Research On Multi-Modal Tactile Rendering Based On Combined Electrotactile And Friction Control Methods

In recent years,tactile sensation has been considered a quite promising way of information transmission that can replace or compensate sight and hearing information.Tactile sensation can not only help the blind or people who have poor eyesight,but also can enrich the way of acquiring information for normal people and improve the efficiency of information interaction.A wearable tactile display system based on electrotactile and multi-modal tactile display system based on combined electrotactile and friction control methods are proposed.In the first place,this paper explains physiological basis of tactile perception,basic theory of electrotactile and theoretical basis of electrovibration.Then this paper analyzes the factors which influence electrostatic force in electrovibration effect.Finally,this paper proposes multi-modal tactile display system based on combined electrotactile and friction control methods.On the basis of theoretical analysis,the wearable tactile display device based on electrotactile and the multi-modal tactile display system based on combined electrotactile and friction control have been designed and developed.Both of them are mainly composed of the touch panel module,the central control module based on TM4C123 microprocessor,the excitation signal module and the high voltage power module.And the hardware and software solutions of both systems are designed.For the wearable tactile display device based on electrotactile,tactile electrode static display method and tactile electrode dynamic display method are adopted and threshold voltage experiment,optimal parameter values of excitation signal experiment,spatial resolution experiment,simple characters recognition experiment and capital English letters recognition experiment are carried out.There are some conclusions based on the experimental results.Firstly,the average success rate of the simple characters is apprpximately 95.2%;Secondly,the average success rate of capital English letters is apprpximately 82.0%.These conclusions demonstrate the proposed system can successfully transfer information.For the multi-modal tactile display system based on combined electrotactile and friction control,threshold voltage experiment based on electrovibration,spatial resolution experiment based on electrovibration,simple characters recognition experiment based on electrovibration,electrotactile and capital English letters recognition experiment based on electrovibration,electrotactile,the fusion of electrotactile and friction control and complex characters recognition experiment based on electrovibration,electrotactile,the fusion of electrotactile and friction control are carried out.Some conclusions are summarized.Firstly,the average success rate of the simple characters based on electrovibration and electrotactile are respectively apprpximately 93.8% and 94.2%;Secondly,the average success rate of capital English letters based on electrovibration,electrotactile and the fusion of electrotactile and friction control are respectively apprpximately 70.8%,78.3% and 85.4%;Finally,the average success rate of complex characters based on electrovibration,electrotactile and the fusion of electrotactile and friction control are respectively apprpximately 70.3%,82.3% and 89.0%.The experimental results suggest that the fusion of electrotactile and electrovibration have the better tactile sensation than single electrotactile and single electrovibration,and it can transfer information much better.In order to research the tactile sensation characteristic of human wrist,the wearable tactile display device based on electrotactile has been designed and implemented;In order to research the tactile sensation characteristic of human fingertip,the multi-modal tactile display system based on combined electrotactile and friction control has been designed and implemented.Both systems we proposed above provide a novel way to obtain information from real world for human and lay a solid foundation for realizing tactile sensation.