Analysis on parameters of grating eddy current displacement sensor

Abstract

The grating eddy current sensor is based on the principle of lateral eddy current. Its precision is greatly influenced by the coil and reflector parameters. It is important to analyze and optimize those parameters so as to improve the precision. Therefore, it is necessary to make further research on how the sensor nonlinear error is influenced by parameters, such as reflector size, shape and coil turns, so that the sensor can be tuned for more high precision occasions. Models of the coil and reflector of the grating eddy current sensor are established with finite elements method (Maxwell software) in this paper. Reflectors with different size and shape and coils with different turns are simulated and calculated. The analytical results demonstrate that the coil turns should be as many as possible and reflector with semicircular on both sides is better. Besides, the optimal reflector length (the length corresponding to the smallest nonlinear error) has a linear relationship with coil width and length. The research has provided a guide to set reasonable parameters of coil and reflector to improve the precision.