Sustained-Action Brake Threshold Learning via Effect Coefficient

Solution Overview

Problem

Automated control of sustained-action brakes in commercial vehicles often fails to optimally implement braking requirements due to the lack of knowledge about braking step threshold values, leading to suboptimal wear patterns in brakes susceptible to wear.

Innovation Solution

A method is developed to learn and detect braking step threshold values by calculating a braking effect variable coefficient, which characterizes the ratio of actual to maximum braking effect, allowing each braking step to be assigned a unique coefficient and threshold value, enabling reliable and low-wear braking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If automated control of sustained-action brakes is implemented without knowledge of braking step threshold values, then automation is achieved, but braking precision and wear optimization deteriorate

Engineering Contradiction:

Improveautomated controlVSAvoidbraking step threshold knowledge

Core Design Contradiction:

Extent of automationVSMeasurement precision

Solution Approach 1:

The system performs preliminary learning operations to detect and store braking step threshold values before normal automated braking control is executed. This preliminary detection phase enables the automated control system to subsequently operate with precise knowledge of when each braking step activates, resolving the contradiction between automation and precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control system continuously monitors the actual braking effect and compares it with expected values to identify threshold points. This feedback mechanism allows the system to learn and adapt the braking step thresholds during operation, maintaining both automation and precision simultaneously.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If sustained-action brake is controlled without accurate threshold values, then automated braking is possible, but brake wear optimization deteriorates

Engineering Contradiction:

Improveautomated braking capabilityVSAvoidwear optimization

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary learning operations to detect and store braking step threshold values before normal automated braking control is executed. This preliminary detection phase enables the automated control system to subsequently operate with precise knowledge of when each braking step activates, resolving the contradiction between automation and precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control system continuously monitors the actual braking effect and compares it with expected values to identify threshold points. This feedback mechanism allows the system to learn and adapt the braking step thresholds during operation, maintaining both automation and precision simultaneously.

Inventive Principle:

Principle #23Feedback

3Device complexity

If braking step threshold values are not detected, then system complexity is reduced, but braking control precision deteriorates

Engineering Contradiction:

Improvesystem structureVSAvoidbraking step threshold knowledge

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The control system automatically detects and stores its own braking step threshold values during normal operation without requiring external calibration or complex pre-programming. This self-learning capability adds minimal complexity while significantly improving braking step precision.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11535213B2Method for learning braking step threshold values of a sustained-action brake operated in braking steps, and braking system

Publication Date: 2022.12.27 ZF CV SYST EURO BV

AI summary

A method for learning braking step threshold values of a sustained-action brake includes detecting a braking requirement setpoint, controlling the sustained-action brake with the braking requirement setpoint to generate a braking effect variable of the sustained-action brake, and detecting a sustained-action brake actual braking effect variable and a maximum sustained-action brake braking effect. The method additionally includes forming a braking effect variable coefficient that characterizes a ratio of the sustained-action brake actual braking effect variable and the maximum sustained-action brake braking effect variable that results from control of the sustained-action brake with the braking requirement setpoint, and assigning the braking effect variable coefficient to a braking step of the sustained-action brake such that each braking step is assigned only one braking effect variable. Additionally, the method includes storing the braking requirement setpoint that results in the braking effect variable coefficient.