|Disturbance Observer-based Trajectory Following Control of Robot Manipulators
Mohamadreza Homayounzade* and Amir Khademhosseini
International Journal of Control, Automation, and Systems, vol. 17, no. 1, pp.203-211, 2019
Abstract : "Robotic manipulators are usually subject to different types of disturbances. If the effects of such disturbances
are not taken into account, it can lead to unsatisfactory tracking performance of the robot and may even
destabilize the robot control system. In this paper a novel nonlinear disturbance observer-based controller is designed
for robotic manipulators. Previous disturbance observer-based controllers which are designed for robotic
systems undergo the restricting assumption that the external disturbance is constant. In this paper a novel two-stage
procedure is proposed to design a disturbance observer that improves disturbance attenuation ability of current disturbance
observer-based controllers. The proposed method can cope with non-constant disturbance. Furthermore,
it is shown that even for the fast time varying disturbance, the controller achieves satisfactory tracking performance.
The proposed controller guarantees semi-global asymptotic position and velocity tracking and moreover, removes
restrictions of previous studies on the number of degrees of freedom (DOFs), joint types, and manipulator configuration.
The effectiveness of the proposed method is verified against different types of external disturbance applied
on the robot manipulator and the results are compared with the results of previous methods. Furthermore, the results
support the theoretical conclusions."
Disturbance observer, robotic manipulators, stability analysis, time varying disturbance, trajectory following