• Journal of Drive and Control
• /
• v.12 no.2
• /
• pp.27-33
• /
• 2015

Excavators are versatile earthmoving equipment that are used in civil engineering, hydraulic engineering, grading and landscaping, pipeline construction and mining. Effective operator training is essential to ensure safe and efficient operating of the machine. The virtual reality excavator based on simulation using conventional large size monitors is limited by the inability to provide a realistic real world training experience. We proposed a flexible observation method with a head tracking system to improve user feeling and sensation when operating a virtual reality excavator. First, an excavation simulator is designed by combining an excavator SimMechanics model and the virtual world. Second, a head mounted display (HMD) device is presented to replace the cumbersome large screens. Moreover, an Inertial Measurement Unit (IMU) sensor is mounted to the HMD for tracking the movement of the operator's head. These signals consequently change the virtual viewpoint of the virtual reality excavator. Simulation results were used to analyze the performance of the proposed system.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.2
• /
• pp.49-64
• /
• 2008

Recently, many researches about making more comfortable input device based on gaze detection technology have been done in human computer interface. However, the system cost becomes high due to the complicated hardware and there is difficulty to use the gaze detection system due to the complicated user calibration procedure. In this paper, we propose a new gaze detection method based on the 2D analysis and a simple user calibration. Our method used a small USB (Universal Serial Bus) camera attached on a HMD (Head-Mounted Display), hot-mirror and IR (Infra-Red) light illuminator. Because the HMD is moved according to user's facial movement, we can implement the gaze detection system of which performance is not affected by facial movement. In addition, we apply our gaze detection system to 3D first person shooting game. From that, the gaze direction of game character is controlled by our gaze detection method and it can target the enemy character and shoot, which can increase the immersion and interest of game. Experimental results showed that the game and gaze detection system could be operated at real-time speed in one desktop computer and we could obtain the gaze detection accuracy of 0.88 degrees. In addition, we could know our gaze detection technology could replace the conventional mouse in the 3D first person shooting game.

• Journal of Broadcast Engineering
• /
• v.21 no.1
• /
• pp.43-50
• /
• 2016

In this paper, we present a distortion correction for wearable Augmented Reality (AR) on mobile phones. Head Mounted Display (HMD) using mobile phones, such as Samsung Gear VR or Google's cardboard, introduces lens distortion of the rendered image to user. Especially, in case of AR the distortion is more complicated due to the duplicated optical systems from mobile phone's camera and HMD's lens. Furthermore, such distortions generate mismatches of the visual cognition or perception of the user. In a natural way, we can assume that transparent wearable displays are the ultimate visual system which generates the least misperception. Therefore, the image from the mobile phone must be corrected to cancel this distortion to make transparent-like AR display with mobile phone based HMD. We developed a transparent-like display in the mobile wearable AR environment focusing on two issues: pincushion distortion and field-of view. We implemented our technique and evaluated their performance.

• Journal of the Ergonomics Society of Korea
• /
• v.36 no.4
• /
• pp.267-280
• /
• 2017

Objective: The aim of this study is to investigate key user experience factors of interactions for Head Mounted Display (HMD) devices in the Virtual Reality Environment (VRE). Background: Virtual reality interaction research has been conducted steadily, while interaction methods and virtual reality devices have improved. Recently, all of the virtual reality devices are head mounted display based ones. Also, HMD-based interaction types include Remote Controller, Head Tracking, and Hand Gesture. However, there is few study on usability evaluation of virtual reality. Especially, the usability of HMD-based virtual reality was not investigated. Therefore, it is necessary to study the usability of HMD-based virtual reality. Method: HMD-based VR devices released recently have only three interaction types, 'Remote Controller', 'Head Tracking', and 'Hand Gesture'. We search 113 types of research to check the user experience factors or evaluation scales by interaction type. Finally, the key user experience factors or relevant evaluation scales are summarized considering the frequency used in the studies. Results: There are various key user experience factors by each interaction type. First, Remote controller's key user experience factors are 'Ease of learning', 'Ease of use', 'Satisfaction', 'Effectiveness', and 'Efficiency'. Also, Head tracking's key user experience factors are 'Sickness', 'Immersion', 'Intuitiveness', 'Stress', 'Fatigue', and 'Ease of learning'. Finally, Hand gesture's key user experience factors are 'Ease of learning', 'Ease of use', 'Feedback', 'Consistent', 'Simple', 'Natural', 'Efficiency', 'Responsiveness', 'Usefulness', 'Intuitiveness', and 'Adaptability'. Conclusion: We identified key user experience factors for each interaction type through literature review. However, we did not consider objective measures because each study adopted different performance factors. Application: The results of this study can be used when evaluating HMD-based interactions in virtual reality in terms of usability.

• Current Optics and Photonics
• /
• v.2 no.3
• /
• pp.280-285
• /
• 2018

A new method to design a see-through off-axis head-mounted-display (OA-HMD) optical system with an ellipsoidal surface is proposed, in which a tilted ellipsoidal surface is used as the combiner, which yields the benefits of easier fabrication and testing compared to a freeform surface. Moreover, we realize a coaxial structure in the relay lens group, which is simple and has looser tolerance requirements, thus making assembly easier. The OA-HMD optical system we realize has a simple structure and consists of a combiner and 7 pieces of coaxial relay lenses. It has a $48^{\circ}{\times}36^{\circ}$ field of view (FOV) and 12-mm exit pupil diameter.

• Journal of the Korea Computer Graphics Society
• /
• v.28 no.3
• /
• pp.113-123
• /
• 2022

Ray tracing-based rendering creates by far more realistic images than the traditional rasterization-based rendering. However, it is still burdensome when implemented for a Head-Mounted Display (HMD) system that demands a wide field of view and a high display refresh rate. Furthermore, for presenting high-quality images on the HMD screen, a sufficient number of ray sampling should be carried out per pixel to alleviate visually annoying spatial and temporal aliases. In this paper, we extend the recent selective foveated ray tracing technique by Kim et al. [1], and propose an improved real-time rendering technique that realizes the rendering effect of the classic Whitted-style ray tracing on the HMD system. In particular, by combining the ray tracing hardware-based acceleration technique and time-constrained rendering scheme, we show that fast HMD ray tracing is possible that is well suited to human visual systems.

• Educational Technology International
• /
• v.18 no.1
• /
• pp.49-71
• /
• 2017

The purpose of the study was to identify key design features of virtual reality with head-mounted displays (HMD) and touchless interface for the hearing-impaired and hard-of-hearing learners. The virtual reality based training program was aimed to help hearing-impaired learners in machine operating learning, which requires spatial understanding to operate. We developed an immersive virtual learning environment prototype with an HMD (Oculus Rift) and a touchless natural user interface (Leap Motion) to identify the key design features required to enhance virtual reality for the hearing-impaired and hard-of-hearing learners. Two usability tests of the prototype were conducted, which revealed that several features in the system need revision and that the technology presents an enormous potential to help hearing-impaired learners by providing realistic and immersive learning experiences. After the usability tests of hearing-impaired students' exploring the 3D virtual space, interviews were conducted, which also established that further revision of the system is needed, which would take into account the learners' physical as well as cognitive characteristics.

• The Journal of the Korea Contents Association
• /
• v.15 no.3
• /
• pp.40-47
• /
• 2015

VR(virtual reality) which already is used commonly in diverse areas including entertainment, design, and simulation training is most important area in ICT. VR already has various uses within the tourism sector. As VR technology continues to evolve, there is little reason to doubt that it will become more prevalent throughout society and the tourism sector in particular. In this paper, we plan to improve the VR content to the market possibility and competitiveness of VR content in the culture industry. Out of focus, lens dust, motion blur, blur effect were minimized to improve the simulation sickness which caused by the cognitive dissonance in the HMD. And also, the content was considered UI design for user's immersion.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.184-187
• /
• 2005

This paper is described about the technique of ultra-precision machining for optical parts in HMD system. Machining technique for PMMA and BK7 with single point diamond turning machining is reported in this paper. The main factors influencing on the machined surface quality are discovered and regularities of machining process are drawn. The purpose of our research is to find the optimum machining conditions fur cutting of PMMA and grinding of BK7. Also, apply the SPDTM technique to the manufacturing of ultra precision optical components of HMD system. Aspheric PMMA lens without a polishing process, the surface roughness of 5 nm Ra, and the form error of ${\lambda}/2\;({\lambda}=632.8nm)$ for reference curved surface 30 mm has been required.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2022.07a
• /
• pp.549-552
• /
• 2022

본 논문에서는 가상현실에서 헤드 마운티드 디스플레이(Head mounted display, HMD) 사용자와 Non-HMD 사용자에게 사용자의 걷기, 뛰기, 절름발이 움직임을 몰입감 있게 표현하기 위한 새로운 가상현실(VR, Virtual Reality) 인터페이스를 제안한다. 가상현실에서는 몰입감을 높이기 위해 시각적 감각을 활용한 HMD와 사용자의 자세나 움직임을 추적하는 장비를 활용하지만, 일반적인 사용자들에게 HMD 보급은 많이 이루어져 있지 않으며, 비용적인 측면과 멀미로 인해 가상현실 콘텐츠에 몰입하기 어렵다. 본 논문에서는 효율적으로 몰입도를 높이고 비용적인 부담을 줄여주기 위해 아두이노를 활용한 새로운 보행 인터페이스 장치를 제안한다. 보행 인터페이스 장치는 사용자의 다리 가속도 정보를 기반으로 사용자의 상태 변화에 맞게 패턴을 설정하여 사용자의 걷기, 뛰기, 절름발이 움직임을 통해 사용자 캐릭터의 움직임을 제어하고 표현할 수 있는 새로운 결과를 보여준다.