Error Measurement and Calibration in Developing Virtual-Reality-Assisted Microassembly System

2015 ◽  
Vol 9 (6) ◽  
pp. 619-628 ◽  
Author(s):  
Ren-Jung Chang ◽  
◽  
Jia-Cheng Jau

The operational error of a virtual reality (VR) assisted vision-based microassembly system is measured and calibrated during the system development stage. The vision-based microassembly system was designed and its opto-mechanical model was established in a virtual environment. By measuring the errors between the representative points in the images of virtual cameras and charge-coupled device (CCD) visual systems, the errors in the virtual environment were compensated by correcting the projection matrix parameters, the view matrix parameters, the initial components position, and the deviation angle for the working stage motion. The effectiveness of the proposed VR-assisted fine calibration method was tested by performing VR calibration on the virtual system.

Computers ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 58
Author(s):  
Dennis Reimer ◽  
Iana Podkosova ◽  
Daniel Scherzer ◽  
Hannes Kaufmann

In colocated multi-user Virtual Reality applications, relative user positions in the virtual environment need to match their relative positions in the physical tracking space. A mismatch between virtual and real relative user positions might lead to harmful events such as physical user collisions. This paper examines three calibration methods that enable colocated Virtual Reality scenarios for SLAM-tracked head-mounted displays without the need for an external tracking system. Two of these methods—fixed-point calibration and marked-based calibration—have been described in previous research; the third method that uses hand tracking capabilities of head-mounted displays is novel. We evaluated the accuracy of these three methods in an experimental procedure with two colocated Oculus Quest devices. The results of the evaluation show that our novel hand tracking-based calibration method provides better accuracy and consistency while at the same time being easy to execute. The paper further discusses the potential of all evaluated calibration methods.


2021 ◽  
Vol 5 (4) ◽  
pp. 15
Author(s):  
Jingyi Li ◽  
Ceenu George ◽  
Andrea Ngao ◽  
Kai Holländer ◽  
Stefan Mayer ◽  
...  

Ubiquitous technology lets us work in flexible and decentralised ways. Passengers can already use travel time to be productive, and we envision even better performance and experience in vehicles with emerging technologies, such as virtual reality (VR) headsets. However, the confined physical space constrains interactions while the virtual space may be conceptually borderless. We therefore conducted a VR study (N = 33) to examine the influence of physical restraints and virtual working environments on performance, presence, and the feeling of safety. Our findings show that virtual borders make passengers touch the car interior less, while performance and presence are comparable across conditions. Although passengers prefer a secluded and unlimited virtual environment (nature), they are more productive in a shared and limited one (office). We further discuss choices for virtual borders and environments, social experience, and safety responsiveness. Our work highlights opportunities and challenges for future research and design of rear-seat VR interaction.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 397
Author(s):  
Qimeng Zhang ◽  
Ji-Su Ban ◽  
Mingyu Kim ◽  
Hae Won Byun ◽  
Chang-Hun Kim

We propose a low-asymmetry interface to improve the presence of non-head-mounted-display (non-HMD) users in shared virtual reality (VR) experiences with HMD users. The low-asymmetry interface ensures that the HMD and non-HMD users’ perception of the VR environment is almost similar. That is, the point-of-view asymmetry and behavior asymmetry between HMD and non-HMD users are reduced. Our system comprises a portable mobile device as a visual display to provide a changing PoV for the non-HMD user and a walking simulator as an in-place walking detection sensor to enable the same level of realistic and unrestricted physical-walking-based locomotion for all users. Because this allows non-HMD users to experience the same level of visualization and free movement as HMD users, both of them can engage as the main actors in movement scenarios. Our user study revealed that the low-asymmetry interface enables non-HMD users to feel a presence similar to that of the HMD users when performing equivalent locomotion tasks in a virtual environment. Furthermore, our system can enable one HMD user and multiple non-HMD users to participate together in a virtual world; moreover, our experiments show that the non-HMD user satisfaction increases with the number of non-HMD participants owing to increased presence and enjoyment.


2015 ◽  
Vol 772 ◽  
pp. 585-590
Author(s):  
Florin Gîrbacia ◽  
Silviu Butnariu ◽  
Daniel Voinea ◽  
Bogdan Tzolea ◽  
Teodora Gîrbacia ◽  
...  

Surgical robots for biopsy procedure require pre-operative planning of trajectories prior to be used for needle guiding procedures. Virtual Reality (VR) technologies allow to simulate robotic biopsy procedure and to generate accurate needle trajectories that avoid vital organs. The paper presents a serial robot which can be used for biopsy procedure and a needle trajectory planning software based on VR technologies. A virtual environment has been modelled and simulations for robotic-assisted biopsy of the prostate have been performed.


2013 ◽  
Vol 8 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Charles Pontonnier ◽  
Georges Dumont ◽  
Asfhin Samani ◽  
Pascal Madeleine ◽  
Marwan Badawi

2013 ◽  
Vol 791-793 ◽  
pp. 1436-1440
Author(s):  
Ling Hang Yang

With the development of computer hardware and software technology, virtual reality technology of computer has been widely used in various fields. Virtual teaching process is one of the main applications of virtual reality computer technology. Tennis is one of the most common sports. Tennis process mainly includes the process of catching a ball, serving a ball and hitting a ball. Virtual process of tennis system must establish an accurate numerical simulation model to calculate the mechanical impedance during the arm movement of human. According to this, it builds a model of the mechanical impedance of human arm in tennis virtual system using three-dimensional simulation software in this paper and gets the curve of mechanical impedance through the simulation. Finally, the article compares calculation results with the theoretical results and concludes that the theoretical results and simulation results are basically consistent which provide a theoretical reference for the design of the development of virtual system for the human.


Author(s):  
Stefan Bittmann

Virtual reality (VR) is the term used to describe representation and perception in a computer-generated, virtual environment. The term was coined by author Damien Broderick in his 1982 novel “The Judas Mandala". The term "Mixed Reality" describes the mixing of virtual reality with pure reality. The term "hyper-reality" is also used. Immersion plays a major role here. Immersion describes the embedding of the user in the virtual world. A virtual world is considered plausible if the interaction is logical in itself. This interactivity creates the illusion that what seems to be happening is actually happening. A common problem with VR is "motion sickness." To create a sense of immersion, special output devices are needed to display virtual worlds. Here, "head-mounted displays", CAVE and shutter glasses are mainly used. Input devices are needed for interaction: 3D mouse, data glove, flystick as well as the omnidirectional treadmill, with which walking in virtual space is controlled by real walking movements, play a role here.


Author(s):  
Sean A. McGlynn ◽  
Ranjani M. Sundaresan ◽  
Wendy A. Rogers

Virtual reality (VR) has potential applications for promoting physical, cognitive, and socio-emotional well-being for users of all ages. The ability for individuals to develop a sense of being physically located in the virtual environment, referred to as spatial presence, is often an essential component of successful VR applications. Thus, it is necessary to understand the psychological aspects of the spatial presence process and identify methods of measuring presence formation and maintenance. This in-progress study addresses gaps in the spatial presence literature through an empirical evaluation of a conceptual model of spatial presence, which emphasizes users’ characteristics and abilities. Age will serve as a proxy for changes in a variety of presence-relevant cognitive and perceptual abilities. The results will have implications for the design of VR systems and applications and for selecting individuals best-suited for these applications.


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