Patent ID: 8880267

Claim:
An electric vehicle comprising: a motor unit configured to drive a wheel; an ECU which is an electronic control unit configured to perform general control of the vehicle; and an inverter unit, the inverter unit including: a power circuitry including an inverter configured to convert a DC power from a battery unit into an AC power used to drive the motor unit; a motor control circuitry configured to control at least the power circuitry in accordance with control from the ECU; a torque fluctuation estimator configured to estimate, according to a predefined rule, a torque fluctuation that is inclusive of fluctuations in torque attributable to a wheel bearing unit, the motor unit or a reducer unit interposed between the motor unit and the wheel, based on (i) a fluctuation in a rotational frequency as determined with a rotation sensor configured to sense a rotational frequency of the wheel or with an angle sensor configured to sense a rotational angle of the motor unit, (ii) a fluctuation in a load acting, between a road surface and a tire, along a direction in which the vehicle travels, as determined with a load sensor that is operatively associated with the wheel bearing unit, or (iii) a fluctuation in a motor current as determined with a current sensor configured to sense a current in the motor unit; and an abnormalities-responsive motor drive limiter configured, upon receiving a determination result from the torque fluctuation estimator, to limit a motor torque command or a motor current produced from the inverter unit.