Steer-by-Wire Neutral Position Holding for Wheel Alignment
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Solution Overview
Problem
The steer-by-wire steering system lacks clarity on the motion position at which the steering actuator should be locked, and there is a need for improved utility in such systems.
Innovation Solution
A steer-by-wire steering system with a controller that executes neutral position setting and motion position hold processing for both the reaction force actuator and steering actuator, using a signal from an operation terminal to determine the appropriate motion positions and lock them, allowing for precise alignment and operation member connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If motion position hold processing is executed for the steering actuator, then the motion position can be held, but it is unclear at which motion position the actuator is locked
Solution Approach 1:
The controller executes neutral position setting processing that detects the neutral position of the steering actuator and feeds back this information. The system provides visual feedback through a display device showing the detected neutral position, ensuring the operator knows exactly where the actuator is locked. This feedback mechanism resolves the contradiction by maintaining reliable position holding while eliminating uncertainty about the locked position.
Solution Approach 2:
A display device serves as an intermediary between the steering actuator and the operator. The display device receives position information from the controller and presents it to the operator in a visible format. This intermediary translates the internal state of the actuator into comprehensible information, solving the problem of unclear locked position while maintaining the holding capability.
2Measurement precision
If neutral position setting processing is executed, then the neutral position can be identified, but additional processing time and complexity are required
Solution Approach 1:
The controller performs multiple functions: it controls the reaction force actuator, controls the steering actuator, executes neutral position setting processing, and manages motion position hold processing. By making the controller multi-functional, the system achieves precise neutral position detection without adding separate dedicated hardware for each function, thus reducing overall device complexity while maintaining measurement precision.
Solution Approach 2:
The neutral position setting processing is merged with the existing control architecture. The controller integrates the neutral position detection function with the motion position hold function, combining multiple processing tasks into a unified control system. This merging reduces the number of separate components and simplifies the overall system structure while achieving precise position measurement.
3Manufacturing precision
If motion position hold processing is executed for both reaction force actuator and steering actuator, then alignment accuracy is improved, but the system becomes more complex to operate
Solution Approach 1:
The display device provides visual feedback showing the neutral positions of both the reaction force actuator and steering actuator. This feedback allows operators to monitor the status of both actuators simultaneously, making it easier to understand what is happening in the system. The operator can see when positions are held and when alignment is complete, reducing the perceived complexity despite the advanced functionality.
Solution Approach 2:
The system performs automatic neutral position detection and motion position holding for both actuators without requiring manual intervention for each individual adjustment. The controller automatically executes the necessary processing sequences, and the display shows the progress. This self-service capability achieves precise alignment while minimizing the operational burden on the user.
Data Source
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AI summary
A steer-by-wire steering system for a vehicle includes: a reaction force actuator (12) to which an operation member (10) is connected such that the reaction force actuator is moved by the operation member (10), the reaction force actuator including a power source (24) by which the reaction force actuator applies an operation reaction force to the operation member; a steering actuator (16) to which a wheel (14) is connected, the steering actuator including a power source (38) by which the steering actuator (16) steers the wheel; and a controller (40, 42) configured to control the reaction force actuator and the steering actuator. The controller is configured to execute, for the reaction force actuator, the steering actuator, or both the reaction force actuator and the steering actuator, a neutral position setting processing of setting a neutral position in a motion range and a motion position hold processing of holding a motion position at the neutral position by the power source.