Tire air pressure detection system and vehicle body side device

• US 10,596,866 B2
• Filed: 10/02/2017
• Issued: 03/24/2020
• Est. Priority Date: 10/05/2016
• Status: Active Grant

• Current Assignee: Autonetworks Technologies, Ltd. (Sumitomo Corporation), Sumitomo Electric Industries Limited (Sumitomo Corporation), Sumitomo Wiring Systems Limited (Sumitomo Corporation)
• Original Assignee: Autonetworks Technologies, Ltd. (Sumitomo Corporation)
• Inventors: Li, Qiying
• Primary Examiner(s): Tun, Nay
• Application Number:
  US16/339,636
• Publication Number:
  US 20190241029A1
• Time in Patent Office: 904 Days
• Field of Search: 340445
• CPC Class Codes: B60C 19/00 Tyre parts or constructions not otherwise provided for
• CPC Class Codes: B60C 23/04 mounted on the wheel or tyre
• CPC Class Codes: B60C 23/0415 Automatically identifying wheel mounted units, e.g. after replacement or exchange of wheels
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/044 Near field triggers, e.g. magnets or triggers with 125 KHz
• CPC Class Codes: B60C 23/0442 the transmitted signal comprises further information, e.g. instruction codes, sensor characteristics or identification data
• CPC Class Codes: B60C 23/0454 Means for changing operation mode, e.g. sleep mode, factory mode or energy save mode
• CPC Class Codes: B60C 23/0461 externally triggered, e.g. by wireless request signal, magnet or manual switch
• CPC Class Codes: G01L 17/00 Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies

Abstract

A tire air pressure detection system and a vehicle body side device to detect air pressure of a plurality of tires. The vehicle body side device causes a transmission unit to transmit to all tire side devices, a transmission stop signal instructing transition to a transmission stop state and then the transmission unit transmits a transmission standby signal at a transmission strength that enables the signal to reach the tire side devices; and then the transmission unit transmits to the one of the tire side devices, a transmission request signal requesting a transmission of a signal including a unique identifier stored in that tire side device; and when it is determined that a reception unit has received a response signal in response to the transmission request signal, the transmission unit transmits a transmission standby signal and a transmission request signal to the tire side device corresponding to the next tire.

Claims

1. A tire air pressure detection system comprising:

a tire side device, provided in each of a plurality of tires mounted on a vehicle, each tire side device including a sensor that detects the air pressure in the corresponding tire, a tire side reception unit that wirelessly receives a signal requesting the sensor to transmit a measurement result, and a tire side transmission unit that wirelessly transmits the measurement result in response to the request; and

a vehicle body side device, provided in a body of the vehicle, the vehicle body side device including a vehicle body side transmission unit and a vehicle body side reception unit that wirelessly transmit and receive signals to and from the tire side devices, and

the vehicle body side device acquiring the air pressure in each tire and detecting a decrease in the air pressure,

wherein each tire side device includes;

a storage unit that stores an identifier identifying that tire side device; and

a control unit that stops the transmission by the tire side transmission unit in the case where a transmission stop signal instructing a transition to a transmission stop state has been received by the tire side reception unit, and that, after the tire side reception unit has received a transmission standby signal instructing a transition to a transmission standby state, causes a response signal including the identifier to be transmitted from the tire side transmission unit in response to the transmission request signal,

the vehicle body side device includes;

a transmission control unit that causes the transmission stop signal to be transmitted from the vehicle body side transmission unit to all of the tire side devices of the plurality of tires, then transmits the transmission standby signal from the vehicle body side transmission unit at a transmission strength that reaches the tire side device in one of the plurality of tires, and then causes the transmission request signal to be transmitted from the vehicle body side transmission unit; and

a determination unit that determines whether or not the vehicle body side reception unit has received a response signal in response to the transmission request signal, and

in the case where the determination unit determines that the response signal has been received, the transmission control unit causes the vehicle body side transmission unit to transmit the transmission standby signal at a transmission strength that reaches the tire side device of the next tire, and then to transmit the transmission request signal, to the tire side device.

2. The tire air pressure detection system according to claim 1,

wherein in the case where the determination unit determines that the response signal has not been received, the transmission control unit causes the vehicle body side transmission unit to transmit the transmission standby signal and the transmission request signal to the one tire side device again at a higher transmission strength then the stated transmission strength.

3. The tire air pressure detection system according to claim 1,

wherein the vehicle body side device transmits the transmission stop signal, the transmission standby signal, and the transmission request signal from antennas provided in corresponding tire housings of the plurality of tires;

the transmission control unit includes a selection unit that selects transmission strengths for the antennas from a plurality of levels in a range that reaches the interior of wheels from the tire housings; and

the transmission strength of the transmission standby signal and the transmission request signal is selected by the selection unit in order from the lowest strength among the plurality of levels.

5. The tire air pressure detection system according to claim 2,

wherein the vehicle body side device transmits the transmission stop signal, the transmission standby signal, and the transmission request signal from antennas provided in corresponding tire housings of the plurality of tires;

the transmission control unit includes a selection unit that selects transmission strengths for the antennas from a plurality of levels in a range that reaches the interior of wheels from the tire housings; and

the transmission strength of the transmission standby signal and the transmission request signal is selected by the selection unit in order from the lowest strength among the plurality of levels.

4. A vehicle body side device, provided in a body of a vehicle, the vehicle body side device comprising a transmission unit and a reception unit that wirelessly transmit and receive signals to and from tire side devices provided in a corresponding plurality of tires mounted on the vehicle, the vehicle body side device further comprising:

a first transmission control unit that causes a transmission stop signal instructing a transition to a transmission stop state to be transmitted from the transmission unit to all of the tire side devices in the plurality of tires;

a second transmission control unit that, after the transmission stop signal has been transmitted by the first transmission control unit, causes the transmission unit to transmit a transmission standby signal instructing a transition to a transmission standby state, at a transmission strength that will reach the tire side device in one of the plurality of tires;

a third transmission control unit that, after the transmission standby signal has been transmitted by the second transmission control unit, causes the transmission unit to transmit a transmission request signal, indicating a request for the transmission of a signal including a unique identifier stored in the tire side device, to the one tire side device; and

a determination unit that determines whether or not the reception unit has received a response signal in response to the transmission request signal,

wherein in the case where the determination unit determines that the response signal has been received, the second transmission control unit causes the transmission standby signal to be transmitted to the tire side device corresponding to the next one tire, and the third transmission control unit then causes the transmission request signal to be transmitted.