Steering Control Device Dynamic Current Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steering control devices for vehicles experience mechanical limits during automatic steering, leading to uncomfortable feelings for drivers as the steering operation is unexpectedly released against their intention.
Innovation Solution
The automatic steering control device adjusts the upper limit value of the current command value as the steering angle approaches its mechanical limit, allowing the steering angle to moderately vary by setting a first threshold and decreasing the upper limit value of the current command value when the steering angle exceeds this threshold, thereby preventing the steering mechanism from reaching its mechanical limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If automatic steering control is executed with a fixed upper limit value of current command value, then the steering response is fast and efficient, but the steering mechanism reaches the mechanical limit causing unexpected release of steering operation
Solution Approach 1:
The upper limit value of the current command value is changed from a fixed parameter to a dynamic parameter that varies with the steering angle. When the absolute value of the steering angle exceeds a predetermined threshold, the upper limit value is decreased to prevent the steering mechanism from reaching the mechanical limit, thereby maintaining both responsive steering and operational stability.
Solution Approach 2:
The patent changes the parameter of the upper limit value of the current command value based on the steering angle condition. By adjusting this parameter dynamically according to the steering angle threshold, the system prevents mechanical limit exposure while maintaining efficient steering response within the safe operating range.
2Reliability
If the upper limit value of current command value is decreased to prevent mechanical limit, then the steering mechanism operates within safe range, but the steering angle varies more slowly reducing responsiveness
Solution Approach 1:
Different upper limit values are applied to different steering angle ranges. When the steering angle is within the threshold, a higher upper limit value is used for fast response. When the steering angle exceeds the threshold, a lower upper limit value is applied to prevent mechanical limit, creating localized control quality matching the operational conditions.
Data Source
Figure 1
Figure 2(A)~2(B)
Figure 3(A)~3(B)
AI summary
A steering control device for a vehicle, the steering control device controlling a steering device, the steering device having a steering mechanism (10) configured to steer wheels in accordance with a steering angle of a steering wheel and a drive unit (40) configured to provide the steering mechanism (10) with steering force for the wheels (15), the steering control device comprising: a detection unit (30) configured to detect the steering angle; and a control unit (30) configured to: calculate a target value of a current to be supplied to the drive unit (40) as a current command value; and execute automatic steering control to automatically control steering of the vehicle by causing the drive unit (40) to be supplied with the current of the current command value;, wherein, when an absolute value of the steering angle comes to a predetermined first threshold or more during the automatic steering control, the control unit (30) decreases an upper limit value of an absolute value of the current command value as the absolute value of the steering angle increases.