Vehicle Brake Control Device EBD Threshold Logic
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Solution Overview
Problem
Existing vehicle brake control systems erroneously intervene with EBD control when rear wheels pass over a hump due to sudden increases in wheel deceleration, leading to instability.
Innovation Solution
A brake control device that calculates wheel deceleration for each wheel and implements a differential braking control system, where EBD control is initiated only when both front and rear wheels meet specific threshold conditions, preventing erroneous intervention by comparing deceleration values and adjusting thresholds based on vehicle turning and lateral acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If EBD control is activated when rear wheel deceleration exceeds a threshold, then braking distribution control is improved, but erroneous intervention occurs when rear wheels pass over humps
Solution Approach 1:
The patent segments the EBD control activation condition into two independent parts: rear wheel deceleration threshold AND front wheel deceleration threshold. Both conditions must be satisfied simultaneously for EBD control to activate. This segmentation prevents erroneous activation when only the rear wheel deceleration threshold is exceeded (such as when passing over humps), while still enabling proper EBD control when both thresholds are exceeded during normal braking.
2Stability of the object's composition
If EBD control is activated early during vehicle turning, then vehicle stability is improved, but false activation may occur due to lateral acceleration effects
Solution Approach 1:
The patent dynamically adjusts the deceleration thresholds based on vehicle operating conditions including lateral acceleration and turning status. When turning is detected, the system modifies the threshold values to account for lateral acceleration effects, enabling early EBD activation for inner wheels when genuinely needed while preventing false activation. This parameter adaptation allows the system to distinguish between deceleration caused by turning dynamics versus deceleration indicating actual braking needs.
Data Source
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AI summary
A vehicle brake control device includes a wheel deceleration calculating unit configured to calculate a wheel deceleration of each of wheels of a vehicle, and a front and rear wheel braking distribution controlling unit configured to execute a front and rear wheel braking distribution control for distributing a braking force on front and rear wheels. The front and rear wheel braking distribution controlling unit is configured to start the front and rear wheel braking distribution control on front and rear wheels of one of left and right sides if an absolute value of a wheel deceleration of the front wheel is equal to or larger than a first threshold and an absolute value of a wheel deceleration of the rear wheel is equal to or larger than a second threshold.