• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권1호
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• pp.33-38
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• 2003

This paper describes control principles of the piezoelectric ultrasonic motor which is operated by the ultrasonic vibration generated by the piezoelectric element. The piezoelectric ultrasonic motor has excellent characteristics such as compact size, noiseless motion, low speed, high torque and controllability, and has been recently applied for the practical utilization in industrial, consumer, medical and automotive fields. In this paper, the design of two-phase push-pull inverter for driving the piezoelectric ultrasonic motor is described, and a new control method of automatic resonant frequency tracking using PLL(Phase-Locked Loop) technique is mainly presented. the experimental results by this inverter system for driving the piezoelectric ultrasonic motor are illustrated herein. The inverter system with PLL technique improved the speed stability of the piezoelectric ultrasonic motor.

• 한국항만학회지
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• 제14권3호
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• pp.291-301
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• 2000

T his paper presents the lateral and longitudinal control algorithm for the driving of a 4WS AGV(Automated Guided Vehicle). The control law to the lateral and longitudinal control of the AGV includes adaptive agin tuning ability, that is the controller gain of the gravity compensated PD controller can be changed on a real-time. The gain tuning law is derived from the Lyapunov direct method using the output error of the reference model and the actual model, And to show the performance of the presented lateral and longitudinal control algorithm, we simulate toe nonlinear AGV equations of the motion by deriving the Newton-Euler Method, The read path is from quay yard area to docking position in loading yard area. The quay yard area is where the quay crane loads the container to the AGV and the docking position is where the container is transferred to the gantry crane. The road types are constructed in a straight line and J-turn. When driving the straight line, the driving velocity is 6㎧ and the J-turn is 3㎧.

• 한국정밀공학회지
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• 제28권1호
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• pp.31-39
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• 2011

This paper presents design and control of a quarter-vehicle magneto-rheological (MR) suspension system for ECS (electronic control suspension). In order to achieve this goal, MR shock absorber is designed and manufactured based on the optimized damping force levels and mechanical dimensions required for a commercial mid-sized passenger vehicle. After experimentally evaluating dynamic characteristics of the manufactured MR shock absorber, the quarter-vehicle MR suspension system consisting of sprung mass, spring, tire and the MR shock absorber is constructed in order to investigate the ride comfort and driving stability. After deriving the equations of the motion for the proposed quarter-vehicle MR suspension system, the skyhook controller is then implemented for the realization of quarter-vehicle MR suspension system. In order to present control performance of MR shock absorber for ECS, ride comfort and driving stability characteristics such as vertical acceleration of sprung mass and tire deflection are experimentally evaluated under various road conditions and presented in both time and frequency domain.

• 한국안전학회지
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• 제14권3호
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• pp.193-197
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• 1999

By the report of KISCO, the 54.20% of total disaster and the 20.87% of death disaster was caused by unsafe position-control. However, it is possible to decrease this kind of disaster rate by designing the control device in the consideration of safety. One of the most popular control device is vehicle instrument panel. Therefore, not only basic function but safe control under the driving environments should be considered when the vehicle instrument panel is designed. For safe control at the driving time, it is especially important to determine the priority of each part using emergency degree and usage frequency, and to set them with this priority for easy control position. In this paper, developing method to determine the priority of each part by pair-wise comparison for emergency degree and usage frequency was suggested and generated the mutual order weights to give them orders. To apply this method to the parts of instrument panel such as function button, audio, air conditioner, and other several detail parts, the direct questionnaire was implemented to drivers about the emergency degree and usage frequency of each part.

• 한국정밀공학회지
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• 제14권3호
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• pp.98-106
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• 1997

In this paper, a new method of position synchronizing control is proposed for multi-axes driving system. The proposed position synchronizing control system is constituted with speed and synchronizing controller. The speed controller is aimed at the following to speed reference. Furthermore, it is designed to guarantee low sensitivity under some disturbance as well as robustness against model uncertainties using $H_{\infty}$technique. The synchronizing controller is designed to keep minimizing the position error using PID control law which is considered to reduce the dimension of transfer function in the control system. Especially, the proposed method can be easily conducted by controlling only slave axis speed, because it, has variable structure which is decided to master and slave axis by the sign of synchronizing error. Therfore, the master axis which is smaller influenced than another axes by disturbance can be controlled without reducing or increasing its speed for precise position synchronization. The effectiveness of the proposed method is sucessfully confirmed through many experiments.s.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.1-9
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• 2010

LED구동회로및 제어회로를 개발하였다. 개발된 LED구동회로는 새로운 PWM회로를 가지고 있으며 LED열의 디밍, 전류 및 온도제어 및 통신 기능을 할 수 있다. 개발된 PWM회로는 기본적인 디지털 논리소자를 사용하여 만들어 질 수 있는 두 개의 링 발진기와 한 개의 카운터로 구성되어 있다. 부가적으로 이 회로는 온-오프 제어 모드, 비상모드, 전력절감모드를 가지고 있으며 직열통신을 이용해서 제어된다. 설계 된 PWM 발생기와 제어회로는 마그나칩/하이닉스의 디지털 공정을 이용하여 제작되었다. 제작된 칩은 LED구동장치와 제어기 보드에 장착되어 테스트 되었으며 성공적으로 동작하였다.

• 드라이브 ㆍ 컨트롤
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• 제16권4호
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• pp.48-55
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• 2019

The Electronic Stability Program (ESP), a system that improves vehicle safety, also known as YMC (Yaw Motion Controller) or VDC (Vehicle Dynamics Control), is a system that operates in unstable or sudden driving and braking situations. Developing conditions such as unstable or sudden driving and braking situations in a vehicle are very dangerous unless you are an experienced professional driver. Additionally, many repetitive tests are required to collect reliable data, and there are many variables to consider such as changes in the weather, road surface, and tire condition. To overcome this problem, in this paper, hardware and control software such as the ESP controller, vehicle engine, ABS, and TCS module, composed of three control zones, are modeled using MATLAB/SIMULINK, and the vehicle, climate, and road surface. Various environmental variables such as the driving course were modeled and studied for the real-time ESP real-time simulator that can be repeatedly tested under the same conditions.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권12호
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• pp.698-704
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• 2005

Passive suspensions with fixed design constants are very restrictive in the inherent suspension problem, the trade-off between the ride quality and the suspension travel. Active suspensions are used to solve some drawbacks of passive suspensions. In this paper, we propose a controller design for vehicle active suspensions considering variable driving conditions. Our controller estimates the current driving conditions by detecting the road frequencies gotten from Fourier Transform and decides which factor must be emphasized between the ride quality and the suspension travel. In one case of focusing on the ride quality, we use the skyhook control law and in the other case of focusing on the suspension travel, the double skyhook control law is used. The control law modified by various road situations outputs the reference force value the electro-hydraulic actuator in active suspension system must generate. To track the reference force, we adopt the sliding control law which is very useful in controlling the nonlinear system like the electro-hydraulic actuator.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.294-301
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• 2016

This paper discusses about analyzing in-wheel vehicle's dynamic motion and load torque. Since in-wheel vehicle controls each left and right driving wheels, it is dangerous if vehicle's wheels are not in a cooperative control. First, this study builds the main wheel control logic using PID control theory and evaluates the stability. Using Carsim-Matlab/Simulink, vehicle dynamic motion is simulated in virtual 3D driving road. Through this, in-wheel vehicle's driving performance can be analyzed. The target vehicle is a rear-wheel drive in D-class sedan. Second, by using the first In-wheel vehicle's performance results, it derivate the drive motor's dynamic load torque for applying the dynamometer. Extracted load torque impute to dynamometer's load motor, linear experiment in dynamometer can replicated the 3-D road driving status. Also it, will be able to evaluate the more accurate performance analysis and stability, as a previous step of actual vehicle experiment.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권10호
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• pp.637-645
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• 2000

This study was represented the improvement of the flexible position control for linear motion of hybrid type linear pulse motor(HLPM). The driving method used a minute 125 microstep drive instead of full step drive method. The digital control method was applied to the PI control for more stable position control, at this time the PI control parameters have gained by a Ziegler-Nichols turning method. The loop transfer function of control system was combined with both motor transfer function and digital PI control equation. Such, the proper for digital PI control system is verified to through the simulation and experimental result of the stability step response and bode plot with proper gain and phase margin.