Dynamic Stability of Mobile Manipulators Considering Suspension Characteristics

In this paper, the previously developed model for dynamic stability of mobile manipulators, by the authors [1], is extended. The extended model not only takes into account the dynamics of the base that can potentially rock back-and-forth but also, includes the flexibility of the contact between the base and the ground. The novel method of virtual links is used to facilitate the dynamic modelling of the mobile manipulator. The application of the study is directed at industrial machines that carry human-operated hydraulic manipulators. The model is therefore used to simulate planar movements of a Caterpillar 215B excavator-based log-loader. It is shown that the flexibility of the contact between the base and the ground reduces the manipulator’s stability. Assuming rigid contact between the base and the ground overestimates the stability of mobile manipulators. Therefore, the flexibility between the base and the ground should be considered in the dynamic model to accurately investigate the stability of the mobile manipulators.