A New Design of Spherical Electro-Magnetic Brake System

Abstract

Magnetic brakes are the popular means to provide efficient damping to the motion of manipulators to avoid any damages. Commercially available magnetic brakes are either single degree of freedom electro-magnetic brakes or spherical brakes being operated by permanent magnet. Fully controlled braking in multi-DOF has only been explored using MR fluid but the risk of fluid leakage limits its application in human sensitive operations. This paper proposes a new design of a spherical electro-magnetic brake (SEMB) system that utilizes the solid friction surfaces to provide controlled braking torque in 3 DOF. The mathematical model of the SEMB has been derived. The design of SEMB is then optimized for maximizing the magnetic forces. The experimental results are compared with FEM simulation results and analytical model.