An Inductive Angular Displacement Sensor Based on Planar Coil and Contrate Rotor

Abstract

This paper introduces a noncontact, low-cost, and reliable inductive sensor for angular displacement measurement. It is suitable to work in harsh industrial environments. The sensor has simple structure consisting of three key parts: 1) a ferromagnetic stator, which is a pure plane; 2) a ferromagnetic rotor, which has face slots; and 3) four layers of planar copper coils, including primary and secondary coils. Primary coils are supplied with two orthogonal 4000-Hz ac, and secondary coils output a signal whose phase is proportional to angular displacement. Primary coils are designed with sinusoidal shape, so that magnetic field between the stator and rotor has approximately sinusoidal distribution, and finally linearity between the phase variation of output signal and angular displacement is well helped by this design. The structure and working principles of the sensor are explained in detail. Moreover, a sensor model was simulated to verify the feasibility of the sensor working principles and a sensor prototype was designed for actual experiment. At last actual experiment results are given and analyzed, showing that the sensor prototype has achieved accuracy better than ±12 arcsec in the range of 0°-360°, and this kind of sensor may have a better performance by improving the layout of primary coils and front-end signal-process circuit.Index Terms-Non-contact inductive sensor, angular displacement, planar coils, contrate rotor, sinusoidal shape.

Micro-electromechanical system based optimized steering angle estimation mechanism for customized self-driving vehicles

“…In the literature, seminal contributions in Refs. 3,[12][13][14] have been made by researchers in developing the ADSs. An inductive angular sensing technology based on eddy current with full circle range is presented in Kumar and George.…”

“…In a research study, non-contact inductive based ADS has been proposed to compute the steering angle by measuring the displacement in the planar sinusoidal-shape coils between the stator and rotor of the sensor. 3 In another research work, the Fiber Optical Displacement (FOD) based theoretical model of ADS has been proposed which measures the angle by subtracting the two positive power signals from fibers attached to both sides of the emitting fiber phase. 4 However, these absolute ADSs are made up of complex electro-mechanical structure which influences the accuracy of the steering angle measurement through continuous backlash in the gear mechanism.…”

Optimal Design of Angular Displacement Sensor with Shared Magnetic Field Based on the Magnetic Equivalent Loop Method

“…Time grating angular displacement sensor as a kind of inductive angular displacement sensor, considers the advantages of resolvers and inductosyns [11,12]. It performs well under unfavorable conditions such as oil, water, dust, vibration, and temperature change, and is cheaper than most sensors with the same accuracy [13,14,15]. Angular displacement sensor with shared magnetic field is improved based on time grating angular displacement sensor.…”

A Missile-Borne Angular Velocity Sensor Based on Triaxial Electromagnetic Induction Coils

“…Scientific researchers mainly use gyroscopes to obtain the angular velocity information of projectiles nowadays [1,2,3,4,5,6,7,8,9,10,11,12]. For example, the angular velocity sensor based on a magnetically suspended control moment gyroscope (MSCMG) [13], the capacitive angular velocity sensor and the angular velocity sensor based on magnetohydrodynamics at low frequency [14,15], etc.…”