EP-4737272-A1 - STEERING CONTROL DEVICE AND STEERING CONTROL METHOD

EP4737272A1EP 4737272 A1EP4737272 A1EP 4737272A1EP-4737272-A1

Abstract

A steering control device (50) is configured to execute a reaction-force-command-value setting process and an operation process. The reaction-force-command-value setting process is a process of calculating a reaction torque command value that is a command value of a torque variable indicating a reaction force, and includes a process of superimposing, on the reaction torque command value, a correction amount that has a negative correlation with an amount of change in a steering torque that is a torque input to a steering shaft (14) by a driver. The operation process is a process of operating a reaction force actuator according to the reaction torque command value.

Inventors

MIYAKE, Junya
TAMAIZUMI, TERUTAKA
Namikawa, Isao
ANRAKU, Koji
HOSONO, HIROSHI

Assignees

JTEKT CORPORATION

Dates

Publication Date: 20260506
Application Date: 20230630

Claims (7)

A steering control device that is configured to operate a reaction force actuator configured to apply a reaction force to a steering shaft configured to be operated to rotate according to steering by a driver with power transmission to a steered wheel being interrupted, wherein: the reaction force actuator includes a first rotary member configured to rotate in conjunction with the steering shaft, a second rotary member configured to be rotated together with the first rotary member as the first rotary member rotates, and a restraining member configured to, when a rotation angle of the second rotary member reaches a predetermined angle, contact the second rotary member to restrain rotation of the second rotary member; the first rotary member and the second rotary member are configured to, when the first rotary member rotates by a predetermined amount from an angle at which the rotation of the second rotary member is restrained, contact each other such that the second rotary member restrains rotation of the first rotary member; the steering control device is configured to execute a reaction-force-command-value setting process and an operation process; the reaction-force-command-value setting process is a process of calculating a reaction torque command value that is a command value of a torque variable indicating the reaction force, and includes a process of superimposing, on the reaction torque command value, a correction amount that has a negative correlation with an amount of change in a steering torque that is a torque input to the steering shaft by the driver; and the operation process is a process of operating the reaction force actuator according to the reaction torque command value.
The steering control device according to claim 1, wherein: the reaction-force-command-value setting process includes a torque derivative calculation process and a correction amount calculation process; the torque derivative calculation process is a process of calculating a time derivative of the steering torque; and the correction amount calculation process is a process of calculating the correction amount using the time derivative of the steering torque as an input.
The steering control device according to claim 2, wherein the steering control device is configured to repeatedly execute the torque derivative calculation process and the correction amount calculation process at predetermined intervals.
The steering control device according to claim 2, wherein the steering control device is configured to execute the correction amount calculation process within a predetermined angle range of the steering shaft, the predetermined angle range including a rotation angle at which switching occurs from one of following states to the other: a state where the first rotary member rotates while causing the second rotary member to be rotated together with the first rotary member, and a state in which the first rotary member rotates without causing the second rotary member to be rotated together with the first rotary member.
The steering control device according to claim 2, wherein the correction amount calculation process is a process of calculating the correction amount according to a value obtained by filtering the time derivative.
The steering control device according to claim 2, wherein: the reaction-force-command-value setting process further includes, in addition to the correction amount calculation process, a phase-lead compensation process; and the phase-lead compensation process is a process of reflecting, in the reaction torque command value, a lead compensation amount for advancing a phase of the reaction torque command value using the time derivative of the steering torque.
A steering control method for operating a reaction force actuator configured to apply a reaction force to a steering shaft configured to be operated to rotate according to steering by a driver with power transmission to a steered wheel being interrupted, wherein: the reaction force actuator includes a first rotary member configured to rotate in conjunction with the steering shaft, a second rotary member configured to be rotated together with the first rotary member as the first rotary member rotates, and a restraining member configured to, when a rotation angle of the second rotary member reaches a predetermined angle, contact the second rotary member to restrain rotation of the second rotary member; the first rotary member and the second rotary member are configured to, when the first rotary member rotates by a predetermined amount from an angle at which the rotation of the second rotary member is restrained, contact each other such that the second rotary member restrains rotation of the first rotary member; the steering control method includes executing a reaction-force-command-value setting process, and executing an operation process; the reaction-force-command-value setting process is a process of calculating a reaction torque command value that is a command value of a torque variable indicating the reaction force, and includes a process of superimposing, on the reaction torque command value, a correction amount that has a negative correlation with an amount of change in a steering torque that is a torque input to the steering shaft by the driver; and the operation process is a process of operating the reaction force actuator according to the reaction torque command value.

Description

TECHNICAL FIELD The present disclosure relates to steering control devices and steering control methods. BACKGROUND ART Patent Document 1 below describes a device that mechanically limits the rotation range of a steering shaft in a steer-by-wire system. Specifically, the device includes a first rotary member that rotates in conjunction with the steering shaft, and a second rotary member that is rotated together with the first rotary member as the first rotary member rotates. The device further includes a restraining member that contacts the second rotary member to restrain rotation of the second rotary member when the rotation angle of the second rotary member reaches a predetermined angle. When the first rotary member rotates by a predetermined amount from a steering angle at which the rotation of the second rotary member is restrained by the restraining member, the first rotary member and the second rotary member contact each other such that the second rotary member restrains rotation of the first rotary member. As a result, rotation of the first rotary member is restrained. Related Art Documents Patent Documents Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-69844 (JP 2020-69844 A) SUMMARY OF THE INVENTION Problem to be Solved by the Invention In the above device, the magnitude of torque that restrains rotation of the steering shaft differs between a state where the second rotary member is rotated together with the first rotary member as the first rotary member rotates and a state where the first rotary member rotates alone. Therefore, when switching occurs from one of the above two states to the other, the torque applied to the steering shaft undergoes a step change, which may impair the steering feel of the driver. Means for Solving the Problem One aspect of the present disclosure provides a steering control device that is configured to operate a reaction force actuator configured to apply a reaction force to a steering shaft configured to be operated to rotate according to steering by a driver with power transmission to a steered wheel being interrupted. The reaction force actuator includes: a first rotary member configured to rotate in conjunction with the steering shaft; a second rotary member configured to be rotated together with the first rotary member as the first rotary member rotates; and a restraining member configured to, when a rotation angle of the second rotary member reaches a predetermined angle, contact the second rotary member to restrain rotation of the second rotary member. The first rotary member and the second rotary member are configured to, when the first rotary member rotates by a predetermined amount from an angle at which the rotation of the second rotary member is restrained, contact each other such that the second rotary member restrains rotation of the first rotary member. The steering control device is configured to execute a reaction-force-command-value setting process and an operation process. The reaction-force-command-value setting process is a process of calculating a reaction torque command value that is a command value of a torque variable indicating the reaction force, and includes a process of superimposing, on the reaction torque command value, a correction amount that has a negative correlation with an amount of change in a steering torque that is a torque input to the steering shaft by the driver. The operation process is a process of operating the reaction force actuator according to the reaction torque command value. Another aspect of the present disclosure provides a steering control method for operating a reaction force actuator configured to apply a reaction force to a steering shaft configured to be operated to rotate according to steering by a driver with power transmission to a steered wheel being interrupted. The reaction force actuator includes: a first rotary member configured to rotate in conjunction with the steering shaft; a second rotary member configured to be rotated together with the first rotary member as the first rotary member rotates; and a restraining member configured to, when a rotation angle of the second rotary member reaches a predetermined angle, contact the second rotary member to restrain rotation of the second rotary member. The first rotary member and the second rotary member are configured to, when the first rotary member rotates by a predetermined amount from an angle at which the rotation of the second rotary member is restrained, contact each other such that the second rotary member restrains rotation of the first rotary member. The steering control method includes: executing a reaction-force-command-value setting process; and executing an operation process. The reaction-force-command-value setting process is a process of calculating a reaction torque command value that is a command value of a torque variable indicating the reaction force, and includes a process of superimposing, on the react