A New 2D Displacement Measurement Method Based on an Eddy Current Sensor and Absolute Encoding

Abstract

A new method of two-dimensional (2D) plane displacement measurement based on an eddy current sensor is proposed in this paper. A series of grooves with different widths and depths are graved on the linear displacement table to form 2D absolute coding using the idea of pseudorandom coding. The eddy current sensor array is arranged above the groove to identify the coding. An artificial neural network is used to establish a measurement model which is the mapping relationship between the output of the eddy current sensor array and the 2D displacement of the workbench. A feasibility experiment showed that in the range of 20 × 20 mm, the root mean square error of measurement in the X- and Y-directions are 83 and 73 μm, respectively. The new method integrates eddy current sensor and artificial neural network modeling to realize 2D displacement measurement, which provides a new solution for displacement and angle measurement.

A Novel Combined Method for Measuring the Three-Dimensional Rotational Angle of a Spherical Joint

“…In addition, by simulating and analyzing the grooves with different parameters on a metal block, the parameter settings of the grooves on the surface of the spherical head were determined. Based on the research results for the output characteristics of the eddy current sensors, it is known that the inductance of the sensor will undergo significant changes when scanning grooves with different parameters, especially when the sensor is located at the center of the groove, where the difference value is the maximum [ 24 ]. For grooves with the same width, the larger the groove depth, the greater the change in inductance; for grooves with the same depth, the larger the groove width, the greater the change in inductance.…”

Single-Ended Eddy Current Micro-Displacement Sensor with High Precision Based on Temperature Compensation

“…However, capacitive sensors are susceptible to influence from media, the environment, and contaminants, thus limiting their application in sealed enclosures or environments with strict control measures. Eddy current sensors, based on the electromagnetic induction principle, convert displacement [ 9 ], amplitude, thickness, size, cracks, and other information of the measured target into measurements of Q value, the equivalent impedance Z, and the equivalent inductance L of the sensor coil [ 10 ]. They have advantages such as a simple structure, low price, high sensitivity, wide frequency band, resistance to influence from oily media, and strong anti-interference ability.…”