A model-free nonlinear output feedback controller for robot manipulators
Abstract：A continuous model-free controller with a linear observer based on the classical PID controller was proposed for trajectory tracking of robot manipulators with nonlinear uncertainties.The controller is composed of a PD and nonlinear integral controllers.The PD control term was used to stabilize the closed-loop system trajectories while the nonlinear integrator to improve the convergence.By considering the difficulty in getting the velocity data,the linear observer was proposed to estimate the actual joint velocity.It was proven that the tracking errors and observation errors tend to zero theorytically.The experimental results on the two rotating joints of SCARA robot manipulator show that the presented controller performed well and the average and maximum tracking errors with observer were reduced by more than 30%.The degree of control chattering is only 60% of that without observer under the same feedback gain.
Keywords：robot manipulatorstrajectory trackingmodel-free controllerlinear observer
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)