Development Of Variable Friction Device Based On Gas Squeeze-Film And Experimental Investigation Of Tactile Display

Multi-channel, multi-media and intelligence are the development trends of human-computer interaction technology. It will break the traditional limitations of visual feedback of human-computer interaction and greatly improve the natural human-computer interaction and high efficiency to interact with computer systems in a parallel and non-precision approach, using a variety of people feeling channels, such as visual, auditory, touch, and smell, etc.Tactile has been widely used in virtual reality system and telepresence system as an important information channel for human knowledging and perceiving world. In virtual reality system and telepresence system, haptic display is an important mathod enhancing interactive vitality and immersion. By the development of virtual reality technology and interactive telerobot technology, it is very important and necessary to design a man-machine interface, which can realize real-time and precision of haptic display. This paper presents a novel real-time precision tactile display based on air squeeze film effectFirstly, the way of tactile representation has been determined through analyzing the mechanism of tactile and the effect of gas film squeezing. According to the mechanism of gas film squeezing and the related theory of Piezoelectricity, the duplex crystal able to generate bending vibration has been selected as the vibration subject. Meanwhile, related mechanical structures, such as the frame made of Piezoelectric and shells of vibration devices and related circuits for figure positioning have been designed.Secondly, to satisfy the optimized structure of tactile representation, the structure of the piezoelectric vibrator, which is the core of tactile representation, has been optimized according to the constraints such as bearing capacity, resonance frequency, theoretical amplitude of vibration and the safe working power of Piezoelectric, etc.Then, the corresponding relation between the driving signals of piezoelectric vibrator and the friction coefficient has been defined by test. And according to the test results, the control signals for twelve kinds of friction tactile and four kinds of textural have been designed. Moreover, the software of human-computer interactive convenient to use has been programmed.Lastly, experiment analysis of the prototype constructed according to the design above verified the feasibility of tactile representation based on the effect of gas film squeezing. Through the investigation of 20 tested people, effectiveness of the device to most groups has been validated.