Design and Optimization of an Eddy Current Speed Sensor for Rotating Rods

Abstract

This paper presents the design and optimization of a novel eddy current speed sensor for rotating rods and cylindrical shafts. The sensor consists of one excitation coil and two pick-up coils. All coils are stationary; we consider air coils, and we also use a magnetic yoke. We utilize a copper coating on an iron rod to increase the sensitivity, and we compare the performance with the pe rformance achieved for an uncoated iron rod. 3D FEM is utilized for analyzing and for optimizing the design of the proposed sensor. The main advantages of the novel sensors are the ir simplicity, their low cost and their robust configuration. A linearity error of 0.5% has been achieved. The level of accuracy is limited by mechanical factors. A 1D analytical model has also been de veloped for rapid analysis and optimization of the sensor. An aluminum rod was also used in the measurements for a comparison with the results achieved with the iron rod.

Novel Structure of a Solid Rotary Inverter Sensor for Speed Measurement of Vehicles

“…In contrast to variable reluctance and optical speed sensors, as well as tachometers and resolvers, the suggested eddy current speed sensor operates without the need for any supplementary components or gears to be affixed to the rotating shaft. An eddy current speed sensor composed of a single excitation coil and two pick-up coils for rotating rods and cylindrical shafts is also presented in [14] A novel non-contact approach to measure rotational speed using electrostatic sensors is proposed in [15]. The percentage error was high at lower RPMs.…”