Optimum impedance control of a collaborative robot using the bees algorithm

In this study, the optimum impedance controller of the Kuka LBR iiwa 14 R820 series collaborative robot with 7 degrees of freedom is designed. First, the D-H parameters of the robot arm are determined and with the help of these parameters, forward and inverse kinematics analysis and numerical calculations are made. After obtaining the mathematical model, the solid model of the system is transferred to the MATLAB program. Impedance and PID controller are designed in MATLAB/Simulink program. Finally, the controller designed using the Bees Algorithm is optimized. The operating performance of the optimized controller is examined in five different scenarios which are following the desired trajectory of the robot arm without external force, applying force in three axes to the robot standing still, applying external force to the robot arm in motion, robot encountering a straight obstacle while in motion, and robot encounters an inclined obstacle while in motion. The obtained results are presented with graphics. The effectiveness of the developed method is demonstrated by numerical applications. In this context, it has been observed that the optimized controller controlling the operation of the robot gives results with very low error values. In five different scenarios, the robot arm successfully has returned to the starting position for the situations where it is stationary and has been able to successfully complete the desired trajectories for the situations in motion, without oscillating with little overshoots and without any steady-state error.