Modelling, Linearity Analysis and Optimization of an Inductive Angular Displacement Sensor Based on Magnetic Focusing in Ships

A sensor for measuring the crankshaft angle of main engine in ships is designed. Compared with existing encoder, this design’s advantage that there no need to add a gear system at free end crankshaft, reducing machining complexity. The purpose providing high resolution over wide speed range achieved. Inductive angular displacement sensors (IADSs) require an eddy current magnetic field as medium generate induced voltage. voltage also requires complex linearization calculation obtain linear relationship between and Therefore, model inductive based on focusing (IADSMF) proposed. Magnetic introduced into IADS replace field. disadvantage traditional IADSs, which they cannot reduce field, mitigated. An approximate square−shaped (12.4 × 12.4 mm2) formed using constraint conductor. When receiving coil undergoes position change relative generated via measured electromagnetic induction principle achieve measurement. mathematical IADSMF derived. Induced voltages different frequencies rotational speeds are simulated analyzed MATLAB. results show frequency factor affecting amplitude. sensitivity 0.2023 mV/°. measurement from 0.06° 0–360°. conventional planar coil−based IADS, loss reduced 2.1304 0.3625 W. Direct achieved through designing coil. After optimizing structure optimization algorithm, linearity error 0.6012%. Finally, provides theoretical basis research ideas development navigation.