the fact that triangles 48
will typically be active at the same time. Similarly, LEDs 1-4 for
both the left and right side could be driven by the same bits and
driver electronics.
[0057] In one embodiment, control module 12 includes program code
for initiating a self test. During self test, all LEDs in side
mirrors 40 and 41 are lit for a predetermined period (e.g., five
seconds) so that the driver can verify that all lights are
operational. Self test is entered automatically during the system
initialization process, or can be initiated by the driver.
[0058] In another embodiment, the LEDs flash on and off for a
predetermined period of time during self test.
[0059] Collision Avoidance
[0060] Collision avoidance systems typically have put transducers
on the rear of the vehicle and measure the distance from the sensor
to the object. This is not optimal since those sensors are
transmitting in an arc. They are looking at the distance from the
sensor to the object and back again. That may not, however, be the
perpendicular distance from the vehicle to the object. A
deficiency, therefore, of such systems is that they do not
communicate to the driver the transverse location of this
object.
[0061] In one embodiment of the system shown in FIGS. 1 and 2, a
plurality of sensors 14 are mounted on the back of the vehicle.
Control module 12 takes the readings from the rear-mounted sensors
14, determines whether it can triangulate and calculates an actual
perpendicular distance from the truck to the object. This is
important because the truck driver really wants to know, not that
the object is off at this angle over here five feet away, is how
far he can back up before he hits the object. In contrast to other
approaches, this triangulation procedure makes systems 10 and 30
precision distance measuring systems.
[0062] FIG. 5a represents the top view of a tractor trailer rig 50
with a post 52 located behind the trailer 54. The post 50
represents a hazard unless the driver knows the precise distance
from the vehicle. Sensor 14 on the right rear of the trailer senses
the post 52 at a distance of six (6) feet. Sensor 14 on the left
rear of the trailer senses the post at a distance of just over six
and one half (6.5) feet. Control System 12 calculates that the
actual distance to the post as 5.2 feet and determines it is
located just to the right of the center of the trailer. The
distance is then displayed digitally on the control module 12. The
transverse location is displayed, for instance, on the bar graph
located just to the right of the digital display and it indicates
the location of the post.
[0063] Perpendicular distance between the rear of a vehicle and
external objects is increasingly important the closer the vehicle
gets to an external object. In the same example as above, when
sensor 14 on the right rear of the trailer senses the post at a
distance of four (4) feet and the sensor 14 on the left rear senses
the post at a distance of 4.8 feet, the actual perpendicular
distance is 2.6 feet. The Precision Measurement System described in
U.S. patent application Ser. No. 09/130,279, the description of
which is hereby incorporated by reference, correctly uses the
sensor 14 distance readings as well as the known distance between
the left and right sensors 14 to calculate the exact perpendicular
distance to the post. This is very important as an aid to the
driver in the prevention of an accident.
[0064] In one embodiment, a third sensor 14 is mounted between the
right and left sensors 14. With the aid of third sensor 14, the
system can determine that the object is a point source (such as a
post) as opposed to a wall or large vehicle. The sensor 14 on the
right rear of the trailer senses the post at a distance of six (6)
feet. The sensor 14 on the left rear of the trailer senses the post
at a distance of just over six and one half (6.6) feet. Control
module 12, knowing that the object is a point source, calculates
that the actual distance to the post is 5.2 feet and is located
just to the right of the center of the trailer. The distance is
displayed digitally on the Operator Interface and Side Display
Modules. The transverse location is displayed in graphic form (e.g.
bar graph) on the Operator Interface. One such embodiment is
described in U.S. patent application Ser. No. 09/130,279, the
description of which is hereby incorporated by reference.
[0065] FIG. 5b represents the top view of a tractor trailer with a
post located far behind the trailer. The post represents a hazard
unless the driver has sufficient information to aid in maneuvering
around the obstacle. The sensor 14 on the right rear of the trailer
senses the post at a distance of 21.0 feet. The sensor 14 on the
left rear of the trailer senses the post at a distance of 22.1
feet. The control module 12 calculates that the actual distance to
the post is 21.0 feet, and that it is located near the right side
of the trailer. The distance is displayed digitally on the operator
interface. The transverse location is displayed on the bar graph
located just to the right of the digital display and it indicates
the location. Precision distance measurement is less of a concern
when obstacles are a long distance from the rear of the vehicle.
However, productivity is a concern. With the aid of the transverse
location information and the ability of the control module 12 to
detect objects up to 25 feet behind the vehicle, the driver of the
tractor trailer shown in FIG. 5b can readily maneuver the vehicle
to avoid the obstacle without having to stop, drive forward, and
then proceed in backing the vehicle.
[0066] In order to triangulate, the distance between sensors 14
must be known. Therefore, the distance between sensors 14 must be
controlled. In one embodiment, the distance between sensors 14 is a
system parameter that can be programmed. In one such programmable
embodiment, a programming device is provided to a dealer or a fleet
owner such that once sensors 14 are installed, they can measure the
actual distance between the sensors and the distance from the
sensors to the sides of the vehicle and program that into control
module 12. Control module 12 can then accurately calculate
distance.
[0067] For example, if a collision avoidance system 10 or 20
provides a measurement, is that object directly behind the vehicle,
or is it off to the left or right? Is it actually far enough off to
the left or far enough off to the right that he won't hit it but
needs to be aware of it? To provide more accurate information, in
one embodiment, control module 12 calculates transverse location
and communicates that information via a graphical indicator. Such
an approach is shown in FIGS. 6a-6c and is described in U.S. patent
application Ser. No. 09/130,279 filed Aug. 6, 1998, the description
of which is hereby incorporated by reference.
[0068] Another issue is the vertical position of the rear-mounted
transducers, relative to the ground, and relative to the impact
point with a loading dock, is an important issue. For example,
loading docks have an impact plank that protrudes out from the
wall. If sensors 14 are mounted too low, you may actually look
underneath the impact plank. If so, the truck could hit the plank
under power with the driver thinking he or she had another 4-6
inches to go. In one embodiment, system 10 includes vertical
compensation as discussed below.
[0069] In one embodiment, vertical compensation is activated
automatically via a front panel switch mounted in a front panel
module 60 such as is shown in FIGS. 6a-6c. The purpose of this
feature is to compensate for the protrusion of loading dock impact
pads in cases where sensors 14 are located below the point of
impact of the trailer with the loading dock impact pad.
[0070] FIG. 5c represents the side view of a tractor-trailer
pulling up to a loading dock. The impact pad is the point of
contact with the trailer. The depth (i.e., front-to-back) of the
impact pad is typically 4.5 inches. The top of the impact pad is
typically 48 inches above the ground. In one embodiment, when the
sensors 14 are located below the point of impact of the trailer
with the impact pad, the systems 10 and 30 adjust the distance
measurement by 4.5 inches if the Transducer Assembly is mounted so
low that it cannot detect the impact pad when the trailer is within
12 inches of the impact pad. For example, if the perpendicular
distance from the rear of the trailer to the loading dock is 1 foot
and the Transducer is 2 feet below the impact bar, the measured
distance of 1.0 feet will be corrected to 0.6 feet.
[0071] In one embodiment of systems 10 and 30, a backup warning
system is provided as shown in FIG. 7. In one such embodiment,
sensors 14 include transducers placed on the rear of the vehicle.
Those transducers are activated when the driver shifts his
transmission into reverse. As soon as the driver shifts into
reverse, the transducers on the back begin to send out sound energy
from the transducers, which bounces off an object, comes back to a
receive transducer. Distance is then calculated as a function of
time of return (e.g., acoustic applications) or intensity of the
return signal (e.g., radar applications). In one embodiment, a
Multiple Hypothesis Ranging algorithm is used to calculate
distance. Such an algorithm is described in U.S. patent application
Ser. No. 09/130,279 filed Aug. 6, 1998, the description of which is
hereby incorporated by reference.
[0072] In addition, in one embodiment, when sensors 14 detect that
there's something back there, systems 10 and 30 alert the driver
immediately (e.g., by flashing 44, 46 or 48), so that he or she can
take action and not back into whatever object is being
detected.
[0073] The intent is to provide immediate feedback to the driver
shortly after the vehicle transmission is shifted into reverse.
This information includes information on objects in the vicinity of
the rear of the vehicle as well as information on objects in the
path of the rear of the vehicle. In one embodiment, in the case
where objects are in close proximity to the rear of the vehicle,
but not in the path of the vehicle, an auditory prompt representing
an "alert" is sounded for the driver. (This is in addition to
lighting the appropriate LEDs in mirrors 40 and 41.) If an object
is detected in the path of the vehicle, in the range of 5 to 10
feet, the system will categorize that as a hazard situation and an
auditory prompt representing a "warning" is sounded for the driver.
If an object is detected in the path of the vehicle, within a range
of 5 feet, the system will categorize that as an emergency
situation and an auditory prompt representing an "emergency" is
sounded for the driver. After the vehicle has been backing up for
two or more seconds, the alert, warning, and emergency will have
cleared and the system will begin providing range feedback to the
driver in the form of distance information, as displayed on the
Operator Interface and Side Display Modules, and auditory feedback
in the form of pulsed tones. The closer the vehicle gets to an
object, the faster the repetition rate of the pulses until the rear
of the vehicle is within one foot at which time the pulses have
turned into a continuous tone. In the process of backing up, if a
person or vehicle suddenly appeared behind the vehicle, the system
will automatically detect a sudden change in range to the object
and the "emergency" auditory prompt will be issued to the driver so
he/she can take action.
[0074] In one such embodiment, when the driver is going to back up,
if there is an object within range, one of three scenarios will
happen. First, if the system senses a truck or other object close
to the truck on either side, systems 10 and 30 will give him an
alert. The system knows that there is no collision potential here,
but just alerts him that there is something there. In one
embodiment systems 10 and 30 provide one set of tones to the driver
for an alert. Second, if there is an object in the range of 5-10
feet as soon as the driver throws it into reverse, systems 10 and
30 sense the object and provide the driver with a different alarm
(e.g., a different set of tones or a different flashing light).
This alarm is called a hazard alarm. And again, that's to alert the
driver so he can take action on the hazard alarm. Third, if there
is an object within 5 feet, the driver receives an emergency alarm
(i.e., a third set of tones, or a third flashing light). Systems 10
and 30 therefore provide feedback indicative of the distance to an
object behind the driver. In one such embodiment, audible or visual
feedback tells the driver he's getting closer; the pulses go faster
and faster to the point where, when he's within a foot, the pulses
are continuous. But, if in the process of backing up, the system
automatically detects that the distance suddenly became shorter, it
will provide the emergency alarm right away so the driver can take
action. For example, if somebody drove in behind the driver, or
some kid ran in back of the vehicle, systems 10 and 30 sense that
and automatically provide the emergency alarm so the driver can
take action. As noted above, some of the systems that are out there
actually detect zones of distance and provide feedback for that.
Systems 10 and 30 go beyond that in that they detect and
differentiate objects outside the area of potential collision from
those inside and secondly, they can detect sudden changes in
distance for an emergency alarm.
[0075] In one embodiment, the side view mirrors of FIGS. 4a and 4b
display information corresponding to the zones. In that embodiment,
detection that the truck is in emergency zone 70 causes rapid
flashing of LEDs 1-4 and triangle 48 to alert the driver of the
proximity of the object. In addition, in one embodiment hazard zone
72 is divided into four zones corresponding to each of LEDs 1-4 as
described above.
[0076] In one embodiment a self test capability is provided. Self
test addresses several issues. One is when systems 10 and 30 are
first turned on (i.e., the driver throws the power switch into an
"on" position) the systems will turn all the indicators on so that
the driver right away can see that all the indicators are lit. In
addition, control module 12 tests its internal circuitry to ensure
that the system comes up running. The second thing the system does
is while it's running, if the micro controller or microprocessor in
control module 12 were to fail, systems 10 and 30 then provide a
"watch-dog timer" that will detect the failure. Thirdly, the driver
can activate self test mode. On doing so, in one embodiment,
control module 12 flashes all of the indicators of front panel 20
and/or of mirrors 40 and 41. In one such embodiment, control panel
20 includes an indicator 24 for each transducer mounted around the
vehicle and, on entering self test, transducer indicators 24 begin
to flash. The driver then walks around the vehicle and gets back in
the cab. Every one of those transducers should detect him; each
time they detect him, the transducer indicator 24 associated with
the transducer goes off (i.e., quits flashing). If the driver gets
back to the cab and there's a transducer still flashing, he knows
that something didn't work and he can investigate the problem.
[0077] Wireless Portable Transducer System
[0078] In one embodiment sensors 14 are provided within a wireless
portable transducer system 40. The problem with wired transducer
systems is that, if you look at the number of trailers out there,
they far exceed the number of truck-tractors out there. And so
truck-tractors are basically moving from trailer to trailer. It
could easily reach the point where establishing a complete
collision avoidance system 10 or 30 on each combination of tractors
and trail would be prohibitively expensive. To better address the
needs of fleet owners, a system 10 is constructed having a wireless
portable system 40. FIGS. 8 and 9 show two embodiments of such
portable systems.
[0079] In FIG. 8, two boxes 70 provide the portable transducer
function. Each box 70 includes an antenna sticking out the side.
Each box 70 mounts under the trailer and clamps to the frame of the
trailer. Inside each box 70 is an ultrasonic transmitter and
receiver, electronic circuitry, and a radio transmitter and
receiver. A two wire cable connects battery from the trailer to the
electronic circuitry to provide power. A cable between each box
provides common control signals from the radio transmitter/receiver
such that signals from either rear mounted antenna control both
Transducer Assemblies.
[0080] In FIG. 9, there is one long extrusion with an antenna
sticking out each side. The extrusion clamps to the frame on the
rear of the trailer. The extrusion may be made of one piece, or two
pieces (one within another) with a mechanism to adjust the width of
the extrusion to the width of the trailer. A Transducer Assembly
(transmitter and receiver) is mounted on each end of the extrusion.
The electronic circuitry, including radio transmitter and receiver
are mounted inside the extrusion. In one embodiment, a two wire
cable connects battery from the trailer to provide power to the
electronic circuitry.
[0081] Signals to and from the boxes 70 are communicated to the
control module of the collision avoidance system via the Wireless
Communicator to detect, measure, and display distance to objects
behind the trailer.
[0082] System 40 is designed so that it can quickly be disconnected
from one trailer and moved to another trailer.
[0083] In one such embodiment, a Wireless Portable Transducer
System provides for wireless communication between the electronics
mounted in the cab of the vehicle and the Portable Transducer Array
mounted on the rear of the trailer. Power to operate the Portable
Transducer Array is provided by connecting in to existing power
wiring provided to the trailer from the truck's electrical
system.
[0084] Dependent on the transducer technology used, the Portable
Transducer Array could be made to be totally battery operated. For
example, if the Portable Transducer Array were designed using
Micropower Impulse Radar, Doppler Radar or other alternative
low-power technologies, the transmitting and receiving functions to
measure distance to objects behind the vehicle would be low power
and could operate on batteries built into the Portable Transducer
Array. The communications between the electronics in the cab of the
vehicle and the Portable Transducer Array could also use Micropower
Impulse Radar, Doppler Radar, or other alternative low-power
technologies, thus enabling portability with built-in battery
power. This solution will eliminate the need to tap into the
truck's electrical system to power the Portable Transducer
Array.
[0085] Wireless embodiments of collision avoidance systems are
described in U.S. patent application Ser. No. 09/130,279, filed
Aug. 6, 1998, the descriptions of which are hereby incorporated by
reference.
[0086] In one embodiment, the bulk of the electronics stays with
the tractor. In addition, the rear transducer array stays with the
tractor (i.e., as the driver goes from trailer to trailer he simply
pulls off system 40 and clamps it on the next trailer. In one such
embodiment, a connector arrangement is provided so the driver can
connect system to the power that's already on the trailer and
quickly get the system up and running.
[0087] In another embodiment, multiple sensors are designed into
the wireless subsystem 40 to detect obstacles to the rear of the
vehicle and on either side of the vehicle. Communication with
control module 12 is via wireless digital signals. Control module
12 is designed to sense when the wireless portable sensor subsystem
is not installed or is not functioning properly.
[0088] Different quick-connect mounting arrangements might be
needed for different style trucks. In one embodiment, as is shown
in FIG. 9, portable wireless sensor subsystem 40 is a tubular
structure with integral electronics, battery pack, and sensors
mounted internal or external to the structure. The unit would clamp
on the trailer chassis or the underride bumper provided on the rear
of many trailers. Antennas would be mounted on one or both sides of
the wireless portable sensor subsystem protruding just outside the
left and right edges of the trailer. In another embodiment, as is
shown in FIG. 8, portable wireless sensor subsystem 40 is enclosed
in two separate housings mounted at the left rear or right rear of
the trailer. Again, quick connect mounting arrangements will be
made to secure each unit to the trailer. A cable will interconnect
each unit to allow the sharing of one battery pack, one controller,
and one wireless transceiver.
[0089] In another embodiment of system 40, the sensors on the
trailer are hardwired together. Communication between the sensors
and control module 12, however, is wireless. In this case, a
Transceiver Module is mounted on the tractor and a second unit on
the trailer. The Transceiver Module on the trailer receives its
power from the tractor-trailer umbilical electrical cable.
Electrical signals are passed between tractor and trailer just like
any non-wireless system with the exception that the signals are
converted to wireless communication and then reconverted back to
their electrical form at the other end. This approach provides
additional flexibility for the customer's needs.
[0090] In one embodiment of system 30, systems may be equipped with
a Side Display Module, such as is shown in FIG. 10. Side Display
Module 35 is mounted internal or adjacent to each side view mirror.
If one or more sensors 14 on the side of the cab detect an object,
Side Display Module 35 will flash a forward-directed arrow on that
side of the vehicle. In one embodiment, if one or more sensors on
the side of the trailer detect an object, Side Display Module 35
flashes a rear-directed arrow on that side of the vehicle. If
objects are detected on both the side of the cab and the side of
the trailer, Side Display Module 35 flashes an arrow pointed both
forward and to the rear. In one such embodiment, Side Display
Module 35 also displays the distance between the rear of the
vehicle and any object behind the vehicle when the transmission is
in reverse.
[0091] In one embodiment, as is shown in FIG. 10, side display
module 35 provides visual feedback to the driver when looking in
the direction of either side view mirror. These modules 35 may be
mounted on the edge of the side view mirrors, or they may be
mounted inside the cab in the approximate line-of-sight as the side
view mirrors.
[0092] In one embodiment, display modules 35 include a plastic
housing, a small PCB Assembly with five LED indicators, two
half-inch high seven segment displays, a cable which runs into the
cab and connects to the rear of the Control module, and a clear
plastic cover on the front of the module. The display module 35
mounted on the left side of the cab is identical to the module
mounted on the right side of the cab. Display module 35 can be used
in addition to the displays in side view mirrors 40 and 41.
[0093] In one embodiment, the seven-segment display drivers and LED
driver are located in the Control module. The display shown in FIG.
10 shows a distance reading of twelve feet (12'). In one
embodiment, distance readings associated with the Forward-Looking
Detector Subsystem are not displayed on Side Display Modules 35.
Only Backup Mode rear distance readings are displayed. If an alarm
condition exists anywhere around the vehicle, all five LED's flash.
The LEDs are not meant to provide any detector-specific
information. Similarly, in one embodiment, the graphics displays
shown in FIGS. 6a-c and/or the displays in mirrors 40 and 41 flash
a visual warning on detection of an alarm condition.
[0094] A collision avoidance system 100 for vehicles such as school
buses will be described next. In one embodiment, as is shown in
FIG. 11, system 100 includes a front sensor 102, two or more side
sensors 104 and a rear sensor 106.
[0095] In one embodiment, system 100 mounts on and monitors the
front, sides, and rear of a school bus. Unlike the standard
collision avoidance system for which front and side sensors are
intended to provide collision warning when the vehicle is above a
certain speed, in one embodiment, system 100 activates front and
side sensors (102, 104) when the bus is below a certain speed
(starting or stopping). The primary intent of system 100 is to warn
the driver of objects and pedestrians in close proximity to the
bus.
[0096] In one embodiment, system 100 consists of multiple sensors
and optional driver interface units (both visual and audible). If
the optional driver interface units are not used, driver interface
information is passed to an integrated vehicle driver information
system via an SAE J1708 or SAE J1939 serial data link. In one
embodiment, sensor arrays 102, 104 and 106 are stand-alone in that
the sensor data processing required for valid object detection
takes place on the sensors without the need (and cost) of a
centralized computer.
[0097] In one embodiment, sensors consist of a combination of
radar-based units (Type A and Type B) and ultrasonic-based units
(Type U). The Type A sensor drives both the Type B and Type U
sensors in a master/slave arrangement, providing the most
cost-effective configuration for multiple sensor applications.
[0098] In one such embodiment, the sensors operate from 12 VDC
vehicle battery power, with protection circuits to protect the
electronics from (1) surges due to an overcharging alternator, (2)
reverse voltage, or (3) electrostatic discharge.
[0099] In one embodiment, all sensor housings effectively seal
against all environmental conditions, solvents, and sprays
encountered on the exterior of a vehicle per SAE J1455. All sensors
are certified to comply with SAE J1455 and with FCC
requirements.
[0100] In one embodiment, all sensor housings are connectorized.
Optional cables and harnesses designed to withstand the
environmental conditions called out in SAE J1455 are available.
Connectors utilize a locking mechanism, are environmentally sealed,
and provide highly reliable electrical connections under continuous
shock and vibration.
[0101] In one embodiment, sensor configurations provide a
built-in-test function that detects a malfunction in any of the
sensors and passes this information on to the driver interface.
[0102] In one embodiment, the Type A Sensor is a stand-alone radar
sensor. In addition to processing it's own radar data, it processes
radar data from up to 2 Type B sensors and ultrasonic data from up
to 3 Type U sensors. The Type A sensor can be programmed during
installation to indicate its position on the bus, as well as the
position of any Type B or Type U sensors connected to it. Driver
alert thresholds (sensitivity) are also field programmable.
Standard configurations (position and sensitivity) are available,
so programming is not required during installation.
[0103] In one embodiment, vehicle information (speed, reverse, stop
flashers) is provided to the Type A sensor either directly, via a
direct link to a radar sensor configured to sense speed and to the
reverse switch and flasher switch, or indirectly, via the J1708 or
J1939 interface on the Vehicle/Driver Interface (VDI) unit.
[0104] In one embodiment, the Type A Sensor can detect an object
the size of a small child at up to 25 feet, with a .+-.45.degree.
beamwidth. The sensor can be turned off or the range limited based
on its position on the vehicle and the vehicle status. The sensor
can be programmed to detect objects that are moving at a speed of
0.2 to 10 mph relative to the vehicle, and to differentiate between
stationary and moving objects.
[0105] In one embodiment, valid detection of an object is reported
to the driver interface within 400 ms of when the object meets the
detection criteria. A sudden change in range for objects with a
radar view equal to or larger than a small child (30" tall) within
10' of the vehicle, is reported to the driver interface within 200
ms of occurrence.
[0106] In one embodiment, front sensors 102 and side sensors 104
are activated when the speed drops below 5 mph and stop flashers
are turned on. Front sensors 102 and side sensors 104 remain active
until the engine is turned off or vehicle speed moves above 10 mph.
In one embodiment, rear sensors 106 are active whenever the
transmission is in reverse.
[0107] In one embodiment, the Type A sensor provides alarm type and
alarm on/off messages to the VDI unit based on its own radar data
and radar and ultrasonic data from any attached slave units. For
alarms based on front sensor data, once an object is detected and
an alarm condition presented to the driver, the alarm remains on
until the object is removed from the front of the vehicle. For
alarms based on side sensor data, once an object is detected and an
alarm condition presented to the driver, the alarm remains on until
the object is removed from the side of the vehicle, or the vehicle
speed exceeds 10 mph. For alarms based on rear sensor data, once an
object is detected and an alarm or range condition is presented to
the driver, the alarm remains on, or the range continues to be
presented, until the object is removed from the rear of the
vehicle, or the transmission is shifted out of reverse. All alarms
are extinguished within 1 second of when the alarm clearing event
occurs.
[0108] The Type B Sensor is identical to the Type A in
functionality and performance with the exception that the Type B is
a slave to the Type A and the Type A does the radar data processing
for the Type B.
[0109] The Type U Sensor is an ultrasonic sensor that is slaved to
a Type A radar sensor. The Type U sensor is primarily intended for
use on the rear of a vehicle, where accurate range information is
valuable to assist the driver while backing the vehicle. Type U
sensors are always used in conjunction with radar sensors so that
if environmental conditions exists which impair the performance of
the ultrasonic sensor (heavy dirt or ice coating, very strong wind,
or very heavy rain or snow), radar data can automatically be
substituted for the ultrasonic data. When this automatic
substitution takes place, an indication that the ultrasonic sensor
is impaired is provided to the driver interface.
[0110] In one embodiment, the Type U sensor measures the range to
any object equal to or larger than a 1" diameter pipe 3' long at a
range of 6" to 12' behind the truck with an accuracy of +/-10% or
+/-2" (whichever is greater). The range measurement tracks actual
range within specification for vehicle speeds up to 5 mph. The
range measurement tracks actual range with an accuracy of +/-20%
for vehicle speeds of 5 mph to 15 mph.
[0111] In one embodiment, the Vehicle/Driver Interface (VDI) unit
provides an interface between the sensor array and both the vehicle
and the driver. The VDI unit reads vehicle information (speed,
reverse, stop flashers) from the J1708 or J1939 data links on the
vehicle and provides this information to the Type A sensors. The
VDI unit also relays driver interface information from the Type A
sensors to the J1708 or J1939 data links on the vehicle for use on
vehicle-integrated driver interface systems. The VDI unit will
drive up to two LED displays (e.g., mirrors 40 and 41) and one
audio unit.
[0112] In one embodiment, the VDI unit operates from 12 VDC vehicle
battery power, with protection circuits to protect the electronics
from (1) surges due to an overcharging alternator, (2) reverse
voltage, or (3) electrostatic discharge.
[0113] In one embodiment, the VDI unit housing effectively seals
against all environmental conditions, solvents, and sprays
encountered on the exterior of a vehicle per SAE J1455. In one such
embodiment, the VDI unit is certified to comply with SAE J1455 and
with FCC requirements.
[0114] In one embodiment, the VDI unit is connectorized. Optional
cables and harnesses designed to withstand the environmental
conditions called out in SAE J1455 are available. Connectors
utilize a locking mechanism, are environmentally sealed, and
provide highly reliable electrical connections under continuous
shock and vibration.
[0115] In one embodiment, the VDI unit provides a built-in-test
function that detects a malfunction in itself or any of the
optional driver interface units and passes this information on to
the driver interface.
[0116] In one embodiment, stand-alone driver interface units (DIUs)
include LED displays, digital readouts (future), and audible
feedback units. These units provide flexible stand-alone
configurations that result in high reliability and minimized
cost.
[0117] In one embodiment, DIUs operate from power provided by the
VDI unit. DIU housings intended for mounting on the exterior of the
vehicle, effectively seal against all environmental conditions,
solvents, and sprays encountered on the exterior of a vehicle per
SAE J1455. In one such embodiment, DIUs are certified to comply
with SAE J1455 and with FCC requirements.
[0118] In one embodiment, all DIU housings are connectorized
(either directly or through a pre-attached connectorized cable).
Optional cables and harnesses designed to withstand the
environmental conditions called out in SAE J1455 are available.
Connectors utilize a locking mechanism, are environmentally sealed,
and provide highly reliable electrical connections under continuous
shock and vibration.
[0119] In one embodiment, each DIU provides a built-in-test
function that displays malfunctions detected in any of the sensors
and passes this information on to the driver interface. All DIUs
provide positive feedback to the driver that shows that they are
fully functional every time the system is powered up. This includes
lighting all display segments and exercising the audio unit in a
pleasant distinctive manner. In one embodiment, if the power-up BIT
functions detect a system failure, the audio unit is exercised in a
less pleasant distinctive manner.
[0120] In one embodiment, a mirror-mount LED display (MLD) 110
provides visual feedback to the driver. In one embodiment, as is
shown in FIG. 12, MLD 110 includes six LEDs (112.1 through 112.6)
mounted vertically in a row, and intended to be mounted on the
outside of each side mirror. MLD 110 is designed for viewing in a
wide range of weather and lighting conditions. It can also be
mounted inside the bus, on an A bar or on the dash. From the top,
the LED functions are: LED 112.1 lights amber for system status,
LED 112.2 lights red for side and front sensors, LEDs 112.3-5 light
amber and LED 112.6 lights red, all for rear sensor 106. In one
embodiment, spacing between the top 3 LEDs (LED 112.1-3) is
slightly wider than the spacing between the bottom 4 LEDs (LED
112.3-6).
[0121] In one embodiment, LEDs 112 are mounted on a printed circuit
board 114 and protected with a translucent top housing and an
opaque bottom housing. Wire termination holes 116 are provided at
the bottom of PCB 114. In one embodiment, PCB 114 is designed to
draw heat away from LEDs 112.
[0122] In one embodiment, LED 112.1 is a system status indicator.
In the normal state (no malfunctions) it turns on and off providing
a 0.5 Hz heartbeat (75% duty cycle, off 250 ms, on 250 ms, off 250
ms, on 1250 ms). For abnormal conditions, LED 112.1 flashes at a 4
Hz rate for 1 minute at power-up and again for 1 minute at any time
that an attempt is made to activate the failed circuitry, and
remains off the rest of the time. It simply remains off all of the
time for certain failure conditions that prevent LED 112.1 from
flashing. A special abnormal condition is when the system detects
that the ultrasonic sensors are not functioning correctly and range
is coming from the radar sensors. In this case status light 112.1
flashes at 4 Hz for 1 second and then off for 1 second. This
continues as long as there are objects detected by the radar
sensors that should be picked up by the ultrasonic sensors, but are
not.
[0123] LED 112.2 is a side and front object detection indicator.
Left and right MLDs 110 are driven independently. For side object
detection, LED 112.2 on MLD 110 on the side on which the object is
detected flashes to indicate the detection. Ranges and flashing
patterns can be customized, but the default is 1 Hz flashing for an
object 4 to 8 ft from the bus and 4 Hz flashing for an object 0 to
4 ft from the bus. For front object detection, the performance is
the same, but both left and right MLDs 110 flash in unison. If a
single MLD 110 is used, LED 112.2 indicates that an object has been
detected on the front or on either side. When in reverse, LED 112.2
can be used to indicate side object detection at a limited range.
The default settings, when in reverse, are 2 to 4 ft for 1 Hz
flashing and 0 to 2 ft for 4 Hz flashing.
[0124] Remaining LEDs 112.3-6 are rear range indicators. LEDs
112.3-5, along with LED 112.6, indicate the range to the nearest
object detected to the rear of the bus when the bus is in reverse.
The default pattern for rear range indication is as follows (where
A1, A2 and A3 indicate LEDs 112.3, 4 and 5, respectively):
1 10' to 20' A1, A2, A3, and red flashing at 2 Hz 5' to 10' A2, A3,
and red flashing at 2 Hz 2' to 5' A3, and red flashing at 2 Hz 6"
to 2' red flashing at 2 Hz .ltoreq.6" all 6 lights flashing at 4
Hz
[0125] A sudden change in range, indicating that a moving object
(child, bicycle, or vehicle) has suddenly moved into the path of
the backing bus, will also result in all 6 lights flashing at 4
Hz.
[0126] In one embodiment, a side-mount LED display (SLD) 120 is
used instead of MLD 110 to provide visual feedback to the driver.
In one embodiment, as is shown in FIG. 13, SLD 120 includes six LED
marker lights (LEDs 122.1 through 122.6) mounted vertically in a
row, and intended to be mounted on the outside surface of the bus
within the sight line of each side mirror. SLD 110 is designed for
viewing in a wide range of weather and lighting conditions. It also
can be mounted inside the bus, on an A bar or on the dash. From the
top, the LED functions are: LED 122.1 lights amber for system
status, LED 122.2 lights red for side and front sensors, LEDs
122.3-5 light amber and LED 122.6 lights red, all for rear sensor
106. In one embodiment, spacing between the top 3 LEDs (LED
112.1-3) is slightly wider than the spacing between the bottom 4
LEDs (LED 112.3-6).
[0127] In one embodiment, SLD 120 operates in a manner similar to
MLD 110 described above.
[0128] In one embodiment, LED marker lights 122 are mounted within
an aluminum frame 124. Spacers 126 are situated as needed within
frame 124. A side view of frame 124 (in FIG. 14) shows holes 128
for screwing frame 124 to the side of the vehicle.
[0129] In one embodiment, a Dash-Mount Audio Unit (DAU) provides
audible feedback to the driver. The DAU housing is designed to fit
into a standard circular knockout on the dashboard. It includes a
single green LED to indicate that it is connected and getting power
from the VDI unit. The DAU provides tones of varying pulse rate and
pulse length to indicate the various alarms and range indications.
The DAU is designed to be heard in the noisy environment of a
school bus.
[0130] In one embodiment, the pulse patterns can be customized, but
the default patterns are as follows:
2 Left side detection at 4 to 8 ft Long/short 1 Hz pattern Left
side detection at 0 to 4 ft Long/short 2 Hz pattern Right side
detection at 4 to 8 ft Short/long 1 Hz pattern Right side detection
at 0 to 4 ft Short/long 2 Hz pattern Front detection at 4 to 8 ft 3
short pulses, 1 Hz pattern Front detection at 0 to 4 ft 3 short
pulses, 2 Hz pattern Rear detection at 10 to 20 ft 0.5 Hz 25% duty
cycle pattern Rear detection at 5 to 10 ft 1 Hz 50% duty cycle
pattern Rear detection at 2 to 5 ft 2 Hz 50% duty cycle pattern
Rear detection at 0.5 to 2 ft 4 Hz 50% duty cycle pattern Rear
detection at <0.5 ft steady tone
[0131] In one embodiment, rear audible alerts continue as long as
the bus is in reverse. Front and side audible alerts can be
programmed to extinguish after a fixed period (eg., 4 seconds),
while the visual alert continues, if conditions remain static. The
audible alert restarts if conditions change (i.e., more movement
than that provided by a parked car with its engine running).
[0132] In one embodiment, a system malfunction is indicated with an
audible alert that consists of a continuous 4 pulses per second,
lasting for 4 seconds. This occurs on power up and when the
malfunction is first detected only. Detection of an ultrasonic
sensor with degraded performance is indicated by an audible alert
that consists of 4 pulses then 1 second rest, in sync with the
status LED, repeated 2 times, whenever an object is picked up by
the radar sensors that the ultrasonic sensor is missing.
[0133] In the above discussion, the term "computer" is defined to
include any digital or analog data processing unit. Examples
include any personal computer, workstation, set top box, mainframe,
server, supercomputer, laptop or personal digital assistant capable
of embodying the inventions described herein.
[0134] Examples of articles comprising computer readable media are
floppy disks, hard drives, CD-ROM or DVD media or any other
read-write or read-only memory device.
[0135] Although specific embodiments have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that any arrangement which is calculated to achieve the
same purpose may be substituted for the specific embodiments shown.
This application is intended to cover any adaptations or variations
of the present invention. Therefore, it is intended that this
invention be limited only by the claims and the equivalents
thereof.
* * * * *