• 수산해양기술연구
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• 제59권2호
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• pp.145-154
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• 2023

In this study, to control the heading angle of a ship, which is constantly subjected to various internal and external disturbances during the voyage, an LADRC (linear active disturbance rejection control) design that focuses more on improving the disturbance removal performance was proposed. The speed rate of change of the ship's heading angle due to the turn of the rudder angle was selected as a significant factor, and the nonlinear model of the ship's maneuvering equation, including the steering gear, was treated as a total disturbance. It is the similar process with an LADRC design for the first-order transfer function model. At this time, the gains of the controller included in LADRC and the gains of the extended state observer were tuned to RCGAs (real-coded genetic algorithms) to minimize the integral time-weighted absolute error as an evaluation function. The simulation was performed by applying the proposed GA-LADRC controller to the heading angle control of the Mariner class vessel. In particular, it was confirmed that the proposed controller satisfactorily maintains and follows the set course even when the disturbances such as nonlinearity, modelling error, uncertainty and noise of the measurement sensor are considered.

• 수산해양기술연구
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• 제22권1호
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• pp.24-28
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• 1986

The maneuverabilities of the M. S. PUSAN 402 are studied, based on maneuvering indices and the data obtained from her Z test. The results obtained are summarized as follows: 1. The maneuvering indices K' and T' of the M. S. PUSAN 402 are 1. 490, 1.030 at 10$^{\circ}$ Z test and 2.644, 1.153 at 20$^{\circ}$ Z test and 3.382. 1. 027 at 30$^{\circ}$ Z test respectively. The above calculated values K', T' showed that her maneuverabilities are more increased when the rudder is used to large angle than to smaIl angle. 2. As her maneuvering indices K' and T' at 10$^{\circ}$ Z test are higher than the standard maneuvering indices of fishing boats, her turning ability was found to be higher but her obeying ability lower. 3. When the M. S. PUSAN 402 took a turn at her 10$^{\circ}$ test, running distance was about 8.4 times her own length and didn't exceed the standard maneuvering distance, 5 to 11 times ship's own length, therefore she was considered to have good maneuverabilities syntheticaIly.

• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.920-927
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• 1998

This paper presents a synthetic control algorithm that generates the rudder command angle to track the optimal route which is composed of straight-lines among way-points with keeping a required error limit. The control algorithm comprises three main lgorithms that is a course-keeping algorithm that eliminates the yaw angle difference between optimal route and current route a track-keeping algorithm that tracks the optimal route among way-points and a turning-control algorithm that includes the generation of optimal turning routes and control method. The effectiveness of the proposed control algorithm is assured through computer simulation.

• Journal of Advanced Research in Ocean Engineering
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• 제2권4호
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• pp.192-201
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• 2016

This study examined a PD controller and its application to automatic berthing control of an unmanned surface vehicle (USV). First, a nonlinear mathematical model was established for the maneuvering of the USV in the presence of environmental forces. A PD control algorithm was then applied to control the rudder and propeller during an automatic berthing process. The algorithm consisted of two parts, namely the forward velocity control and heading angle control. The control algorithm was designed based on longitudinal and yaw dynamic models of the USV. The desired heading angle was obtained using the "line of sight" method. Finally, computer simulations of automatic USV berthing were performed to verify the proposed controller subjected to the influence of disturbance forces. The results of the simulation revealed a good performance of the developed berthing control system.

• Journal of Hydrospace Technology
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• 제1권1호
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• pp.75-88
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• 1995

Auto-Pilot System uses heading angle information via the position sensor and the rudder device to control the ship's direction. Most of the control logics are composed of the state estimation and control algorithms assuming that the measurement device and the actuator have no fault except the measurement noise. But such asumptions could bring the danger in real situation. For example, if the heading angle measuring device is out of order the control action based on those false position information could bring serious safety problem. In this study, the control system including improved method for processing the position information is applied to the Auto-Pilot System. To show the difference between general state estimator and F.D.F., BJDFs for the sensor and the actuator failure detection are designed and the performance are tested. And it is shown that bias error in sensor could be detected by state-augmented estimator. So the residual confined in the 2-dimension in the presence of the sensor failure could be unidirectional in output space and bias sensor error is much easier to be detected.

• 한국항공우주학회지
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• 제41권9호
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• pp.708-713
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• 2013

한국항공우주연구원(KARI)은 고고도 전기추진 장기체공 무인기(EAV-3)를 개발하고 있는 중 이다. 우선 고고도 상승 기술 시연을 위한 축소형 비행체 EAV-2H를 개발하였고 EAV-2H로 초도 비행시험을 수행한 결과 측풍에 대한 방향 안정성 및 조종성의 향상이 요구되므로 Advanced Aircraft Analysis(AAA)를 이용한 수직 꼬리날개와 방향타의 재설계를 진행하였다. 방향 조종성을 개선하기위해 방향타의 크기를 기존의 평균 방향타 시위대 수직 꼬리날개 시위 $C_r/C_v(%)=30$을 $C_r/C_v(%)=60$로 늘려 EAV-2H가 가지는 측풍에 대한 방향 조종성(${\beta}(deg)=25^{\circ}$, $v_1(m/sec)=3.54$)을 개선하였다. 또한, 측풍에 의해 발생하는 측력(side force)의 영향을 최소화하기위해 EAV-2H의 수직미익 크기를 기존 대비 15% 줄여(최소한의 방향 안정성 확보, $Cn_{\beta}=0.0588rad^{-1}$), $C_{y_{\beta}}$는 15% $C_{y_r}$는 22% 감소시킴으로써 측풍이 EAV-2H에 미치는 영향을 최소화 하였다. 설계된 EAV-2H의 꼬리날개의 성능은 비행 시험을 통해 검증하였고 그 결과를 적용하여 고고도 장기체공 전기추진 무인기(EAV-3)의 꼬리날개를 설계하였다.

• 제어로봇시스템학회논문지
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• 제11권3호
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• pp.214-221
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• 2005

For decades, airships have being developed in Europe (especially German) and America. Airships are planning to be used for advertisements and airliners as well. In Korea, KARI (Korea Aerospace Research Institute) is developing stratospheric communication airship and the similar research is carried out in Japan. Among them, Zeppelin of German has the cutting-edge airship technology with Zeppelin NT. In this paper, the flight performance and stability were evaluated by comparing mathematical theory and the real test. The stability was examined through dynamic modeling and assured by designing controllers at each flight mode. Elevator angle, rudder angle, magnitude of thrust and tilting angle of thrust vector were used as control inputs. Moreover, after measuring the airship velocity, flight direction, magnitude and direction of the wind, attitude angles and trajectories of the airship at each flight mode, the results were compared with the simulation. To get the reasonable data, low-pass filter and band-stop filter were designed to get rid of the sensor noise and engine vibration. The test was accomplished at cruise mode, turning mode, and deceleration. To conclude, with comparing the simulation data and flight test data, it could be known that the dynamic model used in this paper was reasonable.

• 한국항해항만학회지
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• 제42권2호
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• pp.87-96
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• 2018

A trajectory control system plays an important role in controlling motions of marine vehicle when a series of way points or a path is given. In this paper, a sliding mode control (SMC)-based trajectory tracking controller for marine vehicles is presented. A small-sized unmanned ship is considered as a control object. Both speed and heading angle of a ship should be controlled for tracking control. The common point of related researches was to separate ship's speed and heading angle in control methods. In this research, a new control law from a general sliding mode theory that can be applied to MIMO (multi input multi output) system is derived and both speed and heading angle of a ship can be controlled simultaneously. The propulsion force and rudder force are also applied in modeling stage to achieve accurate simulation. Disturbance induced by wind is also tackled in the dynamics considering robustness of the proposed control scheme. In the simulation, we employed a way-point method to generate ship's trajectory and applied the proposed control scheme to ship's trajectory tracking control. Our results confirmed that the tracking error was converged to zero, thus demonstrating the effectiveness of the proposed method.

• 수산해양교육연구
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• 제15권1호
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• pp.47-56
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• 2003

최근 한 일, 한 중 어업협정의 발효와 함께 더욱 좁아진 우리 나라 어장에서 트롤선의 조업이 한정된 수역에서 많이 이루어짐으로써 조업중 트롤선끼리의 충돌의 위험성이 높아졌다. 조업중에는 어구의 저항 때문에 충돌회피 동작을 취하려고 해도 조종자의 의도대로 선박이 조종되지 않을 것이다. 따라서 본 논문에서는 조업중인 트롤선의 경우 충돌회피 동작을 위한 안전한계 거리를 실선시험을 통하여 구한 자료를 분석, 검토하였으며, 그 결과는 다음과 같다. 1. $15^{\circ}Z$, $25^{\circ}Z$, $35^{\circ}Z$시험 중 선박의 조종성은 $35^{\circ}Z$시험에서 가장 좋았다. 2. 가 장 먼 거리에서 피항동작에 들어가야 되는 경우는 양 선박의 침로교각이 $60^{\circ}{\sim}90^{\circ}$ 부근이며 이 경우 자선길이의 약 5배 이상이 되어야 한다. 3. 양 선박이 조우하는 침로교각이 둔각인 경우에는 예각일 경우보다 충돌위험이 더 크므로 더 먼 거리에서 피항동작에 들어가야 한다. 4. 피 항선은 물론 유지선의 피항동작도 안전한계 접근거리 밖에서 이루어져야 한다. 5. 횡 단상태에서 양 선박간에 변침만으로 피항동작을 취하는 경우 최대 안전한계 접근거리를 염두에 두고 피항해야 되며, 최대 안전한계 접근거리 이내에서 피항동작을 취하여야 될 경우 예망속력의 조절도 수반되어야 할 것이다.

• 한국산학기술학회논문지
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• 제12권2호
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• pp.821-828
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• 2011

본 논문은 자동항로 추적(Track keeping control), 자동조타(Automatic steering), 자동 접이안(Automatic mooring control) 등으로 구성된 자동운항 시스템 중 자동조타장치의 성능 개선 알고리즘 개발에 대해 다루고 있다. 자동조타는 풍력 또는 조력 등의 영향으로부터 선박의 설정 항로와 실제 침로와의 차이를 계산하여 설정된 항로를 유지하며 항해하므로, 조타에 소요되는 선원의 지속적인 항해로 인한 운전 부담을 경감시키고 불필요한 타조작에 의한 항로 이탈을 줄임으로써 항해거리 단축과 연료비용을 절약할 수 있는 시스템이다. 선박의 모델링을 위하여 Nomoto 모델에 근거하여 전달함수를 구하고, 조종성능(Manoeuvirng) 편리성을 고려하여 타각 입력에 대한 선수각 응답으로 표시된 선박의 4자유도만을 고려한 선형 모델을 제안하고 선박 자동조타장치의 최대각과 타각율을 고려하여 Fuzzy제어기를 설계 하였고 PID제어기로 성능을 비교 분석하였다.