Steering Control Apparatus State Determination
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Solution Overview
Problem
Existing steering control systems in vehicles struggle to accurately determine whether the steering state is a turning state or a returning state, leading to inadequate adjustment of steering feedback and feeling.
Innovation Solution
A steering control apparatus that calculates a reaction force torque command value by combining viscosity and return command values with the steering torque command value, and controls an electric current to a reaction force rotary electric machine, allowing determination of the steering state based on the output torque of a reaction force device and torque sensor detection values, with distinct operational characteristics for turning and returning states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional steering control systems are used, then the system structure is simple, but the steering state determination is inaccurate leading to inadequate steering feedback adjustment
Solution Approach 1:
The system performs preliminary determination of steering state (turning vs. returning) by comparing reaction force device output torque with torque sensor detection values before actual angle changes occur. This allows the control system to proactively adjust steering feedback characteristics based on the predicted steering state, improving determination accuracy without requiring complex additional hardware.
2Ease of operation
If the reaction force device is controlled with two inputs (driver's steering torque and motor torque), then the control is simplified, but the steering feedback adjustment is inadequate
Solution Approach 1:
The system changes control parameters (reaction force amount operation, viscosity amount operation, return amount operation) based on the determined steering state. When a turning state is detected, different parameter characteristics are applied compared to when a returning state is detected, enabling accurate steering feedback adjustment while maintaining simplified two-input control architecture.
Data Source
AI summary
In a steering control apparatus, a reaction force torque command value is calculated so that a detection value of a torque sensor follows a target value obtained by adding at least a viscosity command value and a return command value to a steering torque command value, and an electric current that flows to a reaction force rotary electric machine is controlled based on the reaction force torque command value. Whether a steering state is a turning state or a returning state is determined by comparing a physical quantity corresponding to an output torque of a reaction force device and the detection value of the torque sensor. Characteristics of one or more of a reaction force amount operation, a viscosity amount operation, and a return amount operation are made differ between the turning state and the returning state.