Wheel bearing with sensor

A sensor equipped wheel support bearing assembly comprising:

• a wheel support bearing for rotatably supporting a vehicle wheel relative to a vehicle body structure, the bearing 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 that face the respective rolling surfaces in the outer member, and a plurality of rows of rolling elements interposed between the rolling surfaces in the outer member and the rolling surfaces in the inner member;
• a plurality of load detecting sensor units provided in one of the outer member and the inner member that serves as a stationary member, each of the sensor units including a strain generating member, having two or more contact fixing segments to be fixed to the stationary member in contact therewith, and one or more sensors fitted to the strain generating member for detecting a strain occurring in the strain generating member, the sensor units including upper, lower, right and left sensor units disposed at upper, lower, right and left surface areas of the outer diametric surface of the stationary member, respectively, which correspond respectively to top, bottom, right surface and left surface locations relative to a tire tread surface, in 90° phase difference relative to each other and in equidistantly spaced relation to each other;
• a load estimating unit including a processor configured to estimate a load acting on the vehicle wheel from an output signal of the sensor in each of the sensor units,
• the load estimating unit including a load estimation calculating section for calculating the load acting on the wheel support bearing by applying the output of the sensor in each of the sensor units to an estimation calculating equation, an evaluation value calculation section for calculating one or more evaluation value to be used as an index for switching a parameter in the estimation calculating equation, from the output signal of the sensor in each of the sensor units, and a parameter switching section for comparing the evaluation value with a predetermined threshold value to switch the parameter in the estimation calculating equation in dependence on a result of such comparison;
• the load estimation calculating section including a calculation correcting block for correcting a result of calculation by combining two load estimation results calculated by the estimation calculating equation with the use of the parameters within respective evaluation value regions on both sides of the threshold value in the event that the evaluation value is within a predetermined region containing the threshold value,
• wherein the evaluation value calculation section calculates as the evaluation value a combination of two or more evaluation values, the two or more evaluation values indicative of a travelling speed of an automotive vehicle, a difference between amplitude values of output signals of the upper and lower sensor units, and a difference between amplitude values of output signals of the right and left sensor units.