Nissan Motor Company Limited

Kazuo Sakaguchi

Syoji Terada

Takashi Shima

Provided is a tire air pressure transmission device configured to determine the rotational position of the tire air pressure transmission device based on a gravitational acceleration component of a centrifugal acceleration at the time of transmission of the tire air pressure information and to transmit in a wireless signal and at a prescribed cycle, tire air pressure information and tire air pressure transmission device rotational position information.

Tire air pressure monitoring system

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.

Tire air pressure monitor device

A tire pressure monitoring system has a first abnormality determination means for determining a state to be normal, the normal state being when the front wheel air pressure is higher than a front wheel warning threshold 400 kPa and the rear wheel tire pressure is higher than a rear wheel warning threshold 240 kPa. The first abnormality determination means also turns on a warning light in the state. A second abnormality determination means turns the warning light to an off state regardless of the determination result of the first abnormality determination means when the warning light is turned off while the vehicle is stopped, the tire pressures of two wheels have been determined to be higher than the front wheel warning threshold 400 kPa, and the tire pressures of the remaining two wheels have been determined to be higher than the rear wheel warning threshold 240 kPa.

Tire pressure monitoring system

A tire air pressure monitor device is provided for monitoring air pressure in tires using pressure sensors, which are installed in the tire of each wheel. Each wheel has a transmitter for wirelessly transmitting the air pressure information along with a sensor ID when the wheel is at a predetermined rotation position. A vehicle body has a receiver for receiving the wireless signals. A wheel speed sensor is provided on a vehicle body for each wheel to determine the wheel rotation position. A TPMS control unit acquires the wheels rotation position when a wireless signal containing a certain sensor ID is transmitted. The TPMS control unit accumulates wheel rotation position data, and determines the wheel position corresponding to the wheel rotation position data having the smallest degree of dispersion from among the wheel rotation position data as the wheel position for the transmitter corresponding to the sensor ID.

Tire air pressure monitoring device

A tire air pressure transmission device is provided that is configured to set a sampling period or cycle based on a centrifugal acceleration of a wheel in the centrifugal direction, and to detect the value of the gravitational acceleration component of the centrifugal acceleration at each set sampling period.

Tire air pressure transmission device and tire air pressure monitor system

When the difference between the first rotating period determined based on detection by the G sensor and the second rotating period Ta determined based on the detected value of the wheel velocity sensor is equal to or smaller than the prescribed value, the rotational position of each wheel corresponding to the wireless signal transmitted at the prescribed rotational position is adopted in determining the wheel position; when the difference is over the prescribed value, the rotational position of each wheel corresponding to the wireless signal transmitted at the rotational position different from the rotational position is not used in determining the wheel position.

A tire pressure monitoring system controller is provided that comprises a rotational position calculation unit that detects a rotational position for each wheel when a wireless signal including a specific sensor ID has been transmitted; a wheel position determination unit that acquires the rotational position of each wheel a plurality of times and accumulates rotational position data for each wheel, and determines the wheel position corresponding to the rotational position data with the least degree of dispersion among all the rotation position data as the wheel position of a transmitter corresponding to the sensor ID; and a rotational position detection inhibition unit that inhibits the detection of the rotational position of each wheel by the rotational position calculation unit when braking control that controls a wheel cylinder pressure of the wheels is being executed.

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Ebina, Japan

Kazuo Sakaguchi