UNIQUE HEADER FORMAT FOR TPMS AND SMART ENTRY SYSTEM

• US 20110304449A1
• Filed: 08/05/2010
• Published: 12/15/2011
• Est. Priority Date: 06/15/2010
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Lickfelt, Brian K., Arai, Hideaki, Strock, Nicky
• Granted Patent: US 8,446,271 B2
• Time in Patent Office: Days
• US Class Current: 340/442
• CPC Class Codes: B60C 23/0418 Sharing hardware components like housing, antenna, receiver or signal transmission line with other vehicle systems like keyless entry or brake control units
• CPC Class Codes: B60C 23/044 Near field triggers, e.g. magnets or triggers with 125 KHz
• CPC Class Codes: B60C 23/0442 the transmitted signal comprises further information, e.g. instruction codes, sensor characteristics or identification data
• CPC Class Codes: B60C 23/0444 Antenna structures, control or arrangements thereof, e.g. for directional antennas, diversity antenna, antenna multiplexing or antennas integrated in fenders
• CPC Class Codes: B60C 23/0445 Means for changing operating mode, e.g. sleep mode, factory mode or energy saving mode
• CPC Class Codes: B60C 23/045 Means for detecting electromagnetic field changes being not part of the signal transmission per se, e.g. strength, direction, propagation or masking
• CPC Class Codes: B60C 23/0452 Antenna structure, control or arrangement vehicle tyre mounted antennas H01Q1/2241
• CPC Class Codes: B60C 23/0454 Means for changing operation mode, e.g. sleep mode, factory mode or energy save mode
• CPC Class Codes: B60C 23/0461 externally triggered, e.g. by wireless request signal, magnet or manual switch
• CPC Class Codes: B60C 23/0462 Structure of transmission protocol

Abstract

A vehicle entry/tire pressure management system includes an ECU, tire sensors mounted in, on or adjacent respective tires of the vehicle, a portable transmission/reception unit configured to be carried by an operator of the vehicle, and an antenna mounted on the vehicle and in communication with the ECU. Each tire sensor is configured to transmit an RF signal. The portable transmission/reception unit can transmit RF signals for controlling operations of the vehicle including unlocking doors of the vehicle. The antenna is configured to transmit an LF tire sensor wake up field to wake up the tire sensors. The tire sensor wake up field includes a unique header format. The tire sensors only fully wake up upon receiving the unique header format.

Claims

1. A vehicle entry/tire pressure monitoring system for a vehicle, the system comprising:

an electronic control unit (“

ECU”

);

tire sensors mounted in, on or adjacent respective tires of the vehicle, each tire sensor being configured to transmit an RF signal;

a portable transmission/reception unit configured to be carried by an operator of the vehicle and to transmit RF signals for controlling operations of the vehicle including unlocking doors of the vehicle;

an antenna mounted on the vehicle and in communication with the ECU, the antenna being configured to transmit a low frequency (“

LF”

) tire sensor wake up field to wake up the tire sensors, wherein the tire sensor wake up field includes a unique header format, wherein the tire sensors only fully wake up upon receiving the unique header format.

2. The system of claim 1, wherein the tire sensors partially awake to process the unique header format upon receiving the LF field.

3. The system of claim 1, wherein the portable transmission/reception unit partially awakes to process the unique header format in the LF tire sensor wake up field, and the portable transmission/reception unit enters into a sleep mode upon determining that the unique header format in the LF tire sensor wake up field does not match a predetermined header format.

4. The system of claim 1, wherein the tire sensors take pressure readings of the tires and transmit the RF signals when fully awake.

5. The system of claim 1, wherein the antenna is configured to transmit an LF portable transmission/reception unit wake up field to wake up the portable transmission/reception unit for keyless entry of the vehicle.

6. The system of claim 5, wherein the tire sensors awake to process a header format in the LF portable transmission/reception unit wake up field, and the tire sensors enter into a sleep mode upon determining that the header format in the LF portable transmission/reception unit wake up field does not match a predetermined header format.

7. The system of claim 1, wherein the antenna includes a front antenna mounted towards a front of the vehicle, a rear antenna mounted towards a rear of the vehicle, a left side antenna mounted on or near a left door of the vehicle, and a right side antenna mounted on or near a right door of the vehicle, wherein each antenna is configured to transmit an LF wake up field to wake up two tire sensors and the RF signal transmitted from each tire sensor includes an identification signal associated with the respective tire sensor, where the ECU is configured to receive the identification signals from the respective tire sensors and to determine locations of the respective tire sensors based on which antenna woke up the tire sensor transmitting the respective identification signal and whether the respective identification signal matches other received identification signals.

8. The system of claim 7, wherein each tire sensor includes a receiving antenna and a received signal strength indication (“

RSSI”

) circuit for generating RSSI data that is a function of radiated power from respective LF fields being picked up by the receiving antenna, wherein the RF signal transmitted by the tire sensors includes the RSSI data, wherein the ECU is further configured to determine locations of the respective tires based on RSSI the data.

9. The system of claim 7, further comprising a memory associated with the ECU, wherein the ECU is further configured to store the identification signals in the memory with each identification signal being associated with a corresponding respective tire sensor.

10. The system of claim 7, wherein each tire sensor includes an antenna including two axes for detecting the LF field, wherein a first axis is configured to detect an LF field generated by one of the antennas and the second axis is configured to detect an LF field generated by another of the antennas.

11. The system of claim 1, wherein the antenna includes a left front antenna mounted near a left front corner of the vehicle, a left rear antenna mounted near a left rear corner of the vehicle, a right front antenna mounted near a right front corner of the vehicle, and a right rear antenna mounted near a right rear corner of the vehicle, wherein each antenna is configured to transmit an LF wake up field to wake up two tire sensors and the RF signal transmitted from each tire sensor includes a identification signal associated with the respective tire sensor, wherein the ECU is configured to receive the identification signals from the respective tire sensors and to determine locations of the respective tire sensors based on which antenna woke up the tire sensor transmitting the respective identification signal and whether the respective identification signal matches other received identification signals.

12. The system of claim 11, wherein each tire sensor includes a receiving antenna and a received signal strength indication (“

RSSI”

) circuit for generating RSSI data that is a function of radiated power from respective LF fields being picked up by the receiving antenna, wherein the RF signal transmitted by the tire sensors includes the RSSI data, wherein the ECU is further configured to determine locations of the respective tires based on RSSI the data.

13. The system of claim 11, further comprising a memory associated with the ECU, wherein the ECU is further configured to store the identification signals in the memory with each identification signal being associated with a corresponding respective tire sensor.

14. The system of claim 11, wherein each tire sensor includes an antenna including two axes for detecting the LF field, wherein a first axis is configured to detect an LF field generated by one of the antennas and the second axis is configured to detect an LF field generated by another of the antennas.

15. A method for operating a vehicle entry/tire pressure monitoring system, the method comprising:

transmitting a low frequency (“

LF”

) field from an antenna mounted on a vehicle, wherein the LF field includes a unique header format;

partially waking up a tire sensor to process the unique header format, wherein the tire sensor is disposed in a tire of the vehicle;

partially waking up a portable transmission/reception unit to process the unique header format, wherein the portable transmission/reception unit is configured to communicate with an ECU on the vehicle to control operations of the vehicle;

where the unique header format matches a tire pressure sensor wake up header, fully awakening the tire sensor; and

where the unique header format data matches a portable transmission/reception unit wake up header, fully awakening the portable transmission/reception unit.

16. The method of claim 15, further comprising transmitting RF signals from the tire sensor after fully awakening the tire sensor.

17. The method of claim 16, further comprising taking a tire pressure measurement with the tire sensor after fully awakening the tire sensor.

18. The method of claim 15, wherein the RF signals from the tire sensor include a identification signal, wherein transmitting an LF field from an antenna includes sequentially transmitting LF fields from four antennas each mounted at a different location on the vehicle where each LF field is configured to wake up two tire sensors.

19. The method of claim 15, further comprising determining locations of the respective tire sensors based on which antenna woke up the tire sensor transmitting the respective identification signal and whether the received respective identification signal matches other received identification signals.