Research On Tactile Rendering System Based On Electrovibration

Tactile rendering can be used to express the surface characteristics of virtual objects, like textureand smoothness. Human operators achieve active exploration of virtual environments throughtouching, perceiving and operating virtual objects. The electrovibration based tactile renderingtechnology method, which increases the friction on surface of contact area through increasingelectrostatic attraction force, can realize fine and continuous tactile sitimulation. Thus, it has a widelyapplication prospect. In this thesis, research on electrovibration based tactile rendering system isconducted from three aspects: theoretical analysis of factors which affect electrostatic force, designand implementation of prototype system and experiments verifying.Firstly, the principle of electrovibration is presented. Research on the influences of severalfactors on the resulting electrostatic force is conducted, including the amplitude of voltage and thethickness of insulating layer. What’s more, relationship between voltage frequency and electrostaticforce are given.Based on the theoretical analysis of electrovibration, the electrovibration based tactile renderingsystem is designed in this thesis. The system consists of central control module based on ARM11microprocessor, switch array module, tactile panel module, LCD module and power supply module.This thesis presents the implementation of the system including the production of tactile panel, andthe design work of software of system based on Qt graphics framework in Linux system.To verify the effectiveness of the tactile rendering system, several experiments of perceptionthreshold and cognition of simple graphics are carried out. The former experiments includeexperiment of sensing threshold and discrimination threshold on voltage amplitude, experiment of thesensing frequency range and discrimination threshold on the frequency of excitation signal, andexperiment of threshold on two-dimensional spatial perception. Experimental results show that theaverage threshold of voltage amplitude for human perception is about75.9V, and the averageperceivable frequency range of excition signal is between8.1Hz and891.6Hz. Moreover, thediscrimination threshold on voltage frequency decreases by the increment of excitation voltageamplitude, while the discrimination threshold on voltage frequency does not change when thefrequency of excitation voltage changes. From the experiment results, we can conclude that thesystem described in this thesis can realize tactile rendering successfully and can be applied toapplications of cognition of simple graphics. This thesis carries out research work on electrovibration based tactile rendering system fromdifferent aspects, and lays an important foundation for further study of tactile rendering.