High speed visual servoing of a 6 DOF manipulator using MIMO predictive control

This paper presents a novel approach to model and control high speed 6 DOF visual servo loops. The modelling and control strategy takes into account the dynamics of a velocity controlled 6 DOF manipulator as well as a simplified model of the camera and acquisition system in order to increase the bandwidth of the servo loop. multi-input multi-output (MIMO) generalized predictive control (GPC) is used to optimally control the visual loop with respect to the proposed dynamic model. The visual sensor used in the experiments is a high speed camera that allows to acquire 120 noninterlaced images per second. With this camera, we achieve a sampling frequency of 120 Hz for the visual loop. Experimental results on a 6 DOF industrial robot are presented that validate the proposed model. They show drastic improvement of the loop performance with respect to more classical control strategies like PID type control.