Brake Pad Wear Estimation Using Back Plate Temperature
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Solution Overview
Problem
Existing vehicle brake element wear sensors are limited in performance and reliability, particularly in estimating wear independent of temperature changes over long periods of homogeneous braking events.
Innovation Solution
A method that estimates brake element wear by capturing temperature changes at each braking activation and release, calculating wear increments in real time, using temperature sensors on the back support plate and an electronic processing unit to process these changes, with optional auxiliary sensors for refining the estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If optical measurement methods are used to determine brake pad thickness, then non-contact measurement is achieved, but the complex refractive index of the brake pad material causes inaccurate measurements
Solution Approach 1:
The patent introduces an intermediary substance (coupling agent or liquid) between the optical sensor and the brake pad surface. This intermediary has known optical properties that allow for accurate refractive index compensation, enabling the optical measurement system to function accurately despite the complex optical characteristics of the brake pad material itself.
Solution Approach 2:
The patent employs parameter changes by measuring multiple optical parameters (reflectance, transmittance, phase shift) at different wavelengths or angles, and using these varied measurements to calculate the thickness while compensating for the material's complex refractive index through mathematical modeling and iterative optimization.
2Reliability
If wear indicators are integrated into the brake pad, then wear detection capability is improved, but the structural complexity of the brake element increases
Solution Approach 1:
The patent merges the wear indicator function with the existing brake pad structure by integrating optical markers, reflective layers, or capacitive elements directly into the brake pad composition. This integration allows wear detection without requiring separate, additional components, thereby improving reliability while minimizing structural complexity.
Solution Approach 2:
The patent implements multi-functional elements within the brake pad that serve both their primary structural/function role and wear indication. For example, the brake pad material itself is made optically active or electrically conductive, allowing it to function as both a friction element and a wear sensor, thus avoiding additional complexity.
3Reliability
If continuous monitoring of brake element wear is implemented, then safety and maintenance timing are improved, but energy consumption and system complexity increase
Solution Approach 1:
The patent implements periodic or event-triggered monitoring instead of continuous monitoring. The wear measurement system is activated at specific intervals or when certain conditions are met (e.g., during vehicle operation, at service intervals, or when threshold values are approached), thereby maintaining safety and maintenance timing accuracy while significantly reducing energy consumption compared to continuous operation.
Solution Approach 2:
The patent employs self-powered or passive wear indication mechanisms where the brake pad itself provides the measurement signal without requiring active energy input. For example, passive optical markers that reflect light from ambient sources, or capacitive changes that occur naturally with wear, allowing the system to monitor wear with minimal or no additional energy consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Provides a reliable and real-time estimation of brake element wear, independent of driving style and environmental conditions, with reduced power consumption and improved accuracy.
Implementation Method 1
optical properties such as reflectance, transmittance and/or absorption
Implementation Method 2
optical properties such as reflectance, transmittance and/or absorption
Implementation Method 3
capacitive sensor (42) arranged to detect a capacitance signal in response to wear of the friction lining
Data Source
Figure 1
Figure 1a~1f
Figure 2
AI summary
A method for estimating wear in the braking element of a vehicle that includes at least a braking disc (10), a wear-able block of friction material (20) and a back support plate (40) of the block of friction material (20), at least one temperature sensor (100) configured and positioned to sense the temperature of the back support plate (40), and one electronic processing unit (200) connected to the temperature sensor (100), including the actions of: -capturing, over time, a plurality of temperature values from at least one temperature sensor (100); -processing an estimate of the thickness (600) of said wear-able block of friction material (20) by processing the acquired temperature values, where the estimate of the thickness (600) of the wear-able block of friction material (20) is performed by subsequently subtracting a plurality of wear increases (500) from the thickness of the block (20), where each increase in wear (500) is calculated between capture points t1 and t2 of a corresponding pair of temporally consecutive temperature values, where each increase in wear (500) is calculated by calculating the amount of heat transferred to the wearable block of friction material (20) between said capture points.