This research focuses on development a speed control system of a rotary load shaft with different loading torque by using a clutch featuring magneto-rheological fluid (MRC). Firstly, a new configuration of a speed control system using MRC is proposed. Modeling of the MRC based speed control system is then derived based on Bingham plastic model of magneto-rheological fluid (MRF). Based on the derived model, an optimal design problem for the system is built and the optimal solution is obtained based on finite element analysis. Performance characteristics of the MRC based speed control system are then experimentally investigated. After that, the MRC based speed control system to control a varying rotary load shaft driven by an AC motor is proposed and a PID controller to control the speed is designed and implemented. Experiments on steady speed control of the rotary load shaft is then obtained and presented with remark discussions.
This research focuses on development of 3-DOF haptic master manipulator featuring Magneto-rheological brakes (MRBs) and a mechanism of spherical manipulator. The haptic manipulator is composed of a spherical manipulating mechanism integrated with 3 MR brakes. The first MRB is a rotary disc-type MRB employed at the waist joint to feedback the tangent force in the horizontal plane, the second MRB is also a rotary disc-type MRB employed at the shoulder joint to feedback the tangent force in the elevation plane, and the third MRB is a linear MRB employed at the prismatic joint to feedback the normal force (approach force). Position of the manipulator’s end-effector is measured by two rotary encoders and an LVDT. After the introduction, a configuration and working principle of the 3-DOF haptic spherical manipulator are presented. Mathematical models of the manipulator are then derived. The MRBs are then optimally designed to provide a required force feedback to the operator. A prototype haptic manipulator is then manufactured and its performance characteristics are then experimentally investigated.