KINEMATIC MODELING OF A MULTI-FINGERED HAND PROSTHESIS FOR MANIPULATION TASKS

Abstract

Several different models represent the human hand. These describe hand models with up to 26 degrees of freedom (DoFs) which are needed to obtain an efficient representation of manipulation tasks by prosthesis. However, a great number of degrees of freedom leads to a complex control system and necessitate simplification. Consequently simplified models involve errors when is needed reconstruct hand's postures in daily tasks. This paper analyses a model proposed by InMoov Open Source project whose robotic hand has five fingers, able to perform palmar arc, in a total of 17 DoFs. Here is described a complete kinematic model to this artificial hand, where the model equations are calculated by means Denavit-Hartenberg coordinates. The model is able to perform just flexion joints movements, where the thumb, index and middle fingers have 3 links and 3 flexion joints. The ring and little fingers have 4 links and 4 flexion joints that permit simulation in palmar arc condition. After this some computational simulations are realized to compare the real model and the mathematical model under some simple grasping tasks.