Modeling of PWS mobile manipulator including slipping of carrying objects

Force and torque induced by motions of a mobile manipulator affect dynamically the objects being carried. If the induced inertia force and torque are bigger than the static friction force and torque, the carrying objects start slipping on the mobile manipulator. As the result, the movement of one carrying object may cause the collapse of all carrying objects, since the start of slipping makes the acceleration of the mobile robot increase, interferes with accurate traveling operations and is dangerous. The final purpose of this research is to propose a navigation controller for the mobile manipulator that prevents the carrying objects from slipping. As a first step, we propose a model of an n-link Power Wheeled Steering (PWS) mobile manipulator including the slipping motion of many carrying objects. Using the proposed model, the dynamical influences of slipping are analyzed and the model is justified through several simulations.