Study Of Artificial Hand Control Based On Tactile And Slip Feedback

To improve the living situation and welfare benefits of amputees, research has been made on humanoid the artificial hand, and the artificial hand is also an attentive research project in the fields of robotics and biomedical engineering. Considering the deficiency of the grip control and feeling feedback control in the EMG hand at present, it is necessary to develop some bionic and adaptability intelligent hands than conventional ones.This paper has studied the control system of the artificial hand based on tactile and slip feeling feedback. First the characteristic of EMG signals and the feeling process of the object hold are introduced in the paper, sequentially the proportional controlling project of the artificial hand which has tactile and slip feeling is given. And the paper designs the signal processing circuit of the thin-film PVDF sensor provided with tactile and slip, and pick up the signal characters served for specific feedback information of the control system.Next, the pulse width modulation timing control principle of the direct current electromotor has analyzed and the motor-driven electric circuit has designed. Based on 80C552 single chip microcomputer incorporated with the chip L298, we have used the high-powered peripherals of 80C552 to design control system, which could control the electromotor, sample the sensor and myoelectric signals. Finally the system software has designed in the paper and the capturing experiments of different objects are carried out in order to determine the suitable threshold values judging contact and glide. And the program structure of analogy to digital conversion and pulse wide modulation are also described at the end of the paper.The experiments about the control system demonstrate that this control scheme is feasible. Relying on superficial myoelectrical signals of the forearm and the tactile and slip signals produced by the PVDF sensor on the finger to form a closed-loop control, the myoelectrical hand has the grasp feeling and can snatch at some kinds of different soft hard objects. However, the system of myoelectrical controlled prosthetic hand with tactile and slip is a novel control mode, so it needs the continuous hard work of scholars and engineers.