• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.229-238
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• 2009

In this paper, AWS ECU test method, which is considering behavior of a Bi-modal tram, is described. In order to evaluate the performance of an electronic automotive ECU, the method which combines HILS (Hardware In the Loop Simulation) and RBT (Requirement Based Testing) is introduced. HILS is the method to predict the behavior of a vehicle adopting an ECU. The behavior of a Bi-modal tram can be analyzed by using the vehicle dynamic model. Requirement Based Testing compare the outputs of a real system with a virtual electronic unit (oracle) which created by the requirements. Rear axles of the Bi-modal tram are independently controlled by two AWS ECU. Especially, swing out can happen when an articulated vehicle is operated in the curved road. Therefore dynamic behaviour of a Bi-modal tram is considered at this situation. Through this study, the reliability of ECU can be verified economically and safely using the proposed test method before conducting the track test.

• 한국군사과학기술학회지
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• 제6권1호
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• pp.21-29
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• 2003

The Strap Down Inertial Measurement Unit(SDIMU) is recently used for the sensor package of the modern underwater vehicles such as torpedoes and unmanned underwater-vehicles. For using SDIMU, an initial alignment must be carried out before the fire or navigation stage. The general initial alignment methods require that a mother vehicle Is a stationary condition or the Inertial Navigation System(INS) of vehicle is received the specific of data navigation from the mother vehicle. But an underwater vehicle dropped from aircraft is hard to satisfy above both necessary conditions of the general initial alignment. So, we suggest a new strap down initial alignment method of an underwater vehicle dropped from aircraft without using any aided sensors. The highlight point of this method is that a period of initial alignment is not before the fire but during running stage to fix alignment error. And we verify it by analyzing various data of S/W simulations, Hardware In the Loop Simulation(HILS) tests and sea trials.

• Journal of Power Electronics
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• 제19권6호
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• pp.1496-1504
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• 2019

This paper proposes a new THD reduction algorithm for modular multilevel converters (MMCs) with offset voltage injection operated in nearest level modulation (NLM). High voltage direct current (HVDC) is actively introduced to the grid connection of offshore wind powers, and this paper deals with a voltage generation technique with an MMC for wind power generation. In the proposed method, third harmonic voltage is added for reducing the THD. The third harmonic voltage is adjusted so that each of the pole voltage magnitudes maintains a constant value with a maximum number of (N+1) levels, where N is the number of sub-modules per arm. By using the proposed method, the THD of the output voltage is mitigated without increasing the switching frequency. In addition, the proposed method has advantageous characteristics such as simple implementation. As a part of this study, this paper compares the THD results of the conventional method and the proposed method with offset voltage injection to reduce the THD. In this paper, simulations have been carried out to verify the effectiveness of the proposed scheme, and the proposed method is implemented by a HILS (Hardware in the Loop Simulation) system. The obtained results show agreement with the simulation results. It is confirmed that the new scheme achieved the maximum level output voltage and improved the THD quality.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.268-272
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• 2012

비행체의 경우 운용 중에 센서 등의 고장이 발생하더라도 이를 극복하고 지속적으로 운용이 가능하게 설계하여야 한다. 이러한 비행체에는 중요 센서의 고장에 대비하여 대체 가능한 센서를 여분으로 장착하여 측정값에 대한 신뢰성을 확보하고 있다. 본 논문에서는 시뮬레이션을 통하여 적용 대상 터보제트엔진의 센서 측정값을 MIMO NARX 모델을 사용하여 센서 결함이 발생하더라도 상태추정을 통하여 대치 가능함을 보였고, HILS 장비에 적용할 수 있는 엔진 모델로 사용가능함을 보였다.

• 한국항공우주학회지
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• 제35권11호
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• pp.999-1005
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• 2007

공력미계수에 대한 실시간 추정은 비정상적인 조종면 작동의 경우, 고장에 대한 정보를 분석하여 비행임무를 계속 수행하거나 본부로 회항비행을 지속할 수 있도록 하는 재형상 제어를 위해 필요하다. 본 논문에서는 고장허용제어시스템에 대한 기반 연구로서 무인비행기 안전성 향상을 위하여 조종면 작동불능과 같은 고장에 대해 검출 방법을 제시하였다. 조종면 고장검출을 위한 실시간 시스템식별 알고리듬은 퓨리에 변환기법을 사용하였으며 프로그램 성능 및 검증을 위해 HILS 시험을 수행하였다. 고장 조종면은 피칭모멘트, 요잉모멘트, 롤링모멘트에 대한 조종면 효과를 나타내는 조종미계수들을 실시간 추정하여 정상상태의 값과 비교하여 검출된다. 비행시험 결과를 통해 고장상태의 조종미계수 값은 정상상태의 값보다 작다는 것을 정량적으로 확인하였다.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.166-174
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• 2014

Fuel injection pressure has steadily increased in diesel engines for the purpose of improving fuel efficiency and cleaning exhaust gas, but it has now reached a point, where the cost for higher pressure does not warrant additional gains. Common rail systems on modern diesel engines have fuel pumps that are mechanically driven by crankshaft. The pumps actually house two pumping module inside: a low pressure pump component and a high pressure pump component. Part of the fuel compressed by the low pressure component returns to the tank in the process of maintaining the pressure in the common rail. Since the returning fuel represents pumping loss, fuel economy improves if the returned fuel can be eliminated by using a properly controled electrical fuel pump. As the first step in developing an electrical fuel pump the fuel supply system on a 6 liter diesel engine was modeled with AMESim to analyze the workload and the fuel feed rate of the injection pump, and the results served as basis for selecting a suitable servo motor and a reducer to drive the pump. A motor controller was built using a DSP and a program which controls the common rail pressure using a proportional control method based on the target fuel pressure information from the engine ECU. A test rig to evaluate performance of the fuel pump is implemented and used to show that the newly developed electrically driven fuel pump can satisfy the fuel flow demand of the engine under various operating conditions when the rotational speed of the pump is adequately controlled.

• 한국정밀공학회지
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• 제21권9호
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• pp.56-62
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• 2004

Recently, necessity and usage of the teleoperation have been increased in various fields from industrial automation to home application. Also, the internet is considered as a strong candidate far the transmission media of signals. However, it has an irregular transmission time delay and causes critical problems such as instability and poor performance. This paper presents a practical internet teleoperation system with a streaming buffer system which makes a variable time delay fixed. Validity of the proposed system is demonstrated by implementing the embedded system on a HILS(hardware in the loop system) which models a two-wheel mobile robot.

• 한국항공운항학회지
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• 제21권1호
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• pp.1-7
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• 2013

To have the competitiveness in the future worldwide small aircraft market, we should be able to develop the aircraft which is highly safe, easy to fly, and having excellent flight characteristics. FBW(Fly-By Wire) system is essential for the enhancement of flight safety and control easiness. FBW system that has been applied only to the modern fighter and transport aircraft is recently applied to smaller aircraft such as regional aircraft, business aircraft and even small aircraft. The purpose of this research includes the development of flight control computer, the definition of FBW system component, the design concept of each component for redundant management, OFP(Operational Flight Program) development, FBW system integration and HILS(Hardware In-the Loop Simulation) verification environment to test this FBW system.

• 전자공학회논문지 IE
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• 제49권2호
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• pp.30-39
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• 2012

졸음운전은 사고발생 확률이 높고, 사고 발생 시 심각도가 높기 때문에 효율적인 졸음운전 판단 시스템이 필요하다. 그러나 생체 신호나 비전을 이용한 졸음운전 판단시스템은 비용 측면에서 활용되기가 어렵다. 이에 본 논문에서는 추가적인 비용 없이 대부분의 차량에 기본 장착되어 있는 조향각 센서(steering angle sensor)와 차량정보(brake switch, throttle position signal, vehicle speed)를 이용하여 졸음운전자의 조향패턴 중 하나인 저킹 판단을 이용한 졸음운전 판단 알고리즘을 제안한다. 본 연구에서는 각 변수의 임계값을 제시하고, HILS(Hardware in the Loop Simulation)에서 CAN을 통해 취득한 차량의 데이터와 Matlab 프로그램을 이용하여 알고리즘을 평가한다.

• 항공우주기술
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• 제9권1호
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• pp.1-8
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• 2010

스마트무인기의 비행시험에 앞서 비행제어시스템을 포함한 전체 무인기 체계의 건전성을 검증하기위한 지상통합시험을 수행하였다. 지상통합시험은 비행체 인터페이스 시험, 비행체 HILS시험, 지상파워시험, 4자유도 치구시험, 안전줄 호버시험 순서로 진행되었으며, 각각의 시험을 통해 전체 무인기 시스템의 안전성을 입증하였다. 본 논문에서는 국내 최초로 개발된 틸트로터인 스마트무인기의 지상시험 절차와 각 시험에서 획득한 데이터 분석결과를 제시하였다. 지상시험 결과 비행제어시스템의 안전성이 충분히 입증되었으며, 비행시험이 수행가능하다고 판단되었다.