Tire parameter monitoring system with sensor location using RFID tags

• US 20100134269A1
• Filed: 11/28/2008
• Published: 06/03/2010
• Est. Priority Date: 11/28/2008
• Status: Active Grant

• Current Assignee: Silicon Valley Micro E Corporation
• Original Assignee: Silicon Valley Micro E Corporation
• Inventors: Zhu, Shengbo, Huarg, Su Shiong
• Granted Patent: US 8,289,144 B2
• Time in Patent Office: Days
• US Class Current: 340/447
• CPC Class Codes: B60C 23/041 Means for supplying power to the signal- transmitting means on the wheel
• CPC Class Codes: B60C 23/0413 Wireless charging of active radio frequency circuits
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• 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

Abstract

A tire parameter monitoring system has a plurality of sensor units for monitoring tire parameters, with each sensor unit mounted with a different vehicle tire. Each sensor unit has an RFID tag reader for interrogating an RFID tag securely mounted to the vehicle adjacent the corresponding tire and containing a unique identification code. Each sensor unit has a microcontroller for combining each RFID identification code with corresponding tire parameter signals, and a transmitter for transmitting the combined signals to a receiving location. Received tire parameter signals are correlated with the tire location using the RFID identification code, and driver advisory signals are presented to the driver by a display/alarm unit. Two alternative power supplies are provided. A first type uses a battery and a power management circuit for eliminating power drain when the RFID tag reader is energized. A second type uses inductive power to provide an inexhaustible power source.

Claims

1. A sensor unit for use with a vehicle mounted tire parameter monitoring system having at least one tire parameter sensor, said sensor unit comprising:

an RFID tag reader for sensing RFID tag identification signals generated by an associated RFID tag mounted on the vehicle adjacent the associated sensor unit, said RFID tag identification signals being generated in response to an interrogation by said associated RFID tag reader;

a microcontroller coupled to the RFID tag reader for enabling said RFID tag reader to perform an interrogation of the associated RFID tag and for receiving and processing said RFID tag identification signals and tire parameter signals from an associated tire parameter sensor; and

a signal generator controlled by said microcontroller for transmitting the processed RFID tag identification signals and the tire parameter signals to a receiving location.

2. The sensor unit of claim 1 further including a power source having a battery for supplying electrical power to said microcontroller and said signal generator;

and further including a power management circuit selectively coupled to said battery and said RFID tag reader for storing electrical charges from said battery during a quiescent RFID tag reader operating period and for supplying the stored charges to a power input of said RFID tag reader during an active operating period thereof.

3. The sensor unit of claim 2 wherein said power management circuit includes a capacitor having a charge carrying plate, and a switch means having a power input terminal coupled to said battery, a power output terminal coupled to a power input terminal of said RFID tag reader, and a control input terminal for configuring said switch in at least a first second operational position in which said battery is connected to said charge carrying plate, and a second operational position in which said charge carrying plate is connected to said power input terminal of said RFID tag reader to supply electrical operating power thereto.

4. The sensor unit of claim 3 wherein said control input terminal of said switch means is coupled to and controlled by said microcontroller.

5. The sensor unit of claim 1 further including an inductive power source for supplying electrical power to said RFID tag reader, said microcontroller, and said signal generator.

6. The sensor unit of claim 5 wherein said inductive power source includes a power coil and a power system having an input terminal coupled to said coil and an output terminal coupled to said RFID tag reader, said microcontroller, and said signal generator.

7. The sensor unit of claim 1 further including a tire parameter sensor having an output coupled to said microcontroller.

8. The sensor unit of claim 1 further including a plurality of tire parameter sensors each having an output coupled to said microcontroller for supplying a plurality of tire parameter signals to said microcontroller.

9. A tire parameter monitoring system for monitoring the current values of tire parameters of tires mounted on a vehicle, said system comprising:

a plurality of sensor units each associated to a different tire on the vehicle, each sensor unit including an RFID tag reader for sensing RFID tag identification signals generated by an associated RFID tag mounted on the vehicle adjacent the associated sensor unit, said RFID tag identification signals being generated in response to an interrogation by said associated RFID tag reader;

a microcontroller coupled to the RFID tag reader for receiving and processing said RFID tag identification signals and tire parameter signals from an associated tire parameter sensor; and

a signal generator controlled by said microcontroller for transmitting the processed location signals and the tire parameter signals to a receiving location; and

a plurality of RFID tags each having a unique identification code stored therein for generating a plurality of different identification codes each specifying the unique location on the vehicle of the corresponding RFID tag, each RFID tag being located in proximity to a different one of said plurality of sensor units.

10. The system of claim 9 wherein each said sensor unit includes a power source having a battery for supplying electrical power to said microcontroller and said signal generator;

and further including a power management circuit selectively coupled to said battery and said RFID tag reader for storing electrical charges from said battery during a quiescent RFID tag reader operating period and for supplying the stored charges to a power input of said RFID tag reader during an active operating period thereof.

11. The system of claim 10 wherein wherein each said power management circuit includes a capacitor having a charge carrying plate, and a switch means having a power input terminal coupled to said battery, a power output terminal coupled to a power input terminal of said RFID tag reader, and a control input terminal for configuring said switch in at least a first operational position in which said battery is connected to said charge carrying plate, and a second operational position in which said charge carrying plate is connected to said power input terminal of said RFID tag reader to supply electrical operating power thereto.

12. The system of claim 11 wherein said control input terminal of said switch means is coupled to and controlled by said microcontroller.

13. The system of claim 9 wherein each said sensor unit includes an inductive power source for supplying electrical power to said RFID tag reader, said microcontroller, and said signal generator.

14. The system of claim 13 wherein said inductive power source includes a power coil and a power system having an input terminal coupled to said coil and an output terminal coupled to said RFID tag reader, said microcontroller, and said signal generator.

16. The system of claim 9 wherein each said sensor unit further includes a tire parameter sensor having an output coupled to said microcontroller.

17. The system of claim 9 wherein at least one of said sensor units further includes a plurality of tire parameter sensors each having an output coupled to said microcontroller.

18. The system of claim 9 further including a receiver/processor for receiving and processing the RFID identification signals and tire parameter signals from said sensor units.

19. A method of correlating tire parameter signals generated by sensor units associated to different ones of a plurality of tires on a vehicle with the location of tires whose parameters are monitored by the sensor units, said method comprising the steps of:

(a) generating a plurality of different RFID tag signals in proximity to the sensor units, each different RFID tag signal being associated to a different tire location on the vehicle;

(b) combining each RFID tag signal with the tire parameter signals from the sensor unit at the location specified by the RFID tag signal, and

(c) transmitting the signals combined in step (b) to a receiving location.

20. The method of claim 19 wherein said step (a) of generating includes the step of interrogating an RFID tag with an RFID tag reader located in the sensor unit.