Design of Photoelectric Inclination Sensor and Its Application in Target Tracking

Abstract

As a sensor that converts angle signal into an electrical signal, the inclination sensor is applied in multiple fields. The photoelectric inclination sensor has the advantages of non-contact and high precision, but it is limited to small angle precision measurement and is expensive. A new photoelectric inclination sensor is obtained by combining photoelectric detection with elastic sensing elements and eliminating vibration or other interference errors based on an electromagnetic feedback system. The structure of the whole prototype is designed, the elastomer is calculated theoretically, the electromagnetic feedback part is designed and selected, the voltage-displacement characteristic test of the photodiode is carried out, and the linear interval is calibrated simultaneously. According to the voltage difference generated by the photodiode, a differential amplification circuit is designed to amplify the small voltage signal. The PID regulating circuit is designed to regulate the current on the electromagnetic coil. The A/D chip is used for analog-to-digital conversion, and the data are collected and uploaded through STM32 and RS485. In the test, the prototype test environment is built. It is proved that 0°∼45° is a linear range of the sensor in the open-loop system without electromagnetic feedback. The nonlinearity is 4.365%, the nonlinearity in the −20°~20° interval is less than 1.2%, and the 45°˜90° is the nonlinear range. In the closed-loop system of electromagnetic feedback, the interval of 0°˜90° is linear, the nonlinearity is 6.861%, and the nonlinearity of 0°˜45° is only 1.06%. This type of sensor is used for multi-station maneuvering target tracking. The aircraft to be tested is simulated and analyzed 100 times. It is found that adding a sensor monitoring station can improve the measurement accuracy and suppress the noise. In the closed-loop system of electromagnetic feedback, 0°˜90° is the linear range, the nonlinearity is 6.861%, and the nonlinearity of 0°˜45° is only 1.06%. Such sensor is used for multi-station maneuvering target tracking, and the aircraft to be tested is simulated and analyzed 100 times. Azimuth, pitch angle and errors from target to the sensor are calculated. The results show that the measurement accuracy can be improved and the noise can be suppressed by adding sensor monitoring stations.