Based Finger Tactile Biomechanical Study Of Fluid-structure Interaction

Virtual reality technology has flourished since 1990s, and it is a research hotspot at present. In virtual reality system, tactile sense simulation and display is an important tool to strengthen the realistic sensation and construct the immersion. But the introduction of tactile information in virtual system is not enough now, which greatly decreasing the immersion and interaction.The tactile research focuses on two aspects:tactile biomechanics research and tactile interface research. The former mainly researches tactile mechanism, and the latter mainly researches tactile display. The research of tactile biomechanics is helpful for enhancing the understanding of tactile mechanism and analyzing the factors how to influence tactile sense, which is greatly useful to the design of tactile interface.This paper researches tactile biomechanics by numerical simulations and experiments, mainly including the response of fingertip under static stimulus and dynamic stimulus by single nozzle, which aimed to supply basis for the design of tactile interface and lay foundations for displaying surface texture.Firstly, based on current research status of tactile biomechanics, three-dimensional linear and nonlinear finite element models of fingertip are built from geometry and material properties, and fluid finite element model of nozzle is built. Meanwhile, based on the actual working conditions of pneumatic tactile interface, fluid-structure coupling algorithm is applied. Numerical simulation of fluid-structure interaction is performed based on former models, and the characteristic parameters of tactile are established.Secondly, tactile biomechanics is researched by numerical simulations, and the mechanical responses are analyzed under different loads. The influence of inlet pressure, diameter of nozzle, contact height on the response of fingertip under static stimulus are analyzed relying on characteristic parameters of tactile, which is helpful for the design of tactile interface; the response of fingertip under dynamic stimulus is analyzed, including the features of creep and stress relaxation under step load as well as the response under the load changing as sine wave with time, which is helpful for displaying surface texture.At the last, tactile biomechanics are researched by experiments, which are including building experiment system and the comparison between numerical simulations and the experiments results. The comparison is conducted from two aspects:the force applied to fingertip by nozzle and the deformation of fingertip under pressure. The aspect of deformation includes the deformation profile of fingertip, the maximum deformations under different conditions and the time history response of deformation. The results of experiments prove the nonlinear model is more reasonable in tactile biomechanics research, and the correctness of fluid-structure coupling numerical simulation.