Sensor-equipped bearing for wheel

A sensor equipped wheel support bearing assembly for rotatably supporting a vehicle wheel relative to a vehicle body structure, the wheel support bearing assembly comprising:

• an outer member having an inner periphery formed with a plurality of rolling surfaces;
• an inner member having an outer periphery formed with rolling surfaces held in face-to-face relation with the respective rolling surfaces;
• a plurality of rows of rolling elements interposed between the opposed rolling surfaces;
• a sensor unit for detecting a load acting on one of the outer member and the inner member that serves as a stationary member, the sensor unit including
• a strain generating member having two or more contact fixing segments adapted to be fixed to the stationary member, and
• one or more sensors fitted to the strain generating member for detecting a strain induced in the strain generating member;
• and
• a load estimation processing section for estimating a load acting on the vehicle wheel, from an output signal of the sensor of the sensor unit, the load estimation processing section including
• a principal load estimating section for estimating the load acting on the vehicle wheel, the principal load estimating section having an average value calculating section for calculating an average value of the output signal of the sensor of the sensor unit and a correcting section for correcting the average value, which has been calculated by the average value calculating section,
• an amplitude processed load estimating section for calculating an amplitude processed load estimated value, which corresponds to the load acting on the vehicle wheel, from an amplitude value of a signal waveform of the output signal of the sensor, which is caused by passage of the rolling elements, and
• a drift amount estimating section for estimating a drift amount of the output signal of the sensor appearing in the output of the estimated load, the drift amount being estimated by comparing the output of the estimated load, which is estimated by the principal load estimating section, with the amplitude processed load estimated value, wherein
• the correcting section of the principal load estimating section is operable to correct the output of the estimated load with the drift amount estimated by the drift amount estimating section.