Experimental slip estimation for exact kinematics modeling and control of a Tracked Mobile Robot

Tracked mobile robots (TMRs) can be considered as the most important type of mobile robots. Large contact area of tracks with the ground provides superior advantages for TMRs such as better mobility in unstructured environments, though it may cause a higher risk of slippage. In this paper, an experimental slip model is proposed for exact kinematics modeling, and the parameters of this model will be determined based on experimental analysis of ResQuake. This is a tele-operative rescue mobile robot with great capabilities in climbing obstacles in destructed areas, and its performance was demonstrated in Rescue robot league of RoboCup 2005 in Osaka (Japan), achieving the 2^nd best design award, and RoboCup 2006 in Bremen (Germany) achieving the best operator interface award. Therefore, ResQuake is used here as an experimental platform to study the relationship between slippage of tracks and two main physically meaningful factors, i.e. radius of the tracking path and speed of the robot. The slip coefficients will be obtained as an exponential function of radius of curvature of the path. To validate the obtained results, the proposed model will be used along with two path tracking controllers, and it is empirically demonstrated that the developed model drastically improves the system performance in terms of lower path tracking errors.