An Eddy Current Displacement Sensor Based on Piecewise Linearization of Inverse Function

Eddy current displacement sensor (ECDS) is a common shaft displacement measuring device for various motors. Its output characteristic is partly linear, while the whole is non-linear. This characteristic limits its linear ranges of the sensor. This paper proposes a piecewise linearization method based on the inverse function of its output characteristic, which is used to improve linearity and expand linear range. This method constructs a piecewise linearization circuit based on the inverse function of the output characteristic, and then connects this circuit in series after the ECDS to realize the linearization of its output characteristic. Finally, the feasibility of this method is verified by experiments.