Steering Control Apparatus Viscosity Compensation
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Solution Overview
Problem
The controllability of steering systems with electric motors is affected by viscosity and friction components, which vary with individual differences, aging, and temperature, making it difficult to adapt the control unit optimally for consistent performance.
Innovation Solution
A control apparatus that calculates and compensates for viscosity and friction components using a control circuitry, performing an angle control process, a predetermined component calculation process, and a relationship change process to adjust the output based on these components, thereby improving controllability by varying the relationship between input and output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed control unit is used for the steering system, then the device complexity is reduced, but the controllability and performance consistency deteriorate due to variations in viscosity component
Solution Approach 1:
The control unit dynamically adjusts the relationship between input and output based on the calculated viscosity component in real-time, rather than using a fixed control parameter. This allows the system to adapt to changing viscosity conditions while maintaining a relatively simple overall control structure.
Solution Approach 2:
The system changes the control parameter (relationship between input and output) based on the calculated viscosity component. By calculating the viscosity component from motor torque and angular velocity, and then adjusting the control relationship accordingly, the system achieves adaptability without requiring multiple fixed control units.
2Adaptability or versatility
If the control unit is adapted in advance for optimal viscosity compensation, then the controllability is improved, but the adaptability to individual differences, aging, and temperature variations deteriorates
Solution Approach 1:
The system continuously calculates the viscosity component based on feedback from motor torque and angular velocity sensors, and uses this calculated value to adjust the control relationship in real-time. This closed-loop feedback mechanism ensures both adaptability to viscosity changes and precision in controllability.
Solution Approach 2:
The control system performs self-adjustment by automatically calculating the viscosity component from its own operating parameters (motor torque and angular velocity) and using this information to optimize its control relationship, eliminating the need for external calibration or pre-adaptation.
3Ease of operation
If the viscosity component is not compensated, then the device complexity is reduced, but the controllability and steering responsiveness deteriorate
Solution Approach 1:
Instead of using complex mechanical adjustment mechanisms to compensate for viscosity, the system uses electronic calculation and software-based control relationship adjustment. The viscosity component is calculated from electrical signals (motor torque and angular velocity) and the compensation is applied through electronic control, replacing what would otherwise require complex mechanical systems.
Data Source
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AI summary
A control apparatus for a steering system (10) includes control circuitry configured to perform an angle control process for controlling, to an angle command value, a convertible angle that is convertible into a rotational angle of the electric motor, a predetermined component calculation process for calculating a predetermined component containing at least one of two components that are a viscosity component and a friction component of the steering system (10), while using a value of a variable regarding a control quantity of the electric motor as an input, and a relationship change process for changing a relationship of an output from a control unit for the steering system (10) to an input to the control unit, based on the predetermined component calculated through the predetermined component calculation process.