• Journal of KIISE
• /
• v.43 no.2
• /
• pp.222-228
• /
• 2016

Uniform navigation of NPCs in computer games is an important factor that can decrease the interest of game players. This problem is particularly noticeable in pathfinding when using a waypoint graph because the NPCs navigate using only predefined locations. In this paper we propose a method that enables adaptive navigations of NPCs by observing player movements. The proposed method involves modification of waypoints dynamically by observing the player's point designation and use of the modified waypoints for NPC's pathfinding. Also, we propose an algorithm to find the NPC-specific path by learning the landform preferences of players. We simulate the implemented algorithm in an RPG game made with Unity 4.0 and confirm that NPC navigations had more variety and improved according to player navigations.

• The KIPS Transactions:PartC
• /
• v.17C no.2
• /
• pp.181-189
• /
• 2010

HAP(High Altitude Platform) is a stationary aerial platform positioned in the stratosphere between 17Km and 22Km height and it could act as an MBS (Mobile Base Station). HAP based Network has advantages of both satellite system and terrestrial communication system. In this paper we study the deploy of multiple HAP MBS that can provides efficient communication for users. For this study, EM(Expectation Maximization) clustering algorithm is used to cluster terrestrial mobile nodes. The object of this paper is improving EM algorithm into the clustering algorithm for efficiency in variety aspects considering distance between mobile terminal units and speed of mobile terminal units, and estimating performance of HAP MBS deploy technique with use of improved EM algorithm using RWP (Random Waypoint) node mobility.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.11a
• /
• pp.105-110
• /
• 2008

Unmanned helicopter has several abilities such as vertical take off, hovering, low speed flight at a specific altitude. Such vehicles are becoming popular in actual applications such as search and rescue, aerial reconnaissance and surveillance in the case of a large size disaster and forest fire. In this paper, a flight control system was designed for an unmanned helicopter. This paper was concentrated on describing the systematic design, electronic equipments and their interconnections for realizing the autonomous flight and aerial monitoring. A study on the autonomous waypoint navigation and altitude control performance were performed and tested on a test unmanned helicopter and the performance and the feasibility were represented.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2002.05a
• /
• pp.131-134
• /
• 2002

운항경비의 절감과 같은 경제적 제한과 3D직종 회피현상과 같은 사회적 제한으로 인해 선박의 운항에 소요되는 인원을 최소화하는 요구가 증가되고 있다. 이러한 요구에 부합하기 위해 선박의 자동화 및 지능화기술이 요구된다. 선박의 자동화를 위해서는 GPS와 전자해도에 기반한 지능형 항해시스템의 항로계획이 선행되어야 한다 본 논문에서는 지능형 항해시스템의 자동화된 항로계획을 위해 S-57에 정의되어 있는 좌표쌍을 기반으로한 접점산출기법과 이를 이용한 트리생성 기법, 그리고 생성된 트리구조를 기반으로한 항로산출기법을 제안한다 제안한 항로산출기법의 효율성 검증을 위해 최적화 관점에서 대표적 항로계획 기법인 $A^{*}$ 와 이를 개선한 RPAP 기법과 비교.분석한다.

• International Journal of Aeronautical and Space Sciences
• /
• v.10 no.1
• /
• pp.58-66
• /
• 2009

Formation controller for multiple spacecrafts is designed based on a decentralized approach. The objective of the proposed controller is to make each spacecraft fly to the desired waypoints, while keeping the formation shape of multiple spacecrafts. To design the decentralized formation controller, the output feedback linearization technique using error functions for goal convergence and formation keeping is utilized for spacecraft dynamics. The primary contribution of this paper is to proposed optimal controller for formation flying based on the decentralized approach. To design the optimal controller, eigenvalue assignment technique is used. To verify the effectiveness of the proposed controller, numerical simulations are performed for three-dimensional waypoint-passing missions of multiple spacecrafts.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 1998.10b
• /
• pp.65-73
• /
• 1998

Ship's positino data obtaining method is ine of the very important factor innavigation . Nowadays, GPS(Global Positioning System) using the earth orbiting satellites are equipped and operated for the position finding. Because it provides more precise position information than other equipments and is very convenient for navigator. In this study, it is designed to develop the GPS simulator for everybody being able to proactise the GPS operating skill like as navigation planning, navigation calculating etc. And also, it can be operated with personal computer without real GPS receiver. This simulation system is based on the real GPS receiver system and built by the visual basic 5.0 program. And it displays the ship's position and navigating information and plots the ship's moving track on the screen in real time according as initial setup data-main engine's rpm, rudder angle, depature position and waypoint.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.06a
• /
• pp.287-289
• /
• 2014

선박의 선위 추측(DR, Dead Reckoning)은 수신되거나 측정된 위치 데이터와 속력, 침로 데이터만을 반영하여 계산하므로 대양의 항해나 연근해의 해역에서는 유효할 수 있으나 침로의 변경과 선속의 변화가 잦은 항계 내의 조선에 있어서는 적용이 어렵다는 문제점이 있다. 본 논문에서 제안하는 선박의 추측위치(DRP, Dead Reckoning Position)는 선박의 운항 패턴에 따라 항계 내의 항적 데이터를 수집하고, 수신된 위치 데이터와 속력, 침로 데이터를 점장위도항법(Mercator Sailing)을 통하여 계획항로(Planned Route)의 각 변침점(WP, Waypoint)간 침로(Course)와 항정(Ship's Passage)에 반영하였다. 제안된 추측위치 산출방법을 통하여 항계 내의 조선과정에서 계획항로를 선박의 추측위치와 결합하여 특정 시간 후의 상황패턴을 미리 예측하고 관제사의 의사결정에 기여하고자 한다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.12
• /
• pp.1238-1243
• /
• 2008

This paper presents an HILS(Hardware in the Loop Simulations) based experimental study for the UAV's flight trajectory planning/generation algorithms and guidance/control laws. For the various mission that is loaded on each waypoint, proper trajectory planning and generation algorithms are applied to achieve best performances. Specially, the 'smoothing path' generation and the 'tangent orbit path' guidance laws are presented for the smooth path transitions and in-circle loitering mission, respectively. For the control laws that can minimize the effects of side wind, side slip angle($\beta$) feedback to the rudder scheme is implemented. Finally, being implemented on real hardwares, all the proposed algorithms are validated with integrations of hardware and software altogether via HILS.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.6
• /
• pp.526-530
• /
• 2011

This paper presents a new fuzzy model-based design approach for waypoints-tracking control of nonlinear underwater vehicles (UUVs) on a horizontal plane. The waypoints-tracking control problem is converted into the stabilization one for the error model between the given nonlinear UUV and the waypoints. By using the sector nonlinearity, the error model is modeled in Takagi-Sugeno's form. We then derive stabilization conditions for the error model in the format of linear matrix inequality. A numerical simulation is provided to illustrate the effectiveness of the proposed methodology.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.1
• /
• pp.89-93
• /
• 2009

This paper deals with obstacle avoidance for unmanned vehicle using stereo system. The "DARPA Grand Challenge 2005" shows that the robot can move autonomously under given waypoint. RADAR, IMS (Inertial Measurement System), GPS, camera are used for autonomous navigation. In this paper, we focus on stereo system for autonomous navigation. Our approach is based on Singh et. al. [5]'s approach that is successfully used in an unmanned vehicle and a planetary robot. We propose an improved algorithm for obstacle avoidance by modifying the cost function of Singh et. al. [5]. Proposed algorithm gives more sharp contrast in choosing local path for obstacle avoidance and it is verified in experimental results.