Brake Caliper Force Sensor Layout for Real-Time Torque Estimation

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Solution Overview

Problem

Current brake caliper systems face challenges in precisely measuring braking force and torque due to indirect estimation methods, which lack precision and are influenced by axial forces, requiring a device capable of simultaneous and accurate detection of tangential and normal forces in compact and robust form for real-time braking force estimation.

Innovation Solution

A detection device comprising a plate-shaped casing with a force sensor assembly that generates electrical signals for both normal and tangential forces through piezo-resistive effects, integrated with an electrical interface, allowing for precise detection and processing of these forces, even in harsh environments, using MEMS technology and robust materials like stainless steel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If indirect estimation methods are used to determine braking force and torque, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent combines normal force detection and tangential force detection into a single integrated sensor assembly mounted on the brake caliper. This merging of multiple detection functions into one device achieves direct measurement of both force components simultaneously, resolving the contradiction by providing high measurement precision while maintaining reasonable device complexity through functional integration.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If compact sensor devices are used, then ease of operation is improved, but measurement precision deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidmeasurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent employs a plate-shaped sensor assembly with strategic placement of normal force sensors and tangential force sensors in different spatial dimensions and orientations. This dimensional arrangement allows the compact device to capture multiple force components simultaneously without compromising measurement precision, as each sensor type is positioned to optimally detect its specific force component.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If shear force sensors alone are used, then device complexity is reduced, but measurement precision deteriorates due to disturbance from axial forces

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the force detection function into two independent sensor types: normal force sensors that measure axial forces and tangential force sensors that measure shear forces. This segmentation allows each sensor type to measure its specific force component independently, eliminating the disturbance effect where axial forces interfere with shear force measurements, thereby achieving high measurement precision for braking force and torque.

Inventive Principle:
Principle #1Segmentation

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

The device provides high-precision measurements of tangential and normal forces over a wide range, enabling accurate real-time braking force and torque estimation, suitable for various braking systems and environmental conditions, with compactness and robustness ensuring reliable operation.

Implementation Method 1

the force sensor assembly is configured to generate, by piezoresistive effect, one or more electrical signals representative of the normal force component and of the at least one tangential force component detected

Methodology Applied
Scientific EffectPiezoresistive effect: Piezoresistive Effect

Data Source

PatentEP3983772B1Device and method for a simultaneous detection of tangential and normal forces acting in a detection point at a brake caliper or at a suspension of a vehicle wheel
Publication Date: 2023.07.05 FRENI BREMBO SPA
  • EP3983772B1 patent drawingFigure 1~2
  • EP3983772B1 patent drawingFigure 3
  • EP3983772B1 patent drawingFigure 4A~4B

AI summary

A device is described for the simultaneous detection of the tangential and normal components of a force acting at a brake caliper or suspension of a vehicle wheel. The detection device 1 comprises a plate-shaped casing 2 which contains a force sensor assembly 3 configured to detect both a normal force component fn, and at least one tangential force component ft, and is configured to generate, by piezo-resistive effect, one or more electrical signals SA, SB representative of the normal force component fn and of the at least one tangential force component ft detected. The device 1 further comprises an electrical interface 4 integrated in the casing 2 and connected to biaxial force sensor 3 to conduct and make the aforesaid one or more generated electrical signals SA, SB available. A device and a system are further described for determining a braking force and/or torque due to the action of a vehicle brake caliper, comprising, inter alia, the aforesaid detection device, and a brake caliper system with a braking force estimation function, employing the aforesaid devices. Corresponding methods are further described for simultaneously detecting the tangential and normal components of a force acting at a brake caliper of a vehicle wheel or of a force exchanged between an axle and a suspension of the wheel, and to determine a braking force and/or torque due to the action of a vehicle brake caliper.