Robot joint position tracking with an approximator-free prescribed performance controller

This work addresses the problem of joint position tracking with prescribed performance guarantees and proposes a novel controller able to guarantee i) predefined minimum speed of convergence, maximum steady state error and overshoot concerning the position tracking error and ii) uniformly ultimate boundedness of the system state. Neither the robot dynamic model nor any approximation structures are utilized in the control law. Control gain lower bounds are dependent on some prior robot knowledge but gain tuning is simplified since the only concern is to adopt those values that lead to reasonable input torques. Simulation results of a 3 dof spatial robotic manipulator are given to confirm the theoretical findings.