Steering Device Controller Stabilizing Reaction Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In steer-by-wire steering devices, deviations between the steering wheel and turning wheels can cause fluctuations in the restriction reaction force, leading to a deteriorated steering feel for the driver due to the separation of motive power transmission between the steering and turning units.
Innovation Solution
A controller that calculates and applies a stable restriction reaction force to the steering unit based on information from the steering unit, including the steering end position and vehicle speed, to maintain a consistent steering feel, even when deviations occur between the steering wheel and turning wheels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If motive power transmission between steering unit and turning unit is separated in steer-by-wire steering device, then steering control flexibility is improved, but correspondence relation between steering wheel and turning wheels may deviate causing fluctuation of restriction reaction force
Solution Approach 1:
The control circuit continuously monitors the actual steering angle of the steering wheel and the actual turning angle of the turning wheels, calculates the deviation between them, and uses this feedback to adjust the restriction reaction force applied to the steering wheel. This closed-loop feedback mechanism ensures that even when the correspondence relation deviates due to separation of motive power transmission, the restriction reaction force remains stable and the steering feel remains consistent for the driver.
2Reliability
If restriction reaction force is calculated based on turning wheel position, then turning wheel constraints are maintained, but deviation between steering wheel and turning wheels causes fluctuation of restriction reaction force
Solution Approach 1:
Instead of calculating the restriction reaction force based on the turning wheel position (which causes fluctuation when deviation occurs), the invention inverts the approach by calculating the restriction reaction force based on the steering wheel position. This inversion ensures that the restriction reaction force is determined by the driver's actual steering input rather than the turning wheel output, thereby eliminating fluctuation caused by correspondence relation deviation while maintaining reliable turning wheel constraints through the control system.
3Manufacturing precision
If steering end position is fixed at mechanical limit, then mechanical constraints are satisfied, but deviation causes fluctuation of steering end position
Solution Approach 1:
The invention dynamically adjusts the steering end position based on the detected deviation between the steering wheel and turning wheels. Rather than fixing the steering end position at the mechanical limit, the control circuit modifies the steering end position to compensate for the deviation, ensuring that the steering end position remains stable from the driver's perspective. This dynamic adjustment maintains mechanical constraint satisfaction while eliminating fluctuation in the perceived steering end position.
Data Source
AI summary
In a controller for a steering device, the steering device includes a structure where motive power transmission between a steering unit and a turning unit is separated. The controller includes a control circuit configured to control operation of a steering-side motor that is provided in the steering unit to give steering reaction force that is force against the steering input into the steering unit. In a case where turning of the turning wheels to one direction is restricted, the control circuit is configured to calculate restriction reaction force for restricting steering that is to turn the turning wheels to the one direction. The control circuit is configured to calculate the restriction reaction force based on information on the steering unit.