US Patent 8370022 Suspension system for vehicle

A suspension system is provided to execute a control for avoiding a state in which an operation of an electric motor which is a power source of an electromagnetic actuator is kept halted at a certain operational position while the motor is generating a motor force. Where a target rotational position of the motor becomes equal to a specific operational position (e.g., a rotational position at which an electrifying current amount of one phase reaches a peak value), a control for shifting the target rotational position by δθ is executed. Where the rotational position of the motor is kept located at the certain position for a time period longer than a prescribed time, a control for changing the rotational position of the motor is executed.