Research On Human-Machine Interaction Multimodal Information Feedback Of Paraplegic Exoskeleton Robot

In order to meet the walking and independent living needs of patients with spinal cord injury,intelligent walking aids represented by paraplegic exoskeleton robots have emerged one after another.However,exoskeleton is generally lack of information feedback function.Paraplegic patients can not perceive the current lower limb movement state due to spinal cord injury and loss of proprioceptive sensation.When the movement state changes in complex environment,the patients can't identify the next movement state of exoskeleton,which brings inconvenience to walking efficiency and safety.That is to say,the current human-machine system of exoskeletons only has the process of interaction from human to machine.It is necessary to re-establish the information feedback path from machine to human,so as to realize the two-way human-machine interaction.Information feedback technology relies on human perception system,which can make up for the obstruction of perception pathway and realize information transmission from machine to human.In this paper,multimodal information feedback is used to provide the wearer with the current status information of exoskeleton and the next movement information during gait switching,so that the wearer can adjust the status in time according to the feedback information,maintain the stability and safety of walking,and thus realize the natural two-way human-machine interaction.The main contents are as follows:(1)Vibration tactile feedback for exoskeleton's current motion stateVibration tactile feedback experiment of exoskeleton in current motion state is based on two feedback modes of vibration intensity change and position change.Through experimental data analysis and subjective questionnaire survey,it is proposed to adopt feedback mode based on vibration intensity change,with an accuracy of 90%.Subsequently,the actual system validation experiment of vibration tactile feedback is carried out,and the results show that the feedback method is effective for the "perception" of the wearer's leg motion state when walking.(2)Auditory feedback for exoskeleton's next motion stateThe exoskeleton auditory feedback experiment is based on voice and music.The experimental results and subjective questionnaires show that the effect of voice-based auditory feedback is better with the accuracy of 100%.Subsequently,the application of voice feedback in the actual system of paraplegic exoskeleton is carried out.When voice feedback appeared in the last swing cycle,the subjects could perceive it more accurately and timely.(3)Study on exoskeleton multimodal information feedbackThe exoskeleton two-way interactive multi-modal feedback system uses vibration tactile and voice feedback based on intensity change.The recognition accuracy of exoskeleton next movement state based on the two feedback modes is 98.81%,and the subjects can perceive it in time.In the actual system validation experiment,the subjects completed the walking task more smoothly and naturally,and were not affected by the information feedback.At the same time,the feedback enhanced the sense of safety and perception of walking wearing exoskeletons.Multimodal information feedback technology based on vibration tactile and auditory can help wearers to perceive exoskeleton movement status accurately,maintain stability,safety and fluency of movement,so as to realize the two-way interaction between human and exoskeleton system better.