Electric power steering apparatus and vehicle mounted therewith
An electric power steering apparatus having independent turning mechanisms for respective four wheels of a vehicle, has a problem in that, when a turning motor fails, a turning mechanism for a corresponding wheel stops functioning, resulting in reduction in the maneuverability and the stability of the vehicle. Turning motors of turning mechanisms independently disposed for respective four wheels of a vehicle, each have a redundant configuration. Specifically, each turning motor is configured as three-phase duplexing motors having two three-phase windings and two inverters for separately driving the three-phase windings.
1. An electric power steering apparatus having independent turning mechanisms for respective four wheels of a vehicle, wherein
a turning motor of each of the turning mechanisms has a redundant configuration,
wherein the turning motor is configured as three-phase duplexing motors having two three-phase windings, two inverters, two power source circuits, and two FET drive circuits for separately driving the three-phase windings, and
wherein, when one of the three-phase duplexing motors fails, the three-phase duplexing motor that has failed is stopped from being driven, and a turning angle of a wheel that is turned by the three phase duplexing motor that has failed, is fixed at a neutral position, and
wherein, when the turning angle of the wheel that is turned by the three phase duplexing motor that has failed is fixed at a neutral position, a driving force applied to said wheel is controlled to generate a yaw moment which assists steering.
2. The electric power steering apparatus according to claim 1 , wherein,
when one of the three-phase duplexing motors fails, the three-phase duplexing motor that has failed is stopped from being driven, and drive current of the other three-phase duplexing motor is increased to twice the drive current obtained in a normal case.
3. A vehicle mounted with the electric power steering apparatus according to claim 1 .
4. A vehicle mounted with the electric power steering apparatus according to claim 2 .