• 한국CDE학회논문집
• /
• 제18권4호
• /
• pp.290-298
• /
• 2013

A walking navigation system (usually known as a locomotion interface) is an interactive platform which gives simulated walking sensation to users using sensed bipedal motion signals. This enables us to perform navigation tasks using only bipedal movement. Especially, it is useful for the certain VR task which emphasizes on physical human movement, or accompanies understanding of the size and complexity of building structures. In this work, we described system components of VR walking system and investigated several types of walking platform by literature survey. We adopted a MS Kinect depth sensor for the motion recognition and a treadmill which includes directional turning mechanism for the walking platform. Through the integration of these components with a VR navigation scenario, we developed a simple VR walking navigation system. Finally several technical issues were found during development process, and further research directions were suggested for the system improvement.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.2211-2216
• /
• 2005

This paper describes a novel navigation algorithm using a locomotion interface with two 6-DOF parallel robotic manipulators. The suggested novel navigation system can induce user's real walking and generate realistic visual feedback during navigation, using robotic manipulators. For realistic visual feedback, the virtual environment is designed with three components; 3D object modeler for buildings and terrains, scene manager and communication manager component. The walking velocity of the user is directly translated to VR actions for navigation. Finally, the functions of the RPC interface are utilized for each interaction mode. The suggested navigation system can allow a user to explore into various virtual terrains with real walking and realistic visual feedback.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권6호
• /
• pp.221-227
• /
• 2002

In this paper, the system model for the compensation of the low-cost personal navigation system is derived and the error compensation method using GPS is also proposed. WNS(Walking Navigation System) is a kind of personal navigation system using the number of a walk, stride and azimuth. Because the accuracy of these variables determines the navigation performance, computational methods have been investigated. The step is detected using the walking patterns, stride is determined by neural network and azimuth is calculated with gyro output. The neural network filters off unnecessary motions. However, the error compensation method is needed, because the error of navigation information increases with time. In this paper, the accumulated error due to the step detection error, stride error and gyro bias is compensated by the integrating with GPS. Loosely coupled Kalman filter is used for the integration of WNS and GPS. It is shown by simulation that the error is bounded even though GPS signal is blocked.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제12권6호
• /
• pp.358-366
• /
• 2006

본 논문은 2개의 6자유도 제어가능 발판타입 플랫폼으로 이뤄진 이동인터페이스를 이용한 새로운 네비게이션 알고리즘을 제시하고 있다. 제안된 이동인터페이스는 2개의 플랫폼 위에 사람이 위치한 상태에서 사람의 걸음 모션을 센서시스템으로 예측하여 플랫폼 위에서 지속적인 걸음이 가능하도록 플랫폼을 제어하고 사용자 걸음 모션 정보를 가상환경에서의 네비게이션 입력정보로 사용한다. 따라서, 제안된 이동인터페이스는 사용자의 실제 걸음을 유도하고 걸음 동안 사용자에게 실감의 시각 피드백 제공으로 몰입감을 가지고 가상환경과 전신 운동의 상호작용을 할 수 있도록 허락한다. 이때, 가상환경 상에서 자연스런 네비게이션이 가능하도록 보행 분석에 사용되는 걸음 조건들을 사용하여 플랫폼 위에서의 자연스런 걸음 및 가상환경시스템에서의 자연스런 네비게이션이 가능토록 알고리즘을 제시하였다. 제안된 네비게이션 알고리즘 평가를 위해 3차원 객체모델러, 화면 매니져, 통신 매니져로 구성된 가상도시를 구축하여 발판타입 이동인터페이스에 네비게이션 알고리즘을 적용하였다. 실험 결과 평지 및 경사에서 사용자의 자연스런 걸음 및 시각 피드백이 가능함을 알 수 있었고, 제안된 이동인터페이스 및 네비게이션 알고리즘을 통해 다양한 형상의 가상지면에서 실감의 네비게이션이 가능함을 확인하였다.

• Journal of Electrical Engineering and Technology
• /
• 제10권5호
• /
• pp.2142-2148
• /
• 2015

This paper proposes novel real-time footstep planning and following methods for the navigation of humanoid robots. A footstep command is defined by a walking direction and step lengths for footstep planning. The walking direction is determined by a uni-vector field navigation method, and the allowable yawing range caused by hardware limitation is considered. The lateral step length is determined to avoid collisions between the two legs while walking. The sagittal step length is modified by a binary search algorithm when collision occurs between the robot body and obstacles in a narrow space. If the robot body still collides with obstacles despite the modification of the sagittal step length, the lateral step length is shifted at the next footstep. For footstep following, a walking pattern generator based on a 3-D linear inverted pendulum model is utilized, which can generate modifiable walking patterns using the zero-moment point variation scheme. Therefore, it enables a humanoid robot to follow the footstep command planned for each footstep. The effectiveness of the proposed method is verified through simulation and experiment.

• 한국항해항만학회지
• /
• 제37권3호
• /
• pp.239-244
• /
• 2013

본 연구는 승선 생활에 미숙련된 일반승객이 해상재난 발생 시 여객선 내에서의 안전성을 확보하고 피난성능을 향상시키기 위한 기술 개발에 반드시 필요한 선박 항해 환경에 따른 승선 중 보행속도를 실측실험을 통해 취득하고 이를 비교 분석한 것이다. 81명의 남녀 대학신입생이 참가한 승선 실험에서, 평면복도 직선부에서의 평균보행속도는 항해시가 정박시보다 27.2%, 평면복도 코너부에서는 23.2% 느려지는 것으로 나타나 항해중 선박 동요에 따른 속도 저하가 크다는 사실을 알 수 있다. 항해상태에서 실측된 상향계단과 하향계단에서의 평균보행속도는 각각 0.71m/s, 0.75m/s으로 측정되었다. 군집충돌 이동실험에서는 인근 보행자와의 보행 간섭으로 인해 후미로 갈수록 보행속도가 느려지고, 선두의 이동속도가 군집 전체의 이동속도에 큰 영향을 준다는 사실을 확인하였다.

• Journal of Positioning, Navigation, and Timing
• /
• 제12권4호
• /
• pp.399-408
• /
• 2023

In this paper, we propose a solution that enables continuous indoor/outdoor positioning of smartphone users through the integration of Pedestrian Dead Reckoning (PDR) and GPS/WiFi signals. Considering that accurate step detection affects the accuracy of PDR, we propose a Deep Neural Network (DNN)-based technology to distinguish between walking and non-walking signals such as walking in place. Furthermore, in order to integrate PDR with GPS and WiFi signals, a technique is used to select a proper measurement by distinguishing between indoor/outdoor environments based on GPS Dilution of Precision (DOP) information. In addition, we propose a technology to adaptively change the measurement error covariance matrix by detecting measurement outliers that mainly occur in the indoor/outdoor transition section through a residual-based χ² test. It is verified through experiments on a testbed that these technologies significantly improve the performance of PDR and PDR/GPS/WiFi fingerprinting-based integrated pedestrian navigation.

• Educational Technology International
• /
• 제21권2호
• /
• pp.125-153
• /
• 2020

The advancement of virtual reality technology offers various locomotion options that support users' navigation behaviors in a virtual reality environment. This study was aimed at examining the effects of two navigation methods-joystick-controlling and walking-around-on users' perceived usability, behavioral engagement, and virtual presence. Fifty South Korean college students were recruited in the study, and they were assigned randomly to one of the two navigation conditions. Participants from each group were asked to observe a 3D object and complete the surveys. They were then asked to repeat the procedure with a 2D image. Using repeated-measures ANOVAs and MANOVA, we found that users using joystick-controlling reported higher usability and showed superior performance to the walking-around group on two tasks. Participants reported a higher behavioral engagement when observing the 2D image. Besides, they perceived a significantly higher virtual presence when observing the 2D image. Finally, we discussed the implications of the findings for the navigation method design.

• 한국정밀공학회지
• /
• 제16권4호통권97호
• /
• pp.138-147
• /
• 1999

For autonomous navigation, a legged robot should be able to walk over irregular terrain and adapt itself to variation of supporting surface. Walking through slope is one of the typical tasks for such case. Robot needs not only to change foot trajectory but also to adjust its configuration to the slope angle for maintaining stability against gravity. This paper suggests such adaptation algorithm for stable walking which uses feedback of reaction forces at feet. Adjusting algorithm of foot trajectory was studied with the estimated angel of slope without visual feedback. A concept of virtual slope angle was introduced to adjust body configuration against slope change of the supporting terrain. Regeneration of foot trajectory also used this concept for maintaining its stable walking against unexpected landing point.

• 제어로봇시스템학회논문지
• /
• 제8권12호
• /
• pp.1067-1075
• /
• 2002

The system error model for the compensation of the low-cost personal navigation system is derived and the error compensation method using GPS is also proposed. The walking navigation system (WNS) that calculates navigation information through walking detection has small error than INS, but the error also increases with time. In order to improve reliability of the system regardless of time, WNS is integrated with GPS. Since WNS is usually used in urban area, the blockage of CPS signal is frequently occurred. Therefore tightly coupled Kalman filter is used for the integration of WNS and GPS. In this paper, the system model for the design of tightly coupled Kかm filter is designed and measurement is linearized in consideration of moving distance error. It is shown by Monte Carlo simulation that the error is bounded even through the number of visible satellite is less than 4.