Study Of Wearable Tactile Display Device For Upper Arm And Related Tactile Perception Experiments

Tactile sensation is a sensation arising from the excitation of superficial skin receptors by a slight external mechanical stimulus.The device that transmits information through the sense of touch acting on the skin is called the tactile display device,and the wearability greatly broadens the scope of applications of tactile display devices,such as immersive game experience,navigation for the blind,providing directional information to drivers,teleoperation,virtual reality,etc.Therefore,the research on wearable tactile display devices is of great practical significance.A novel wearable tactile display device is designed in this thesis,which is capable of providing skin squeezing,stretching and vibrating tactile stimuli simultaneously,enriching the types of tactile signals provided to convey more tactile information and achieve more functions compared with many existing devices.The wearable tactile display device was also utilized as a tool to study the mutual interference and influence of each stimulus by quantifying the absolute and differential thresholds of the test subjects,and the specific research work,conclusions and contributions are briefly described as follows:(1)A multi-sensory wearable tactile display device based on the upper arm is designed,integrating three tactile stimulation modules: squeeze,stretch and vibration,which can work independently or be combined together to provide different types of stimulation at the same time.The squeeze module is powered by two motors rotating in the opposite direction at the same time,driving the inelastic nylon belt to produce squeeze stimulation on the skin;the stretch module is powered by two motors rotating in the same direction at the same time,driving the inelastic nylon belt to produce shear stimulation on the skin;the vibration module is composed of four micro-vibrators,which are fixed on the top,bottom,left and right side of the user’s arm by the elastic nylon belt,evenly distributed at 90 degrees.Compared with other similar devices,firstly,the device is unique in its structural design,with the control module and power supply embedded in the 3D printed housing in addition to the integration of three stimulation modules;secondly,the extrusion module,stretching module and vibration module act in different positions of the upper arm,which can minimize perceptual interference and improve perceptual accuracy.(2)Based on this tactile display device,a psychophysical experiment on sensory thresholds was designed,and the effect of interference on the perception of the squeeze and stretch stimulus was investigated using the constant stimulus method,as proposed.The results of the study showed that the addition of interference stimuli had significant effects on the absolute thresholds of both the squeeze and stretch stimuli,where the interference effects of the squeeze and stretch stimuli on the perception of each other’s absolute thresholds were more significant,while the interference effects of the vibration stimuli on them were less;for the difference threshold experiment,the presence of interference stimuli had no significant effects on the difference thresholds of the squeeze stimuli,but affected the difference thresholds.These findings not only reveal the interaction and relationship between interference and perception of squeeze and stretch stimuli,which provide a reference for the design of further tactile information encoding,but also provide a basis for the design of future wearable tactile display devices.(3)The designed wearable tactile display device chooses micro-motor and lightweight 3D printing material to reduce weight,the whole device size is145mm×90mm×62mm,weight is 368 g,and the device bottom adopts ergonomic curved structure,so that the device can be better worn on the left upper arm,with good portability and operability.At the same time,the psychophysical experiments of sensory threshold proved that the tactile stimuli provided by the combination of three tactile modules of the device have good resolution,so the device can transmit more information by combining three stimuli,which improves the effectiveness and richness of information transmission.In addition,the experimental results show that although the presence of interference stimuli leads to an increase in the difference threshold of the stretch stimuli,the multisensory wearable tactile display device designed in this thesis reduces the effect of interference on the stretch stimuli and improves the resolution of the tactile stimuli compared with existing multisensory wearable tactile devices.