ABS Braking Pressure Control for Counter Steering Yaw Rate
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Solution Overview
Problem
During ABS braking, the formation of a yaw rate in counter steering situations is delayed, leading to decreased lateral force and suboptimal steering performance, as the existing ABS-VDC cooperative control fails to maintain optimal braking pressure on the front axle curve-travelling outer wheel.
Innovation Solution
A method that determines over-steer situations and counter steering sections by analyzing steering angles and yaw rates, applying ABS wheel pressure control to maintain optimal slip ratios without VDC intervention, thereby preventing lateral force decrease and ensuring timely formation of a linear yaw rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ABS-VDC cooperative control improves braking pressure for the front axle curve-travelling outer wheel during counter steering, then oversteer control is enhanced, but lateral force decreases and yaw rate formation is delayed
Solution Approach 1:
The system detects counter steering conditions in advance by monitoring steering angle and yaw rate relationships. When counter steering is detected, the VDC intervention is preemptively adjusted to maintain optimal slip ratios, preventing the delay in yaw rate formation before it occurs. This preliminary detection and response mechanism ensures that the braking pressure is maintained at levels that promote timely yaw rate development while still providing oversteer control.
2Stability of the object's composition
If VDC intervention increases braking pressure for oversteer control in counter steering section, then vehicle stability is improved, but lateral force decreases
Solution Approach 1:
The system dynamically adjusts the slip ratio target based on detected counter steering conditions. By changing the control parameter from the standard slip ratio to an optimized slip ratio that accounts for counter steering, the system maintains lateral force while achieving the required oversteer control and vehicle stability. This parameter adaptation allows the braking system to operate in a regime that preserves tire lateral force generation capability.
3Force
If ABS maintains optimal slip ratio during counter steering, then lateral force is maintained, but oversteer control effectiveness is reduced
Solution Approach 1:
The system implements dynamic control by continuously monitoring steering angle, yaw rate, and their relationships to detect counter steering conditions. Based on this real-time information, the system dynamically adjusts the slip ratio target and braking pressure modulation to achieve both lateral force maintenance and oversteer control. This dynamic adaptation allows the system to switch between different control strategies depending on the instantaneous driving conditions.
Data Source
AI summary
Disclosed may be a method for controlling counter steering of a vehicle, which, in a counter steering section for controlling over-steer while a vehicle travels a curve, prevents lateral force from being decreased by maintaining a braking pressure according to an operation of an antilock braking system (ABS) for a vehicle wheel (a front axle curve-travelling outer wheel) of a counter steering target at an optimal slip level (before an improvement of a target slip), and improves steering performance by forming a linear yaw rate in a direction for counter steering without a delay in forming the yaw rate.