Transmitter of tire condition monitoring apparatus

• US 20030115945A1
• Filed: 06/04/2002
• Published: 06/26/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Pacific Industrial Company Limited
• Original Assignee: Pacific Industrial Company Limited
• Inventors: Tsujita, Yasuhisa
• Granted Patent: US 6,938,467 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• 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 transmitter for a tire condition monitoring apparatus, which is powered by a battery. The transmitter includes a sensor for periodically detecting the condition of the tire, a transmission circuit for wirelessly transmitting data representing the detected tire condition, and a controller for controlling the sensor and the transmission circuit. When the detected tire condition is abnormal, the controller shortens the detection interval of the sensor. As a result, the transmitter immediately informs a driver of abnormality in the condition of the tire.

Claims

1. A transmitter for a monitoring apparatus that monitors the condition of a vehicle tire, wherein the transmitter is powered by a battery, the transmitter comprising:

a sensor for periodically detecting the condition of the tire;

a transmission circuit for wirelessly transmitting data representing the detected condition of the tire; and

a controller for controlling the sensor and the transmission circuit, wherein the controller changes a detection interval of the sensor in accordance with the detected tire condition.

2. The transmitter according to claim 1, wherein, when the detected tire condition is less than a predetermined value, the controller controls the detection interval of the sensor to be shorter than that when the detected tire condition is greater than or equal to the predetermined value.

3. The transmitter according to claim 1, wherein, when the detected tire condition is greater than or equal to a predetermined value, the controller controls the detection interval of the sensor to be shorter than that when the detected tire condition is less than the predetermined value.

4. The transmitter according to claim 1, wherein, when the detected tire condition is out of a predetermined range, the controller controls the detection interval of the sensor to be shorter than that when the detected tire condition is within the predetermined range.

5. The transmitter according to claim 1, wherein, when a variation amount of the detected tire condition is greater than or equal to a predetermined value, the controller controls the detection interval of the sensor to be shorter than that when the variation amount is less than the predetermined value.

6. The transmitter according to claim 5, wherein the variation amount of the detected tire condition is the absolute value of the difference between the detected tire condition of the previous measurement and the detected tire condition of the current measurement.

7. The transmitter according to claim 1, wherein the controller determines whether the tire condition is normal based on the detected tire condition, wherein, when determining that the tire condition is normal, the controller controls the sensor to measure the tire condition at a predetermined first time interval, and wherein, when determining that the tire condition is abnormal, the controller controls the sensor to measure the tire condition at a second time interval, which is shorter than the first time interval.

8. The transmitter according to claim 7, wherein the transmission circuit periodically transmits data representing the tire condition, and wherein, when determining that the tire condition is abnormal, the controller controls the transmission interval of the transmission circuit to be shorter than that when it is determined that the tire condition is normal.

9. The transmitter according to claim 7, wherein, when determining that the tire condition is normal, the controller controls the transmission circuit to transmit data every time the tire condition is measured predetermined number of times at the first time interval, and wherein, when determining that the tire condition is abnormal, the controller controls the transmission circuit to transmit data every time the tire condition is measured at the second time interval.

10. The transmitter according to claim 1, wherein the controller controls the sensor to measure the tire condition at a predetermined first time interval, and wherein, when determining that the tire condition is abnormal based on the measurement result obtained from the measurement performed at the first time interval, the controller controls the sensor to measure the tire condition at a second time interval, which is shorter than the first time interval, at least during the period of the first time interval.

11. A transmitter for a monitoring apparatus that monitors the air pressure of a vehicle tire, wherein the transmitter is powered by a battery, the transmitter comprising:

a sensor for periodically detecting the air pressure of the tire;

a transmission circuit for periodically transmitting data representing the detected air pressure of the tire; and

a controller for controlling the sensor and the transmission circuit, wherein the controller judges whether the air pressure of the tire is normal based on the detected air pressure of the tire, wherein, when determining that the air pressure of the tire is normal, the controller controls the sensor to measure the air pressure of the tire at a predetermined first time interval, and wherein, when determining that the air pressure of the tire is abnormal, the controller controls the sensor to measure the air pressure of the tire at a second time interval, which is shorter than the first time interval, and the controller controls a transmission interval of the transmission circuit to be shorter than that when it is determined that the air pressure of the tire is normal.

12. The transmitter according to claim 11, wherein, when determining that the air pressure of the tire is normal, the controller controls the transmission circuit to transmit data every time the air pressure of the tire is measured predetermined number of times at the first time interval, and wherein, when determining that the tire condition is abnormal, the controller controls the transmission circuit to transmit data every time the air pressure of the tire is measured at the second time interval.

13. The transmitter according to claim 11, wherein, when a variation amount of the detected air pressure of the tire is greater than or equal to a predetermined value, the controller determines that the air pressure of the tire is abnormal.

14. The transmitter according to claim 13, wherein the variation amount of the detected air pressure of the tire is the absolute value of the difference between the detected tire pressure of the previous measurement and the detected tire pressure of the current measurement.

15. A method for monitoring the condition of a vehicle tire, comprising:

detecting the tire condition periodically;

transmitting a radio signal representing the detected tire condition periodically; and

changing a detection interval and a transmission interval in accordance with the detected tire condition.

16. The method according to claim 15, further comprising:

determining whether the detected tire condition is normal; and

shortening the detection interval and the transmission interval when it is determined that the tire condition is abnormal from the detection interval and the transmission interval when it is determined that the tire condition is normal.