Apparatus and method for sensing a condition of a vehicle tire

• US 20020075144A1
• Filed: 06/19/2001
• Published: 06/20/2002
• Est. Priority Date: 12/20/1999
• Status: Active Grant

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: DeZorzi, Timothy
• Granted Patent: US 6,518,875 B2
• Time in Patent Office: Days
• US Class Current: 340/442
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

A tire condition sensor module (14) for a vehicle (10) includes a tire condition sensor (78, 84, 88) operative to sense a condition of an associated vehicle tire (20) and provide a tire condition signal having a characteristic indicative thereof. A motion detector (32) is operative to detect movement of the associated vehicle tire (20) and provide a motion signal that indicates movement of the associated vehicle tire (20). The sensor module (14) also includes a transmitter (44) which is operative to transmit a tire transmitter signal having a characteristic based on the tire condition signal. A controller (74) has one operating mode responsive to the motion signal in which the controller (74) controls the transmitter (44) to intermittently transmit the tire transmitter signal. The controller (74) has another operating mode also responsive to the motion signal in which the controller controls the transmitter (44) to transmit the tire transmitter signal only after the controller determines that the tire condition signal indicates that the sensed tire condition is either above or below a first predetermined threshold. The controller (74) also controls the tire condition sensor (78, 84, 88) to sense the tire condition of the associated vehicle tire (20) during each of the operating modes.

Claims

1. A tire condition sensor module for a vehicle comprising:

a tire condition sensor operative to sense a tire condition of an associated vehicle tire and provide a tire condition signal having a characteristic indicative thereof;

a motion detector operative to detect movement of the associated vehicle tire and to provide a motion signal having a characteristic indicating movement of the associated vehicle tire;

a transmitter operative to transmit a tire transmitter signal having a characteristic based on the tire condition signal; and

a controller having one operating mode responsive to the motion signal in which said controller controls said transmitter to intermittently transmit the tire transmitter signal, said controller having another operating mode responsive to the motion signal in which said controller controls said transmitter to transmit the tire transmitter signal only after said controller determines that the tire condition signal indicates that the sensed tire condition is at least one of below and above a first predetermined tire condition threshold, said controller controlling said tire condition sensor to sense tire condition during each of said operating modes.

2. A module as set forth in claim 1 wherein said controller, when in said another operating mode, controls said tire condition sensor to periodically sense the tire condition at a rate that is less than the rate at which the tire condition is sensed when in said one operating mode.

3. A module as set forth in claim 2 wherein said controller, when in said one operating mode, controls said transmitter to effect an increase in the rate of intermittent transmission of the tire transmitter signal in response to determining at least a predetermined change between the sensed tire condition and a reference tire condition which was indicated in a previously transmitted tire transmitter signal.

4. A module as set forth in claim 3 wherein said controller controls said transmitter to transmit at the increased rate for at least one of a predetermined time period and a predetermined number of transmissions.

5. A module as set forth in claim 1 wherein said controller, when in said another operating mode, controls said transmitter to periodically transmit the tire transmitter signal over a predetermined time period while said tire condition signal indicates that the sensed tire condition is at least one of below and above the first predetermined threshold.

6. A module as set forth in claim 5 wherein said controller, when in said another operating mode, controls said transmitter to periodically transmit the tire transmitter signal for a predetermined number of transmissions while said tire condition signal indicates that the sensed tire condition is at least one of below and above the first predetermined threshold.

7. A module as set forth in claim 1 wherein said tire condition sensor is a pressure sensor that provides the tire condition signal having a characteristic indicative of a sensed tire pressure measurement of the associated vehicle tire.

8. A module as set forth in claim 1 wherein said tire condition sensor is a temperature sensor that provides the tire condition signal having a characteristic indicative of a temperature measurement of the associated vehicle tire.

9. A module as set forth in claim 1 wherein said controller enters said one operating mode in response to said motion signal indicating at least a predetermined amount of movement of the associated vehicle tire, said controller entering said another operating mode in response to said motion signal indicating less than the predetermined amount of movement of the associated vehicle tire and the sensed tire condition being greater than a second predetermined threshold.

10. A module as set forth in claim 1 further including a control switch electrically connected to said controller and said tire condition sensor, said controller activating said control switch to electrically connect said tire condition sensor with a source of electrical energy based on the motion signal, thereby activating said tire condition sensor to sense the tire condition of the associated vehicle tire.

11. A method for monitoring a condition of a vehicle tire, said method comprising the steps of:

detecting movement of the vehicle tire;

providing a motion signal indicative of detected movement;

determining whether the motion signal indicates movement of the vehicle tire;

periodically activating a sensor to sense a condition of the vehicle tire;

providing a tire condition signal having a characteristic indicative of the sensed condition of the vehicle tire;

intermittently transmitting tire condition data based on the tire condition signal at a first rate when the motion signal indicates at least a first amount of detected movement of the vehicle tire; and

transmitting tire condition data only after determining that the tire condition signal indicates that the sensed tire condition is at least one of below and above a first predetermined threshold when the motion signal indicates less than the first amount of detected movement of the vehicle tire.

12. A method as set forth in claim 11 wherein said step of sensing the tire condition further includes sensing the tire condition at a predetermined rate that exceeds the rate at which tire condition data is transmitted when the motion signal indicates at least the first amount of detected movement of the vehicle tire.

13. A method as set forth in claim 11 further including the step of periodically sensing the tire condition at a rate that varies in response to the motion signal.

14. A method as set forth in claim 13 further including the step of electrically connecting the sensor with a source of electrical to control said step of periodically sensing the tire condition.

15. A method as set forth in claim 14 further including the step of controlling a switch connected with the sensor and the source of electrical energy to effect said step of electrically connecting.

16. A method as set forth in claim 11 further including the step of controlling said transmitter to periodically transmit the tire transmitter signal when both the motion signal indicates less than the first amount of detected movement of the vehicle tire and the tire condition signal indicates that the sensed tire condition is at least one of below and above the first predetermined threshold.