Effects of magnetic field distribution on position/orientation sensor design

This paper presents a new method for developing position/orientation sensors by measuring magnetic fields generated by a permanent magnet in three dimensional space. Existing position/orientation sensors commercially available in the market, though capable of providing linear or angular high-resolution measurements, mainly rely on mechanical connectors and linkages that introduce frictions, backlashes, and motion singularities. The system becomes bulky and complicated. In addition, multi-degree of freedom (DOF) motion should be deduced from the individual orthogonal measurements. To overcome such difficulties, the method presented in the paper aims to develop an efficient method for designing a magnetic field-based orientation sensor system for devices. The method utilizes Distributed Multipole (DMP) model to accurately characterize magnetic fields of a magnet. The field is furthermore approximated in a compact form to efficiently configure system parameters and maximize sensor capacities and performance of measurement. The simulation results show the effectiveness of the method along with its ability to characterize the magnetic fields and compute position/orientation, which can offer a number of advantages in real-time measurement and control systems.