Steering Control Device Emergency Ratio Adjustment
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Solution Overview
Problem
In vehicle steering systems with steer-by-wire technology, the lack of redundancy in steering control systems limits the ability to provide stable steering assistance during failures or emergencies, as the remaining controllers can only provide limited steering assistance, potentially leading to accidents.
Innovation Solution
A steering control device and method that determines a steering ratio change condition to adjust the average steering ratio using a preset virtual C-factor, controlling the steering motor output and adjusting the rack stroke and speed to ensure stable steering assistance during emergencies and failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a redundant system with two or more controllers is implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The system dynamically switches between normal control mode and emergency control mode based on failure detection. The controller adapts its behavior by changing the average steering ratio when emergency steering is detected, allowing the system to maintain reliability through flexible control strategies rather than fixed redundant hardware configurations.
Solution Approach 2:
The system changes the average steering ratio parameter when emergency steering is detected. By adjusting this parameter, the controller can provide enhanced steering assistance during failures, improving reliability through parameter adaptation rather than requiring additional hardware components.
2Reliability
If the average steering ratio is changed during emergency steering, then steering assistance is improved, but control complexity increases
Solution Approach 1:
The system pre-establishes the emergency control algorithm that includes the virtual C-factor and the logic for changing the average steering ratio. When failure is detected, the system simply executes the pre-planned response by switching to emergency mode and applying the predetermined control strategy, reducing the complexity of real-time decision-making.
Solution Approach 2:
The virtual C-factor acts as an intermediary parameter that mediates between the steering wheel angle and the rack position during emergency steering. This intermediary allows the system to provide enhanced steering assistance through a mathematically defined relationship rather than requiring complex real-time control calculations.
3Manufacturing precision
If rack stroke and rack speed are adjusted, then steering precision is improved, but response time increases
Solution Approach 1:
The system uses periodic PWM signals to control the steering motor during emergency steering. By adjusting the duty cycle of these periodic signals, the system can control the average steering ratio and thereby adjust rack stroke and speed in a time-efficient manner, maintaining steering precision without excessive response delay.
Data Source
AI summary
The present embodiments relates to a steering control device and method of a vehicle and may provide a steering control device and method for a vehicle, which may secure stably steered driving by controlling the output of the steering motor by changing the average steering ratio when the driver causes urgent steering in a failure situation and adjusting the rack stroke and rack speed.