Hardware-in-the-Loop Optimization of an Interaction Controller for Improved Coupled Dynamics

This paper presents the implementation of an optimization method to find, without knowledge of the environment characteristics, the best interaction controller parameters to revamp the coupled dynamics. The objective is to improve various industrial robot applications that involves mechanical contact. An enhanced contact is accomplished by lowering the following metrics: rise time, total variation and steady state error. Hence, the impedance controller was the interaction control technique chosen to be optimized. Contact is established between a Kuka KR16 robot TCP and an aluminum platform, where the force data was acquired by a 6-axis force-torque sensor located in the robot's end-effector. Using a hardware-in-the-loop optimization approach, the force feedback is processed by a NSGA-II algorithm. Each individual of the GA represents a specific impedance controller and as the generations passes, these values get more suitable for lowering the metrics. Results show convergence in 5 generations.