The Research Of Human-Computer Interactive Technology Based On Electromyography

The human-computer interactive technology based on bioelectricity is currently the frontier of the teleoperation systems and human-computer interaction. This thesis is under the supply of"973"Key Research Program and fund for the return scholars from abroad provided by Ministry of Education. The content of the thesis include the mechanisms of myoelectric signal's emergence and transmission, how to record myoelectric signal, how to extract the features, how to classify upper limbs action base on myoelectric signal and how to apply the technology in the field of teleoperation robots.At the beginning, the tendency of the human-computer interactive technology based on bioelectricity is epitomed.Then the thesis summarizes the mechanisms of myoelectric signal's emergence and transmission. And points out the innervation zones are centralize in the bellies of muscle, so the electrode system should be put on one side of the bellies of muscle to in order decrease the non-stationary of the signal.The experimental system of electromyography (EMG) is constructed in chapter 3. The system includes portable amplifier of EMG and virtual instrument software DAS.A method is given to recognize the human-being upper limbs action's start moment by EMG. Using the method to recognize the start moment of given movement increases the efficiency of man-computer interface greatly. Because it saves the time of action potential transfer in the muscle fiber and the time of chemical reaction between Ca2+ and ATP in the muscle cell.An actions pattern recognition method based on accurate synchronization of start time is expatiated in the thesis. The importance for actions recognition of the exact start time of sampling is proved then. The time-domain statistical and time-frequency wavelet features of the 256ms EMG signal after start time is extracted. The first 20 primary components of the features are put to the recognition backpropagation network. And variable learning rate BP method is used as the train's method. The experiments indicate that the correct ratio could be 95% by using this method to recognize 8 type of actions.The strongpoint and shortcoming of using the EMG actions recognition method on the field of teleoperation robot are also analyzed. And a control strategy of robot hand is put forword.At last, the future's research direction in this field is pointed.