Piezoelectric Brake Shear Sensor Layout for Crosstalk Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piezoelectric shear force sensors integrated into braking devices face challenges in producing reliable and repeatable measurements when subjected to both shear force and normal force simultaneously, due to the phenomenon of 'crosstalk' which complicates signal interpretation.
Innovation Solution
A sensorized braking device incorporating a piezoelectric shear force sensor with a specific electrode configuration, where the second electrode has extensions on the first face separated from the first electrode and arranged symmetrically with respect to the y and z axes, allowing for effective charge collection and reduced crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a piezoelectric shear force sensor is used to measure shear force in a braking device, then the sensor can detect shear force through piezoelectric charge generation, but the sensor produces unreliable and non-repeatable measurements when subjected to both shear force and normal force simultaneously due to crosstalk
Solution Approach 1:
The piezoelectric sensor is divided into multiple independent piezoelectric elements arranged in a specific pattern. Each element responds to different components of the applied force, allowing the sensor to distinguish between shear force and normal force signals. This segmentation enables selective measurement of shear force while rejecting normal force interference through differential signal processing.
Solution Approach 2:
Different regions of the sensor have different electrode configurations and piezoelectric element orientations optimized for specific measurement functions. The electrode patterns are locally adapted to enhance sensitivity to shear force in certain areas while being less sensitive to normal force, creating spatially varying measurement characteristics that enable crosstalk reduction.
2Ease of manufacture
If traditional electrode configurations are used in piezoelectric shear sensors, then the sensor structure is simple and easy to manufacture, but the sensor cannot effectively distinguish between shear force and normal force signals
Solution Approach 1:
The electrode configuration uses asymmetric patterns where the first and second electrodes are positioned and dimensioned differently. This asymmetry creates differential sensitivity to shear and normal forces, allowing the sensor to distinguish between the two force types. The asymmetric design maintains compatibility with standard manufacturing processes while achieving superior signal discrimination.
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 proposed solution enables the sensorized braking device to produce reliable and repeatable measurements of shear force even when normal force is applied, effectively mitigating the issue of crosstalk and improving measurement accuracy.
Implementation Method 1
Piezoelectricity is the property of certain materials to polarize, generating an accumulation of electrical charge, and therefore a difference in potential, when mechanically stressed.
Data Source
AI summary
The sensorized braking device (1) for a vehicle, comprising at least one piezoelectric sensor (2) for measuring shear force, an electrical circuit (12) configured to collect signals from the sensor (2), wherein the sensor (2) comprises a piezoelectric material (3), a first and at least a second readout electrode (6, 7), wherein the piezoelectric material (3) comprises a first flat face (4) and a second flat face (5) facing the first flat face (4), the first and second flat faces (4, 5) extending in parallel planes identified by two orthogonal directions y and z, wherein the piezoelectric material (3) is polarized in the z direction, wherein the first electrode (6) is positioned on the first face (4) and the second electrode (7) is positioned on the second face (5) and has at least one extension (7a, 7b) on the first face (4) separated from the first electrode (6), and wherein the extension (7a. 7b) of the second electrode (7) is arranged symmetrically with respect to the y- and z-axes.