• Proceedings of the KSR Conference
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• 2009.05a
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• pp.424-432
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• 2009

This paper discusses about the implementation of a simulator for the Navigation Control System(NCS) of bimodal tram. To operate a NCS of bimodal tram, values of all sorts of sensors installed in bimodal tram should be transmitted to the NCS, and the NCS calculates the measured sensor values to determine traveling direction, traveling speed, current position etc. The implementation of the simulator consists of a device applying driver's input transaction function & virtual sensor program and a sub-rack device that controls communication with the NCS to evaluate navigation control function. The virtual sensor program can create routes (map), traveling profiles & seat information et cetera in order to transmit to the NCS, analyzes driver's input values and NCS output values to create virtual sensor values. The sub-rack device takes charge of communication with the NCS using CAN-OPEN, CAN-J1939, MVP protocols. This paper discusses about the implementation of the simulator and afterwards analyzes and evaluates the NCS simulation results.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.196-202
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• 2021

Currently, as Korea enters into a fast aging society, the problem of dementia population is increasing. In this paper, we intend to contribute to the improvement of welfare for the elderly by developing virtual reality technology and related interface technology to effectively perform hand movements known as effective methods for preventing and treating dementia. As the content of the research and development of this paper, it is designed to be easy for the elderly to use and stimulate brain function by applying VR technology using sensors, and to activate mental and physical activities for the elderly who are marginalized in terms of cultural welfare. We intend to develop by classifying the types of games and contents that can induce them. As a result of this thesis, we developed contents using virtual reality to improve cognitive abilities for elderly people with poor cognitive ability to activate the brains of users' cognition, memory, and attention to prevent and treat dementia I want to contribute.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.845-850
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• 2009

Localization which estimates a robot's position and orientation in a given environment is very important for mobile robot navigation. Although low-cost sensors are preferred for practical service robots, they suffer from the inaccurate and insufficient range information. This paper proposes a novel approach to increasing the success rate of low-cost sensor-based localization. In this paper, both the previous and the current data obtained from the IR sensors are used for localization in order to utilize as much environment information as possible without increasing the number of sensors. The sensor model used in the monte carlo localization (MCL) is modified so that the accumulated range information may be used to increase the accuracy in estimating the current robot pose. The experimental results show that the proposed method can robustly estimate the robot's pose in indoor environments with several similar places.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.120-122
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• 2004

Wearable input device that can make free-space typewriting possible is introduced. We named this device as $SCURRY^{TM}$. To measure the angular velocity of hand and the acceleration rates at the ends of fingers, we buried MEMS inertial sensors in this keyboard. We processed sensor signals to get the information on hand movement and finger-click motion. With this signal processing, apparent finger movements were depicted over the virtual keyboard shown on output device of a target computing system. In this paper, a finger-click recognition method is proposed to improve the recognition performance for finger clicking of $SCURRY^{TM}$. The proposed method is composed of three parts including feature extraction part, valid click part, and cross-talk avoidance part. The experiments were conducted to verify the effectiveness and efficiency of the proposed algorithms.

• Electronics and Telecommunications Trends
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• v.34 no.2
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• pp.10-18
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• 2019

Since the introduction of CRT(Cathode Ray Tube) in the 1950s, display technologies have been developed continuously. Flat panel displays such as PDP(Plasma Display Panel) and LCD(Liquid Crystal Display) were commercialized in the late 1990s, and OLED(Organic Light Emitting Diodes) and Micro-LED(Micro-Light Emitting Diodes) are now being developed and are becoming widespread. In the future, we expect to develop ultra-realistic, flexible, embedded sensor displays. Ultra-realistic display can be applied to AR/VR(Augmented Reality/Virtual Reality) devices and spatial light modulators for holography. The sensor-embedded display can be applied to robots; electronic skin; and security devices, including iris recognition sensors, fingerprint recognition sensors, and tactile sensors. AR/VR technology must be developed to meet technical requirements such as viewing angle, resolution, and refresh rate. Holography requires optical modulation technology that can significantly improve resolution, viewing angle, and modulation method to enable wide-view and high-quality hologram stereoscopic images. For electronic skin, stable mass production technology, large-area arrays, and system integration technologies should be developed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.141-146
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• 1996

Hand posture and force, which define aspects of the way an object is grasped, are features of robotics manipulation. A means for specifying these grasping "flavors" has been developed that uses an instrumented glove equipped with joint and force sensors. The new grasp specification system is being used at the Pennsylvania State University (Penn State) in a Virtual Reality based Point-and-Direct(VR-PAD) robotics implementation. In the Computer Integrated Manufacturing (CIM) Laboratory at Penn State, hand posture and force data were collected for manipulating bricks and other items that require varying amounts of force at multiple pressure points. The feasibility of measuring desired grasp characteristics was demonstrated for a modified Cyberglove impregnated with FSR (Force Sensitive Resistor) pressure sensors in the fingertips. A joint/force model relating the parameters of finger articulation and pressure to various lifting tasks was validated for the instrumented "wired" glove. Operators using such a modified glove may ultimately be able to configure robot grasping tasks in environments involving hazardous waste remediation, flexible manufacturing, space operations and other flexible robotics applications. In each case, the VR-PAD approach improved the computational and delay problems of real-time multiple-degree-of-freedom force feedback telemanipulation.ck telemanipulation.

• Journal of the Ergonomics Society of Korea
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• v.15 no.2
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• pp.165-176
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• 1996

Hand posture and force, which define aspects of the way an object is grasped, are features of robotic manipulation. A means for specifying these grasping "flavors" has been developed that uses an instrumented glove equipped with joint and force sensors. The new grasp specification system is being used at the Pennsylvania State University (Penn State) in a Virtual Reality based Point-and-Direct (VR-PAD) robotics implementation. In the Computer Integrated Manufacturing (CIM) Laboratory at Penn State, hand posture and force data were collected for manipulating bricks and other items that require varying amounts of force at multiple pressure points. The feasibility of measuring desired grasp characteristics was demonstrated for a modified Cyberglove impregnated with FSR (Force Sensitive Resistor) pressure sensors in the fingertips. A joint/force model relating the parameters of finger articulation and pressure to various lifting tasks was validated for the instrumented "wired" glove. Operators using such a modified glove may ultimately be able to configure robot grasping tasks in environments involving hazardous waste remediation, flexible manufactruing, space operations and other flexible robotics applications. In each case, the VR-PAD approach improved the computational and delay problems of real-time multiple- degree-of-freedom force feedback telemanipulation.

• Journal of Mechanical Science and Technology
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• v.19 no.6
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• pp.1290-1303
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• 2005

In this research, a remote control system has been developed and implemented, which combines autonomous obstacle avoidance in real-time with force-reflective tele-operation. A tele-operated mobile robot is controlled by a local two-degrees-of-freedom force-reflective joystick that a human operator holds while he is monitoring the screen. In the system, the force-reflective joystick transforms the relation between a mobile robot and the environment to the operator as a virtual force which is generated in the form of a new collision vector and reflected to the operator. This reflected force makes the tele-operation of a mobile robot safe from collision in an uncertain and obstacle-cluttered remote environment. A mobile robot controlled by a local operator usually takes pictures of remote environments and sends the images back to the operator over the Internet. Because of limitations of communication bandwidth and the narrow view-angles of the camera, the operator cannot observe shadow regions and curved spaces frequently. To overcome this problem, a new form of virtual force is generated along the collision vector according to both distance and approaching velocity between an obstacle and the mobile robot, which is obtained from ultrasonic sensors. This virtual force is transferred back to the two-degrees-of-freedom master joystick over the Internet to enable a human operator to feel the geometrical relation between the mobile robot and the obstacle. It is demonstrated by experiments that this haptic reflection improves the performance of a tele-operated mobile robot significantly.

• Journal of KIBIM
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• v.9 no.3
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• pp.1-7
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• 2019

Digital twin technology has been actively developed to monitor and assess the current state of actual structures. The digital twin changes the traditional observation method performed in the field to the real-time observation and detection system using virtual online model. Thus, this study designed a digital twin model for a beam and examined the feasibility of the digital twin for bridges. To reflect the current state of the bridge, model updating was performed according to the field test data to construct an analysis model. Based on the constructed bridge analysis model, the relationship between strain and displacement was used to represent a virtual model that behaves in the same way as the actual structure. The strain and displacement relationship was expressed as a matrix derived using an approximate analytical theory. Then, displacements can be obtained using the measured data obtained from strain sensors installed on the bridge. The coordinates of the obtained displacements are used to construct a virtual digital model for the bridge. For verification, a beam was fabricated and tested to evaluate the digital twin model constructed in this study. The displacements obtained from the strain and displacement relationship agrees well with the actual displacements of the beam. In addition, the displacements obtained from the virtual model was visualized at the locations of the strain sensor.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.261-268
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• 2022

In road work zones, pedestrian workers' habituated inattention to warning alarms from construction vehicles can lead to fatal accidents. Previous studies have theorized that human factors such as personality traits may affect workers' inattentiveness to workplace hazards. However, there has been no study that directly examined how road construction workers' personality traits affect their attention to warning alarms within a work zone and the likelihood of engagement in a struck-by accident. This study examines how workers' sensation-seeking (especially boredom susceptibility) is related to inattention to warning alarms while performing a task in road work zones. An experiment with actual road construction workers was conducted using a virtual road construction environment. Workers' attention to repeatedly presented warning alarms was measured using eye-tracking sensors. In response to workers' frequent inattentive behaviors, a virtual accident was simulated. Results revealed a significant association between boredom susceptibility and workers' engagement in the virtual accident, a consequence of inattentiveness to warning alarms. The findings suggest that workers' personality traits predispose them to tune out warning alarms and become vulnerable to accidents in road work zones. The findings of this study can be used to develop targeted interventions aimed at preventing workers' inattention to repeatedly exposed workplace hazards, thereby contributing to reducing fatal accidents in road work zones.