A nine-degree-of-freedom modular redundant robotic manipulator: Development and experimentation

Performing interactive tasks in complex obstacle environments is a formidable challenge for manipulators. Redundant manipulators have the advantage of being highly flexible and can be used to perform interactive tasks in complex environments. This paper presents a nine-degree-of-freedom (DOF) modular redundant manipulator with nine identical modular joints. To improve the obstacle avoidance capability in narrow environments, the bidirectional rapidly-exploring random trees (bi-RRT) algorithm and the oriented bounding box (OBB) are combined for trajectory planning of redundant robotic manipulators. To enhance the interaction capability in uncalibrated dynamic environments, an improved virtual semi-active damping control (VSADC) algorithm based on particle swarm optimization (PSO) is proposed, and it can effectively estimate impedance parameters and positions of the dynamic environment. Finally, combined with the proposed control schemes, simulation and experimental results demonstrate that the designed redundant manipulator can traverse complex obstacle environments and interact with the unknown dynamic environment.