Visual servo control algorithm for soccer robots considering time-delay

Abstract

An efficient visual servo control algorithm which uses primary/secondary controller and the Smith predictor based an an accurate model of robot soccer system including time-delay is suggested for micro-robot soccer tournament (MIROSOT). In this paper, we analyze and design control system of soccer robot in the frame of visual servoing. We think that our approach encourages more systematic approaches to soccer robot system. MIROSOT system is a typical direct visual servo system with a fixed camera and mobile robots with internal sensors such as encoders. In real games, encoders often offer wrong position data due to slips and collisions between robots or between a robot and a walt However, vision provides positions and orientations of robots in certain accuracy regardless of slips or collisions. In spite of this advantage inevitable time-delay arising from vision and communication subsystems seriously causes undesired effects in control of robots. In this paper we present a visual servo controller considering the time-delay. First, we present an accurate dynamic model of organic cooperation of robot soccer systems [3] that includes the time-delay. And we design the Smith predictor [13] using the model to cancel out the deteriorating effect of time-delay in our soccer robot system And using the model, we also propose control structure with primary/secondary controller [12] to control the system precisely. Finally, we show performance of the proposed controller and the predictor in simulation studies.