The Development Of The Digital Eddy Current Displacement Sensor

Eddy current displacement sensor is a non-power into electrical signals of a can ofnon-contact measurement device, Its high sensitivity, good stability, strong anti-interferenceability, the market demand. The stability of the eddy current displacement sensor and how toimprove the eddy current displacement sensor measuring range and reduce the size of theprobe coil that we need to solve critical issues at present, This has important practicalsignificance to improve the performance of eddy current displacement sensor.In order to solve the above-described problems, The following aspects of the research forthe application of the eddy current displacement sensor: One is the analysis of the effect ofcoil parameters on the eddy current sensor，from the coil to change shape, using the finiteelement simulation model of the electromagnetic field, through the simplified analysis of twodimen sional model, get eddy current coil electromagnetic field model, see theelectromagnetic field different displacement from the model the distribution of the magneticfield lines, analyze the solution and the results were compared with works, draw the modelingof the rationality；Two is on circuit design by using frequency modulation type measuringmethod based on frequency signal as a digital output hardware conversion circuit, singlechipmicrocomputer control peripheral circuit of the frequency signal can be directly receivedrecognition, circuit design is simple, can effectively overcome the parameters on the influenceof the frequency signal circuit transformation, improve the accuracy of measure-ment. Insoftware for data acquisition, data storage and data display module progr-am design, tocompile the simulation program, and introduced the nonlinear correction algorithm is tominimize measurement errors;Three is in order to reduce the nonlinear error of eddy currentdisplacement sensor, improve the linear measure-ment range of sensor, experimental datawere collected on a variety of curve fitting analysis, and introduce artificial neural network to map data, analysis of the optimal method of data processing, sensor’s sensitivity to reduce thenonlinearity, provide a basis to improve the sensor performance.The experimental results show that: The digital circuit can achieve a large displacementof the eddy current sensor data acquisition and better stability.Through the non-contactmeasurement circuit design can be better implementation of large displacement measurementrequirements，Not only save the cost,And improve the efficiency of the measurementsystem,For the perfection of the non-contact measuring system laid a certain foundation.