Steering control device

Patent metadata

Field	Value
Publication number	US-12466468-B2
Application number	US-202318181102-A
Country	US
Kind code	B2
Filing date	Mar 9, 2023
Priority date	Mar 9, 2022
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A steering control device calculates a target angle of a shaft that rotates in conjunction with a turning operation of a turning wheel that is isolated from dynamic power transmission with a steering wheel, depending on a steering state of the steering wheel, and executes a feedback control to cause an actual angle to follow the target angle, for controlling electricity supply to a turning motor to turn the turning wheel, the steering control device including: a first processing unit to execute a process to alter the target angle independently of the steering state of the steering wheel; and a second processing unit to calculate a turning state amount for a guide monitor function to assist traveling of a vehicle, by reducing or removing an influence of an alteration of the target angle on the actual angle of the shaft.

First claim

What is claimed is:

1 . A steering control device for controlling electricity supply to a turning motor generating a turning force for turning a turning wheel of a vehicle and that (i) calculates a target angle of a shaft depending on a steering state of a steering wheel and (ii) executes a feedback control to cause an actual angle of the shaft to follow the target angle, the shaft rotating in conjunction with a turning operation of the turning wheel, which is isolated from dynamic power transmission with the steering wheel,
the steering control device comprising a memory and a processor programmed to execute:
a first processing to alter the target angle independently of the steering state of the steering wheel; and
a second processing (i) to calculate a turning state amount for a guide monitor function by reducing or removing an influence of an alteration of the target angle by the first processing on the actual angle of the shaft and (ii) to display the calculated turning state amount on a display of the vehicle to assist a driver during traveling of the vehicle.

2 . The steering control device according to claim 1 , wherein the second processing executed by the processor calculates the turning state amount by (i) calculating a change amount of the target angle due to the first processing and (ii) subtracting the change amount of the target angle from the actual angle of the shaft or the target angle based on the steering state of the steering wheel.

3 . The steering control device according to claim 1 , wherein when a vehicle electric power source is switched on, the first processing executed by the processor includes a first alteration process (i) to calculate an offset angle, (ii) to gradually change the offset angle toward zero by performing a gradual change process to the offset angle, and (iii) to alter a value of the target angle by adding the offset angle after the gradual change process to the target angle, the offset angle being a deviation amount between the target angle that is calculated based on a present steering angle of the steering wheel and the actual angle of the shaft that reflects an actual turning state of the turning wheel.

4 . The steering control device according to claim 3 , wherein the second processing executed by the processor includes a process to take the offset angle after the gradual change process as a first change amount, and to calculate the turning state amount by subtracting the first change amount from the actual angle of the shaft or the target angle based on the steering state of the steering wheel.

5 . The steering control device according to claim 3 , wherein when a turning shaft for turning the turning wheel moves to a position in a prescribed high shaft force range, the first processing executed by the processor further includes a second alteration process to alter the value of the target angle such that a position of the turning shaft departs from the high shaft force range to a turning neutral position side.

6 . The steering control device according to claim 4 , wherein when a turning shaft for turning the turning wheel moves to a position in a prescribed high shaft force range, the first processing executed by the processor further includes a second alteration process to alter the value of the target angle such that a position of the turning shaft departs from the high shaft force range to a turning neutral position side.

7 . The steering control device according to claim 5 , wherein the second processing executed by the processor includes a process (i) to calculate a second change amount by subtracting the target angle before an execution of the second alteration process from the target angle after the execution of the second alteration process, and (ii) to calculate the turning state amount by subtracting the second change amount from the actual angle of the shaft or the target angle based on the steering state of the steering wheel.

8 . The steering control device according to claim 3 , wherein the first processing executed by the processor further includes a third alteration process to alter the value of the target angle for reducing residual current that is generated in the turning motor.

9 . The steering control device according to claim 8 , wherein the second processing executed by the processor includes a process (i) to calculate a third change amount by subtracting the target angle before an execution of the third alteration process from the target angle after the execution of the third alteration process, and (ii) to calculate the turning state amount by subtracting the third change amount from the actual angle of the shaft or the target angle based on the steering state of the steering wheel.

10 . The steering control device according to claim 1 , wherein the turning state amount is a rotation angle of a pinion shaft that engages with a turning shaft to turn the turning wheel.

Assignees

• Jtekt Corp
• Toyota Motor Co Ltd

Inventors

• Miyake Junya
• Ishihara Atsushi
• KAKIMOTO Yusuke
• Toyama Hidetsugu
• Iida Tomoyuki

Classifications

• B62D5/0424

  the axes of motor and final driven element of steering gear, e.g. rack, being parallel · CPC title

• B62D15/0275

  by overlaying a vehicle path based on present steering angle over an image without processing that image · CPC title

• B62D5/001

  Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup · CPC title

• B62D6/008

  Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications · CPC title

• B62D5/0463

  calculating assisting torque from the motor based on driver input · CPC title