• 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.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.14-23
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• 2010

This paper analyzes braking performance of ABS with Sliding Mode Controller, which is designed in this research and compared with that of a commercial ABS-ECU only. HILS system for this paper has an existing hydraulic brake line with an ECU of commercial passenger vehicle and it is designed to be cooperated with Sliding Mode Controller and hydraulic line. This paper shows the simulation results to meet the target slip ratio on the various road conditions and displays the performance with Sliding Mode Controller has an improvement than a commercial ABS.

• 한국산학기술학회논문지
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• 제20권5호
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• pp.621-626
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• 2019

자동차의 과도한 차체 운동과 조종 불안정성을 유발하는 대표적인 외란 입력으로는 운전자에 의해 가해지는 조향 핸들 조작이다. 급격하고 과도한 핸들 조작은 SUV 차량처럼 기하학적 및 동역학적 특성에 따라 차량 전복 현상도 발생시킬 수 있다. 본 연구에서는 이에 대응할 수 있는 제어 시스템의 구조화에 대하여 다음과 같이 기초 연구를 수행하였다. 운전자 조종으로 유발되는 횡방향 거동에 대한 수학적 모델링을 수행하고, 이를 토대로 차체 운동을 제어할 수 있는 제어기를 설계하였다. 파라미터 불확실성으로 인한 모델링 오차에 대해 강건한 제어 성능을 확보하기 위하여 $H_{\infty}$ 알고리즘을 적용하였다. 비 연성화된 1/4 차량을 기반으로, 차체에 작용하는 모우멘트에 상응하는 동적 부하를 모사할 수 있는 모델을 제시하였다. 동적 시뮬레이션을 수행하여 부하 모사 모델의 타당성을 파악하였다. 차체- 차축- 서스펜션- 타이어로 조합되는 1/4 실험 차량 장치와 부하 모사 모듈, 서스펜션 제어 모듈 및 Hils 기술을 적용하는 차체 거동 제어 시스템에 대한 프레임워크를 제안하였다.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.429-447
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• 2020

The considered simulation tasks are based on an electrometallurgical process development strategy and associated telemanipulator simulation systems are proposed with various scales of experimental facilities. Fundamentally, target facilities are assumed to be operated only by remote handling systems because the considered process is operated in hazardous environments. Futhermore, the feasibility at various scales should be experimentally verified with gradual increase in throughput. In this regard, bench, engineering, and pilot-scale simulation systems are important early-stage tools for assessing the practical operability of the target process with the material handling systems. Such simulation systems are highly customized for applications and are a precursor to larger pilot and demonstration-scale plants. This paper introduced and classified the developed simulator systems for this approach at various scales using remote handling systems which were assembled inside a virtual target facility, and the manmachine interface was included for a more realistic operation of the simulator. The results obtained for each simulator show the feasibility and requirement for improvement of the systems for the considered test issues with respect to the operation and maintenance of the process.

• 전력전자학회논문지
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• 제26권4호
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• pp.294-297
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• 2021

A grid voltage estimation method for modular plug-in active power decoupling (APD) circuits is proposed in this study as direct replacements of electrolytic capacitors. Since modular plug-in APD circuits cannot have additional grid voltage sensors and should be operated independently without information exchange with the front-end converter, it is impossible to obtain the phase information of the grid directly. Therefore, the proposed method uses the second-order harmonic component of the DC-link voltage to estimate the grid voltage necessary to control the APD circuit. By employing the proposed method, the concept of modular plug-in APD circuits can be realized and implemented without direct detection of the grid voltage. The experimental results based on hardware-in-the-loop simulation (HILS) validate the effectiveness of the proposed control method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.548-552
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• 2003

In the braking system, the friction force is the most important factor of the design. For long time, many researchers have been strived for getting the exact friction coefficients. But the friction coefficients are affected by the road condition and changed by lots of parameters, such as normal force and characteristics between two contacted materials, temperature, etc. For the development of ABS of the aircraft, HILS(Hardware-In-the-Loop-Simulation) test and dynamometer test was carried out. For the calculation of the friction coefficients, the wheel moments were measured using the load cell mounted on the housing of the wheel. The test conditions were dry and greasy, as the 0.7 and 0.4 in friction coefficient, respectively. In this paper, the test results of the friction coefficients were represented and the improvement method was suggested.

• 전기학회논문지
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• 제66권7호
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• pp.1078-1082
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• 2017

This paper presents an L1 optimization based filtering technique which effectively eliminates the optical misalignment effects encountered in the squint guidance mode with strapdown seekers. We formulated a series of L1 optimization problems in order to separate the bias and the gradient components from the measured data, and solved them via the alternating direction method of multipliers (ADMM) and sparse matrix decomposition techniques. The proposed technique was able to rapidly detect arbitrary discontinuities and gradient changes from the measured signals, and was shown to effectively cancel the undesirable effects coming from the seeker misalignment angles. The technique was implemented on embedded flight computers and the real-time operational performance was verified via the hardware-in-the-loop simulation (HILS) tests in parallel with the automatic target recognition algorithms and the intra-red synthetic target images.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.1009-1013
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• 2009

In this paper, a robust fault detection method for varying temperature based on fuzzy model is proposed. To develop a robust force estimation model, it needs temperature information because the output of force sensor is affected by a temperature variation. The nonlinear dynamic system, such as the parking force of the EPB (Electronic Parking Brake) system is necessary to have a higher order equation model. But, because of the calculation time, the higher order equation model is hard to be used in real application. In case of the lower order equation model, the result is not as accurate as acceptable. To solve this problem, the robust fuzzy model-based fault detection is developed. A proposed fault detection method for varying temperature is verified by HILS (hardware in the loop simulation).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.222-224
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• 2005

In the development of Antiskid Brake System(ABS) for a fixed-wing aircraft, the braking efficiency is the most essential parameters to evaluate the ABS, especially in slippery road conditions. The braking distance and landing distance of the aircraft depends on it. Since the ABS has been designed and implemented as a subsystem of the aircrafts, the braking performance was evaluated under dynamometer test, where the dynamometer emulates the aircraft mass. Under simulated wet road conditions, the dynamometer starts to be braked. This paper suggests practical braking efficiency calculation methods and the results and finally compares each method.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1003-1008
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• 2007

Compliance effect consideration method for real-time multibody vehicle dynamics is proposed using quasi-static analysis. The multibody vehicle model without bush elements is used based on the subsystem synthesis method which provides real-time computation on the multibody vehicle model. Reaction forces are computed in the suspension subsystem. According to deformation from the quasi-static analysis using reaction forces and bush stiffness, suspension hardpoint locations and suspension linkage orientation are changed. To validate the proposed method, quarter car simulations of McPherson strut and multilink suspension subsystems. Full car bump run simulations are also carried out comparing with the ADAMS vehicle model with bush elements. CPU times are also measured to see the real-time capabilities of the proposed method.