Some issues of the human arm motion obtained from its kinematic model

Abstract

A possible direction in the development of future robot manipulators is in the so-called humanoid robot systems. The objective is to develop robots that behave, work, and communicate like humans. This will open a new era in robot applications, in particular in service robotics, will facilitate robot programming, and create a more effective human-robot interface. This paper presents some potential motion properties of a future humanoid robot manipulator retrieved from kinematical models of the human arm, such as the kinematic redundancy, the workspace properties, and the velocity-torque capabilities. Special attention is given to the utilisation of the kinematic singularities in handling heavy objects. Based on experiments, it is unequivocally demonstrated that the human arm takes advantage of the kinematic singularities in order to compensate weak actuation, while in the actual robotic practice the kinematic singularities are avoided.