Application of Optimal-Jerk Trajectory Planning in Gait-balance Training Robot

To accommodate the gait and balance disorder of the elderly with age progression and the occurrence of various senile diseases, this paper proposes a novel gait balance training robot (G-Balance) based on a six degree-of-freedom parallel platform. Using the platform movement and IMU wearable sensors, two training modes, i.e., active and passive, are developed to achieve vestibular stimulation. Virtual reality technology is applied to achieve visual stimulation. In the active training mode, the elderly actively exercises to control the posture change of the platform and the switching of the virtual scene. In the passive training mode, the platform movement is combined with the virtual scene to simulate bumpy environments, such as earthquakes, to enhance the human anti-interference ability. To achieve a smooth switching of the scene, continuous speed and acceleration of the platform motion are required in some scenarios, in which a trajectory planning algorithm is applied. This paper describes the application of the trajectory planning algorithm in the balance training mode and the optimization of jerk (differential of acceleration) based on cubic spline planning, which can reduce impact on the joint and enhance stability.

Building Virtual Scene Construction and Environmental Impact Analysis Based on Image Processing

With the rapid development of computer technology, the virtual scene construction technology of image processing has gradually become a hotspot in computer research. The application of virtual scene construction technology in the construction industry is also expanding, with the intelligentization of architectural design and construction. With the rapid development of the industry, virtual technology can better provide users with diversified services and experiences. The main content of the article is as follows: (1) The article introduces image construction technology and analyzes the three-dimensional presentation of virtual technology in construction design and the diversified application of virtual technology in construction design. (2) The article introduces two virtual scene construction techniques: one is to combine the real scene obtained by taking pictures with the virtual scene by image technology processing to construct a natural virtual scene; the other is the use of geometric construction by architects. The virtual building model is drawn by the model method, and the virtual building model is thus obtained. (3) The article chooses two representative buildings as cases. The virtual platform monitors and records the movement trajectory of volunteers in the virtual environment in real time. The experimental results show that the number and shape characteristics of the escalators in the building all have a little impact on volunteers’ awareness. (4) The article sets up three control groups of normal mode, fixed skin, and variable skin. It analyzes the environmental impact of buildings from three different aspects of wind environment, thermal environment, and light environment and proposes related control measures.

Application of Augmented Reality (AR) Technology in Low-Voltage Line Interruption Training and Power Grid Emergency Training

Augmented reality technology uses computer performance to create a virtual scene and accurately integrate the virtual scene with the real world, and finally uses a video projector to present the virtual and real scene to the user, thereby significantly improving the user’s visual experience and Feeling knowledge. Therefore, augmented reality technology can be well applied to training companies. The use of virtual reality and augmented reality technology in the aerospace, construction and shipbuilding industries has achieved remarkable results, and the era of augmented reality applications in the power grid has also arrived. With the development of mobile terminals such as mobile phones, it has become an excellent platform for augmented reality applications. This article focuses on the application of augmented reality (AR) technology in low-voltage line interruption training and network emergency training. First, the basic technology of augmented reality (AR) and the application of augmented reality (AR) in power grid emergency training are introduced using bibliographic research methods. Then design a network emergency training system for low-voltage disconnection training, and finally test the algorithm used in this article. The detection result shows that the detection of feature points using AGAST takes less than 3ms, while the Shi-Tomasi operator is about 20ms. It can be seen that the use of AGAST operator to detect feature points has a great improvement in speed.

Tailored Reality: Perception-aware Scene Restructuring for Adaptive VR Navigation

In virtual reality (VR), the virtual scenes are pre-designed by creators. Our physical surroundings, however, comprise significantly varied sizes, layouts, and components. To bridge the gap and further enable natural navigation, recent solutions have been proposed to redirect users or recreate the virtual content. However, they suffer from either interrupted experience or distorted appearances. We present a novel VR-oriented algorithm that automatically restructures a given virtual scene for a user’s physical environment. Different from the previous methods, we introduce neither interrupted walking experience nor curved appearances. Instead, a perception-aware function optimizes our retargeting technique to preserve the fidelity of the virtual scene that appears in VR head-mounted displays. Besides geometric and topological properties, it emphasizes the unique first-person view perceptual factors in VR, such as dynamic visibility and objectwise relationships. We conduct both analytical experiments and subjective studies. The results demonstrate our system’s versatile capability and practicability for natural navigation in VR: It reduces the virtual space by 40% without statistical loss of perceptual identicality.

“Saudades da festa!”: Triggering sensory memories of DIY electronic music through multimodal practices

DIY electronic music parties in São Paulo are deeply immersive, corporeal and sensorial. In March 2020, due to the pandemic, the parties stopped, and the scene gradually moved online manifesting itself on a new type of canvas. However, the digital manifestations of the virtual scene lost their performative and multisensorial appeal. By using multimodal elicitation methods (photos, videos, audio tracks, internet memories) this article is exploring the triggered or involuntary memory of embodied and sensorial affects that are being recalled and missed by the “clubbers.” The article intends to exhibit autoethnographic memories of party participation while problematizing the way in which the memory of this missed intense experience comes from a regular attendance to electronic music gatherings and its relationship with the complex feeling of “saudade.”

Experimental Performance Evaluation of Enhanced User Interaction Components for Web-Based Collaborative Extended Reality

COVID-19-related quarantine measures resulted in a significant increase of interest in online collaboration tools. This includes virtual reality (VR) or, in more general term, extended reality (XR) solutions. Shared XR allows for activities such as presentations, training of personnel or therapy to take place in a virtual space instead of a real one. To make online XR as accessible as possible, a significant effort has been put into the development of solutions that can run directly in web browsers. One of the most recognized solutions is the A-Frame software framework, created by Mozilla VR team and supporting most of the contemporary XR hardware. In addition, an extension called Networked-Aframe allows multiple users to share virtual environments, created using A-Frame, in real time. In this article, we introduce and experimentally evaluate three components that extend the functionality of A-Frame and Networked-Aframe. The first one extends Networked-Aframe with the ability to monitor and control users in a shared virtual scene. The second one implements six degrees of freedom motion tracking for smartphone-based VR headsets. The third one brings hand gesture support to the Microsoft HoloLens holographic computer. The evaluation was performed in a dedicated local network environment with 5, 10, 15 and 20 client computers. Each computer represented one user in a shared virtual scene. Since the experiments were carried out with and without the introduced components, the results presented here can also be regarded as a performance evaluation of A-Frame and Networked-Aframe themselves.