Wireless Pressure Sensor for Vehicle Fluid Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pressure sensors for fluid circuits and sealed enclosures in vehicles require wires for operation, which complicates their manufacture and maintenance, and occupy valuable space, especially in hazardous or isolated environments like fuel systems and battery packs.
Innovation Solution
A wireless pressure sensor design featuring an elastically deformable membrane with a resonant RLC circuit and a readout circuit, where the capacitor's electrodes are integrated on the membrane and the coils are positioned to optimize space and eliminate the need for wires, allowing for flexible and compact installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wires are used to connect the capacitor and coil to readout the pressure sensor signal, then the sensor can function properly, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent replaces the mechanical wire connection system with an electromagnetic field-based wireless communication system. The pressure sensor signal is transmitted from the membrane-mounted capacitor and coil to the external readout circuit through electromagnetic coupling, eliminating the need for physical wire connections and reducing device complexity while maintaining functionality.
Solution Approach 2:
The patent introduces an electromagnetic field as an intermediary between the pressure sensor elements (capacitor and coil on the membrane) and the external readout circuit. This intermediary enables signal transmission without direct physical connection, resolving the contradiction between maintaining sensor functionality and reducing wiring complexity.
2Loss of information
If wires are present for the pressure sensor, then the sensor can transmit data, but the space available in hazardous or isolated environments is reduced
Solution Approach 1:
The patent substitutes the mechanical wire transmission system with an electromagnetic field-based wireless transmission system. The pressure data is transmitted from the membrane-mounted resonant circuit to the external readout circuit through electromagnetic coupling, eliminating the space occupied by wires while maintaining data transmission capability.
3Volume of moving object
If the capacitor is positioned away from the membrane, then it occupies less space, but the sensor cannot accurately measure membrane deformation
Solution Approach 1:
The patent places both the capacitor and coil on the two-dimensional surface of the membrane rather than extending into the third dimension above it. This dimensional arrangement allows the capacitor to remain close to the membrane for accurate deformation measurement while occupying minimal space, as the components are distributed across the membrane surface area rather than projecting outward.
4Device complexity
If the first coil is positioned away from the membrane, then the sensor structure is simpler, but the resonant frequency detection accuracy decreases
Solution Approach 1:
The patent positions the first coil on or above the membrane surface in a two-dimensional arrangement rather than extending it into the third dimension. This positioning maintains close proximity to the membrane for accurate resonant frequency detection while keeping the overall sensor structure compact and simple, resolving the contradiction between structural simplicity and measurement precision.
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
This design enables efficient pressure measurement without wires, simplifying manufacturing and maintenance, while minimizing space usage, making it suitable for hazardous environments like fuel systems and battery packs in vehicles.
Implementation Method 1
an elastically deformable membrane comprising two opposite faces, a first face of which is intended to be in contact with a fluid
Implementation Method 2
a resonant circuit of the RLC type comprising a capacitor which is located on one of the two faces of the membrane and whose capacitance varies as a function of the amplitude of elastic deformation of said membrane
Implementation Method 3
said resonant circuit being configured so as to have a resonant frequency which varies as a function of the capacitance of the capacitor and therefore of the elastic deformation of the membrane
Implementation Method 4
a readout circuit offset from the membrane and comprising a second coil located opposite the first coil and configured to detect the resonant frequency of said resonant circuit
Data Source
AI summary
A pressure sensor (10) for a fluid circuit, in particular, of a motor vehicle, the sensor comprising a body (12) comprising a fluid inlet (14), a fluid outlet (16) and an internal chamber (18) for connecting the inlet to the fluid outlet for the fluid flow in said body, the sensor further comprising an elastically deformable membrane (20) located in said chamber and comprising a first face (20a) intended to be in contact with the fluid flowing in the body, wherein the sensor further comprises a resonant circuit (22) of the RLC type located in said chamber and associated with a readout circuit (23) located outside the chamber (18).