Modeling of Impact Phenomena with Biped Locomotion Mechanisms – Theory and Experiments

 

Aleksandar Rodić

Khalid Addi

Georges Dalleau

 

This paper suggests a generalized approach to the mathematical modeling of biped locomotion systems (humans or humanoid robots) with a special attention paid to impact and contact dynamics. Modeling of impact dynamics with different locomotion mechanisms has a significant importance in robotics and military applications due to the necessity of mechanism adaptation to unknown and unstructured terrains. Instead of the usual inductive approach that starts from the analysis of different situations of real motion (walking, running, jumping, climbing the obstacles, taking up the loads, etc.) and tries to make a generalization, a deductive approach is pursued, whereby an entirely general problem is considered. Impact dynamics is modeled applying the Linear Complementarity Problem (LCP) formulation. General methodology is explained and demonstrated with humanoid robots via the synthesis of a spatial biped model. The validity of the modeling approach is proved by experimental measurements on a human subject in laboratory conditions. Plenty of graphic presentations illustrating experimental results as well as the results of the corresponding simulations tests are shown.

Key words: robotics, locomotion systems, system modeling, mathematical modeling, contact dynamics, contact load, impact load.