The application of multi-body simulation approach in the kinematic analysis of beetle leg joints

Abstract

Locomotion of insects is exceptionally efficient and this efficiency is partially due to the kinematics within leg joints, which in different movement scenarios depends on their inner contacting conditions. The investigation of functionality of the leg joints can potentially provide new innovative problem solutions in robotics. The previously published information about the shape of the joints is not sufficient, because without knowledge about the movements of the articulating surfaces within the joint, the kinematics cannot be understood. To understand the joint movements, we have performed motion tracking experiments in the beetle Pachnoda marginata (Scarabaeidae, Cetoniinae) in different locomotory scenarios. We aimed at understanding the range of motion within single leg joints depending on their function in the entire leg movement scenario. For this purpose, we combined the motion analysis of living beetles with the results of the simulation of a multi-body system. The results of the multi-body simulation allowed the kinematic characterization of articulating joints by their degrees of freedom and the identification of the rotation axes. The simulated range of motion predicted by the limitations of the exoskeleton of the joints partially matched those obtained from the motion analysis of the living beetle. We showed that the range of motion of the single leg joints depends strongly on the type of the beetle locomotory scenario. It is also concluded that the simulation of multi-body systems is a powerful tool for the kinematic analysis of insect tribological systems.