KINEMATIC TRAJECTORIES RECONSTRUCTION BASED ON MOTORS ENCODERS FEEDBACK FOR A ROVER SKID-STEERING ROBOT

摘要

In this paper some procedures for accurately defining the kinematic trajectories described by skid-steering robots by using only the kinematic data of the wheels (or tracks) are presented and discussed. These procedures have been analysed with several experimental tests carried out moving a rover skid-steering robot on different surfaces. The particularity of the skid steering mobile robots is the presence of the high slippage effects that heavily influence the correct kinematic reconstruction by using the classical kinematic equation. For this reason, the possibility of using particular strategies based on the instantaneous centre radiuses is here considered; these strategies use parameters such as the equivalent ‘carriageway’, the slipping coefficients and the slipping ratio for including the effect of vehicle dynamics. Moreover, the effect of different surfaces is evident on the parameters that characterize the considered strategies for kinematic reconstruction; anyway, the high repeatability of the experiments carried out on the same conditions and a certain trend of the slipping ratio that seems to characterise the different types of surfaces, allow foreseeing positive developments of the considered strategies. The experiments have been carried out on a particular skid-steering robot (rover 4WD1); the generalization of the results for other types of skid-steering robot may be easily foreshadowed. The original value of the paper is related to the systematic experimental validation of the procedures indicated and to the comments that may be very useful in defining the limits of the procedure for the kinematic reconstruction with high slipping effects.