Dynamic Modeling and Simulation of 4-Wheel Skid-Steering Mobile Robot with Considering Tires Longitudinal and Lateral Slips

Skid-steered vehicles are regularly considered for outdoor activities due to their structural robustness and extraordinary maneuverability. Dynamic model of ground vehicles should predict a faithful motion in unknown environments and ability to design a proper controller. The purpose of this paper is to develop a nonlinear model for a 4-wheel skid-steering mobile robot considering dynamic model of tires with all slides. Unlike previous friction models which are considering only frictional forces without tire's slips, the proposed model consists of longitudinal and lateral tires' slips and will be used to predict a real robot's (P3-AT) motion in some specified situations such as moving straight on horizontal and ascent planes and moving on a curve on a horizontal plane. For validation purposes, obtained results will be compared to similar simulations on an Adams/View model. This comparison shows the accuracy of the model. Finally, advantage and disadvantage of the proposed model will be discussed.