• 한국군사과학기술학회지
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• 제19권6호
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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.

• 제어로봇시스템학회논문지
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• 제18권10호
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• pp.940-946
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• 2012

This paper proposes a method to predict maximum traction for unmanned robots on rough terrain in order to improve traversability. For a traction prediction, we use a friction-slip model based on modified Brixius model derived empirically in terramechanics which is a function of mobility number $B_n$ and slip ratio S. A friction-slip model includes characteristics of various rough terrains where robots are operated such as soil, sandy soil and grass-covered soil. Using a friction-slip model, we build a prediction model for terrain parameters on which we can know maximum static friction and optimal slip with respect to mobility number $B_n$. In this paper, Mobility number $B_n$ is estimated by modified Willoughby Sinkage model which is a function of sinkage z and slip ratio S. Therefore, if sinkage z and slip ratio are measured once by sensors such as a laser sensor and a velocity sensor, then mobility number $B_n$ is estimated and maximum traction is predicted through a prediction model for terrain parameters. Estimation results for maximum traction are shown on simulation using MATLAB. Prediction Performance for maximum traction of various terrains is evaluated as high accuracy by analyzing estimation errors.

• Journal of Astronomy and Space Sciences
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• 제29권4호
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• pp.413-422
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• 2012

In recent years, a number of missions have been planned and conducted worldwide on the planets such as Mars, which involves the unmanned robotic exploration with the use of rover. The rover is an important system for unmanned planetary exploration, performing the locomotion and sample collection and analysis at the exploration target of the planetary surface designated by the operator. This study investigates the development of mobility system for the rover ground model necessary to the planetary surface exploration for the benefit of future planetary exploration mission in Korea. First, the requirements for the rover mobility system are summarized and a new mechanism is proposed for a stable performance on rough terrain which consists of the passive suspension system with 8 wheeled double 4-bar linkage (DFBL), followed by the performance evaluation for the mechanism of the mobility system based on the shape design and simulation. The proposed mobility system DFBL was compared with the Rocker-Bogie suspension system of US space agency National Aeronautics and Space Administration and 8 wheeled mobility system CRAB8 developed in Switzerland, using the simulation to demonstrate the superiority with respect to the stability of locomotion. On the basis of the simulation results, a general system configuration was proposed and designed for the rover manufacture.

• 항공우주시스템공학회지
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• 제15권4호
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• pp.64-74
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• 2021

Unmanned Aircraft Systems (UAS) are rapidly emerging not only as a key military power, such as surveillance and reconnaissance for military purposes but also as a new air transportation means in the form of Urban Air Mobility (UAM). Currently, airworthiness certification is carried out focused on the verification of technical standards for flight safety suitability of aircraft design in accordance with the Military Aircraft Flight Safety Certification Act and does not employ the model for operational risk assessment for mission areas and airspace. In this study, in order to evaluate the risk of the mission area from the perspective of the UAS operator, a risk assessment simulation has been conducted by applying the Specific Operations Risk Assessment (SORA) model to the operating environment of the Korean military UAS. Also, the validity of the SORA model has been verified through the analysis of simulation results, and a new application plan for airworthiness certification of the military unmanned aerial system has been presented.

• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.235-242
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• 2021

Unmanned Aerial Vehicles (UAVs), which were used for military purposes, are gradually expanding their application fields under the influence of electrification and digitalization. Starting from the field of aerial imaging and Intelligence Surveillance and Reconnaissance (ISR) mission, nowadays the possibility of Urban Air Mobility (UAM), which transports passengers and cargo with drones, is widely under discussion. In order to occupy the rapidly growing global unmanned aerial vehicle market in advance, it is necessary to secure core technologies and develop key UAVs components based on the new technologies. In the navigation field, it is necessary to secure a precise position with guaranteed reliability and continuity, unrelated to the operating environments. The reliability and continuity should be secured in the algorithm level and in the H/W component levels also. In order to achieve this technical goal, the Ministry of Science and ICT has launched the 'Unmanned Vehicle Core Technology Research and Development Program' in 2019 to support the R&D on the unmanned vehicle technologies. In this paper, authors introduce the unmanned vehicle core technology research and development program to the related researchers. The authors summarize the backgrounds of the program and show the technological tasks and objectives on the sub-programs in the unmanned vehicle navigation program. We present the program schedules especially focused on the test and evaluation of the developed technologies and components.

• 대한산업공학회지
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• 제40권4호
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• pp.388-395
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• 2014

Nowadays unmanned ground systems are used in supporting of surveillance and explosive ordnance disposal. Also, we expect that will be used to remarkably enhance combat capability through network-based cooperative operations with other combat systems. In order to effectively develop those unmanned systems, we needs a systematic method to analyze combat effectiveness and validate required operation capabilities. In this paper, we propose a practical approach to simulate remote-operated unmanned ground systems by using OneSAF, an US-Army simulation framework. First of all, we design a simulation model of unmanned system by integrating with core components for wireless communications and remote control of mobility and fire. Next, we extend OneSAF functionality to create communication links that connects a remote controller with an unmanned vehicle and define a simulated behavior to operate unmanned vehicles via the communication links. Finally, we demonstrate the feasibility of the proposed model within OneSAF and summarize system effectiveness analysis results.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.1-9
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• 2007

A major concern for Autonomous Military Robot in the rough terrain is the problem of moving robot from an initial configuration to goal configuration. In this paper, We generate a local path to looking for the best route to move an goal configuration while avoiding known obstacle from world model, not violating the mobility constraints of robot. Trough a Simulator for Unmanned Autonomous Vehicle, We can simulate a traversability of unmanned autonomous vehicle based on steering, acceleration, braking command obtained from local path planning.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1773-1795
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• 2020

Unmanned aerial vehicles (UAVs) network are a very vibrant research area nowadays. They have many military and civil applications. Limited bandwidth, the high mobility and secure communication of micro UAVs represent their three main problems. In this paper, we try to address these problems by means of secure clustering, and a security clustering algorithm based on integrated trust value for UAVs network is proposed. First, an improved the k-means++ algorithm is presented to determine the optimal number of clusters by the network bandwidth parameter, which ensures the optimal use of network bandwidth. Second, we considered variables representing the link expiration time to improve node clustering, and used the integrated trust value to rapidly detect malicious nodes and establish a head list. Node clustering reduce impact of high mobility and head list enhance the security of clustering algorithm. Finally, combined the remaining energy ratio, relative mobility, and the relative degrees of the nodes to select the best cluster head. The results of a simulation showed that the proposed clustering algorithm incurred a smaller computational load and higher network security.

• 한국군사과학기술학회지
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• 제13권3호
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• pp.343-348
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• 2010

Recently, unmanned electric vehicles are increasingly interested among all of the world since they can provide low exhaust gas, high efficiency and high mobility. To exploit their silent maneuver and high mobility, unmanned electric vehicles have been developed since early 1980's for military. However, it is not easy to design and control a power system satisfying operating duration and mobility performance requirements based on various mission profiles for military use under the conditions of limited space and weight. Moreover it is also necessary to prevent over-charge, over-discharge and voltage unbalance between cells of battery to secure high voltage battery which is serially connected with muti-cells. In this paper, we presents power control and optimal management method for the dog-horse robot which adopts a electric power system and suggests a guide-line to manage and control to secure high voltage battery.

• 전자통신동향분석
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• 제38권3호
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• pp.1-10
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• 2023

In this study, the status of global advanced air mobility (AAM) was investigated to derive information and communications technologies (ICTs) that should be prepared according to directions of domestic AAM development. AAM is an urban air traffic system for moving from city to city by electric vertical take-off and landing or personal aircraft. It is expected to establish a three-dimensional air traffic system that can solve ground traffic congestion caused by the rapid global urbanization. With the full-scale commercialization of AAM solutions, high-density air traffic is expected, and with the advent of the personal air vehicle (PAV), the flight space usage is expected to expand. Therefore, it is necessary to develop a safe AAM service through early research on core ICTs for autonomous flight.