Observer-Based Robust Adaptive Control for the Synchronization of Uncertain Multiple Robot Manipulators

Robotics research in today's era is mainly focused on multi-robot manipulator systems, since a single robot manipulator is no longer the best solution for several applications such as robotic exploration in hazardous environments, automated production plants and space. Trajectory planning of the robotic manipulators is significant in these applications. The performance of the manipulator in this endeavor is influenced by parametric uncertainties, non-parametric uncertainties, unmodeled dynamics and external disturbances. These influences in addition to the operational errors, will result in the reduced life span of the manipulators. This paper proposes a robust adaptive control strategy with a time-varying high-gain observer to synchronize multiple robot manipulators. The objective is to minimize undesirable disturbances and make the system follow a chosen reference model dynamics or trajectory. The Lyapunov method is used to derive the tuning parameters and the stability of the proposed scheme. Simulation results carried out on three identical two-degree-of-freedom robot manipulators show that the proposed robust adaptive synchronization control scheme achieves boundedness for all the closed-loop signals and ensures convergence of both the tracking and synchronization errors.