STEERING CONTROL DEVICE

• US 20200130738A1
• Filed: 10/24/2019
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Abandoned Application

• Current Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Original Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Inventors: KODERA, Takashi
• Application Number:
  US16/662,598
• Publication Number:
  US 20200130738A1
• Time in Patent Office: Days
• CPC Class Codes: B62D 5/006 power actuated
• CPC Class Codes: B62D 5/0469 End-of-stroke control
• CPC Class Codes: B62D 6/008 Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications

Abstract

A steering-side control unit includes a steering force component calculation unit that calculates a steering force component, a reaction force component calculation unit that calculates a reaction force component, a target steering angle calculation unit that calculates a target steering angle based on the steering force component and the reaction force component, and a target reaction force torque calculation unit that calculates a target reaction force torque through angle feedback control that makes the steering angle follow the target steering angle. The reaction force component calculation unit includes an end reaction force calculation unit that calculates an end reaction force, and an obstacle contact reaction force calculation unit that calculates an obstacle contact reaction force. When at least one of the end reaction force and the obstacle contact reaction force exceeds a prescribed reaction force, the steering force component calculation unit reduces an absolute value of the steering force component.

Claims

1. A steering control device that controls a steering system configured such that power transmission is disconnected between a steering unit and a turning unit that turns steered wheels in accordance with a steering force input to the steering unit, the steering control device comprising:

a steering-side control unit that controls an operation of a steering-side motor that applies a steering reaction force, the steering reaction force being a force against the steering force input to the steering unit;

wherein;

the steering-side control unit includes

a steering force component calculation unit that calculates a steering force component that is a force applied in a same direction as a steering torque input to the steering system, and

a reaction force component calculation unit that calculates a reaction force component that is a force applied to the steering system in an opposite direction to the steering torque;

the steering-side control unit calculates a target reaction force torque representing a target value of the steering reaction force, based on the steering force component and the reaction force component;

the reaction force component calculation unit includes a restriction reaction force calculation unit that calculates a restriction reaction force for restricting steering that turns the steered wheels in at least one direction when turning of the steered wheels in at least one direction is restricted; and

when turning of the steered wheels in at least one direction is restricted, the steering force component calculation unit makes an absolute value of the steering force component smaller compared to when turning of the steered wheels is not restricted.

2. The steering control device according to claim 1, wherein:

the steering force component calculation unit includes an additional torque calculation unit that calculates an additional torque applied in the same direction based on the steering torque; and

the additional torque calculation unit sets an absolute value of the additional torque to zero when steering of the steered wheels in at least one direction is restricted.

3. The steering control device according to claim 1, wherein the restriction reaction force calculation unit includes an end reaction force calculation unit that calculates an end reaction force as the restriction reaction force when a steering angle of a steering wheel coupled to the steering unit exceeds a steering angle threshold specified for the steering system.

4. The steering control device according to claim 1, wherein the restriction reaction force calculation unit includes an obstacle contact reaction force calculation unit that calculates an obstacle contact reaction force as the restriction reaction force when at least one of the steered wheels is turned and brought into contact with an obstacle.

5. The steering control device according to claim 1, wherein the steering force component calculation unit calculates the steering force component, based on the steering torque and the additional torque.

6. The steering control device according to claim 1, wherein the reaction force component calculation unit includes an axial force calculation unit that calculates an axial force applied to a steered shaft with the steered wheels coupled thereto in the opposite direction, and calculates the reaction force component, based on the axial force and the restriction reaction force.