Research On Array Electrotactile Feedback System And Strategy For Bionic Prosthetic Hand

Bionic prosthetic hands have made great progress in mechanical structure and control methods.But how to perceive the objects and acquire the sense of proprioception as a human hand is an important factor that affects the acceptance of prosthetic hands.In this paper,based on electrical stimulation feedback,an array tactile feedback system is established as well as the corresponding feedback strategy is proposed.Besides,using HIT-V prosthetic hand,this paper conducts an interactive control experiment.Overviews about newly developed bidirectional interfaces and interactive control methods of anthropomorphic prosthetic hands are given in details.Firstly,the methods and research status of tactile feedback at home and abroad are analysed in details.Then the fundamental means and technical route are established that a system based on array electrical stimulation feedback is built and related researches are carried out on this basis.In order to reduce electrical stimulation noise and enhance electrical stimulation effect during electrical stimulation,based on the electric field model and neural excitation model of human tissue during electrical stimulation,this paper proposes an optimal design method for electrical stimulation electrode.In addition,the theoretical model is supplemented and verified by finite element simulation and preliminary experiments on the safety of electrodes are carried out.In order to ensure quick response of human body to understand the electrotactile feedback information,an electrical stimulator with independent multichannel skin-electrode impedance measurement function is designed in this paper based on voltage source stimulation.The system has the following functions: 16-channels' electrical stimulation waveform modulation,real-time impedance measurement,stimulating voltage dynamic regulation.As a result,it ensures the safety and the consistency of sense perceptions during electrical stimulation processes.In order to propose appropriate feedback strategies for electrical stimulation,this paper proposes a mixed tactile feedback strategy based on array space-time coding by comparing the discriminative accuracy of different strategies during the experiments of cognitive psychology.Besides,this paper proves the feasibility of tactile feedback system and its strategy by carried out verification experiment,the force tracking experiment.In order to verify the reliability of tactile feedback system in interactive control actually,the feedback system is integrated with the HIT-V prosthetic hand system and the experiment of grasping object is carried out.Experiment result shows that equipped with the designed tactile feedback system and its strategy,the prosthetic hand can have the abillity to control the grasping force effectively according to human consciousness.It have practical significance that it ensures the rapidity and stability during the grasping process.