In the past, several robot position control methods formulated in Cartesian coordinates were proposed. However, none of them can maintain fast and accurate motion control in the face of modeling errors and external disturbance. In this paper, we propose a nonlinear robust control scheme for robot motion control in Cartesian coordinates. The control input of this scheme consists of nonlinear and linear parts. The nonlinear part decouples and stabilizes robot dynamics in Cartesian coordinates. The linear part utilizes the robust servomechanism theory to suppress effects of modeling errors or unknown external disturbance. This scheme is used in the control of a two-joint SCARA-type robot, and simulation results demonstrate that it can achieve fast and yet precise tracking control in Cartesian coordinates even in the presence of severe modeling errors.
ASJC Scopus subject areas
- Control and Systems Engineering
- Electrical and Electronic Engineering