Computation of equivalent size for tractor-trailer wheeled mobile robot

Equivalent size (ES) of tractor-trailer wheeled mobile robot (TTWMR) is used to enlarge obstacles in static workspace so as to plan path effectively for this kind of robot. We analysed motion characteristics of the trailers when the tractor moved along a circular path, and considered the deviation between the paths followed by the tractor and the trailers respectively. A new method for computing ES was proposed by means of the relation between the steady deviation and the transient one. Then how to use ES in path planning and mechanism constructing was discussed. Finally, a simulation example of our super-hero tractor-trailer robot was presented. The experiment results show the validity of our method.