Steering Torque Control Using Nominal Model Error Correction

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Solution Overview

Problem

The workload required to adapt feedback control parameters to improve response is excessively large in existing steering control systems.

Innovation Solution

A steering control device and method that includes a manipulated variable calculation, correction process, and operation process, utilizing steering torque as a controlled variable, with a correction process to adjust for differences between estimated and actual steering torque, and operating a motor to generate torque based on corrected variables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If feedback control parameters are adjusted to improve response, then steering torque response is improved, but the workload required to adapt parameters becomes excessively large

Engineering Contradiction:

Improvesteering torque responseVSAvoidworkload to adapt parameters

Core Design Contradiction:

SpeedVSEase of operation

Solution Approach 1:

The patent implements a disturbance observer that continuously monitors the difference between actual steering torque and torque estimated by the nominal model, using this feedback to automatically calculate and apply correction amounts to the manipulated variable, eliminating the need for manual parameter adjustment

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The correction process automatically adjusts the manipulated variable by calculating correction amounts based on the disturbance observer's output, enabling the system to self-correct without requiring external intervention or complex parameter tuning by operators

Inventive Principle:

Principle #25Self-service

2Speed

If feedback control parameters are adjusted to improve response, then steering torque response is improved, but controller design complexity increases

Engineering Contradiction:

Improvesteering torque responseVSAvoidcontroller design complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The controller is divided into distinct functional modules: a nominal model for basic control, a disturbance observer for error detection, and a correction process for automatic adjustment. This segmentation simplifies design by assigning specific functions to each module rather than requiring complex integrated parameter tuning

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The disturbance observer acts as an intermediary that bridges the nominal model and the actual system behavior, automatically calculating the difference and generating correction amounts that are applied to the manipulated variable, thereby simplifying the overall controller design

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20260048786A1Steering control device and steering control method

Publication Date: 2026.02.19 JTEKT CORP

AI summary

A steering control device is configured to perform a manipulated variable calculation process, a correction process, and an operation process. The manipulated variable calculation process is a process of calculating a manipulated variable of control that uses steering torque as a controlled variable and uses desired steering torque as a desired value of the controlled variable. The correction process is a process that uses the steering torque and the manipulated variable as inputs, and is a process of correcting the manipulated variable with a correction amount according to a difference between the steering torque estimated by a nominal model and actual steering torque. The operation process is a process of operating a motor of the steering system so as to generate torque according to the manipulated variable corrected by the correction process.