Electromagnetic Analysis and Validation of an Ironless Inductive Position Sensor

The ironless inductive position sensor is a linear position sensing structure, which exhibits intrinsic immunity to external magnetic fields since it is characterized by air-cored windings. This new solution may be of major interest for applications where external magnetic fields can be a source of interference. In this paper, an analytical model of the working principle of the sensor is proposed. The effect of the moving coil flux on the overall sensed magnetic flux is described. The model is preliminarily verified by simulations on a finite-element structure of the sensor, in order to assess its soundness. Finally, experimental measurements on a custom sensor's prototype give the definitive benchmarking of the model as a valid design tool, in the framework of the design and synthesis of the device.