• 한국해양공학회지
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• 제26권5호
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• pp.81-86
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• 2012

Unmanned underwater vehicles have many applications in scientific, military, and commercial areas because of their autonomy. In many cases, an underwater vehicle adopts a control algorithm based on a tactical inertial sensor for precise control. However, a control algorithm that uses a tactical inertial sensor is unsuitable for some underwater vehicle missions such as torpedo decoys. This paper proposes a control algorithm for an unmanned underwater vehicle that does not require precise control. The control algorithm proposed for an unmanned underwater vehicle adopts a low cost MEMS inertial sensor, and simulations using the specifications of the MEMS inertial sensor under development are performed to verify the control algorithm under a real environment. The results of these simulations are presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1308-1311
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• 1996

We propose a new linearized model which can be used very efficiently for the design and analysis of the autopilot of aerodynamically controlled skid-to-turn missiles. Proposed model is based on the linearized equations of the missile dynamics derived in the aerodynamic frame where xz plane contains the missile longitudinal axis and velocity vector. However, to take the effect due to the small perturbation of the missile body into consideration, we introduce a new frame which is identical to the aerodynamic frame in the trim state but after small perturbation it moves fixed with the missile body, and finally, the proposed model is set up in this frame. It is shown by nonlinear simulations and stability analysis of a numerical example that the new model describes the missile motion better than the conventional one linearized in the body frame with a certain amount of simplification.

• 대한조선학회논문집
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• 제34권2호
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• pp.56-63
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• 1997

본 논문에서는 신경망을 이용한 자동조타장치의 개발에 관한 연구결과를 소개한다. 본 연구에서는 먼저 신경망이론에 사용되는 대표적인 방법인 Back-Propagation 알고리즘의 원리를 설명하고 이를 이용하여 선박의 조종모델을 신경망으로 재구성하는 방법을 제시하였다. 신경망이론을 사용하여 선박운동모델을 System Identification 하는 경우의 문제점을 간단한 조종모델을 이용하여 수치적으로 검증하고 보다 복잡한 모델로 적용하는 경우에 대한 토의를 하였다. 본 논문에서 개발된 신경망이론들은 비선형성을 내포하고 있는 선박운동을 재구성하는데 효과적으로 사용될 수 있을 것으로 기대된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.48.3-48
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• 2001

A gain-scheduled autopilot design for a bank-to-turn (BTT) missile is developed by using the Linear Matrix Inequality (LMI) optimization technique and a state-space lineal interpolation method. The missile dynamics are brought to a quasilinear parameter varying (quasi-LPV) form. Robust linear control design method is used to obtain state feedback controllers for the LPV systems with exogenous disturbances at the frozen values of the scheduling parameters. Two gam-scheduled controllers for the pitch axis and the yaw/roll axis are constructed by linearly interpolating the robust state-feedback gains. The designed controller is applied to a nonlinear six-degree-of-freedom (6-DOF) simulations.

• 제어로봇시스템학회논문지
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• 제6권8호
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• pp.727-731
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• 2000

This paper presents a new practical autopilot design approach to acceleration control for tail-controlled STT(Skid-to-Turn) missiles. The approach is novel in that the proposed parametric affine missile model adopts acceleration as th controlled output and considers the couplings between the forces as well as the moments and control fin deflections. The aerodynamic coefficients in the proposed model are expressed in a closed form with fittable parameters over the whole operating range. The parameters are fitted from aerodynamic coefficient look-up tables by the function approximation technique which is based on the combination of local parametric models through curve fitting using the corresponding influence functions. In this paper in order to employ the results of parametric affine modeling in the autopilot controller design we derived a parametric affine missile model and designed a feedback linearizing controller for the obtained model. Stability analysis for the overall closed loop sys-tem is provided considering the uncertainties arising from approximation errors. the validity of the proposed modeling and control approach is demonstrated through simulations for an STT missile.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.577-585
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• 2015

This paper deals with development of an autopilot system for leisure yacht based on NMEA 2000 network and android platform. The developed system can operate both for manual steering and automatic navigation mode. In automatic steering mode, after manipulation of commands which are NMEA 0183 sentences by android platform, the developed system translates and sends the packets through NMEA 2000 network. Then the controller which is connected to NMEA 2000 network receives the commands and controls the boat's rudder system automatically. The automatic steering mode is achieved by cooperation of two controllers; one for controlling the rudder system, and the other for controlling the vessel's heading. To control the vessel's rudder and heading angle two PID controllers are developed with an adjustable dead-band gain. Also, in order to eliminate the steady-state error occurred by applying dead-band, an integral controller which specifically supervises the system's behavior inside the dead-band area is developed. In this paper, at the first stage, simulations are accomplished using computer in order to examine the feasibility of the proposed based on simulation results. In the next step, the system on a real hydraulic steering model is implemented and at the end the performance examination by implementing it on a real boat and doing test navigation is executed.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1996년도 The Korean Institute of Navigation 1996년도 춘계학술발표회 논문집
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• pp.77-92
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• 1996

When an automatic course-keeping is concerned as is quite popular in modern navigation the closed-loop steering system consists of autopilot device power unit (or telemotor unit) steering gear magnetic or gyro compass and ship dynamics. The consideration of irregular disturbances to ship dyanmics and a few non-linear mechanisms involved in the system inevitably or artificially are known to be very important in properly evaluating or analyzing the automatic steering system. In the present study the mathematical model of each element of an automatic steering system is derived which takes account of a fex non-linear mechanisms. PD(Proportional-Derivative) controller and low-pass filter with a weather adjustment are adopted to modelling the characteristics of an autopilot. The calculation method of imposing irregular disturbances to ship dynamics is proposed where irregular disturbances implying irregular wave and the fluctuating component of wind. For he evaluation of automatic steering system of ships in the open seas an important term "performance index" is introduced from the viewpoint of energy saving which derived from the concept of energy loss on ship propulsion. Finally the present methods are applied to two typical types of ship ; an ore carrier and a fishing boat. The various effects of linear and/or non-linear control constants of autopilot on propulsive energy loss are investigated to validate and clarify the present smulation technique.

• 전자공학회논문지S
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• 제36S권6호
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• pp.45-56
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• 1999

본 논문에서는 추종 성능을 향상시키기 위해 표준모델의 2자유도 위너-호프 제어 기법을 이용하여 BTT유도탄의 자동조종장치를 설계하였다. 유도탄의 비선형 방정식으로부터 여러 동작점에 대한 선형화 모델을 구하여 선형 제어기를 설계하였으며 최종 자동조종장치는 설계된 제어기들을 이득 계획 기법을 이용하여 구성하였다. 실제 적용성을 검증하기 위하여 유도탄의 정확한 비선형 방정식과 공력 계수의 변화 등을 포함하는 6 자유도 방정식 프로그램을 이용하여 유도탄의 비행 동작에 대한 모의실험을 수행하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.361-366
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• 1991

A ground and airborne control system for remotely piloted vehicle (RPV) is described. 1) Ground control system 2) airborne control system 3) the method of measuring aircraft attitude and heading 4) autopilot 5) the method of treating emergency status 6) the method of transmitting and receiving communication data 7) the method of displaying aircraft status 8) the characteristics of the aircraft control system are discussed in some detail.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1063-1067
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• 1993

Fuzzy logic is applied to a roll autopilot for missiles. Fuzzy rules are made so that the response duplicates that of the conventional control law for some flight condition. A scaling factor of the fuzzy controller is then scheduled by the missile velocity and altitude information to cope with the variation of the roll dynamics from that flight condition. By computer simulations and calculation of the stability margin, it is shown that the fuzzy control is robuster than the conventional one over the flight envelope even though two control laws work similarly for some flight conditions.