Measurement errors in visual servoing

In recent years, a number of hybrid visual servoing control algorithms have been proposed and evaluated. For some time now, it has been clear that classical control approaches-image and position based-have some inherent problems. Hybrid approaches try to combine them to overcome these problems. However, most of the proposed approaches concentrate on the design of the control law, neglecting the issue of errors resulting from the sensory system. This paper addresses the issue of measurement errors in visual servoing. The particular contribution is the analysis of the propagation of image error through pose estimation and visual servoing control law. We have chosen to investigate the properties of the vision system and their effect to the performance of the control system. Two approaches are evaluated: i) position, and ii) 2 1/2 D visual servoing. We believe that our evaluation offers a tool to build and analyze hybrid control systems based on, for example, switching or partitioning.