Vehicle Braking Control Gain Adjustment for Slip Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle braking systems experience interference between automatic braking control and anti-skid control, particularly when the road surface friction is low, leading to excessive brake fluid pressure and wheel slip issues.
Innovation Solution
A vehicle braking control device that adjusts braking torque based on target deceleration and wheel speed, using a controller to execute feedback control and adjust control gain during anti-skid operations, thereby reducing interference between automatic braking and anti-skid controls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If automatic braking control increases brake fluid pressure to achieve target deceleration, then deceleration performance is improved, but wheel slip increases on low-friction surfaces
Solution Approach 1:
The patent dynamically adjusts the brake fluid pressure based on real-time wheel slip detection. When wheel slip is detected during automatic braking, the control system modifies the pressure increase rate and magnitude to prevent excessive slip while maintaining deceleration performance. This dynamic adjustment resolves the contradiction by adapting the braking force to actual road conditions.
Solution Approach 2:
The patent implements a feedback control mechanism where wheel speed sensors continuously monitor wheel rotation during automatic braking. The detected wheel slip information is fed back to the control unit, which then adjusts the brake fluid pressure accordingly. This closed-loop feedback system ensures that deceleration targets are met while preventing wheel slip on low-friction surfaces.
2Reliability
If anti-skid control decreases brake fluid pressure to reduce wheel slip, then wheel slip is suppressed, but deceleration performance deteriorates
Solution Approach 1:
The control system dynamically balances wheel slip suppression with deceleration performance by continuously adjusting brake fluid pressure based on real-time conditions. When wheel slip is detected, the system applies anti-skid control to reduce slip, then smoothly transitions back to automatic braking control to restore deceleration performance. This dynamic balancing act resolves the contradiction between slip suppression and deceleration effectiveness.
Solution Approach 2:
The patent employs periodic modulation of brake fluid pressure during anti-skid control operations. Instead of maintaining constant low pressure, the system applies periodic pressure increases and decreases to keep wheels at the threshold of slip without actually slipping. This periodic action maintains both wheel grip and deceleration performance simultaneously.
3Adaptability or versatility
If both automatic braking control and anti-skid control operate simultaneously, then comprehensive braking control is achieved, but control interference occurs
Solution Approach 1:
The patent implements dynamic control mode switching between automatic braking and anti-skid control based on real-time wheel slip detection. When wheel slip exceeds a threshold, the system automatically transitions from pure automatic braking control to a combined mode with anti-skid intervention. This dynamic switching resolves control interference by coordinating both control systems rather than allowing them to operate independently and conflict.
Solution Approach 2:
The control unit acts as an intermediary that coordinates between automatic braking control and anti-skid control systems. It receives inputs from both control algorithms, detects wheel slip conditions, and synthesizes a unified brake fluid pressure command that satisfies both deceleration targets and slip prevention requirements. This intermediary coordination eliminates control interference while maintaining comprehensive braking functionality.
Data Source
AI summary
This vehicle braking control device executes automatic braking control to adjust a braking torque on the basis of a vehicle target deceleration value corresponding to a distance between the vehicle and an object in front of the vehicle, and executes anti-skid control to suppress excessive wheel slip by adjusting the braking torque on the basis of a wheel speed. The braking control device calculates an actual deceleration value corresponding to the target deceleration value, and executes feedback control on the basis of the target deceleration value and the actual deceleration value such that the actual deceleration value approaches the target deceleration value. The configuration is such that a control gain of the feedback control is reduced when anti-skid control is executed. Further, the configuration may be such that execution of feedback control is prohibited when anti-skid control is executed.