Abstract: When information related to road surface conditions is conveyed from a vehicle body side system to a tire-mounted sensor and the tire-mounted sensor determines the road surface condition, an integrated voltage value is corrected based on the information related to the road surface condition. It is thus possible to estimate the road surface condition more accurately. Furthermore, in as much as the road surface condition is estimated at each tire-mounted sensor, the road surface condition can be estimated for each wheel.

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 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 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 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 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 wheel position detecting device can suppress an erroneous detection of a wheel position even if a moving direction of a vehicle cannot be determined by wheel speed sensors whether in a forward direction or in a rearward direction. When an edge number (or a tooth number) is incremented based on detection signals of the wheel speed sensors of one, two or three wheels while the vehicle is at a halt, the edge number (or the tooth number) is not used as learning data. Thus, it is less likely that the wheel position is erroneously detected based on erroneous learning data. Therefore, even if the moving direction of the vehicle cannot be determined whether in the forward direction or the rearward direction by the wheel speed sensors, the wheel position detecting device can suppress the erroneous wheel position detection.

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 mount sensor detects a road surface condition such as a type of a road surface and a road surface ?, and transmits road surface data indicating a detection result to a communication center. The communication center collects road surface data more precisely, and the vehicle receives the more precise road surface data from the communication center. Based on received more precise road surface data, the risk of the vehicle is determined. Thus, the road surface condition is detected using the tire mount sensor, so that the road surface condition is detected without braking. Accordingly, it is possible to detect the road surface condition with high frequency, so that the road surface condition is detected in wider area, and it is possible to perform the control more appropriately for avoiding the risk based on the road surface condition during a travel.

Abstract: A protruding portion is provided on a molded resin portion of a tire mount sensor, and the longitudinal direction of the protruding portion is aligned with the longitudinal direction of an antenna. Further, the longitudinal direction of the antenna is set at a predetermined angle with respect to the acceleration detection direction of the G sensor. For example, with a predetermined angle of 0°, the longitudinal direction of the antenna may be matched with the acceleration detection direction of the G sensor.

Abstract: In order to detect a road surface condition, a road surface condition estimation device extracts a detection signal of a portion that detects vibration in a tire tangential direction in a vibration detection and power generation unit which is in a ground contact section, for example, a vibration power generation element. In this case, it is identified that the vibration detection and power generation unit is in the ground contact section, based on whether a centrifugal force acting on the vibration detection and power generation unit is generated, or not, and it is identified that a time when no centrifugal force is generated is in the ground contact section. As a result, even if a pulse level of an output voltage of the vibration detection generation unit changes according to a traveling speed of the vehicle, the ground contact section can be accurately identified.

Abstract: A tire-mounted sensor fixed to an inner wall of a tire includes: a sensor holding member including a sensor as a built-in sensor for detecting a physical amount applied to the tire and having a sensor terminal being exposed, a base portion as an attachment surface attached to the tire; and a sensor device being detachable from the sensor holding member including a controller receiving an input of a detection result of the sensor and performing signal processing, a transmitter transmitting information according to the detection result of the sensor acquired by the signal processing at the controller, and a terminal inputting the detection result of the sensor to the controller which is being exposed to have an electrical connection to the sensor terminal when the sensor device is attached to the sensor holding member.

Abstract: A road surface condition estimation device includes a tire side device and a vehicle side device. The tire side device includes a vibration detection unit attached to a back surface of a tire tread and outputting a detection signal indicating a tire vibration magnitude, a signal processing unit, and a transmitter. The signal processing unit extracts a ground contact duration during which a portion of the tread corresponding to an arrangement position of the vibration detection unit is in contact with a ground, and calculates a high frequency component level of the detection signal detected during the ground contact duration as road surface condition data. When the ground contact duration is ended, a transmission trigger is transmitted to the transmitter and the transmitter transmits the road surface condition data. The vehicle side device estimates a road surface condition of the travelling road based on the road surface condition data.

Abstract: A road surface condition estimation device includes a tire side device and a vehicle side device. The tire side device includes a vibration detection unit outputting a detection signal indicating a tire vibration magnitude, a signal processing unit, and a transmitter. The signal processing unit extracts a ground contact duration during which a portion of the tread corresponding to an arrangement position of the vibration detection unit is in contact with a ground, calculates a high frequency component level of the detection signal detected during the ground contact duration, counts cumulative rotation number of the tire, and corrects the level of the high frequency component based on the cumulative rotation number of the tire. The transmitter transmits corrected level of the high frequency component as road surface condition data. The vehicle side device estimates a road surface condition of the travelling road based on the received road surface condition data.

Abstract: A road-surface-condition estimation device is configured by a tire-side device and a vehicle-side device so as to grasp a road surface condition based on road surface condition data transmitted from a tire-side device. As a result, the road surface condition or a road surface ? of a traveling road surface of a vehicle can be accurately detected, and a more accurate lane keeping control can be performed according to the detection result. In particular, since the tire-side device estimates the road surface condition by detecting the vibration of a ground contact surface of the tire, the road surface condition can be estimated more accurately. Therefore, the more accurate lane keeping control can be performed.

Abstract: A road surface condition estimation device extracts a detection signal of a vibration power generation element during a ground contact section to detect a road surface condition. A threshold used for determination of the ground contact section is variable according to a traveling speed of a vehicle. As a result, even if a pulse level of an output voltage of the vibration power generation element changes according to the traveling speed of the vehicle, the threshold corresponding to the change can be set. The ground contact section is determined with the use of the above thresholds, thereby being capable of performing the determination with high accuracy. Therefore, the road surface condition can be detected with high accuracy based on the ground contact section determined with high accuracy.

Abstract: An erroneous start is controlled based on vibrations of a tire, irrespective of a poor visibility or an algorithm of an image processing. A tire-side unit detects a vibration of a tire when the tire has collided with a wheel stop or the like, and outputs collision data to a vehicle-side unit. The vehicle-side unit determines an erroneous start of the vehicle. Therefore, the erroneous start of the vehicle can be controlled without being affected by the poor visibility or the algorithm of the image processing as in a case of utilizing a camera or a radar.

Abstract: A vehicle control device including a tire-side device and a vehicle-side device is provided. The tire-side device includes a vibration detection unit that outputs a detection signal corresponding to a magnitude of vibration of a tire, a signal processing unit that generates ? data representing a friction coefficient between the tire and a road surface by processing the detection signal, and a transmitter that transmits the ? data. The vehicle-side device includes a receiver that receives the ? data and a travel control unit that estimates the friction coefficient based on the ? data, acquires a braking distance of the vehicle based on the friction coefficient, and controls acceleration and deceleration of the vehicle based on the braking distance.

Abstract: A tire air pressure detection device has transmitters each detecting a running state of a vehicle on the basis of a detection signal of an acceleration sensor and transmitting a frame when it is determined that the vehicle is running. Because acceleration varies independently of a tire rotation speed, a frame can be transmitted even before a vehicle speed reaches or exceeds, for example, 30 km/h. Consequently, data on a tire air pressure can be transmitted in a short time period from a running start of the vehicle and hence a decrease in tire air pressure can be detected in a short time period from the running start of the vehicle.

Abstract: A user identification system is provided, which includes an in-vehicle apparatus used by multiple users and a vehicular portable device carried by a user acting as a driver and associated with the in-vehicle apparatus. The vehicular portable device detects received signal strength of signals received from the portable terminals at multiple time points, and based on the received signal strength detected by the received signal strength detector, determines a driver terminal which is the portable terminal carried by the user acting as the driver. The vehicular portable device determines as the driver terminal the portable terminal that provides a smallest degree of change of the received signal strength detected multiple times.