Tire mounting state detection system, tire mounting state detection method, and tire mounting state detection program

A tire mounting state detection method for detecting the state of a plurality of transmitters respectively equipped on a plurality of tires mounted on a vehicle, using a receiving unit disposed in the vehicle and receiving a radio signal transmitted from the plurality of transmitters;

• the tire mounting state detection method comprising:
• detecting a number of transmitters based on the radio signal received by the receiving unit;
• detecting whether or not the number of transmitters exceeds or is short of the number of wheels, based on the number of wheels based on a vehicle configuration including the number of wheels of the vehicle and a number of transmitters detected;
• and
• outputting that a state of the transmitter is abnormal when it is determined that the number of the transmitters exceeds or is short for the number of the wheels;
• wherein the receiving unit includes a first receiver and a second receiver, the first receiver is disposed on one side of a widthwise center line between a left wheel and a right wheel, and the second receiver is disposed on the other side with respect to the widthwise center line,
• measure a first signal strength, which is the strength of the radio signal received by the first receiver, for each transmitter;
• measure a second signal strength, which is the strength of the radio signal received by the second receiver, for each transmitter;
• calculate a strength ratio, which is a ratio using the first signal strength and the second signal strength, for each transmitter;
• and
• detect, based on a magnitude relationship of the strength ratio, that the number of transmitters exceeds the number of wheels or that a tire having one of the plurality of transmitters not activated is mounted at a wheel position on either a left side of the vehicle or a right side of the vehicle.

A non-transitory computer-readable medium including a tire mounting state detection program for detecting the state of a plurality of transmitters respectively mounted on plurality of tires mounted on a vehicle, using a receiving unit disposed in the vehicle and receiving a radio signal transmitted from the plurality of transmitters;

• the tire mounting state detection program causing a computer to execute:
• a process of holding a vehicle configuration including a number of wheels of the vehicle;
• a process of detecting a number of the transmitters based on the radio signal received by the receiving unit;
• a process of detecting whether or not the number of transmitters exceeds or is short of the number of wheels, based on the number of wheels based on the vehicle configuration and the number of transmitters detected;
• and
• a process of outputting that a state of the transmitter is abnormal when it is determined that the number of the transmitters exceeds or is short for the number of the wheels;
• wherein the receiving unit includes a first receiver and a second receiver, the first receiver is disposed on one side of a widthwise center line between a left wheel and a right wheel, and the second receiver is disposed on the other side with respect to the widthwise center line,
• a process of measuring a first signal strength, which is the strength of the radio signal received by the first receiver, for each transmitter;
• a process of measuring a second signal strength, which is the strength of the radio signal received by the second receiver, for each transmitter;
• a process of calculating a strength ratio, which is a ratio using the first signal strength and the second signal strength, for each transmitter;
• and
• a process of detecting, based on a magnitude relationship of the strength ratio, that the number of transmitters exceeds the number of wheels or that a tire having one of the plurality of transmitters not activated is mounted at a wheel position on either a left side of the vehicle or a right side of the vehicle.