Research On Absolute Inductor Angular Displacement Sensor

Electromagnetic induction type angular displacement sensor is widely used in automation industry and military industry because of its strong anti-interference,simple structure,high reliability and the advantages of not high requirements for working environment.Traditional electromagnetic inductive displacement sensors,such as resolver,LVDT,induction synchronizer and inductive time grid displacement sensor,due to the use of traditional winding process leads to the "size" of large,with the development of angular displacement sensors to miniaturization,therefore,the traditional electromagnetic inductive angular displacement sensor is obviously insufficient.In order to enhance the adaptability of the sensor,reduce its weight and size,improve the application performance and expand the application range,therefore,this paper is based on the principle of electromagnetic induction and today's more mature PCB(Printed Circuit Board)technology to miniaturize the absolute angular displacement sensor system research.The main research work of this paper is as follows.1)Using the principle of electromagnetic induction,determine the mechanism of sensor implementation.The angular displacement sensor consists of a rotor coil of conductive material weakening the uniform alternating magnetic field generated by the excitation coil,so that its uniform alternating magnetic field generates an amplitude step,which causes the receiving coil to generate an induced electric potential to realize the sensing of the rotor position.The main sensing element of this angular displacement sensor consists of three parts: the excitation coil,the receiving coil and the rotor coil.2)Theoretical modeling and simulation analysis of the angular displacement sensor were carried out.The theoretical model was derived and established for the stator(excitation coil and receiver coil)and the rotor(rotor coil),and the coupling simulation analysis was carried out,and it was concluded that when the rotor was added to the uniform strong alternating magnetic field,an obvious step of magnetic field amplitude appeared,thus verifying the correctness of sensing between the stator and the rotor of this angular displacement sensor.3)The structural design and simulation analysis of the angular displacement sensor were carried out.In this paper,the stator and rotor are designed with double code channel(absolute)and single code channel,and the receiving coil and excitation coil are precisely constrained on a PCB stator substrate,and the model is simulated.4)The design of the angular displacement sensor angle measurement system and signal processing were carried out.According to the characteristics of the angular displacement sensor,the signal processing circuit based on the principle of amplitude discrimination is designed,and the debugging work such as detection,filtering and amplification is carried out.5)The performance test platform and experimental research of the prototype angular displacement transducer were built.The experimental platform of the angular displacement transducer has been built,and the accuracy experiment and error analysis of the prototype angular displacement transducer have been carried out.Experiments show that the absolute inductive angular displacement sensor with a PCB substrate of 70 mm outer diameter,40 mm inner diameter and 28 mm thickness(including the housing)has an original maximum error of 68? for the whole cycle and an original maximum error of 28? for the short cycle.