Research On SSVEP-based Pure 3D Space Manipulator Shared Control System

The brain-controlled robot systems have received enormous attention from researchers due to its ability of helping patients to complete daily activities.There is a growing trend towards research in this field about how to fully combine the advantages of Brain-Computer Interface(BCI)system and traditional robot control system to construct a brain-controlled robot system with high environmental adaptability and ease of use.This leads to the generating of the shared control brain-controlled robotic system,which fully integrated the intelligence of people and machines.At present,the BCI system based on Steady-State Visual Evoked Potential(SSVEP)is able to achieve relatively high information transmission rate and accuracy,and the augment reality(AR)technology can make the interaction process more natural.However,current research protocols still have limitations the stimuli are presented in two-dimensional space.To make the interaction process more natural,immersive and realistic,it is necessary to update the presenting method of stimuli,and explore the three-dimensional AR visual stimuli technology.In this paper,the implementation method of pure three-dimensional space manipulator shared control system based on SSVEP was explored,and the feasibility of the proposed method was verified by design experiments.First,this paper built a pure three-dimensional space manipulator shared control system based on SSVEP.The main functions are as follows: BCI system collected EEG signals through self-developed portable EEG acquisition system,and decoded them as control instructions.The 3D measurement system identifies and locates target objects,and the 3D AR stimulation system presents stimulus and feedback information in 3D space.The control system was responsible for precise control of the robotic arm.The shared control system used the target-process shared control method to coordinate and schedule the various subsystems.Secondly,this paper designed a three-dimensional AR stimulus feasibility experiment for the first proposed three-dimensional AR stimulation system.In the experiment,two kinds of stimulation conditions,namely screen and three-dimensional AR stimulation,were set up.Using the filter bank task-related component analysis algorithm,with 1s EEG data,the average correct offline classification rate of the ten healthy subjects was: 96.22%,97.5%,and the online average classification correct rate is: 95.67%,96.67%.There was no significant difference in the correct rate under the two conditions,which verifies the feasibility of the three-dimensional AR stimulation system.Finally,this paper designed two online control experiment task of the robotic arm for grabbing and putting back target objects.In the target object capture experiment,the three-dimensional AR stimulation system projected SSVEP stimulation onto the target object,the shared control system controlled the robotic arm to complete the target grasping task by integrating results from the BCI system and the three-dimensional measurement system.In the experiment,the intended position was determined by using the combined results from the space quadruple paradigm and the iteration paradigm,and the shared controller controled the robot arm to move the target object to the exact position.Ten healthy subjects were able to complete two experimental tasks with a high accuracy rate,which verified the feasibility of the method proposed in this paper.