Abstract:
Medical robots, with manipulator arms having multiple degrees of freedom, play a crucial
role in surgery for complex surgical tasks performed by instruments mounted to it. This
thesis proposes and implements a tracking control of three-degree-of-freedom medical
assistant robot manipulator. However, controlling the robot manipulator is difficult due
to the nonlinear, coupled and complex natures of the robots manipulator dynamics. The
research work focused on developing an intelligent control system, Artificial Neural
Network (ANN) controller, that provides smooth motion tracking for it. The proposed
ANN controller is implemented and tested using MATLAB/Simulink. The performance of
controller is evaluated using the Root Mean Square Error (RMSE) and Integral Time
Absolute Error (ITAE) metrics. We compare the performance of the ANN controller
with manually tuned PID and genetic algorithm tuned PID (GAPID) controller. The
robustness of the controller is tested by introducing external time-varying and constant
torque disturbance. Simulation results show that the proposed controller effectively
tracks reference trajectories with minimal error as compared with PID and GAPID.
Moreover, the ANN controller result shows promising performance in the presence of
external disturbances. Hence, replacing the GA-PID controller by ANN controller
enhances the disturbance rejection ability of the GA-PID controller.
Keywords: Artificial neural network, Genetic algorithm tuned PID (GA-PID) controller,
Minimal invasive surgery, 3-DOF medical assistant robot, Trajectory tracking.