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As an important method for humans to perceive their environment, touch has not been fully integrated into virtual reality technology. Existing tactile feedback devices have the problem of being large and expensive, and most studies have not explored the ability of the affected area to distinguish an external stimulus, thus it is difficult to perform natural human-computer interactions. This article describes the development of a device that can transmit multimodal tactile information in accordance with the characteristics of human hand skin perception during a human-computer interaction. The device has 10 miniature vibrators ( $\Phi =10$ mm, d=2.7 mm) and 2 semiconductor refrigerators (23 mm $\times23$ mm $\times4$ mm), which can achieve temperature and vibration feedback. First, the structure and working principle of the device were introduced, and the device’s performance was analyzed. Subsequently, an experiment based on the perception characteristics of human hand skin was designed. The experiment determined the vibration level (1-5), heating level (I-IV), and cooling level (I-III) that are consistent with the perception characteristics of the hand skin. Finally, a chemical experiment was designed to test the performance of the device. The results of the experiment showed that 92% of the volunteers thought the device had a higher sense of authenticity and immersion than the traditional virtual reality experience.

With the promotion of national fitness and the development of socialization of sport, physical and mental health has gradually become an important demand of the Chinese people in the new era in pursuit of a better life. As a simple and efficient way of fitness and entertainment, VR spinning bikes are not restricted by the weather, time, place, and air pollution, and are slightly loved by the public. However, the current virtual cycling system based on dynamic cycling still has problems such as a single riding scene, inconsistent visual somatosensory, and poor portability. In response to the lack of interactivity and presence of traditional virtual cyclingsystems, this article has developed a cross-platform Multi-scenario VR cycling system with high immersion. The system has multiple riding environments for users to choose personally. The core solves the problem of inconsistent VR riding body sensation, improves the user's immersion and reduces the user's dizziness In addition, the system can run on a varietyof platforms to meet the needs of users' personalized riding.

The intersection workspace of multi-finger hands means the overlapping workspace in 3D Euclidean space where several fingertips can reach together, and is very valuable for grasp space planning, motion control and mechanical design for multi-finger hands. But, the intersection workspaces usually have sophisticated forms, which are really hard for robotic experts to image them. We present a general approach to visualize and analyze the intersection workspace of multi-finger hands. We firstly deduce the displacement equation of the fingertip, then generate 3D workspace of the fingertip and lastly obtain the intersection workspace of the multi-finger hands. This approach can visualize intersection workspaces with integrated forms and contours, and analyze the volume of the intersection workspaces. The vivid form and volume analysis of intersection workspaces are useful for robotic experts to accurately and intuitionally understand the fingertip motion ranges, plan the motion routes of fingers and avoid the motion collision among fingers.

A serious trouble of virtual bicycle ride has to be faced currently, that is the visual information of scene motion perceived by riders doesn’t synchronize with the proprioceptive information of actual ride. This phenomenon makes riders deeply depressing in immersion and interaction. This paper proposes three different interpolation algorithms of Catmull- Rom curve to evaluate the consistency of visual and proprioceptive perceptions for virtual bicycle ride. Experimental results show that the realtime interpolation algorithm of Catmull-Rom curve shall help to match visual and proprioceptive perceptions, and improve the immersion and interaction of virtual bicycle ride.

Image tactile interaction is a new interaction between human and digital images, allowing users to know digital images by touch. In order to improve the authenticity of image tactile perception, this paper proposes a tactile perception model based on image region features. Aiming at the phenomenon of over-partitioning and computational complexity of JSEG algorithm, we propose an improved JSEG algorithm, which can effectively reduce the computational complexity and divide the image areas which are more in line with the subjective visual judgment, and can be used for region-based image tactile generation. The experimental results show that the proposed algorithm can correctly distinguish the image area and improve the accuracy of image tactile perception.

Finger workspace is one of the most important features to evaluate the kinematic performances of the multi-finger hands. It is also benefit for grasp planning, mechanical design, and motion control. Although many multi-finger hands have been developed over the last few decades, how to generate and visualize their workspaces is still a challengeable problem. We propose a workspace generation and visualization approach to explain the workspace characteristics of a multi-finger hand (ZSTU hand), which can help to solve the problem of choosing a grasp with the gripper constrains. Compared with previous researches, this approach can model more integrated fingertip workspaces with vivid forms and contours, which is valuable for researchers to accurately and intuitionally understand the fingertip motion ranges and the analysis of the workspace volume. These performances can help researchers to optimize the mechanical structures of the multi-finger hand, and improve the kinematic performances of the multi-finger hand.

Based on our previous research, this paper integrated four aspects of the haptic rendering for virtual hand interaction, which included the contact, static grasp, movement, and collision of virtual hand. We presented a method of contact force rendering of virtual hand based on the human fingers’ force characteristics. A physically-based static grasp force rendering method was used to calculate the grasp force for virtual hand holding objects. Then, we deduced the algorithms to generate the realistic action force of the virtual hand grasping an object and moving in virtual environments. The algorithms were based on the kinematics and dynamics of the robot theory. With the impulse theorem and coefficient of elastic recovery, we analyzed the collision force with friction for virtual hand interaction. A special series of experimental results showed that the physically-based haptic rendering approaches for virtual hand interaction were computationally efficient while retaining a good level of realism.

This paper explores new approaches to recognize Chinese characters in images through touch sense. We extract the gradient image fused with brightness and chrominance information by the flow-based Gauss difference algorithm, and use the edge tangential flow method to smooth image contour, to obtain smooth character contours with significant edge features. Then, we use a tactile generation algorithm with five mechanical elements to generate stable and continuous tactile information based on the normal vector of triangular patches of the surface. To verify the feasibility and effectiveness of the proposed methods, we developed a Chinese character tactile sensing system. Experiments show that Chinese characters in images can be recognized by touch sense with higher recognition accuracy rate.