Dynamics modeling and tip-over stability of suspended wheeled mobile robots with multiple arms

Field Robots are machines that work in unstructured environments. Handling the mobility performance requirements of a challenging rough terrain makes a suspended wheeled mobile robot (SWMR), with multiple dexterous manipulators, an appropriate field robot design. In this study, first a general systematic procedure for dynamics modeling of such complicated systems is presented based on application of Newton-Euler's formulation for a chain of rigid bodies. Then, to verify the obtained dynamics model, another model for the considered system has been developed using ADAMS simulation software. Comparison between the results obtained from these two models confirms the thoroughness of the proposed analytical model. The presented approach can provide the interaction wrench(es) between the mobile base and the mounted arm(s). Next, using the obtained dynamics, the tip-over stability of such systems will be investigated. To this end, the new dynamic tip-over Moment- Height Stability (MHS) measure will be extended for suspended wheeled mobile robotic systems. Proposing the concept of virtual structure, the obtained planar model of SWMR has been employed to evaluate the behavior of the system on rough terrain in terms of its stability. Therefore the presented model and the MHS measure can be employed for stable planning and model-based control of autonomous SWMR during object manipulation tasks.