Multibody model of the human-inspired robot CHARMIE

Abstract

The rapid ageing of the worldwide population raises pressing concerns related to ensuring proper healthcare and quality of life for older adults. A human-like mobile domestic robot, named CHARMIE, is being produced to aid in these situations by performing household chores, thus increasing the autonomy of persons with mobility limitations. The present work provides a valuable contribution to the development of CHARMIE by building a simulation environment that computes the system’s main dynamics. The obtained environment is used to evaluate the quality of the robot’s control system, to perform its structural optimization and to allow a proper selection of actuators. The system is tackled as a kinematic tree that starts on the robot’s base and then splits into three branches at the torso: the left arm, the right arm, and the head. The multibody model solves the forward kinematics and inverse dynamics of the main mechanisms by employing two recursive algorithms centred around the Newton–Euler formulation. A novel, modular, and efficient seven-step methodology was created to implement these two algorithms and program a simulator from start to finish. These seven steps include studying the system’s configuration, converting its properties into software inputs, and computing the phenomena that cannot be automatically addressed by the two recursive formulations. The presented methodology was fully validated by comparing its results to those obtained from a commercial software; the two models produced identical results.