Abstract: A control unit of a tire side device has a feature amount extraction part, a feature amount storage part, a change determination part, a vehicle speed estimation part, and an algorithm switching part. The change determination part determines whether or not there is a change in the road surface condition based on a present feature amount and a previous feature amount stored in the feature amount storage part, and transmits a road surface data including the present feature amount when there is a change in the road surface condition. The algorithm switching part switches based on the vehicle speed estimation by the vehicle speed estimation part whether to transmit the road surface data from the transmission unit when the road surface condition is changed, or to transmit the road surface data without determining whether or not the road surface condition is changed by the change determination part.

Abstract: In a vehicle, a vehicle body-side apparatus is configured to perform a main area determination and an auxiliary area determination. The main area determination determines whether a portable terminal is present in a main area based on a first reception intensity measured by the vehicle body-side apparatus in a wireless signal from the portable terminal. The auxiliary area determination determines whether the portable terminal is present in an auxiliary area based on a second reception intensity measured by a vehicle tire-side apparatus in a wireless signal from the portable terminal.

Abstract: A tire air pressure detection device includes a plurality of transceivers and a receiver. The plurality of transceivers are correspondingly provided in a plurality of wheels of a vehicle. Each wheel has a tire. The receiver is attached to a vehicle body. Each of the plurality of transceivers outputs a detection signal indicative of an air pressure of the tire of the corresponding wheel. Each of the plurality of transceivers processes the detection signal, and generates a frame storing the processed detection signal as data related to the air pressure of the tire. The receiver receives the frame. The receiver detects the air pressure of the tire based on the data stored in the received frame.

Abstract: A tire side device includes a vibration detection unit that outputs a detection signal according to a magnitude of vibration of a tire, an air pressure detection unit that detects the tire pressure, a data acquisition unit that calculates a contact length of the tire with a road surface based on the detection signal and acquires a wheel load data that is a data related to the wheel load based on the contact length, and a data transmission unit that transmits a data related to the tire pressure and the wheel load data. A vehicle side device includes a receiving unit that receives data on tire pressure and wheel load data, a threshold setting unit that sets an alarm threshold for tire pressure based on the wheel load data, and an alarm determination unit that determines that the tire pressure has decreased when the tire pressure indicated by the data on the tire pressure decreases below the alarm threshold.

Abstract: A control unit of a tire-mounted sensor determines whether a tire has been exchanged. When the tire has been exchanged, the control unit changes the threshold value of a road surface state determination condition used for detecting the road surface state from vibration data of the tire detected by an acceleration sensor of the tire-mounted sensor. For example, the threshold value of the road surface state determination condition is reset upon determining that the tire has been exchanged, by transmitting an instruction to the tire-mounted sensor through a tool at an automobile maintenance shop, etc.

Abstract: A tire wear detection apparatus includes a tire side device and a vehicle body side system. The tire side device includes a vibration detection unit, a vehicle speed estimation unit, a signal processing unit, and a first data communication unit. The vibration detection unit is configured to output a detection signal. The vehicle speed estimation unit is configured to estimate the vehicle speed. The signal processing unit is configured to generate wear data. The vehicle body side system includes a second data communication unit and a controller. The controller has a wear determination unit configured to determine a tire wear state based on the wear data. The signal processing unit is configured to acquire the detection signal within a detection signal acquiring range, and calculate a level value of a vibration level of the acquired detection signal within a predetermined frequency range based on a natural frequency of the tire.

Abstract: A tire wear detection apparatus for a vehicle includes a tire side apparatus and a vehicle body side system. In response to a wet road surface being detected, from a vibration waveform of a tire indicated by a detection signal according to a magnitude of a vibration of the tire, the tire side apparatus is configured to (i) acquire a peak level value of a vibration level at a stepping time at which an apparatus corresponding position in the tire corresponding to an arranged position of the tire side apparatus starts to contact the road surface, and/or (ii) calculate a level value of the vibration level in a post-kicking range after the apparatus corresponding position kicks to separate from the road surface, so as to generate a wear data indicating a wear state of the tire.

Abstract: A transceiver of a spare wheel includes a sensing unit having a pressure sensor and an acceleration sensor configured to output a detection signal according to a tire pressure of the spare wheel and an acceleration generated in the spare wheel, a first control unit configured to create a frame that processes the detection signal indicating the tire pressure and stores it as data related to the tire pressure, and a first transmitter receiver configured to transmit the frame. A receiver includes a second transceiver configured to receive a frame and transmit a response signal indicating that the frame is received and a second control unit configured to detect the tire pressure and transmit a response signal from the second transceiver when the frame is received.

Abstract: A condition in which an abnormality can occur in a tire is accurately detected on the basis of a detection signal from an acceleration sensor used to detect a road surface state and a possibility that an abnormality has occurred in the tire is also detected. In addition, the detection result is stored as a diagnosis history. The diagnosis history or the possibility that an abnormality has occurred in the tire are notified through a notification device in a vehicle body side system so that a user is informed in advance of the possibility that an abnormality has occurred in the tire. In addition, when the diagnosis history is checked through a tool in a car repair shop, etc., the diagnosis history stored in a tire-mounted sensor is read out. Accordingly, the possibility of abnormality of the tire can be informed also in the car repair shop, etc.

Abstract: A tire-mounted sensor includes a vibration detector, an acceleration sensor, a signal processor, and a transmitter. The vibration detector outputs a detection signal according to amplitude of a vibration of the tire. The acceleration outputs a detection signal according to an acceleration of the tire in a radial direction. The signal processor detects a rotational angle of the tire reaching a ground angle during each rotation of the tire, sets a measurement period including a time period during which the rotational angle of the tire is at the ground angle, extracts a ground contact section during which the portion of the tread provided with the vibration sensor is in contact with the ground, in the measurement period, and generates a road surface data based on the detection signal output from the vibration detector during the ground contact section. The transmitter transmits the road surface data.

Abstract: A wheel position detection apparatus applied to a vehicle including a vehicle body attached with multiple travelling wheels. The apparatus includes: multiple transmitters respectively disposed at travelling wheels; and a receiver disposed at the vehicle body. The transmitter includes: an acceleration sensor outputting a detection signal according to an acceleration including a gravitational acceleration component being varied by a rotation of the corresponding travelling wheel attached with the transmitter; and a first controller creating a frame including unique identification information, and transmit the frame in response to the receiver outputting a transmission command.

Abstract: A hydroplaning determination device that determines occurrence of a hydroplaning phenomenon in a vehicle includes a tire mount sensor including a vibration detection unit, a signal process unit and a transmission unit, and a vehicle body system including a receiver, a condition determination unit and a hydroplaning determination unit. The vibration detection unit is attached to a rear surface of a tire provided in a vehicle and outputs a detection signal according to a magnitude of vibration of the tire. The signal process unit generates a vibration data based on the detection signal. The hydroplaning determination unit determines, based on the vibration data, whether a hydroplaning phenomenon has occurred when the condition determination unit determines that a road surface condition is a wet condition in which a water film exists between the tire and a road surface.

Abstract: A tire side device is provided with a vibration detection unit that outputs a detection signal corresponding to the magnitude of tire vibration, a control unit that performs to generate road surface data indicating a road surface condition that appears in the waveform of the detection signal, and a first data communication unit that transmits the road surface data. Furthermore, a vehicle body side system is provided with a second data communication unit that receives the road surface data transmitted from the first data communication unit, and a road surface determination unit that determines the condition of the road surface that the vehicle is traveling on the basis of the road surface data.

Abstract: A road surface condition estimation apparatus may output a detection signal corresponding to a magnitude of a vibration of a tire. The road surface condition estimation apparatus may calculate a level of high frequency component of the detection signal in a contact section. The road surface condition estimation apparatus may transmit a calculation result of the level of high frequency component as road surface condition data each time the tire rotates for a predetermined number of times. The road surface condition estimation apparatus may estimate a condition of road surface based on the road surface condition data. The road surface condition estimation apparatus may stop transmitting the road surface condition data when estimating that the vehicle accelerates or decelerates.

Abstract: A tire-mounted sensor is mounted to a rear surface of a tread of a tire. the tire-mounted sensor includes: a vibration detector, a signal processor, a transmitter, and an activation controller. The vibration detector outputs a detection signal according to amplitude of a vibration of the tire. The signal processor extracts a ground contact section during which the portion of the tread provided with the vibration sensor is in contact with the ground, from the detection signal, and generates a road surface data based on the detection signal during the ground contact section. The transmitter transmits the road surface data. The activation controller starts an activation of the signal processor at a time in association with the ground contact starting time at which the portion of the tread provided with the vibration detector begins to be in contact with the ground.

Abstract: A vehicle body side system is provided with a second data communication unit that performs bidirectional communication with a tire side device and receives road surface data and measurement data transmitted from a first data communication unit, a road surface determination unit that determines the road surface condition of a road surface on which a vehicle travels based on the road surface data, a reception strength measurement unit that measures the reception strength of the measurement data, and a transmission angle setting unit that stores the reception strength of the measurement data during one rotation of a tire, sets as a transmission angle, a presence angle when the reception strength of the measurement data during one rotation of the tire is high, and transmits data indicating the transmission angle to the tire side device via the second data communication unit.

Abstract: A road surface state determination device includes a tire-side device and a vehicle-body-side system. The tire-side device is attached to each of a plurality of tires included in a vehicle. The vehicle-body-side system is included in a body of the vehicle. The tire-side device may output a detection signal corresponding to a magnitude of vibration of the tire. The tire-side device may sense the detection signal and generate road surface data indicative of a road surface state appearing in a waveform of the detection signal. The tire-side device may transmit the road surface data. The vehicle-body-side system may perform bidirectional communication with the tire-side device and receive the road surface data. The vehicle-body-side system may determine the road surface state of a road surface on which the vehicle is traveling based on the road surface data.

Abstract: In a vehicle, a vehicle body-side apparatus is configured to perform a main area determination and an auxiliary area determination. The main area determination determines whether a portable terminal is present in a main area based on a first reception intensity measured by the vehicle body-side apparatus in a wireless signal from the portable terminal. The auxiliary area determination determines whether the portable terminal is present in an auxiliary area based on a second reception intensity measured by a vehicle tire-side apparatus in a wireless signal from the portable terminal.

Abstract: A road surface state determination device includes a tire-side device and a vehicle-body-side system. The tire-side device is attached to a back surface of a tread of each of a plurality of tires included in a vehicle. The vehicle-body-side system is included in a body of the vehicle. The tire-side device outputs a detection signal corresponding to a magnitude of vibration applied to the tire. The tire-side device generates road surface data indicative of a road surface state appearing in a waveform of the detection signal. The tire-side device transmits the road surface data. The vehicle-body-side system performs bidirectional communication with the tire-side device and receives the road surface data. The vehicle-body-side system determines the road surface state of a road surface on which the vehicle is traveling based on the road surface data.

Abstract: A road surface state determination device includes a tire-side device and a vehicle-body-side system. The tire-side device is attached to each of a plurality of tires included in a vehicle. The vehicle-body-side system is included in a body of the vehicle. The tire-side device may output a detection signal corresponding to a magnitude of vibration applied to the tire. The tire-side device may extract data items of a road surface state indicative of the vibration of the tire during one rotation of the tire from the detection signal. The tire-side device may generate road surface data. The tire-side device may transmit the road surface data. The vehicle-body-side system may receive the road surface data. The vehicle-body-side system may determine the road surface state based on the road surface data.