Vehicle Braking Control Device Wheel Slip Suppression
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Solution Overview
Problem
Existing braking control systems experience excessive wheel slip due to time delays in increasing braking force, which can lead to instability during sudden braking operations.
Innovation Solution
A braking control device that includes a wheel speed sensor, a pressing force sensor, and a controller to detect the actual pressing force and command pressing force, allowing for real-time adjustment of the target pressing force to match the actual force, thereby reducing wheel slip by sharp reduction of the command pressing force at the start of slip-suppression control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If field weakening control is performed to improve braking responsiveness, then the rotational speed of the electric motor increases, but a time delay for braking force generation still occurs causing excessive wheel slip
Solution Approach 1:
The controller calculates the target pressing force sharply at the moment slip-suppression control is determined to be executed, using the actual pressing force at that instant. This preliminary calculation eliminates the gradual increase delay, allowing the braking force to respond immediately to the wheel slip condition.
Solution Approach 2:
The system continuously monitors the actual pressing force via a pressing force sensor and feeds this information back to the controller. The controller adjusts the target pressing force based on the deviation between command and actual pressing forces, enabling real-time correction of the braking force to prevent excessive wheel slip.
2Stability of the object's composition
If the command pressing force is gradually increased to generate braking force, then the electric motor operates smoothly, but excessive wheel slip occurs due to the time delay in force generation
Solution Approach 1:
The controller performs preliminary calculation of the target pressing force at the exact moment slip-suppression control is initiated, rather than gradually increasing it. This sharp calculation uses the actual pressing force at that instant, enabling immediate response to prevent wheel slip while maintaining smooth motor operation through controlled execution.
Solution Approach 2:
The system dynamically adjusts the target pressing force based on real-time wheel slip conditions and actual pressing force measurements. The control strategy transitions from gradual increase to sharp calculation when wheel slip is detected, optimizing the balance between smooth operation and slip prevention.
3Device complexity
If a simple rotation sensor is used to detect motor angle, then the structure remains simple and inexpensive, but the responsiveness to braking force generation is insufficient
Solution Approach 1:
The system implements feedback control by continuously measuring the actual pressing force with a sensor and comparing it to the command pressing force. The controller adjusts the target pressing force based on this feedback, compensating for the limitations of simple sensors and improving responsiveness without increasing device complexity.
Solution Approach 2:
The patent replaces reliance on mechanical sensor precision with an electronic feedback control system that measures actual pressing force and dynamically adjusts control commands. This substitution of mechanical precision requirements with electronic control improves responsiveness while maintaining simple sensor hardware.
Data Source
AI summary
A braking control device drives an electric motor based on a command pressing force corresponding to the required wheel braking force, and presses a friction member against a rotation member fixed to the wheel to generate a wheel braking force. The braking control device includes: a sensor for detecting wheel speed; a sensor for detecting the actual pressing force applied by the friction member; and a controller for calculating the target pressing force based on the command pressing force, and controlling the motor so that the target and actual pressing forces match. The controller calculates wheel slip state quantity based on the wheel speed, and executes, based on the slip state quantity, slip suppression control for reducing the degree of wheel slippage. Based on the actual pressing force at the start of the slip suppression control, the controller reduces the command pressing force and calculates the target pressing force.