Steering Control Device Curvature Lateral Acceleration Offset
Solution Overview
Problem
Existing steering control systems cause discomfort to drivers due to fluctuations in steering reaction force characteristics, particularly when navigating curves, as they fail to effectively manage self-aligning torque and lateral acceleration.
Innovation Solution
A steering control device and method that calculates an offset amount based on curvature and lateral acceleration, adjusting the steering reaction force characteristic to align with self-aligning torque, thereby maintaining a consistent steering experience and reducing driver discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the steering reaction force characteristic is adjusted to reduce steering load during turning, then driver comfort improves, but the steering reaction force becomes unstable and causes discomfort
Solution Approach 1:
The steering reaction force characteristic is made dynamically adjustable based on detected curvature and lateral acceleration. The control device modifies the steering reaction force characteristic in real-time according to vehicle operating conditions, allowing the system to adapt between different steering feel requirements rather than using a fixed characteristic.
Solution Approach 2:
The invention changes the parameters of the steering reaction force characteristic (specifically the self-aligning torque component) based on detected curvature and lateral acceleration values. By modifying these parameters dynamically, the system achieves both reduced steering load and maintained stability.
2Stability of the object's composition
If the steering reaction force characteristic is modified to maintain consistency during turning, then driver comfort improves, but the ability to adapt to different curvature conditions decreases
Solution Approach 1:
The system uses dynamic adjustment based on real-time detection of curvature and lateral acceleration to maintain steering reaction force consistency while adapting to different turning conditions. The characteristic is modified proportionally to the detected parameters.
Solution Approach 2:
The control device uses feedback from curvature detection and lateral acceleration detection to continuously adjust the steering reaction force characteristic. This closed-loop approach ensures the system maintains consistency while adapting to varying road conditions.
3Ease of operation
If the steering reaction force is reduced during high curvature turns, then ease of steering improves, but the steering reaction force becomes unpredictable and causes driver discomfort
Solution Approach 1:
The invention systematically changes the steering reaction force parameter based on the relationship between curvature and lateral acceleration. This structured parameter modification ensures predictable steering behavior while maintaining ease of steering during high curvature turns.
Solution Approach 2:
The control device preemptively adjusts the steering reaction force characteristic based on detected curvature and lateral acceleration before the driver experiences potential discomfort. This preliminary adjustment prevents unpredictable steering reactions while maintaining steering ease.
Data Source
AI summary
The present invention comprises a steering unit 1 that receives steering input from a driver and that is mechanically separated from a turning unit 2 that turns left and a right front wheels (5FL, 5FR) (the turnable wheels); a steering reaction force control unit 20 that sets a steering reaction force characteristic to coordinates, of which the coordinate axes are the self-aligning torque and the steering reaction force, so that the self-aligning torque increases as the steering reaction force increases, and the control unit applies the steering reaction force to the steering unit 1 based on the steering reaction force characteristic; a curvature calculation unit 34a that detects curvature of a white line; a lateral force offset unit 34 (an offset means) that calculates an offset amount that increases as the detected curvature increases and that offsets the steering reaction force characteristic at the coordinates only by the offset amount in the same coding direction as the self-aligning torque; a lateral acceleration inference unit 342 (a lateral acceleration detection means) that detects the lateral acceleration of a vehicle; and a limiter processing unit 34e (an offset suppression means) that suppresses an increase in the lateral force offset amount more as the absolute value of the detected lateral acceleration G increases.