Design and control of a multisensory five-finger prosthetic hand

A five-fingered, multi-sensory and biomimetic prosthetic hand is presented in this paper. The HIT-Hand is a multisensory and integrated five fingered hand with in total 11 DOFs. The hand has five fingers and each of them can be driven individually by the embedded actuation and control system fitted in the palm. Each finger has 2 DOFs and two joints, the two joints are mechanically coupled by a cable driving. The thumb has an additional DOF to realize the motion relative to the palm. All actuators are integrated in the finger´s base or the finger´s body directly, the electronics and communication controllers are fully integrated in the fingertip in order to realize modularity of the hand and minimize weight and amount of cables needed for a hand. The Prosthetic Hand is controlled by a multiprocessor controller based on FPGA/DSP, the control system is composed of finger control system and palm control system, and each finger control system is integrated in the fingertip. This anthropomorphic prosthetic hand controlled by means of myoelectric commands, and the hierarchical shared control strategies is used. The impedance control approach allows the fingers to behave as virtual springs. Experiments showed that users were able to successfully operate the device in the hierarchical control strategies, and that the grasp success increased with more interactive control.