U.S. patent application number 09/773105 was filed with the patent office on 2002-08-01 for system and method for shared vehicle tire pressure monitoring, remote keyless entry, and vehicle immobilization.
Invention is credited to Ghabra, Riad, Khreizat, Salman, Nantz, John S., Tang, Qingfeng.
Application Number | 20020101335 09/773105 |
Document ID | / |
Family ID | 25097224 |
Filed Date | 2002-08-01 |
United States Patent
Application |
20020101335 |
Kind Code |
A1 |
Ghabra, Riad ; et
al. |
August 1, 2002 |
SYSTEM AND METHOD FOR SHARED VEHICLE TIRE PRESSURE MONITORING,
REMOTE KEYLESS ENTRY, AND VEHICLE IMMOBILIZATION
Abstract
A combined vehicle remote access, tire monitoring and vehicle
immobilization system and method including a tire monitor for
monitoring a tire parameter, the monitor including a transmitter
for transmitting a radio frequency tire data signal, a vehicle
access transmitter for transmitting a radio frequency vehicle
access signal, and a vehicle activation transponder for receiving
an interrogation signal and transmitting a vehicle activation
signal for use in vehicle immobilization. The system and method
further include a control module having a receiver and a controller
for receiving and processing the tire data, vehicle access, and
vehicle activation signals, and generating a display signal to
display the information represented by the tire data signal, a
vehicle access control signal to perform the vehicle access
function, and a vehicle immobilization control signal to immobilize
the vehicle if the controller fails to authenticate the vehicle
activation signal.
Inventors: |
Ghabra, Riad; (Dearborn
Heights, MI) ; Nantz, John S.; (Brighton, MI)
; Tang, Qingfeng; (Novi, MI) ; Khreizat,
Salman; (Dearborn, MI) |
Correspondence
Address: |
Jeffrey M. Szuma
Brooks & Kushman P.C.
22nd Floor
1000 Town Center
Southfield
MI
48075-1351
US
|
Family ID: |
25097224 |
Appl. No.: |
09/773105 |
Filed: |
January 31, 2001 |
Current U.S.
Class: |
340/426.11 ;
340/425.5; 340/426.33 |
Current CPC
Class: |
B60C 23/0408
20130101 |
Class at
Publication: |
340/426 ;
340/425.5 |
International
Class: |
B60R 025/10 |
Claims
What is claimed is:
1. For use with an automotive vehicle, a combined vehicle remote
access, tire monitoring and vehicle immobilization system
comprising: a tire monitor for mounting in a vehicle tire for
monitoring at least one tire parameter, the monitor including a
transmitter for transmitting a radio frequency tire data signal
representing information concerning the at least one tire
parameter; a handheld remote vehicle access transmitter for
transmitting a radio frequency vehicle access signal for use in
performing at least one vehicle access function; a vehicle
activation transponder for receiving an interrogation signal and
transmitting a vehicle activation signal for use in a vehicle
immobilization function; and a control module for mounting on-board
the vehicle, the control module including a receiver for receiving
the tire data, vehicle access, and vehicle activation signals, and
a controller for processing the tire data, vehicle access, and
vehicle activation signals and generating a display signal
operative to display to a vehicle operator the information
represented by the tire data signal, a vehicle access control
signal operative to perform the at least one vehicle access
function, and a vehicle immobilization control signal operative to
immobilize the vehicle if the controller fails to authenticate the
vehicle activation signal.
2. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the tire monitor
transmitter utilizes frequency shift keying modulation.
3. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the at least one tire
parameter includes pressure.
4. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the remote vehicle access
transmitter utilizes signal modulation from the group consisting of
on-off keying and amplitude shift keying.
5. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the at least one vehicle
access function includes operating a vehicle door lock and
activating a vehicle alarm.
6. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the vehicle activation
transponder comprises a battery-less, inductively coupled
transponder and the vehicle activation signal comprises a low
frequency signal.
7. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the vehicle activation
transponder comprises a radio frequency transponder and the vehicle
activation signal comprises a radio frequency signal.
8. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 7 further comprising a transponder
for transmitting a low frequency signal operative to activate the
vehicle activation transponder for transmitting the vehicle
activation signal.
9. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 1 wherein the vehicle access
transmitter and the vehicle activation transponder are located in a
vehicle ignition keyhead.
10. The combined vehicle remote access, tire monitoring and vehicle
immobilization system of claim 4 wherein the control module further
comprises an amplifier and a data slicer, and wherein the receiver
comprises an integrated circuit including a frequency shift keying
demodulator for demodulating the tire data signal, and a received
signal strength indicator for providing a received signal strength
output signal to the data slicer through the amplifier for
demodulating the vehicle access signal.
11. For use with an automotive vehicle, a method for combined
vehicle remote access, tire monitoring and vehicle immobilization
comprising: providing a tire monitor for mounting in a vehicle tire
for monitoring at least one tire parameter, the monitor including a
transmitter for transmitting a radio frequency tire data signal
representing information concerning the at least one tire
parameter; providing a handheld remote vehicle access transmitter
for transmitting a radio frequency vehicle access signal for use in
performing at least one vehicle access function; providing a
vehicle activation transponder for receiving an interrogation
signal and transmitting a vehicle activation signal for use in a
vehicle immobilization function; and providing a control module for
mounting on-board the vehicle, the control module including a
receiver for receiving the tire data, vehicle access, and vehicle
activation signals, and a controller for processing the tire data,
vehicle access, and vehicle activation signals and generating a
display signal operative to display to a vehicle operator the
information represented by the tire data signal, a vehicle access
control signal operative to perform the at least one vehicle access
function, and a vehicle immobilization control signal operative to
immobilize the vehicle if the controller fails to authenticate the
vehicle activation signal.
12. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the tire monitor
transmitter utilizes frequency shift keying modulation.
13. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the at least one tire
parameter includes pressure.
14. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the vehicle access signal
comprises a radio frequency signal and the remote vehicle access
transmitter utilizes signal modulation from the group consisting of
on-off keying and amplitude shift keying.
15. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the at least one vehicle
access function includes operating a vehicle door lock and
activating a vehicle alarm.
16. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the vehicle activation
transponder comprises a battery-less, inductively coupled
transponder and the vehicle activation signal comprises a low
frequency signal.
17. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the vehicle activation
transponder comprises a radio frequency transponder and the vehicle
activation signal comprises a radio frequency signal.
18. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 17 further comprising providing a
transponder for transmitting a low frequency signal operative to
activate the vehicle activation transponder for transmitting the
vehicle activation signal.
19. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 11 wherein the vehicle access
transmitter and the vehicle activation transponder are located in a
vehicle ignition keyhead.
20. The combined vehicle remote access, tire monitoring and vehicle
immobilization method of claim 14 wherein the control module
further comprises an amplifier and a data slicer, and wherein the
receiver comprises an integrated circuit including a frequency
shift keying demodulator for demodulating the tire data signal, and
a received signal strength indicator for providing a received
signal strength output signal to the data slicer through the
amplifier for demodulating the vehicle access signal.
Description
TECHNICAL FIELD
[0001] The present invention relates generally to wireless vehicle
tire pressure monitoring, vehicle remote keyless access, and
vehicle immobilization and, more particularly, to a system and
method employing a combined receiver for shared vehicle tire
pressure monitoring, remote keyless entry, and immobilization
functions.
BACKGROUND ART
[0002] It is well known in the automotive industry to provide for
remote keyless entry (RKE) to a vehicle through the use of a hand
held transmitter, which is commonly referred to as a "fob."
Currently available RKE fobs may be separate units, or may be part
of an ignition keyhead, preferably along with a vehicle
immobilization transponder. Such RKE fobs generally utilize an
antenna to transmit radio frequency (RF) signals to a vehicle in
order to lock or unlock vehicle doors, open or close a vehicle
sliding door, unlock a vehicle trunk, activate internal and/or
external vehicle lights, and/or activate a "panic" alarm. Remote
access systems using such RKE fobs typically employ on-off keying
(OOK) or amplitude shift keying (ASK) modulation schemes for the RF
signals.
[0003] It is also known in the industry to provide for wireless
monitoring of vehicle tire parameters, particularly tire pressure.
An exemplary tire monitoring system is described and shown in U.S.
Pat. Nos. 5,600,301 and 5,463,374, which also describes a vehicle
remote access device. In such tire monitoring systems, RF
transmitters mounted inside each tire, typically adjacent the
inflation valve stem, transmit information concerning tire pressure
to a receiver located on-board the vehicle. The information
delivered by the RF signals from the transmitters is subsequently
conveyed to a vehicle operator, typically in the form of a display.
Like vehicle remote access systems, such tire monitoring systems
also typically employ OOK or ASK modulation schemes for the RF
signals. When such modulation schemes are used, however, there can
be strong adverse effects on reception of the RF signal, because
the amplitude of a signal transmitted from a rotating tire can vary
significantly during the period of the transmission.
[0004] Finally, in order to deter theft, it is also known in the
automotive industry to provide systems for vehicle immobilization.
U.S. Pat. No. 5,670,933 illustrates an example of such an
immobilization system. Such vehicle anti-theft devices typically
employ low frequency (LF) transponders in a vehicle ignition
keyhead. In such systems, upon insertion of the vehicle ignition
key into the vehicle ignition keyhole, an interrogation signal is
sent by the vehicle. In response, the keyhead transponder transmits
an encrypted code to a control unit, such as a microprocessor,
on-board the vehicle. If the code sent by the transponder is valid
(i.e., the control unit authenticates the received code), then the
control unit generates a signal operative to permit the vehicle to
be activated. However, if the code is not received by the control
unit, or if the code is not valid (i.e., the control unit cannot
authenticate the received code), then the control unit generates a
signal operative to immobilize the vehicle, for example by cutting
off the fuel supply to the vehicle engine.
[0005] It would be desirable to provide a system and method for
shared vehicle remote access, tire monitoring and vehicle
immobilization. Such a combined system and method would provide an
improved and simplified design for such functionality, thereby
optimizing performance and providing a cost advantage. In
particular, such a system and method would preferably employ a
combined RKE, tire monitoring and vehicle immobilization receiver
and a single microprocessor controller. Such a system and method
would also preferably use an OOK or ASK modulation scheme for RKE,
while employing a more advantageous frequency shift keying (FSK)
modulation scheme for tire monitoring, thereby overcoming the
problems of the prior art tire monitoring systems described above.
Still further, such a system and method would also preferably
provide an advantageous RF link for use in vehicle
immobilization.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of the present invention to
provide a system and method for shared vehicle remote access, tire
monitoring and vehicle immobilization functions in order to improve
performance and reduce expense. In that regard, it is a further
object of the present invention to preferably employ a combined
remote keyless entry (RKE), tire monitoring and vehicle
immobilization receiver and a single microprocessor controller. It
is also an object of the present invention to preferably use an
on-off keying (OOK) or amplitude shift keying (ASK) modulation
scheme for RKE, while preferably employing a more advantageous
frequency shift keying (FSK) modulation scheme for tire monitoring,
as well as to preferably provide an advantageous radio frequency
(RF) link for use in vehicle immobilization.
[0007] According to the preferred embodiment of the present
invention, a combined vehicle remote access, tire monitoring and
vehicle immobilization system is provided for use with an
automotive vehicle. The system comprises a tire monitor for
mounting in a vehicle tire for monitoring at least one tire
parameter, the monitor including a transmitter for transmitting a
radio frequency tire data signal representing information
concerning the at least one tire parameter, a handheld remote
vehicle access transmitter for transmitting a radio frequency
vehicle access signal for use in performing at least one vehicle
access function, and a vehicle activation transponder for receiving
an interrogation signal and transmitting a vehicle activation
signal for use in a vehicle immobilization function. The system
further comprises a control module for mounting on-board the
vehicle, the control module including a receiver for receiving the
tire data, vehicle access, and vehicle activation signals, and a
controller for processing the tire data, vehicle access, and
vehicle activation signals and generating a display signal
operative to display to a vehicle operator the information
represented by the tire data signal, a vehicle access control
signal operative to perform the at least one vehicle access
function, and a vehicle immobilization control signal operative to
immobilize the vehicle if the controller fails to authenticate the
vehicle activation signal.
[0008] According to another aspect of the present invention, a
method for combined vehicle remote access, tire monitoring and
vehicle immobilization is also provided for use with an automotive
vehicle. The method comprises providing a tire monitor for mounting
in a vehicle tire for monitoring at least one tire parameter, the
monitor including a transmitter for transmitting a radio frequency
tire data signal representing information concerning the at least
one tire parameter, providing a handheld remote vehicle access
transmitter for transmitting a radio frequency vehicle access
signal for use in performing at least one vehicle access function,
and providing a vehicle activation transponder for receiving an
interrogation signal and transmitting a vehicle activation signal
for use in a vehicle immobilization function. The method further
comprises providing a control module for mounting on-board the
vehicle, the control module including a receiver for receiving the
tire data, vehicle access, and vehicle activation signals, and a
controller for processing the tire data, vehicle access, and
vehicle activation signals and generating a display signal
operative to display to a vehicle operator the information
represented by the tire data signal, a vehicle access control
signal operative to perform the at least one vehicle access
function, and a vehicle immobilization control signal operative to
immobilize the vehicle if the controller fails to authenticate the
vehicle activation signal.
[0009] These and other objects, features and advantages of the
present invention will be readily apparent upon consideration of
the following detailed description of the invention in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is an overall block diagram of the combined vehicle
access, tire monitoring and vehicle immobilization system of the
present invention;
[0011] FIG. 2 is a simplified block diagram of the control module
of the combined vehicle access, tire monitoring and vehicle
immobilization system of the present invention;
[0012] FIG. 3 is a simplified flowchart of the combined vehicle
access, tire monitoring and vehicle immobilization method of the
present invention; and
[0013] FIGS. 4a-c are simplified flowcharts illustrating operations
of the combined vehicle access, tire monitoring and vehicle
immobilization method of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014] Referring to FIGS. 1-4, the preferred embodiment of the
present invention will now be described. As previously noted, it is
known in the automotive industry to provide for remote keyless
entry (RKE) to a vehicle through the use of a hand held
transmitter, which may be part of a separate RKE fob, or part of a
vehicle ignition keyhead with a keyhead transponder for use in
vehicle immobilization. Such transmitters generally utilize an
antenna to transmit radio frequency (RF) signals to a vehicle in
order to lock or unlock vehicle doors, open or close a vehicle
sliding door, unlock a vehicle trunk, activate internal and/or
external vehicle lights, and/or activate a "panic" alarm. Such RKE
fobs typically employ on-off keying (OOK) or amplitude shift keying
(ASK) modulation schemes for the RF signals.
[0015] As also previously noted, it is also known in the industry
to provide for wireless monitoring of vehicle tire parameters,
particularly tire pressure. In such tire monitoring systems, RF
transmitters located inside each tire transmit information
concerning tire parameter, such as pressure, to a receiver located
in the vehicle, which information is ultimately displayed to a
vehicle operator. Like vehicle remote access systems, such tire
monitoring systems also typically employ OOK or ASK modulation
schemes for the RF signals. With such modulation schemes, however,
there can be strong adverse effects on signal reception, because
the amplitude of a signal transmitted from a rotating tire can vary
significantly during transmission.
[0016] Finally, as also noted previously, it is also known in the
automotive industry to provide systems for vehicle immobilization
to deter theft. Such anti-theft devices typically employ low
frequency (LF) transponders in a vehicle ignition keyhead. Upon
insertion of the vehicle ignition key into the vehicle ignition
keyhole, an interrogation signal is sent by the vehicle. In
response, the keyhead transponder transmits an encrypted code to a
control unit on-board the vehicle. If the code sent by the
transponder is valid (i.e., the control unit authenticates the
received code), then the control unit permits the vehicle to be
activated. However, if the code is not received by the control
unit, or if the code is not valid (i.e., the control unit cannot
authenticate the received code), then the control unit acts to
immobilize the vehicle, for example by cutting off the fuel supply
to the vehicle engine.
[0017] As noted, it would be desirable to provide a system and
method for shared vehicle remote access, tire monitoring and
vehicle immobilization. Such a combined system and method would
provide an improved and simplified design for such functionality,
thereby optimizing performance and providing a cost advantage. In
particular, such a system and method would preferably employ a
combined RKE, tire monitoring and vehicle immobilization receiver,
as well as a single microprocessor controller. Such a system and
method would preferably use an OOK or ASK modulation scheme for
RKE, while employing a more advantageous frequency shift keying
(FSK) modulation scheme for tire monitoring, thereby overcoming the
problems of the prior art tire monitoring systems described above.
Still further, such a system and method would also preferably
provide an advantageous RF link for use in vehicle
immobilization.
[0018] Referring now to FIG. 1, an overall block diagram of the
combined vehicle access, tire monitoring and vehicle immobilization
system of the present invention is shown, denoted generally by
reference numeral 10. As seen therein, the system (10) includes a
tire monitor (12) for mounting in a tire (14), preferably located
inside the tire adjacent the tire inflation valve stem (not shown).
Tire monitor (12) includes appropriate sensors and other devices
for monitoring any number of tire parameters, such as tire
pressure, temperature, status (i.e., whether or not the tire is in
motion) and/or speed, in any fashion well known to those of
ordinary skill in the art. Tire monitor (12) includes a transmitter
(16) for transmitting a radio frequency (RF) tire data signal (18)
representing information concerning the tire pressure, temperature,
status and/or speed determined by tire monitor (12), which
information, as described in greater detail below, is ultimately
conveyed to a vehicle operator via a display. It should be noted
that a single tire monitor (12) is shown in FIG. 1 only for the
sake of simplicity. It is to be understood that, according to the
present invention, tire monitors are preferably included in each
vehicle tire.
[0019] As previously noted, the amplitude of tire data signal (18)
coming from a rotating tire can vary significantly during
transmission. This can have strong adverse effects on the ultimate
reception of tire data signal (18) if it is encoded using on-off
keying (OOK) or amplitude shift keying (ASK) modulation. To
overcome this problem, the present invention preferably employs
frequency shift keying (FSK) modulation to encode the tire data
signal. It should be noted, however, that on-off keying (OOK) or
amplitude shift keying (ASK) could also be used.
[0020] The combined vehicle access, tire monitoring and vehicle
immobilization system (10) of the present invention also includes a
hand held remote vehicle access transmitter (20). As shown in FIG.
1, transmitter (20) is a remote keyless entry (RKE) fob of the type
typically employed in the automotive industry. It should be noted,
however, that transmitter (20) may alternatively be included with a
vehicle activation transponder (26) in a vehicle ignition keyhead
(30) as described below, as is also well known in the industry. RKE
fob (20) preferably includes a radio frequency (RF) transmitter
(22) for transmitting an RF vehicle access signal (24) for use in
performing any number of vehicle access functions, such as
operating (i.e., locking or unlocking) a vehicle door lock,
activating internal and/or external vehicle lights, operating
(i.e., opening or closing) a vehicle sliding door, unlocking a
vehicle trunk, activating a vehicle horn, activating a vehicle
"panic" alarm, or other functions. In that regard, unlike the
situation with tire data signal (18), amplitude changes are not a
problem with vehicle access signal (24). As a result, frequency
shift keying (FSK) modulation is not required for vehicle access
signal (24). Instead, the present invention preferably utilizes
on-off keying (OOK) or amplitude shift keying (ASK) modulation for
vehicle access signal (24), although frequency shift keying (FSK)
could also be used.
[0021] Still referring to FIG. 1, the system (10) of the present
invention further includes a vehicle activation transponder (26)
for receiving an interrogation signal and transmitting a vehicle
activation signal (28) in the form of an encrypted, secret code, in
a fashion well known in the art. In that regard, transponder (26)
is located in a vehicle ignition keyhead (30). As a result of
insertion of the vehicle ignition key into the vehicle ignition
keyhole, an interrogation signal is sent from the vehicle. Upon
receiving the interrogation signal, vehicle activation transponder
(26) sends vehicle activation signal (28) representing the
encrypted code. In that regard, vehicle activation transponder (26)
may comprise a low frequency (LF), inductively coupled,
battery-less transponder such that vehicle activation signal (28)
is an LF signal. As used herein, LF includes frequencies up to
about 15 Mhz.
[0022] As noted above, vehicle activation transponder (26) may be
located in vehicle ignition keyhead (30) along with vehicle access
transmitter (22). In that regard, it should be noted that a single
microprocessor (not shown) could be used in keyhead (30) for both
vehicle access transmitter (22) and vehicle activation transponder
(26). Alternatively, a microprocessor could be used for vehicle
access transmitter (22), while a transponder circuit could be used
for vehicle activation transponder (26). Moreover, vehicle
activation transponder (26) may also alternatively comprise a radio
frequency (RF) transponder, such that vehicle activation signal
(28) is an RF signal. In that regard, such an RF vehicle activation
transponder (26) could be activated to send RF vehicle activation
signal (28) by an LF transponder located in vehicle ignition
keyhead (30). As described in greater detail below, the encrypted
code represented by vehicle activation signal (28) is used in
determining whether the vehicle should be immobilized, or disabled,
such as by cutting of the fuel supply to the engine. In that
regard, an RF vehicle activation signal (28) may be advantageously
used in order to guarantee its reception by a control module (32)
described below, thereby preventing inadvertent or undesired
vehicle immobilization.
[0023] Referring still to FIG. 1, the system (10) also includes
control module (32), including a receiver (34) provided in
communication with a controller (36). Receiver (34) is operative to
receive tire data signal (18), vehicle access signal (24) and
vehicle activation signal (28). Controller (36) is operative to
process tire data signal (18) from receiver (34), and to generate a
display signal (38) operative to display the tire information
represented by tire data signal (18) to a vehicle operator via a
display unit (40), such as an LED or lighted icon in the vehicle
dashboard or a vehicle console. It should be noted that the
information displayed to the vehicle operator may include a
warning, which may also be audible, if tire pressure and/or other
tire parameters, such as temperature, are outside recommended
ranges. Controller (36) is also operative to process vehicle access
signal (24) from receiver (34) and to generate a vehicle access
control signal (42) operative to activate a vehicle access actuator
(44) in order to perform the desired vehicle access function. In
that regard, actuator (44) may operate a vehicle door lock, door,
lights, horn, alarm, or other device.
[0024] Similarly, controller (36) is further operative to process
vehicle activation signal (28) from receiver (34). More
particularly, in a fashion well known in the art, controller (36)
is operative to decrypt and authenticate the vehicle activation
signal (28). That is, controller (36) determines whether the code
represented by the vehicle activation signal (28) is valid. If not,
controller (36) is further operative to generate a vehicle
immobilization signal (46), which is operative to activate a
vehicle immobilization actuator (48) in order to immobilize the
vehicle. In that regard, actuator (48) may operate to cut off the
fuel supply to the vehicle engine, deactivate the vehicle throttle,
or activate the vehicle brakes. It should be noted that controller
(36) is preferably an appropriately programmed microprocessor, or
an equivalent thereto. It should also be noted that while
controller (36) preferably comprises a single microprocessor,
thereby providing cost advantages, multiple microprocessors could
also be used.
[0025] Referring next to FIG. 2, a simplified block diagram of the
control module of the combined vehicle access, tire monitoring and
vehicle immobilization system of the present invention is shown. As
seen therein, and as previously described in conjunction with FIG.
1, control module (32) includes receiver (34) for receiving tire
data, vehicle access, and vehicle activation signals (18, 24, 28).
As previously described, tire data signal (18) is preferably an FSK
modulated signal, while vehicle access signal (24) is preferably an
OOK or ASK modulated signal. According to the present invention,
control module (32) is capable of receiving and processing both
types of signals. In that regard, control module (32) preferably
further comprises an amplifier (50) and a data slicer, preferably
in the form of a comparator (52). Receiver (34) preferably includes
a radio frequency (RF) integrated circuit (not shown) that is an
FSK demodulator and which includes a received signal strength
indicator (RSSI). As a result, FSK data from the tire data signal
(18) can be accessed through a data output pin of the integrated
circuit, and OOK or ASK data from the vehicle access signal (24)
can be received by connecting output from the RSSI to amplifier
(50) followed by comparator (52).
[0026] In such a fashion, a single RF integrated circuit can be
used to detect both FSK and OOK or ASK signals depending only on
the type of incoming signal, thereby providing a low cost means for
implementing the use of both FSK (for tire monitoring) and OOK or
ASK (for vehicle access) signals in a combined system. While the
above described embodiment is preferred, it should be noted that
multiple integrated circuits could also be employed. For example,
two integrated circuits could be used, one for receiving RF tire
data and vehicle access signals (OOK, ASK or FSK), and another for
receiving an LF vehicle activation signal. Alternatively, three
integrated circuits could also be used, one for receiving an FSK
modulated tire data signal, another for receiving an OOK or ASK
modulated vehicle access signal, and still another for receiving an
LF vehicle activation signal.
[0027] Referring next to FIG. 3, a simplified flowchart of the
combined vehicle access, tire monitoring and vehicle immobilization
method of the present invention is shown, denoted generally by
reference numeral 60. As seen therein, the method (60) includes, as
described above, providing (62) a tire monitor for mounting in a
vehicle tire for monitoring at least one tire parameter, such as
tire pressure, temperature, status and/or speed. The monitor
including a transmitter which preferably employs frequency shift
keying (FSK) modulation (although on-off keying (OOK) or amplitude
shift keying (ASK) could also be used) for transmitting a radio
frequency (RF) tire data signal representing information concerning
the at least one tire parameter. The method (60) of the present
invention further includes providing (64) a hand held remote
vehicle access transmitter for transmitting an RF vehicle access
signal for use in performing at least one vehicle access function,
which may include operating (i.e., locking or unlocking) a vehicle
door lock, activating internal and/or external vehicle lights,
operating (i.e., opening or closing) a vehicle sliding door,
unlocking a vehicle trunk, activating a vehicle horn, activating a
vehicle "panic" alarm, or other functions. In that regard, the
vehicle access transmitter preferably employs either on-off keying
(OOK) or amplitude shift keying (ASK) modulation for encoding the
vehicle access signal, although frequency shift keying (FSK) could
also be used.
[0028] Still referring to FIG. 3, the method (60) also includes
providing (66) a vehicle activation transponder for receiving an
interrogation signal and transmitting a vehicle activation signal
for use in a vehicle immobilization function. The vehicle
activation transponder may comprise a low frequency (LF),
inductively coupled, battery-less transponder located in a vehicle
ignition keyhead, such that the vehicle activation signal comprises
an LF signal. Alternatively, however, vehicle activation
transponder may comprise a radio frequency (RF) transponder,
thereby transmitting a vehicle activation signal (28) that is an RF
signal. In yet another alternative embodiment, an RF vehicle
activation transponder may be activated to transmit an RF vehicle
activation signal by an LF transponder located in vehicle ignition
keyhead (30).
[0029] As seen in FIG. 3, the method (60) of the present invention
still further includes providing (68) a control module for mounting
on-board the vehicle, the control module including a receiver for
receiving the tire data, vehicle access, and vehicle activation
signals, and a controller for processing the tire data, vehicle
access, and vehicle activation signals and generating a display
signal operative to display to a vehicle operator the information
represented by the tire data signal, a vehicle access control
signal operative to perform the at least one vehicle access
function, and a vehicle immobilization control signal operative to
immobilize the vehicle if the controller fails to authenticate the
vehicle activation signal. In that regard, the control module
preferably further comprises an amplifier and a data slicer, and
the receiver preferably comprises an integrated circuit including a
frequency shift keying demodulator for demodulating the tire data
signal, and a received signal strength indicator for providing a
received signal strength output signal to the data slicer through
the amplifier for demodulating the vehicle access signal. In such a
fashion, as described in detail above, a single RF integrated
circuit can be used to detect both FSK and OOK or ASK signals
depending only on the type of incoming signal, thereby providing a
low cost means for implementing the use of both FSK (for tire
monitoring) and OOK or ASK (for vehicle access) signals in a
combined vehicle remote access, tire monitoring, and vehicle
immobilization system and method. As previously described, however,
a number of alternative configurations and modulation schemes could
also be used.
[0030] Referring finally to FIGS. 4a-c, simplified flowcharts
illustrating operations of the combined vehicle access, tire
monitoring and vehicle immobilization method of the present
invention are shown. As seen in FIG. 4a, the radio frequency (RF)
tire data signal is transmitted (70) by the tire monitor, and
subsequently received and processed (72) by the control module as
described in detail above to determine any number of tire
parameters, including pressure, temperature, status and/or speed.
In that regard, it may be determined (74) if the tire pressure is
within the recommended operating range. If so, a information to
that effect is displayed (76) to the vehicle operator. If not, a
warning may be displayed (78) to the vehicle operator. Such a
warning display may be accompanied by an audible signal. As
previously described, frequency shift keying (FSK) is utilized to
transmit the tire data signal.
[0031] As seen in FIG. 4b, the RF vehicle access signal is
transmitted (80) by the remote keyless entry (RKE) fob, and
subsequently received and processed (82) by the control module as
described in detail above to determine the nature of the vehicle
access function desired by a vehicle operator, which may include
operating (i.e., locking or unlocking) a vehicle door lock,
activating internal and/or external vehicle lights, operating
(i.e., opening or closing) a vehicle sliding door, unlocking a
vehicle trunk, activating a vehicle horn, activating a vehicle
"panic" alarm, or other functions. Thereafter, a vehicle access
control signal is generated (84) in order to activate (86) the
appropriate vehicle access actuator, such as a door lock or light,
to perform the desired vehicle access function. As previously
described, on-off keying (OOK) or amplitude shift keying (ASK) is
utilized to modulate the vehicle access signal.
[0032] Finally, as seen in FIG. 4c, after receipt (88) of an
interrogation signal, the vehicle activation signal is transmitted
(90), such as from a vehicle activation transponder located in a
vehicle ignition keyhead, and subsequently received and processed
(92) by the control module as described in detail above to
determine whether the vehicle should be immobilized. In that
regard, it is determined (94) whether the code represented by the
vehicle activation signal is valid. If so, no action is undertaken
to disable the vehicle (96). If not, a vehicle immobilization
signal is generated (98) in order to activate (100) the appropriate
vehicle immobilization actuator to disable the vehicle, such as by
cutting off the fuel supply to the vehicle engine, deactivating the
vehicle throttle, or activating the vehicle brakes.
[0033] From the foregoing description, it can be seen that the
present invention provides a system and method for shared vehicle
remote access, tire monitoring and vehicle immobilization functions
that improves performance and reduces expense. In that regard, the
present invention preferably employs a combined remote keyless
entry (RKE), tire monitoring and vehicle immobilization receiver,
as well as a single microprocessor controller. The present
invention also preferably uses an on-off keying (OOK) or amplitude
shift keying (ASK) modulation scheme for RKE, while preferably
employing a more advantageous frequency shift keying (FSK)
modulation scheme for tire monitoring, and provides either a low
frequency (LF) or a radio frequency (RF) link for use in vehicle
immobilization. In such a fashion, the present invention preferably
combines the above vehicle functions in one module using a single
microprocessor controller, yet still advantageously uses two
different modulation schemes for tire monitoring and remote access
for optimum operation of each application, while simultaneously
improving and simplifying the vehicle immobilization function by
providing an RF link.
[0034] While various embodiments of the invention have been
illustrated and described, it is not intended that these
embodiments illustrate and describe all possible forms of the
present invention. Rather, the words used in the specification are
words of description rather than limitation, and it is understood
that various changes may be made without departing from the spirit
and scope of the invention. Indeed, many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description, and the present
invention is intended to embrace all such alternatives.
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