EPS Controller Steering Return and Energization Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vehicle control systems with electric power steering (EPS) devices face challenges in managing heat generation when maintaining a steering angle, as continuous current supply is required, leading to increased heat, and discontinuing current supply can result in deviation from the target steering angle.
Innovation Solution
A vehicle control system that includes a controller to perform a steering return process and energization suppression process, reducing motor energization when the vehicle is stationary, and stopping the suppression process when the vehicle starts moving, to minimize heat generation and maintain the steering angle accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current is continuously supplied to the EPS device to maintain steering angle, then steering angle holding accuracy is improved, but heat generation of the EPS device increases
Solution Approach 1:
The patent implements periodic action by alternately switching between steering holding control (supplying current to maintain steering angle) and energization suppression control (reducing current to decrease heat). The controller determines whether to hold steering angle or suppress energization based on vehicle speed conditions, creating a periodic control pattern that balances steering accuracy and heat reduction
Solution Approach 2:
The patent applies dynamics by making the control strategy adaptive to vehicle operating conditions. The controller dynamically switches between different control modes (steering holding vs. energization suppression) based on real-time vehicle speed detection, optimizing performance according to changing conditions rather than using a fixed control approach
2Temperature
If current supply to EPS device is cut off to reduce heat generation, then heat generation is reduced, but actual steering angle deviates from target holding steering angle
Solution Approach 1:
The controller implements periodic switching between energization suppression mode (to reduce heat) and steering holding mode (to maintain accuracy). When vehicle speed exceeds the threshold, the controller alternates between reducing current to the EPS device and restoring current to maintain steering angle, creating a rhythmic control pattern that addresses both heat reduction and accuracy maintenance
Solution Approach 2:
The system uses feedback by continuously monitoring vehicle speed and comparing it against a predetermined threshold. Based on this feedback, the controller automatically adjusts the control strategy - suppressing energization when speed is high (reducing heat) and maintaining full energization when speed is low (maintaining accuracy), creating a closed-loop control system
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
The solution effectively reduces heat generation in the EPS device while maintaining the steering angle, preventing deviations and ensuring efficient steering control, even during stationary holding and subsequent vehicle movement.
Implementation Method 1
an electric motor for generating a steering assist torque
Implementation Method 2
heat generation of the EPS device
Data Source
AI summary
The vehicle control system is applied as a system of a vehicle mounted with an EPS device having an electric motor driven to control the steering angle. The vehicle control system includes a controller configured to perform steering control for controlling an energization of the electric motor to control the steering angle of the wheels. When the wheels are held after being steered by a specific steering in the steering control, the controller performs a steering return process in which the wheels are turned back and held in a direction opposite to a steering direction of the specific steering. And during a stationary steering-holding in which the steering angle is held and the vehicle is stopped, the controller performs an energization suppression process for reducing energization to the electric motor to be smaller than the energization before the stationary steering-holding.