Preliminary Research On Signal Processing System Of Compliant Eddy Current Displacement Sensor

With the development of the flexible circuit board technology and sensor material, the probe(material and composite material) that has compliant performance has been made by now. Because of the difference between compliant probe and traditional probe, the front-end must be re-design. The main research of this paper is the signal processing system for the compliant-eddy current sensor based on the compliant probe. Concrete study content as follows:1. Studying the influence of sensor sensitivity by the size of the probe.Using the MATLAB software simulates influence of sensor sensitivity by the size of the probe. Drawing the following conclusions:(1) planar eddy current coil sensitivity increases with increasing number of coils.(2) planar eddy current coil sensitivity increases with increasing outside coil diameter.(3) planar eddy current coil sensitivity increases with decreasing inner coil diameter.2. Designing, analyzing and simulating the circuit of the compliant-eddy current sensorThis paper presents the overall design scheme of compliant-eddy current sensor. The modularization are put forward to designing the measuring circuit. And the circuit is divided into six modules that are:generating square wave module, amplifier and filer module, signal extraction module, A/D conversion module, data display module and communication module. This paper will use Multisim11to simulate and feasibly to analyze the main circuit modules (including generating square wave module, amplifier and filer module and signal extraction module) mentioned in section. Then Altium Designer Release10is used to design the schematic circuit.3. MCU programming This paper select the MSP430F149as the control core of the test circuit system and complete the program design of A/D conversion module, data display module and communication module.4. The program design of the upper computer based on the Lab VIEW platformTo make the calibration for the compliant-eddy current sensor easier, this paper will develop a kind of upper computer software which has the function of auto-calibration. The upper computer program is divided into three modules those are: collecting data, reading data and fitting curve.5. The test of the compliant-eddy current sensor’s signal processing systemAt last, the paper proposes the scheme of the micrometric displacement platform. The45#metal material is used for testing the measuring circuit. The performance of the compliant-eddy current sensor is obtained by analyzing the experimental data. The test data supports the following conclusions that:range of measurement:0～1mm; The sensitivity:0～0.1mm,0.246V/0.1mm;0.1mm～0.4mm,0.062V/0.1mm;0.6mm～1mm,0.013V/0.1mm. Resolution:0.05mm.