An improved 3D shape haptic rendering algorithm for finger mounted vibrotactile device

To improve the sense of reality on perception, an improved algorithm of 3D shape haptic rendering is put forward based on a finger mounted vibrotactile device. The principle is that the interactive information and the shape information are conveyed to users when they touch virtual objects at mobile terminals by attaching the vibrotactile feedback on a fingertip. The extraction of shape characteristics, the interactive information and the mapping of shape in formation of vibration stimulation are key parts of the proposed algorithm to realize the real tactile rendering. The contact status of the interaction process, the height information and local gradient of the touch point are regarded as shape information and used to control the vibration intension, rhythm and distribution of the vibrators. With different contact status and shape information, the vibration pattern can be adjusted in time to imitate the outlines of virtual objects. Finally, the effectiveness of the algorithm is verified by shape perception experiments. The results show that the improved algorithm is effective for 3D shape haptic rendering.

Development of augmented reality serious games with a vibrotactile feedback jacket

Background In the past few years,augmented reality(AR)has rapidly advanced and has been applied in different fields.One of the successful AR applications is the immersive and interactive serious games,which can be used for education and learning purposes.Methods In this project,a prototype of an AR serious game is developed and demonstrated.Gamers utilize a head-mounted device and a vibrotactile feedback jacket to explore and interact with the AR serious game.Fourteen vibration actuators are embedded in the vibrotactile feedback jacket to generate immersive AR experience.These vibration actuators are triggered in accordance with the designed game scripts.Various vibration patterns and intensity levels are synthesized in different game scenes.This article presents the details of the entire software development of the AR serious game,including game scripts,game scenes with AR effects design,signal processing flow,behavior design,and communication configuration.Graphics computations are processed using the graphics processing unit in the system.Results/Conclusions The performance of the AR serious game prototype is evaluated and analyzed.The computation loads and resource utilization of normal game scenes and heavy computation scenes are compared.With 14 vibration actuators placed at different body positions,various vibration patterns and intensity levels can be generated by the vibrotactile feedback jacket,providing different real-world feedback.The prototype of this AR serious game can be valuable in building large-scale AR or virtual reality educational and entertainment games.Possible future improvements of the proposed prototype are also discussed in this article.

Vibrotactile Sensation:A Systematic Review of the Artificial Pacinian Corpuscle

Pacinian corpuscle is a tactile receptor that responds to high-frequency(20-1000 Hz)vibration and has high-pass filtering and mechanical signal amplification functions.It is the main receptor of vibration tactility closely related to fine touch sensation,which is the ability to perceive and localize objects’shape,texture,and size.Currently,it is still difficult to measure and calculate the friction generated by robots grasping objects.The resolution of touch and vibration sensors cannot satisfy the demand for understanding tribological behavior.The simulation of Pacinian corpuscles’structure and replication of its key functions will bring richer touch information to robots.In this review article,the structure and functions of Pacinian corpuscles are summarized from the internal structure of a single Pacinian corpuscle and the spatial distribution of multiple Pacinian corpuscles.Then,theoretical models and research on the bionics design of Pacinian corpuscles are introduced based on the three reception processes of Pacinian corpuscles:mechanical transmission,electromechanical transduction,and neural excitation.Finally,the bottlenecks of current research on the simulation of Pacinian corpuscles are summarized,followed by the proposal of research ideas on the simulation of Pacinian corpuscles.

Compression of surface texture acceleration signal based on spectrum characteristics

Background Adequate data collection can enhance the realism of online rendering or offline playback of haptic surface textures.A parallel challenge is to reduce communication delays and improve storage space utilization.Methods Based on the similarity of the short-term amplitude spectrum trend,this study proposes a frequency-domain compression method.A compression framework is designed,which first maps the amplitude spectrum into grayscale images,compresses them with a still image compression method,and then adaptively encodes the maximum amplitude and part of the initial phase for each time window to achieve the final compression.Results The comparison between the original signal and the recovered signal shows that when the time-frequency similarity is 90%,the average compression ratio of our method is 9.85%in the case of a single interaction point.The subjective score for similarity was found to be high,with an average of 87.85.Conclusions Our method can be used for offline compression of vibrotactile data.For multi-interaction points in space,the trend similarity grayscale image can be reused,and the compression ratio is further reduced.

Evaluating effectiveness of four-parameter compound tactons for conveying urban navigation information

To guide pedestrians to navigate in a strange city and reduce the cognitive overload suffered when walking, thermal change direction, vibration stimulation direction, intensity variation and body location are employed to construct four-parameter compound tactons.They are mapped to four different types of navigation message： route attribute, intersection type, distance and heading direction. One psychological experiment was conducted. The derived confusion matrices were used to investigate recognition rates and information transfer for compound tactons,and non-parameter tests were employed to analyze the effect of each parameter on the number of correct responses.Experimental results show that the overall identification rate for four-parameter tactons is 88.72% by using different tactile parameters,and 19.64 icons can be identified reliably in all 32 tactile icons according to the information transfer value. Thermal changes can be an effective supplement to vibrotactile icons. This suggests that compound tactons will be a promising method of conveying complex information when navigating in a virtual or real urban environment.