Displacement Sensor With Inclined Deformable Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive sensing techniques for displacement measurement face challenges such as interference from the object causing displacement and high dependence on manufacturing tolerances due to sensitive capacitive coupling changes with small changes in conductor separation.
Innovation Solution
A displacement sensor comprising a reference electrode and a deformable electrode with an inclined contact surface, insulated by an insulator layer, which compresses to reduce volume and change capacitive coupling when displaced, allowing a controller to measure and determine displacement based on capacitive coupling characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitive sensing techniques are used for displacement measurement, then mechanical wear is reduced and reliability is improved, but the measurements are affected by interference from the object causing displacement
Solution Approach 1:
The sensor is divided into two separate capacitive measurement systems: a first capacitive sensor measures displacement between the object and first electrode, while a second capacitive sensor measures capacitance change between the object and second electrode. By segmenting the sensing function and combining the measurements, the system can differentiate between displacement effects and interference effects, thereby maintaining reliability while reducing interference.
2Reliability
If capacitive sensing techniques are used for displacement measurement, then the system is more aesthetically pleasing and reliable, but there is high dependence on manufacturing tolerances due to sensitive capacitive coupling changes
Solution Approach 1:
The system uses feedback by measuring capacitance changes with the second capacitive sensor and using this information to compensate for manufacturing variations in the first capacitive sensor. The controller processes both measurements and adjusts the displacement calculation to account for tolerances, thereby reducing sensitivity to manufacturing precision while maintaining reliability.
Solution Approach 2:
The invention changes the measurement parameter from direct displacement measurement to a combination of displacement measurement and capacitance change measurement. By measuring capacitance change as an additional parameter and using it to compensate for manufacturing variations, the system reduces dependence on manufacturing tolerances while maintaining reliable displacement sensing.
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 solution effectively isolates displacement measurements from interference and reduces sensitivity to manufacturing tolerances, providing reliable and accurate displacement sensing using capacitive coupling changes.
Implementation Method 1
a controller element configured to measure a characteristic of capacitive coupling associated with the reference electrode and/or the deformable electrode
Data Source
AI summary
A displacement sensor for sensing a change in separation between a first element and a second element along a displacement direction. The sensor comprises a reference electrode mounted to the second element in the form of a conductive trace on a surface of the second element facing the first element. A deformable electrode, e.g. a conductive elastomeric material, is arranged between the first element and the second element so as to overlie the reference electrode. The deformable electrode has a contact surface facing the reference electrode and insulated therefrom. At least part of the contact surface is inclined relative to an opposing surface of the reference electrode such that when the deformable electrode is compressed along the displacement direction there is a reduction in volume between the contact surface and the opposing surface of the reference electrode, thereby changing the capacitive coupling between them. The sensor further comprises a controller element configured to measure a characteristic of the capacitive coupling between the reference electrode and the deformable electrode and to determine if a change in separation between the first element and the second element has occurred be determining if there is a change in the characteristic of capacitive coupling between the reference electrode and the deformable electrode.