Affiliations: [a] State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China | [b] Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipment and Control, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
Correspondence:
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Corresponding author: Jinchun Hu, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China and Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China. Tel.: +86 10 62797853; Fax: +86 10 62797543; E-mail: hujinchun@tsinghua.edu.cn
Abstract: Employing the attached magnetic fields of permanent magnet synchronous planar motors for position sensing has been widely investigated, as it is low-cost and requires no complex setup compared to optical ways. An optimized position sensing method requiring only simple calculations to achieve precision planar 3-degree-of-freedom (DOF) position is proposed in this paper. By adding sensors and new decoupling operation, this optimized method complements the unmeasured position areas in the previous work, guaranteeing the ability to measure position in whole motion region. Simulation results verify the 3-DOF position sensing ability for global motion region and show that translational accuracy is 10 μm-order and rotational accuracy is 0.1°-order under a conventional noise level. To demonstrate the feasibility, experiments have been conducted on a self-developed platform. Compared to commercial position devices, the results illustrate that the optimized method is able to measure planar 3-DOF position while its accuracy is limited by the imperfections of the magnetic field. X mean and standard deviation of −16.2 μm and 18.7 μm, and Y error mean and standard deviation of −11.3 μm and 16.4 μm are achieved in small-range comparison measurements.
Keywords: Multi-DOF position measurement, sensor systems and applications, linear-Hall sensors, permanent magnet synchronous planar motors
