Vehicle Brake Wear Estimation Using Electromechanical Actuators

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for determining wear values on vehicle brakes are often expensive and not capable of continuous, accurate monitoring, leading to potential early replacement of brake linings.

Innovation Solution

A method that determines wear values on vehicle brakes by using mathematical models based on influencing parameters such as distance driven, time in service, and braking history, with electromechanical actuator units to measure and record operating parameters, allowing for precise estimation of brake lining wear without direct measurement on all brakes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direct measurement methods are used to determine brake lining wear, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvewear value determination accuracyVSAvoidmeasurement system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an electromechanical actuator unit as an intermediary component that indirectly measures brake lining wear. Instead of directly measuring the friction lining thickness, the system measures the actuator's operating parameters (current, voltage, temperature) during brake activation. These intermediary measurements are then correlated to wear values through mathematical models, achieving accurate wear determination without complex direct measurement devices.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex mechanical direct measurement systems with an electromechanical sensing approach. The electromechanical actuator unit uses electrical and thermal parameters to infer mechanical wear conditions. By substituting direct mechanical measurement with electrical parameter monitoring, the system achieves high measurement precision while reducing device complexity and cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of information

If wear measurement is performed on all vehicle brakes, then measurement completeness is improved, but loss of time and productivity decrease

Engineering Contradiction:

Improvewear information completenessVSAvoidmeasurement time

Core Design Contradiction:

Loss of informationVSLoss of time

Solution Approach 1:

The patent segments the vehicle brake system into monitored and unmonitored groups. The electromechanical actuator unit is installed on specific brakes (e.g., rear brakes with park brake function) to serve as representative sampling points. By segmenting the monitoring scope, the system obtains sufficient wear information to infer the state of all brakes on the vehicle without physically measuring every single brake, thus reducing measurement time while maintaining information completeness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses wear data from a subset of brakes as a 'copy' or representative sample to infer the wear state of all brakes. The mathematical models correlate wear patterns from monitored brakes to predict wear on unmonitored brakes, assuming similar usage conditions. This copying approach provides comprehensive wear information without the time cost of measuring every brake individually.

Inventive Principle:

Principle #26Copying

3Productivity

If continuous monitoring is implemented, then productivity is improved, but use of energy increases

Engineering Contradiction:

Improvewear monitoring efficiencyVSAvoidactuator energy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic rather than continuous monitoring by activating the electromechanical actuator unit at specific intervals or under specific conditions (e.g., during park brake activation, at scheduled service intervals). The control unit evaluates whether measurement conditions are met before initiating actuator operation. This periodic action maintains high monitoring efficiency by capturing wear data at critical moments while significantly reducing energy consumption compared to constant monitoring.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system uses feedback control to optimize energy usage. The control unit continuously evaluates measurement conditions (wear thresholds, actuator availability, vehicle state) and only activates the electromechanical actuator when conditions warrant measurement. This feedback mechanism ensures continuous monitoring effectiveness by maintaining awareness of brake wear status while minimizing unnecessary actuator operation and associated energy consumption.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20230271597A1Method for determining wear values on at least a first and a second vehicle brake of a motor vehicle

Publication Date: 2023.08.31 ZF ACTIVE SAFETY GMBH

AI summary

A method is disclosed for determining wear values on at least a first and a second vehicle brake of a motor vehicle. The first and second vehicle brakes are assigned to a first or second vehicle wheel of a same first wheel axle. The first vehicle brake has an actuator piston which presses a friction lining against a brake disc mounted such that it rotates in an actuating position, and an electromechanical actuator unit.