Vehicle Steering Device Anti-One-Side Pull Control
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Solution Overview
Problem
Existing vehicle steering systems face challenges in maintaining steering comfort when transitioning from low to high vehicle speeds during anti-one-side pull control, particularly on cant roads or in crosswinds, due to fluctuations in steering angle and increased physical burden on the driver.
Innovation Solution
A vehicle steering device equipped with an electric motor, steering torque and angle sensors, and a controller that computes an anti-one-side pull current value using integrated torque values and mapping information to reduce steering torque fluctuations, optimizing control based on vehicle speed thresholds to minimize driver effort and stabilize the vehicle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If anti-one-side pull control is executed using integrated torque value to suppress vehicle drift on cant roads or in crosswinds, then steering comfort is improved, but steering angle fluctuations occur when vehicle speed transitions from low to high range, causing driver discomfort
Solution Approach 1:
The patent applies dynamics by making the midpoint steering angle movable rather than fixed. The anti-one-side pull steering angle (midpoint) is dynamically adjusted based on the integrated torque value to suppress vehicle drift. When vehicle speed transitions from low to high range, the midpoint convergence determination unit determines whether the midpoint has converged to a proper angle, and the movement prohibition unit temporarily prohibits midpoint movement during transition periods, ensuring stability while maintaining the ability to adapt when needed.
Solution Approach 2:
The patent changes parameters by adjusting the anti-one-side pull steering angle (midpoint) based on the integrated torque value to suppress one-side pull behavior. The system monitors vehicle speed and determines when to permit or prohibit midpoint movement, changing the operational parameters of the control system based on driving conditions to balance comfort and stability.
2Object-affected harmful factors
If the midpoint steering angle is moved based on integrated torque value to suppress one-side pull behavior, then vehicle drift suppression is improved, but convergence time increases when transitioning from low to high vehicle speed range, causing prolonged driver discomfort
Solution Approach 1:
The patent applies preliminary action by detecting vehicle speed transitions from low to high range in advance and temporarily prohibiting midpoint movement during the transition period. This preliminary intervention prevents steering angle fluctuations before they occur, allowing the midpoint to converge more quickly to a proper angle once the transition is complete, thereby reducing the overall time of driver discomfort.
Solution Approach 2:
The patent uses feedback by continuously monitoring vehicle speed and determining whether the vehicle speed has transitioned from low to high range. The midpoint convergence determination unit receives feedback about the integrated torque value and vehicle speed state, and adjusts the control strategy accordingly - permitting midpoint movement when converged and prohibiting it during transitions, creating a closed-loop control system that optimizes convergence time.
Data Source
AI summary
A vehicle steering device includes an electric motor; a steering angle sensor; a steering torque sensor; a wheel speed sensor; a cruise controller; and a wheel-alignment support controller configured to compute an anti-one-side pull current value fed to the electric motor for suppressing a one-side pull behavior of a vehicle. The wheel-alignment support controller calculates, according to an integrated torque value, the amount of displacement of an anti-one-side pull steering angle value that corresponds to a midpoint steering angle of a steering system for suppressing the one-side pull behavior of the vehicle. When the vehicle is under cruise control and the vehicle speed is below a first threshold Vth1, the wheel-alignment support controller makes the amount of displacement of the anti-one-side pull steering angle value smaller than that obtained when the vehicle speed is equal to or above the first threshold Vth1.