Electric power steering system

摘要

There is provided an electric power steering system that makes it possible to improve the driver's steering feel, and that includes a controller that controls driving of a motor. The controller computes a first assist component based on a steering torque. The controller computes a torque command value based on a basic drive torque that is the sum of the steering torque and the first assist component, and computes an assist compensation component through feedback control based on the torque command value. The controller computes a steered angle command value based on a value obtained by adding the assist compensation component to the basic drive torque, and computes a second assist component through feedback control based on the steered angle command value. The controller controls driving of the motor based on an assist command value that is the sum of the first assist component and the second assist component.

主权项

1. An electric power steering system comprising:
an assist mechanism that applies assist torque generated by a motor to a steering mechanism of a vehicle; and a controller that controls driving of the motor based on an assist command value corresponding to a target value of the assist torque, wherein the controller includes
a basic assist component computing unit that computes a first assist component that is a basic component of the assist torque based on steering torque that is applied to the steering mechanism in response to a steering operation of the vehicle,a torque command value computing unit that computes a torque command value that is a target value of the steering torque,a torque feedback control unit that computes an assist compensation component by executing torque feedback control of causing the steering torque to follow the torque command value,a steered angle command value computing unit that computes a steered angle command value corresponding to a target value of a steered angle of steered wheels of the vehicle based on a sum of a basic drive torque and the assist compensation component,a steered angle feedback control unit that computes a second assist component by executing steered angle feedback control of causing an actual steered angle of the steered wheels to follow the steered angle command value, andan assist command value computing unit that computes the assist command value based on a sum of the first assist component and the second assist component.