Vehicle Braking Force Distribution Control for Yaw Stabilization
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Solution Overview
Problem
Existing braking force distribution control systems struggle to stabilize vehicle yaw moment when there is a significant difference in braking slip between wheels, leading to rapid variations in vehicle stability and increased turning deviation, especially when controlling front and rear wheels.
Innovation Solution
A braking force distribution control device that references wheels with higher braking force sharing rates as control reference wheels and those with lower rates as control object wheels, adjusting braking forces to converge the braking slip index magnitude relationship between the left and right wheels, with target difference values calculated based on reference differences and actual wheel load ratios to stabilize vehicle behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If braking force is increased on the side of lower braking slip and decreased on the side of higher braking slip to reduce yaw moment, then turning deviation is reduced, but vehicle stability rapidly varies
Solution Approach 1:
The patent divides the four wheels into two groups: control reference wheels (front or rear wheels with higher braking force sharing rate) and control object wheels (front or rear wheels with lower braking force sharing rate). This segmentation allows independent control strategies for different wheel groups, reducing overall yaw moment while maintaining vehicle stability through coordinated control of both groups.
Solution Approach 2:
The patent changes the control parameter from direct braking force adjustment to braking slip index difference value control. By calculating the difference value between braking slip index values of left and right control reference wheels and using it to determine target difference values for control object wheels, the system achieves smoother braking force distribution that reduces yaw moment without causing rapid vehicle stability variations.
2Force
If braking force distribution control is executed on wheels with higher braking force sharing rate, then yaw moment is reduced more effectively, but vehicle behavior varies rapidly
Solution Approach 1:
The patent segments the wheel control into reference wheels (higher braking force sharing rate) and object wheels (lower braking force sharing rate). The control reference wheels serve as the basis for determining braking force distribution, while the control object wheels are adjusted to achieve the desired braking slip index difference. This segmentation enables effective yaw moment reduction through reference wheel control while maintaining vehicle behavior stability through more conservative object wheel adjustment.
Solution Approach 2:
The patent uses the braking slip index difference value as an intermediary parameter to coordinate control between reference wheels and object wheels. The target difference value for control object wheels is determined based on the actual difference value from control reference wheels, creating a mediated control relationship that achieves yaw moment reduction while preventing excessive vehicle behavior variation.
3Manufacturing precision
If braking force is adjusted to converge braking slip index values between left and right wheels, then turning deviation is suppressed, but control complexity increases
Solution Approach 1:
The patent simplifies control complexity by segmenting wheels into reference and object groups. Instead of independently controlling all four wheels, the system uses control reference wheels (front or rear wheels with higher braking force sharing rate) as the basis for control decisions, then adjusts control object wheels (front or rear wheels with lower braking force sharing rate) to achieve the desired braking slip index difference. This segmented approach reduces the computational complexity while maintaining precise braking slip control.
Solution Approach 2:
The patent changes the control approach from direct braking force adjustment to braking slip index difference value control. By calculating the difference value between braking slip index values of left and right control reference wheels and using it to determine target difference values for control object wheels, the system achieves precise convergence of braking slip index values with simplified control logic.
Data Source
AI summary
Disclosed is a braking force distribution control device for a vehicle which has a braking apparatus capable of individually controlling braking forces of the wheels as required. Front or rear wheels having higher braking force sharing rate being referred to control reference wheels and the front or rear wheels having lower braking force sharing rate are referred to control object wheels. A difference value between braking slip index values of the left and right wheels of said control object wheels is referred to a reference difference value. A braking force distribution control is executed on the control object wheels so that the magnitude relationship in wheel speeds of the left and right wheels of the control object wheels is converse to that of the left and right wheels of the control reference wheels.