Non-singular terminal sliding mode control of an omnidirectional mobile manipulator based on extended state observer

Abstract

This paper presents a non-singular terminal sliding mode control (NTSMC) design based on an improved extended state observer (IESO) with application to an omnidirectional mobile manipulator (OMM) for trajectory tracking control. Firstly, a unified dynamic model is derived based on Lagrange method for an OMM prototype. An IESO that can reduce the initial peaking phenomenon is applied to estimate the model uncertainties and external disturbances. Then a non-singular terminal sliding mode controller is applied for trajectory tracking control. Stability of the closed-loop system is analyzed using Lyapunov theory. Finally, both simulations and experimental tests verify the effectiveness of the proposed control scheme.

Implementation of a robust data-driven control approach for an ommi-directional mobile manipulator based on koopman operator

“…A robust neural network-based sliding mode controller was designed by Xu et al 5 for trajectory tracking problem for a redundantly actuated OMM in the presence of uncertainties and disturbances. Li et al 6 presented a non-singular terminal sliding mode control method for an OMM based on extended state observer, wherein the nominal dynamic model is used. An experimental mobile manipulator assembled on an omnidirectional platform with a dualarm torso with a human-like structure was presented by Sua´rez et al 7 A controller based on constrained optimization was developed for tracking problems of mobile manipulation by Avanzini et al 8 However, for the research works mentioned above, the controller design completely or partially depends on the nominal dynamic model.…”