A Fast and Efficient Simulation Method for Inductive Position Sensors Design

Inductive position sensors (IPSs) are contactless sensors used for detecting the absolute position of an item in case of angular or linear motion. The active sensing part is manufactured by positioning copper traces on a printed circuit board (PCB) in order to obtain a system of transmitting and receiving coils. A designing procedure based on trial-and-error method is not considerable because of the low time and costs efficiency of the process. Therefore, the here presented coil design process aims at efficiently evaluating the performance of each sensor before its industrial production and application. The simulation is based on the sequential solution of different eddy current problems in the frequency domain by using a fast and efficient surface integral formulation in place of the much more widely diffused commercial finite element (FE) codes. Due to this innovative practice, simulation time can be reduced to some tens of seconds thus allowing the evaluation of many design and the final performance of the sensor can be deeply enhanced, reducing the maximum linearity error from more than 2% up to 0.2% FS.