Towards Online Impact Force Dynamic Parameters Identification for Hydraulic Legged Robots

The design and control of legged robots capable of performing dynamic tasks, such as those involving impact in a stable manner, is of growing concern within the robotics community. Under these conditions, ground reaction force rate increase dramatically and, if the control system fails to response appropriately, the internal vibrations will damage the robotic structure. To deal with these problems, design integration between control, mechanics and electronics is required. As a means to co-develop these tasks, we present an alternative method, based on the Virtual Prototyping (VP) and cosimulation concept, to model impact phenomena for design purposes. This model has been built starting from the identification of all the parameters that affect object dynamics within the mechanical structure. Two campaigns of experimental tests have been carried out: the first one for the parameters identification, while the second one for the model validation process. The agreement between numerical results and experiments is very satisfactory, demonstrating the possibility of using the model for future mechanical and control co-development.