Assisted Steering Gain Modulation for Vehicle Trajectory Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power steering systems struggle to effectively modulate assistance functions across various dynamic driving situations, such as steering, over-steering, off-steering, and counter-steering, which can lead to undesired vehicle trajectories due to inadequate grip conditions and mass transfer effects.
Innovation Solution
A method for modulating the application of assistance functions in power steering systems by evaluating and multiplying gains based on yaw rate, steering wheel angle, longitudinal acceleration, and lateral acceleration, along with a compensation gain for pull torque phenomena, to provide a progressive and adaptive assistance torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If assistance functions are applied in power steering systems without proper modulation across dynamic driving situations, then the steering assistance is provided, but undesired vehicle trajectories occur due to inadequate grip conditions and mass transfer effects
Solution Approach 1:
The assistance function application is dynamically modulated by continuously adjusting the application gain based on real-time vehicle state parameters (yaw rate, steering wheel angle, longitudinal acceleration, lateral acceleration). This dynamic adjustment allows the power steering system to adapt its assistance level to current driving conditions, resolving the contradiction between providing reliable steering assistance and adapting to varying grip conditions and mass transfer effects during different driving maneuvers.
Solution Approach 2:
The system changes the application gain parameter based on multiple vehicle state parameters to modulate the assistance function application. By varying the application gain according to yaw rate, steering wheel angle, longitudinal acceleration, and lateral acceleration, the system optimizes trajectory control reliability across different dynamic driving situations including steering, over-steering, off-steering, and counter-steering conditions.
2Reliability
If the assistance function application is modulated based on multiple parameters (yaw rate, steering wheel angle, longitudinal acceleration, lateral acceleration), then the vehicle control and stability are enhanced, but the computational complexity increases
Solution Approach 1:
The power steering control system performs multiple functions through a unified control architecture: it simultaneously processes yaw rate, steering wheel angle, longitudinal acceleration, and lateral acceleration to compute the application gain. This multi-functional approach enhances vehicle control stability across all dynamic driving situations while avoiding the need for separate control systems for different driving conditions, thereby managing computational complexity through integration rather than multiplication of systems.
3Ease of operation
If the application gain is continuously adjusted based on driving conditions, then seamless transition of assistance functions is achieved, but the real-time computation requirements increase
Solution Approach 1:
The system pre-establishes the relationship between vehicle state parameters and application gain through the defined gain function, allowing real-time computation to simply evaluate rather than calculate complex control strategies. This preliminary formulation of the control logic enables seamless transition of assistance functions while minimizing real-time computation time, as the system only needs to substitute current sensor values into the pre-defined gain equation.
Data Source
AI summary
A method for modulating an assistance function application of an assisted steering system in a vehicle, the vehicle including at least two wheels, a steering wheel and an assistance motor applying an assistance torque on a rack, the method implementing a step of evaluating an application gain of the assistance function, a step of estimating the assistance torque associated with the assistance function and a step of multiplying the assistance torque associated with the assistance function and the application gain, characterised in that the step of evaluating the application gain includes a first phase of determining a first gain depending on a yaw speed and an angle of the steering wheel.