A vehicle position detecting device according to an embodiment includes a wheel speed acquisition unit, a skid detection unit, a vehicle body speed calculation unit, and a position calculation unit. The wheel speed acquisition unit acquires a wheel speed of a wheel of a vehicle corresponding to rotation of the wheel. The skid detection unit detects a skid of the wheel. The vehicle body speed calculation unit calculates, when the skid is not detected by the skid detection unit, a vehicle body speed corresponding to the speed of a vehicle body of the vehicle based on the wheel speed acquired by the wheel speed acquisition unit, and corrects, in response to detection of the skid by the skid detection unit, the wheel speed acquired by the wheel speed acquisition unit based on correction information and calculates the vehicle body speed based on the corrected wheel speed. The position calculation unit calculates the position of the vehicle based on the vehicle body speed calculated by the vehicle body speed calculation unit depending on the presence of the skid.

Adjusting emulated encoder frequencies in an example embodiment can include determining a difference between an encoder count and a theoretical encoder count and adjusting a frequency of an emulated encoder signal to mitigate at least some of the difference between the encoder count and the theoretical encoder count.

Adjusting emulated encoder frequencies in an example embodiment can include determining a difference between an encoder count and a theoretical encoder count and adjusting a frequency of an emulated encoder signal to mitigate at least some of the difference between the encoder count and the theoretical encoder count.

A speed sensing system for a bicycle includes a sensing device for mounting on the bicycle, a first sensed element, and a second sensed element, the first sensed element varies from the second sensed element by a characteristic, and the sensing device is configured to detect the characteristic.

A speed sensing system for a bicycle includes a sensing device for mounting on the bicycle, a first sensed element, and a second sensed element, the first sensed element varies from the second sensed element by a characteristic, and the sensing device is configured to detect the characteristic.

An abnormality is detected in a sensor system mounted on a vehicle and including first and second external sensors for acquiring external information and an internal sensor for acquiring internal information. An error, occurring in an internal motion physical quantity based on the internal information, is estimated based on the external information, and the error is corrected. A first external motion physical quantity based on the external information acquired by the first external sensor, a second external motion physical quantity based on the external information acquired by the second external sensor, and the internal motion physical quantity in which the error is corrected by the correction block are compared to determine an abnormality in the sensor system.

An abnormality is detected in a sensor system mounted on a vehicle and including first and second external sensors for acquiring external information and an internal sensor for acquiring internal information. An error, occurring in an internal motion physical quantity based on the internal information, is estimated based on the external information, and the error is corrected. A first external motion physical quantity based on the external information acquired by the first external sensor, a second external motion physical quantity based on the external information acquired by the second external sensor, and the internal motion physical quantity in which the error is corrected by the correction block are compared to determine an abnormality in the sensor system.

If a controller determines the calculation of a measured vehicle body velocity is possible, the controller calculates the measured vehicle body velocity as an estimated vehicle body velocity to conduct update processing for a K table and an AB table. If the controller determines the calculation of the measured vehicle body velocity is impossible, the controller extracts a conversion coefficient from the K table based on a detected running state while extracting a sensitivity coefficient and an offset coefficient from the AB table based on the temperature by a temperature sensor. The vehicle mounted apparatus calculates an axle pulse-based vehicle body velocity from the extracted conversion coefficient while calculating an acceleration-based vehicle body velocity from the extracted sensitivity coefficient and offset coefficient. The vehicle mounted apparatus calculates the estimated vehicle body velocity by weighting the calculation values of the axle pulse-based vehicle body velocity and the acceleration-based vehicle body velocity.

If a controller determines the calculation of a measured vehicle body velocity is possible, the controller calculates the measured vehicle body velocity as an estimated vehicle body velocity to conduct update processing for a K table and an AB table. If the controller determines the calculation of the measured vehicle body velocity is impossible, the controller extracts a conversion coefficient from the K table based on a detected running state while extracting a sensitivity coefficient and an offset coefficient from the AB table based on the temperature by a temperature sensor. The vehicle mounted apparatus calculates an axle pulse-based vehicle body velocity from the extracted conversion coefficient while calculating an acceleration-based vehicle body velocity from the extracted sensitivity coefficient and offset coefficient. The vehicle mounted apparatus calculates the estimated vehicle body velocity by weighting the calculation values of the axle pulse-based vehicle body velocity and the acceleration-based vehicle body velocity.

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. In addition, a control unit causes the first data communication unit to transmit the road surface data when the presence angle becomes the transmission angle.