Steer-by-Wire Reaction Force Control for High-Speed Collision Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed vehicle collisions with obstacles, such as curbs, cause significant steering reaction torque, leading to abrupt steering wheel movement and driver shock in steer-by-wire type steering systems.
Innovation Solution
A steer-by-wire type steering apparatus with a control device that includes a vehicle speed acquisition unit, a reaction force actuator control unit, a steering actuator control unit, a deviation recognition unit, and a reaction force actuator output amount decrease unit, which decreases the reaction force actuator's output when increased vehicle speed and angular deviation are detected, thereby reducing steering reaction torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the reaction force actuator maintains high output to provide strong steering reaction force, then steering stability is improved, but steering wheel abrupt movement and driver shock occur during high-speed collisions with obstacles
Solution Approach 1:
The reaction force actuator output is made dynamic rather than static. The control device continuously adjusts the reaction force actuator output based on real-time detection of vehicle speed and steering angle deviation. At high vehicle speeds with large deviation, the output is reduced to prevent driver shock, while at normal conditions the output is maintained for steering stability. This dynamic adjustment resolves the contradiction between maintaining steering stability and preventing driver shock.
Solution Approach 2:
The patent changes the parameter of reaction force actuator output based on operating conditions. Specifically, when vehicle speed exceeds a predetermined threshold and steering angle deviation exceeds a predetermined value, the reaction force actuator output is reduced. This parameter change allows the system to adapt to different operational states, preventing driver shock during high-speed collisions while maintaining steering stability during normal operation.
2Object-affected harmful factors
If the reaction force actuator output is reduced during high-speed collisions, then driver shock is prevented, but steering control precision may deteriorate
Solution Approach 1:
The control device applies preliminary anti-action by detecting the collision condition (high vehicle speed combined with large steering angle deviation) before the driver shock becomes severe. By proactively reducing the reaction force actuator output in advance, the system prevents the harmful effect while maintaining adequate steering control through the steering actuator.
Solution Approach 2:
The control device acts as an intermediary between the steering actuator and the reaction force actuator. It processes information from both components and makes intelligent decisions about reaction force actuator output adjustment. This intermediary function allows the system to balance driver comfort and steering control precision by selectively adjusting reaction force based on real-time operational conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents abrupt steering wheel movement and driver shock during high-speed collisions by reducing steering reaction torque, enhancing driving safety.
Implementation Method 1
a reaction force actuator that applies a given steering reaction force to the steering operation input member
Implementation Method 2
a steering actuator that causes steered road wheels to be steered through the steering member
Data Source
AI summary
A steer-by-wire type steering apparatus includes a steering input device; a steering device; and a control device. The steering input device includes a reaction force actuator configured to apply steering reaction force to a steering operation input member. The steering device includes a steering actuator configured to cause steered road wheels to be steered through a steering member. The control device includes a reaction force actuator output amount decrease unit configured to decrease an output amount of the reaction force actuator when a deviation between an operation amount of the steering operation input member and a steering amount of the steering member increases and vehicle speed of a vehicle increases. This can prevent the steering operation input member from being abruptly moved in spite of a collision of the steered road wheels with an obstacle or other factors at the time of high vehicle speed.