title: An orientation measurement method based on Hall-effect sensors for permanent magnet spherical actuators with 3D magnet array.
abstract: An orientation measurement method based on Hall-effect sensors is proposed for permanent magnet (PM) spherical actuators with three-dimensional (3D) magnet array. As there is no contact between the measurement system and the rotor, this method could effectively avoid friction torque and additional inertial moment existing in conventional approaches. Curved surface fitting method based on exponential approximation is proposed to formulate the magnetic field distribution in 3D space. The comparison with conventional modeling method shows that it helps to improve the model accuracy. The Hall-effect sensors are distributed around the rotor with PM poles to detect the flux density at different points, and thus the rotor orientation can be computed from the measured results and analytical models. Experiments have been conducted on the developed research prototype of the spherical actuator to validate the accuracy of the analytical equations relating the rotor orientation and the value of magnetic flux density. The experimental results show that the proposed method can measure the rotor orientation precisely, and the measurement accuracy could be improved by the novel 3D magnet array. The study result could be used for real-time motion control of PM spherical actuators.
authors.affiliation: 1] School of Automation Science and Electrical Engineering, Beihang University, Beijing, 100191 China [2] Research Institute of Beihang University in Shenzhen, Shenzhen, 518000 China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yan
authors.affiliation: Research Institute of Beihang University in Shenzhen, Shenzhen, 518000 China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Research Institute of Beihang University in Shenzhen, Shenzhen, 518000 China.
authors.forename: Zongxia
authors.initials: Z
authors.lastname: Jiao
authors.affiliation: Institute of Advanced Manufacturing Technology, Ningbo Institute of Material Technology and Engineering, Ningbo, 315201 China.
authors.forename: Chin-Yin
authors.initials: CY
authors.lastname: Chen
authors.affiliation: School of Mechanical and Aerospace Engineering, Nanyang Technological University, 639798 Singapore.
authors.forename: I-Ming
authors.initials: IM
authors.lastname: Chen