• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.779-788
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• 2016

In this paper, a global path replanning method is proposed in order to plan a global path minimizing the risk of the unmanned vehicle on the battlefield. We first introduce 4D environmental information consisting of mobility, visibility, kill, and hit attributes, and a unified threat map and a mobility map are defined by the four attributes. Using the mobility map, the unmanned vehicle can find the shortest path on the traversable area. And then taking into account the deterrent according to the type of the unmanned vehicle on the integrated threat map, the vehicle can generate a route to suppress or avoid the threat of enemy as well. Moreover, we present a waypoints bypassing method to exclude unnecessary waypoints rather than the mission point when planning paths for the multiple waypoints.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.4
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• pp.430-435
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• 2011

In this paper, a navigation technology of an unmanned vehicle using relative localization and magnetic guidance is proposed. Magnetic guidance system had been developed as a robust autonomous driving technology as long as magnetic fields on the path are detected. Otherwise, if magnetic fields were not detected due to some reasons, the vehicle could not drive. Therefore, in order to overcome the drawback, we propose that relative localization would be combined to magnetic guidance system. To validate the usefulness of the proposed method, a robotic vehicle was set up with the magnetic guidance system and the relative localization. In addition, the unmanned driving test was realized on the road without the magnetic fields so that the proposed method is verified by the experiment.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.114-126
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• 2009

The authors adopt the Unmanned Undersea Vehicle(UUV), which has taken the shape of manta(Sohn et al. 2006). They call here it Manta-type Unmanned Undersea Test Vehicle(MUUTV). MUUTV is based on the same design concept as UUV called Manta Test Vehicle, which was originally built and operated by the Naval Undersea Warfare Center(Lisiewicz and French 2000, Sirmalis et al. 2001). In order to evaluate manoeuvring motion characteristics of MUUTV, numerical simulation technique has been utilized. Previous mathematical model on manoeuvring motion of MUUTV(Sohn et al. 2006) is basically adopted. Result of static experiment carried out in circulating water channel and a part of NSRDC standard model(Feldman 1979) on rotational mode are supplemented. Some of the hydrodynamic derivatives are obtained from model experiment in circulating water channel and the rest of them are estimated.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.1
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• pp.31-40
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• 2021

The important goal of the unmanned vehicle technology is on controlling the direction and speed of the vehicle with information acquired from various sensors, without the intervention of the driver, until the vehicle reaches to its destination. In this paper, our focus is on developing an unmanned conveyance system by exploiting low-cost sensing technology for indoor factories or warehouses, where the moving range of the vehicle is limited. To this end, we propose an architecture of a scalable automated conveyance system. Our proposed system includes a number of unmanned conveyance vehicles, and the efficient control mechanism of the vehicles without neither conflicts nor deadlock between the vehicles being simultaneously moved. By implementing the real prototype of the system, we successfully verify the efficiency and functionality of the proposed system.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.4
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• pp.243-248
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• 2005

The UAV (Unmanned Aerial Vehicle) systems like unmanned autonomous helicopters are used in various missions of flight navigation and used to collect the environmental information of the surroundings. To realize the full functionalities of the UAV, the software part becomes a challenging problem. In this paper embedded real-time software architecture for unmanned autonomous helicopter is proposed that guarantee real-time performance of hard-real time tasks and re-configurability of soft-real time and non-real time tasks. The proposed software architecture has four layers: hardware, execution, service agent and remote user interface layer according to the reactiveness level for external events. In addition, the layered separation of concurrent tasks makes different kinds of mission reconfiguration possible in the system. An Unmanned autonomous helicopter system was implemented (Kyosho RC Helicopter) in our lab to test and evaluate the performance of the proposed system.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.78-84
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• 2006

This paper describes UAV (Unmanned Aerial Vehicle) control system which employs PC104 modules. It is controlled by application program based on Linux OS. This application consists of both Linux device driver in kernel-space and user application in user-space. In order to get data required in the unmanned flight, external devices are connected to PC104 modules. We explain how Linux device drivers deal with data transmitted by external devices and we account for how the user application controls UAV on the basis of data processed in the device driver as well. Furthermore we look into the role of GCS (Ground Control Station) which is to monitor the state of UAV.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.359-370
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• 2007

Lane tracking and obstacle avoidance are considered two of the key technologies on an unmanned ground vehicle system. In this paper, we propose a method of lane tracking and obstacle avoidance, which can be expressed as vehicle control, modeling, and sensor experiments. First, obstacle avoidance consists of two parts: a longitudinal control system for acceleration and deceleration and a lateral control system for steering control. Each system is used for unmanned ground vehicle control, which notes the vehicle's location, recognizes obstacles surrounding it, and makes a decision how fast to proceed according to circumstances. During the operation, the control strategy of the vehicle can detect obstacle and perform obstacle avoidance on the road, which involves vehicle velocity. Second, we explain a method of lane tracking by means of a vision system, which consists of two parts: First, vehicle control is included in the road model through lateral and longitudinal control. Second, the image processing method deals with the lane tracking method, the image processing algorithm, and the filtering method. Finally, in this paper, we propose a method for vehicle control, modeling, lane tracking, and obstacle avoidance, which are confirmed through vehicles tests.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.856-864
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• 2008

This paper describes a vehicle low speed driving assistant (VLDA) system that is composed of laser scanner. This vehicle is designed for following lead vehicle (LV) without driver's operation. The system is made up several component systems that are based on unmanned ground vehicle (UGV). Each component system is applied to use advanced safety vehicle developed to complete UGV system. VLDA system was divided into vehicle control system and obstacle detecting system. The obstacle detecting system calculate distance and angle of LV and transmit these data to vehicle control system using front, left and right laser scanners. Vehicle control system makes vehicle control values such as steering angle, acceleration and brake position and control vehicle's movement with steering, acceleration and brake actuators. In this research, we designed VLDA system like as low speed cruise control system and test it on real road environments.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.553-558
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• 2010

In this paper, we proposed a teleoperation scheme of unmanned grounded vehicle to improve telepresence. Especially, bilateral control architecture for transmitting realistic steering feeling to the remote driver is investigated. System architecture of the teleoperated remote vehicle is introduced with visual, auditory and kinesthetic haptic channel. Several bilateral control architectures are proposed for transmitting remote steering feeling, and subject tests are done to evaluate the performance. Position-force bilateral control architecture with returning torque compensation algorithm shows best performance.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.27-35
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• 2008

A navigation system is one of the important components of an unmanned ground vehicle (UGV). A GPS receiver collects data signals transmitted by (Earth orbiting) satellites. However, these data signals may contain many errors resulting misinformation and depending on one's position (environment), reception may be impossible. The proposed self-driven algorithm uses three low-cost GPS in order to minimize errors of existing inexpensive single GPS's driving algorithm. By using reliable final data, which is analyzed and combined from each of three GPS's received data signals, gathering a vehicle's steering performance information and its current pin-point position is improved even with error containing signals or from a place where signal gathering is impossible. The purpose of this thesis is to explain navigation system algorithm using multiple GPS and compass sensor and prove the algorithm through experiments.