Steering Control Device Virtual Range Adaptation
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Solution Overview
Problem
Existing steering control devices in steer-by-wire systems experience unintended steering behaviors when the vehicle decelerates or accelerates, causing discomfort or error feelings for the driver due to changes in the virtual operation range of the steering wheel with vehicle speed.
Innovation Solution
A steering control device with processors that adjust the virtual operation range of the steering wheel based on the steering state and vehicle state, fixing the vehicle speed when the steering wheel reaches the limit position, and limiting the change in steering reaction force to prevent unintended steering movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the virtual operation range of the steering wheel is changed according to vehicle speed, then steering characteristics are improved, but unintended steering behaviors occur when the vehicle decelerates or accelerates
Solution Approach 1:
The patent implements dynamic adjustment of the virtual operation range limit position based on vehicle speed, allowing the steering system to adapt to different driving conditions. The limit position is dynamically changed according to vehicle speed while preventing unintended movements through change amount limitations
Solution Approach 2:
The patent changes the parameter of the virtual operation range limit position according to vehicle speed. By adjusting this parameter dynamically and controlling the change amount, the system achieves both improved steering characteristics and prevented unintended steering behaviors
2Ease of operation
If the steering reaction force is rapidly increased to limit the operation range, then the operation range is virtually changed, but the driver feels discomfort due to sudden force changes
Solution Approach 1:
The patent applies beforehand cushioning by calculating and limiting the change amount of the virtual operation range limit position before actual steering operations occur. This prevents sudden force changes that would cause driver discomfort while still achieving virtual operation range limitation
Solution Approach 2:
The patent implements preliminary anti-action by pre-calculating the maximum allowable change amount of the limit position and applying this constraint before unintended steering behaviors can occur. This prevents harmful force changes while maintaining operation range control
Data Source
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AI summary
A steering control device (50) controls a reaction motor that generates a steering reaction force applied to a steering wheel of which power transmission to and from turning wheels is cut off. the steering control device (50) includes: a first processor (101) configured to change a virtual operation range of the steering wheel according to a steering state or a vehicle state by controlling the reaction motor; and a second processor configured to change a degree of change of the virtual operation range of the steering wheel according to the steering state or the vehicle state when an operation position of the steering wheel reaches a position in a vicinity of a limit position of the virtual operation range.