Tire Monitoring Device and System

• US 20110132081A1
• Filed: 12/02/2010
• Published: 06/09/2011
• Est. Priority Date: 12/03/2009
• Status: Active Grant

• Current Assignee: Seetron Inc.
• Original Assignee: Seetron Inc.
• Inventors: Uh, Sung Sun, Lee, Kyu Cheol, Jung, Hee Yong
• Granted Patent: US 8,266,955 B2
• Time in Patent Office: Days
• US Class Current: 73/146.5
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force
• CPC Class Codes: B60C 23/0489 for detecting the actual angular position of the monitoring device while the wheel is turning

Abstract

A tire monitoring device may be used in conjunction with a tire monitoring system for a vehicle. The tire monitoring device includes a tire monitoring sensor unit having a state monitoring sensor monitoring a tire state, such as a tire pressure, and a first acceleration sensor and a second acceleration sensor respectively measuring accelerations in first and second directions on a plane perpendicular to a wheel axis, and a controller. The controller is configured to determine whether a wheel is on the left or right side of the vehicle on the basis of a relationship between alternating signals of the first acceleration sensor and the second acceleration sensor and determining whether or not a tire event has occurred with reference to a calculated value based on the accelerations measured by the first acceleration sensor and the second acceleration sensor. The tire monitoring device performs minimum operation required for automatic tire location recognition, thereby minimizing battery consumption and reducing the calculation load of the tire monitoring device itself and a central control unit.

Claims

1. A tire monitoring system for a vehicle, comprising:

a plurality of tire monitoring devices including a tire monitoring sensor unit having a state monitoring sensor monitoring a tire state and a first acceleration sensor and a second acceleration sensor respectively measuring accelerations in first and second directions on a plane perpendicular to a wheel axis, an RF transmitter, and a controller determining whether a wheel is on a left or right side of a vehicle on the basis of a relationship between alternating signals of the first acceleration sensor and the second acceleration sensor and determining whether or not a tire event has occurred with reference to a calculated value of the accelerations measured by the first acceleration sensor and the second acceleration sensor, and attached to wheels; and

a central control unit mounted on the vehicle and including a receiver receiving a signal from the RF transmitter.

2. The tire monitoring system of claim 1, wherein the first direction is a tangential direction of the wheels, and the second direction is a centrifugal direction of the wheels.

3. The tire monitoring system of claim 1, wherein the controller starts an operation of recognizing whether the tire is on the left or right side or controls a transmission mode of the RF transmitter according to whether or not a tire event has occurred.

4. The tire monitoring system of claim 1, wherein:

the calculated value is a sum of absolute values of the accelerations measured by the first acceleration sensor and the second acceleration sensor, and

the controller determines that a tire event has occurred when the calculated value is equal to or less than a reference value for duration of a first period.

5. The tire monitoring system of claim 4, wherein when a tire event has occurred and the calculated value is equal to or larger than the reference value for duration of a second period, the controller performs an operation of recognizing whether the RF transmitter is on the left or right side of the vehicle.

6. A tire monitoring device, comprising:

a pressure sensor;

a first acceleration sensor and a second acceleration sensor respectively configured to measure accelerations in a first direction and a second direction on a plane;

a radio frequency (RF) transmitter configured to transmit measured values of the pressure sensor and the acceleration sensors; and

a controller configured to determine whether or not a tire event has occurred with reference to a calculated value based on the accelerations measured by the first acceleration sensor and the second acceleration sensor.

7. The tire monitoring device of claim 6, wherein the first direction and the second direction are perpendicular to each other.

8. The tire monitoring device of claim 6, wherein:

the controller has a memory having a tire event field whose flag value varies according to whether or not a tire event has occurred, and

the controller checks the tire event field to start an operation of recognizing whether a tire is on a left or right side or control a transmission mode of the RF transmitter.

9. The tire monitoring device of claim 6, wherein:

the calculated value is a sum of absolute values of the accelerations measured by the first acceleration sensor and the second acceleration sensor, and

the controller determines that a tire event has occurred when the calculated value is equal to or less than a reference value for duration of a first period.

10. The tire monitoring device of claim 9, wherein:

when a tire event has occurred and the calculated value is equal to or larger than the reference value for duration of a second period, the controller performs an operation of recognizing whether the RF transmitter is on the left or right side of a vehicle on which the tire monitoring device is mounted.

11. The tire monitoring device of claim 6, wherein:

the first acceleration sensor outputs a first acceleration value;

the second acceleration sensor outputs a second acceleration value;

the calculated value is a sum of the absolute values of the first acceleration value and the second acceleration value;

the controller is configured to determine whether the calculated value is equal to or less than a reference value for duration of a first period; and

if the calculated value is equal to or less than the reference value for duration of a first period, the controller sets a flag to indicate that a tire event has occurred, the tire event signifying at least one of a tire exchange and a tire replacement.

12. A tire monitoring system for a vehicle having a plurality of wheels, comprising:

a tire monitoring device mounted on each wheel, the tire monitoring device comprising;

a pressure sensor;

a first acceleration sensor and a second acceleration sensor respectively configured to measure accelerations in a first direction and a second direction on a plane;

a radio frequency (RF) transmitter configured to transmit measured values of the pressure sensor and the acceleration sensors; and

a controller configured to determine whether or not a tire event has occurred with reference to a calculated value based on the accelerations measured by the first acceleration sensor and the second acceleration sensor; and

a central control unit mounted on the vehicle, the central control unit including a receiver configured to receive signals from the RF transmitter of each tire monitoring device.

13. The tire monitoring system of claim 12, wherein:

if a tire event has occurred, the controller starts an operation of recognizing whether the tire is on the left or right side of the vehicle.

14. The tire monitoring system of claim 12, wherein:

the first acceleration sensor outputs a first acceleration value;

the second acceleration sensor outputs a second acceleration value;

the calculated value is a sum of the absolute values of the first acceleration value and the second acceleration value;

the controller is configured to determine whether the calculated value is equal to or less than a reference value for duration of a first period; and

if the calculated value is equal to or less than the reference value for duration of a first period, the controller sets a flag to indicate that a tire event has occurred, the tire event signifying at least one of a tire exchange and a tire replacement.

15. The tire monitoring system of claim 14, wherein:

when a tire event has occurred and the calculated value is equal to or larger than the reference value for duration of a second period, the controller performs an operation of recognizing whether the RF transmitter is on the left or right side of the vehicle.