A Novel Decentralized Adaptive Control Strategy for an Open-Chain Robotic Manipulator

摘要

Virtual decomposition control (VDC) is a powerful approach to control/regulate the motion of high degrees-of-freedom (DOF) robots. It is a control strategy based on Newton-Euler (N‑E) formulation with recursive implementations. As a result, this work is focused on designing a fully decentralized control structure for an open-chain robotic mechanism. The dynamics of the target robot is formulated based on N-E formulation, while the robotic system is controlled using the function approximation technique (FAT)-based adaptive control. The key idea is to control each robot link subsystem individually such that the coupling interaction term is estimated using the FAT. The stability of each link subsystem and the whole system is proved using the Lyapunov theory. In this work, we assume that the target robot is equipped with direct-drive motors such that the joint dynamics is integrated with the link subsystem. To this end, a six-link biped robot is simulated using MATLAB/SIMULINK package with the proposed controller. In effect, to stabilize the locomotion of a biped mechanism a multi-level control strategy is required. However, the current controller is considered a low-level control for tracking the desired joint references. The results prove the precise tracking for the proposed control architecture.