Brake Control Bad Road Detection Using Selective Wheel Acceleration
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Solution Overview
Problem
The accuracy of bad road determination in vehicle brake control systems is compromised due to reliance on wheel speed and acceleration of either the front or rear wheel, leading to inconsistent results based on vehicle state.
Innovation Solution
A vehicle brake control device that utilizes both front and rear wheel accelerations, with selective use based on anti-lock brake control execution and vehicle acceleration, and includes threshold-based determination using filtered acceleration values to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If bad road determination is executed based on wheel speed and acceleration of either front or rear wheel, then the determination process is simple, but the accuracy of bad road determination is lowered depending on vehicle state
Solution Approach 1:
The patent divides the wheel acceleration data into two segments: front wheel acceleration and rear wheel acceleration. By segmenting the data source and selecting the appropriate segment based on vehicle state (acceleration or deceleration), the system achieves more accurate bad road determination while maintaining a relatively simple determination process.
2Measurement precision
If only front wheel acceleration is used for bad road determination, then the determination process is simple, but the accuracy is insufficient during deceleration when anti-lock brake control is executed
Solution Approach 1:
The patent implements a dynamic selection mechanism that automatically switches between front wheel acceleration and rear wheel acceleration based on the current vehicle state (acceleration or deceleration) and anti-lock brake control execution status. This dynamic adaptation ensures high accuracy across all operating conditions without requiring complex manual intervention.
3Measurement precision
If wheel acceleration is used directly for bad road determination, then the response is fast, but high-frequency noise reduces determination accuracy
Solution Approach 1:
The patent applies a moderate level of filtering to the wheel acceleration data, removing high-frequency noise components while preserving the essential acceleration characteristics needed for accurate bad road determination. This partial filtering action strikes a balance between noise reduction and maintaining responsive detection capability.
Data Source
AI summary
A vehicle brake control device including a front wheel speed acquisition section, a rear wheel speed acquisition section, a front wheel acceleration calculation section, a rear wheel acceleration calculation section, a front wheel anti-lock brake control section capable of executing an anti-lock brake control for the front wheel, a vehicle acceleration acquisition section, and a bad road determination section configured to determine whether or not a running road surface is a bad road based on the front wheel acceleration or the rear wheel acceleration. The bad road determination section executes a bad road determination by selectively using one of the front wheel acceleration and the rear wheel acceleration at least based on information on whether or not the anti-lock brake control for the front wheel is executed and the vehicle acceleration.