DSP Based Read Out System for Contactless High-Frequency Inductive Position Sensors

This paper presents a precise and low cost absolute position inductive measurement system for rough industrial environments. This transducer works on similar principles as contactless resolvers but consists of a rectangular antenna PCB, a passive LC resonance target and a signal processing unit. The read out electronics utilize undersampling to demodulate the transducer in–phase and quadra ture output signals. Furthermore, the corresponding position is estimated from a lookup table (LUT) to avoid singularities in the inverse tangent and cotangent calculation. The mechanical transducer arrangement, signal condition electronics design and measured results will be presented.