Design Of Frameless Gimbal Motor For UAV Applications

Abstract

Recently, application areas of the Unmanned Aerial Vehicle (UAV) systems have started to expand very rapidly due to the fact that offering more effective, economical, reliable and safe solutions compared to manned air platforms, satellites and/or various ground platforms. However, desire to develop higher performance, resourceful, lighter, small and low powered payload make the gimbal platforms mandatory part of the UAVs in a short time and their role is getting increased day by day. In parallel with the increasing demand for precise stabilization, robustness, lightness and agility in gimbal systems, it has become an important trend to use more-electric (ME) customed systems instead of traditional market products. The electric motors that control the speed and position of the gimbal system are simply referred to as gimbal motors. Related design study focuses on designing direct-drive in-runner frameless gimbal motor with the following features; 8.5 VAC line voltages, 24-slot/28-pole combination, 60 rpm, 80 mN.m. Permanent magnet synchronous motor topology is determined to offer higher torque density, higher precision and fast response required for gimbal platforms. The selecting criteria of dimensions, performance parameters, materials, machine type with rotor structures and motor duty cycle are also explained. The gimbal motor is performed analytically in Ansys RMxprt with parametric assignments, statistically and sensitively tuned in Maxwell 2D and optimized in Maxwell 3D by finite element method (FEM) optimetric convergence approach with magnetostatic and transient solutions to get the final machine shape. This study is currently part of the gimbal system to be produced for medium sized surveillance UAV. Since the gimbal motor has been prototyped, all dimensions given are valid.