Optimal Designand Analysis Of Eddy Current Angle Sensor And Secondary Instruments

Compared with other major angle sensors, the eddy current angle sensor has its unique advantage and application field. The eddy current sensor is not only cost-effective, but is also reliable, is especially applied with harsh working conditions. With the continuous improvement of the terminal device’s performance, accuracy and measurement range of the traditional eddy current angle sensor has no longer met the application requirements.Hardware optimization and software compensation are the two major ways to improve sensor’s performance. On the one hand, the technology of secondary instruments, based on non-linearity compensation strategy, has been widely applied in sensor field; on the other hand, the research on performance improvement of eddy current angle sensor, is still staying on the hardware optimization stage.This subject aims to optimizing design and analysis of the eddy current angle sensor which is based on the secondary instruments technology for non-linearity compensation. The first step is to analyze the structure and characteristic of the traditional sensor, and to choose the Digital Signal Controller dsPIC33 F, which does not only have standard logical judgment function but also is good at digital signal processing, as the main chip of the embedded system; then conduct the hardware system design and electrical circuit design surrounding with dsPIC33 F, and add Butterworth Filter and Shield Assembly to reduce noise interference; after that, make the study on the least-squares curve fitting of the non-linearity compensation method, and further study on the output characteristic curve of the traditional sensor, for developing calibration and working program on embedded system, which include the non-linearity compensation algorithm, signal sampling routine, and PC-communicated routine; at last, develop the calibration and testing hardware platform based on sensor performance goal, develop the calibration and testing application software based on LabVIEW platform, and make adjustment/calibration to the sub-assembly installation to assure the accuracy of the whole system.In the experiment, calibration and testing have been performed on the sample. Then the performance indicators(Linearity, Repeatability, Hysteresis, etc.) of the sensor are verified to confirm that the new design has better performance than the traditional eddy current angle sensor.