TIRE AIR PRESSURE MONITOR DEVICE

• US 20140088816A1
• Filed: 02/20/2012
• Published: 03/27/2014
• Est. Priority Date: 05/17/2011
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Shima, Takashi, Sakaguchi, Kazuo, Terada, Syoji
• Granted Patent: US 9,322,744 B2
• Time in Patent Office: Days
• US Class Current: 701/29.1
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0459 self triggered by motion sensor
• 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
• CPC Class Codes: G01M 17/02 Tyres

Abstract

Provided is a tire air pressure monitoring device capable of accurately determining the wheel position of a transmitter. The tire air pressure monitoring device comprises: a transmitter installed on each wheel for transmitting detected air pressure information via a wireless signal; a rotational position detection mechanism disposed on the vehicle body side which detects the rotational position of each wheel and also outputs rotational position information to a communications line at prescribed time intervals; and a vehicle body side rotation position estimation mechanism that estimates the rotational position (i.e., number of teeth) at the time of transmission by the transmitters, on the basis of the reception information for the wireless signal from the transmitters and the rotation position information for the wheels input via the communications line.

Claims

1. A tire pressure monitoring device for monitoring the air pressure of each tire comprising:

a tire pressure detection mechanism installed on the tire of each wheel for detecting the air pressure of the tire;

a transmitter installed on each wheel for transmitting the air pressure in a wireless signal with identification information unique to each transmitter included in the wireless signal;

a receiver mounted on the side of a vehicle body for receiving the wireless signal;

a rotational position detection mechanism installed on the vehicle body in correspondence with each wheel for detecting a rotational position of each wheel and outputting the rotational position a predetermined time interval to a communication line;

a vehicle body side rotational position estimate mechanism installed on the vehicle body for estimating an estimated rotational position of the transmitter at a time of transmission based on information received from the transmitter and the rotational position the wheel input via the communication line; and

a wheel position determination mechanism for identifying a position of the wheel on which the transmitter is installed based on the estimated rotational position and the identification information included in the wireless signal,

wherein the vehicle body side rotational position estimate mechanism is configured to estimate the estimated rotational position at the time of transmission from the transmitter based on the rotational position of each wheel input immediately before a receiving start time of the wireless signal and immediately after a receipt completion time respectively input via the communication line, a time of input of rotational position of the wheel, and the receiving start time or the receipt completion time.

3. The tire pressure monitoring device as claimed in claim 1, wherein the vehicle body side rotational position estimate mechanism corrects a transmission delay of the transmitter included in the information received in the wireless signal.

4. The tire pressure monitoring device as claimed in claim 1, wherein the transmitter sends the wireless signal in duplicate as a plurality of frames and the vehicle body side rotational position estimate mechanism estimates the estimated rotational position at the transmission of the transmitter based on the information received from the plurality of frames.

5. The tire air pressure monitoring device as claimed in claim 4, wherein the transmitter transmits each of the plurality of frames at intervals from each other and causes the estimated rotational position of the transmitter to be included in each frame at the transmission of each frame.

6. The tire air pressure monitoring device as claimed in claim 5, wherein each wheel is provided with a rotational position estimate mechanism that estimates the estimated rotational position of the transmitter at the transmission of each frame, the transmitter configured to include in each frame the estimated rotational position as rotational position information.

7. The tire air pressure monitoring device as claimed in claim 5, wherein the transmitter is configured to send a predetermined reference frame out of the plurality of frames at a predetermined rotational position, transmit each frame at a predetermined interval, and include as the rotational position information a transmission order information, wherein

the rotational position estimate mechanism estimates the predetermined rotational position based on the information received among the plurality of the frames, and wherein

the wheel position determination mechanism determines the position of wheel on which the transmitter is installed.

8. The tire air pressure monitoring device as claimed in claim 7, wherein the transmitter transmits each frame with different time intervals placed from each other.

9. The tire air pressure monitoring device as claimed in claim 8, wherein the transmitter transmits three or more frames to transmit each frame at a different time interval.

10. The tire air pressure monitoring device as claimed in claim 7, wherein the transmitter transmits each frame with a predetermined rotational position interval.

2. (canceled)

11. A tire pressure monitoring device for monitoring the air pressure of each tire comprising:

a tire pressure detection mechanism installed on a tire of each wheel for detecting the air pressure of the tire;

a transmitter installed on each wheel for transmitting the air pressure in a wireless signal with identification information unique to each transmitter included in the wireless signal;

a receiver mounted on a side of the vehicle body for receiving the wireless signal;

a rotational position detection mechanism installed on the vehicle body in correspondence with each wheel for detecting a rotational position of each wheel and outputting the rotational position of each wheel at a predetermined time interval to a communication line;

a vehicle body side rotational position estimate mechanism installed on the vehicle body for estimating an estimated rotational position of the transmitter at a time of transmission based on information received from the transmitter and the rotational position of each wheel input via the communication line; and

a wheel position determination mechanism for identifying a position of the wheel on which the transmitter is installed based on the estimated rotational position and the identification information included in the wireless signal, wherein;

the transmitter sends the wireless signal in duplicate as a plurality of frames to transmit a predetermined reference frame among the plurality of frames at a predetermined rotational position while transmitting each of the plurality of frames at intervals from each other and to cause the estimated rotational position of the transmitter to be included in each frame at the transmission of the frame,

the vehicle body side rotational position estimate mechanism estimates the predetermined rotational position based on the information received among the plurality of frames,

the wheel position determination mechanism determines the position of the wheel on which the transmitter is installed based on the predetermined rotational position, and

the transmitter transmits the plurality of frames in a plurality of groups and transmits a reference frame of each group;

at a predetermined rotational position provided for each group at a predetermined interval.

12. The tire air pressure monitoring device as claimed in claim 11, wherein:

the transmitter includes group information in each frame indicative to which group the frame belongs,

the vehicle body side rotational position estimate mechanism estimates a predetermined rotational position for a predetermined reference group among the plurality of groups based on the predetermined rotational position of the group to which the frame is estimated to belong with respect to the received frame and the group information, and

the wheel position determination mechanism determines the position of the wheel on which the transmitter is installed based on the predetermined rotational position of the estimated reference group.

13. A tire pressure monitoring device for monitoring the air pressure of each tire comprising:

a tire pressure detection mechanism installed on a tire of each wheel for detecting the air pressure of the tire;

a transmitter installed on each wheel for transmitting the air pressure in a wireless signal with identification information unique to each transmitter included in the wireless signal;

a receiver mounted on a vehicle body for receiving the wireless signal;

a rotational position detection mechanism installed on the vehicle body in correspondence with each wheel for detecting a rotational position of each wheel and outputting the rotational position at a predetermined time interval to a communication line;

a vehicle body side rotational position estimate mechanism installed on the vehicle body for estimating an estimated rotational position of the transmitter at a time of transmission based on a time of receipt of the wireless signal from the transmitter, the rotational position of each wheel input via the communication line, and an input time of the rotational position; and

a wheel position determination mechanism for identifying a position of the wheel on which the transmitter is installed based on the estimated rotational position and the identification information included in the wireless signal.