Trajectory planning and control of a 7-DOF robotic manipulator

This paper presents a biological inverse kinematics (IK) method and a trajectory tracking approach for a 7-DOF robotic manipulator. The system structure of the manipulator is first designed and its forward kinematics is then derived using its Denavit-Hartenberg (DH) parameters. Based on the DH model, an inverse kinematics method using the combination of particle-swarm optimization (PSO) and real coded genetic algorithm (RGA) is proposed to find the seven joint angles of the manipulator while moving from one point to another, and then a smooth continuous trajectory is planned by connecting several via points. For trajectory tracking, a Jacobian inverse kinematic method along with a P controller and PI speed joint controllers is used to achieve trajectory tracking control with an acceptable accuracy. The effectiveness and merit of the proposed trajectory planning and tracking methods are well exemplified by conducting two simulations.