• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
• /
• pp.352-357
• /
• 1987

The Auto Tuning Controller is designed using Fuzzy set theory. And to verify its validity it is Applied to the Auto Tuner of hydraulic Control System. Fuzzy Tuning Procedures are written by linguistic model and translated into C language formation by preprocessor. Then it is executed with state feedback controller in real time, Fuzzy Logic Controller adjusts state feedback gain by proper tuning logic in each step to satisfy the desired maximum overshoot and settling time.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1994년도 추계학술대회 논문집
• /
• pp.455-459
• /
• 1994

One relay control implementation to the servo control systepm is contrlved mainly for the high power electric or electro hydraulic type drive system. Proposed SERME control is relay emulated software scheme accounting a reay producing maximum torque in both direction in the insufficient bandwidth control system. Possibillty is proposed mathematically prlor to emperical work out.

• 대한기계학회논문집
• /
• 제19권3호
• /
• pp.868-876
• /
• 1995

This study deals with a position control of an electro-hydraulic servo system which consist of cylinder and high speed on-off valves operated by microcomputer. The merits of PWM control of hydraulic equipment are the robustness of the high spee on-off valve, its low price and the direct control without D/A converter. In the PWM control of high speed on-off valve, the time lag and switching time existing between the input and output signals of valve are considered as demerit points. To get analytical results, the effects of these demerits have to be clarified in detail. The object of this study is to propose a mathematical model for the behavior of high speed on-off valve and to get analytical results of this system. The dynamic characteristics of this system is examined by digital computer simulation analytically and compared with experimental results to varify the proposed mathematical model.

• 드라이브 ㆍ 컨트롤
• /
• 제14권4호
• /
• pp.61-70
• /
• 2017

In this study, an extended-state-observer (ESO) based non-linear servo control is introduced for an electro-hydrostatic actuator (EHA). Almost hydraulic systems not only are highly non-linear system that has mismatched uncertainties and external disturbances, but also can not measure some states. ESO that only use an output signal can be used to compensate these uncertainties and estimate unmeasurable states. To improve the position tracking performance, the barrier Lyapunov function (BLF) that can guarantee an output tolerance is introduced for the position tracking error signal of back stepping control procedures. Finally, the proposed servo control is compared with the proportional-integral (PI) control.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.971-976
• /
• 1996

A flexible pointing system mounted on top of a vehicle suffers from performance degradation due to bending vibrations as the vehicle runs on a bump course. In order to improve the pointing performance, the pointing structure's vibrations should be suppressed. In this paper, a nonlinear controller is designed to control the tip position of the pointing system while actively suppressing the vibrations. To cope with high order dynamics and nonlinearities of the plant and hydraulic actuating system, a two-stage sliding mode controller is devised. The desired actuating pressure is obtained in the first stage and then the in put current In the hydraulic servo system is computed to generate the pressure. The simulation results show the effectiveness of this scheme and improvements in pointing accuracy.

• 한국산업융합학회 논문집
• /
• 제25권1호
• /
• pp.87-99
• /
• 2022

We propoes a study on the dynamic characteristics analysis and position control of 5-degree multi-joint manipulators for untact remote working at construction sites and manufacturing plants. The main frame of freedom multi-joint manipulator consists of five elements, boom cylinder, boom cylinder, arm cylinder, bucket cylinder, and rotation joint and link. In addition, the main purpose of the proposed system is to realize the work of the manufacturing process or construction site by remote control. Motion control of the entire system is a servo valve control method by hydraulic servo cylinders for one to four joints, and a servo motor control method is applied for five joints. The reliability of the proposed method was verified through performance experiments by computer simulation.

• 대한기계학회논문집
• /
• 제12권2호
• /
• pp.221-230
• /
• 1988

본 연구의 목적은 마이크로컴퓨터를 사용하여 유압모터로 구성된 전기 유압 서보 시스템의 속도제어를 하는데 있어서 제어방법과 제어기 기본 하드웨어인 마이크로프로세서와 A/D, D/A 변환기의 해상도(resolution)가 전체 시스템의 성능에 미치는 영향을 주로 실험적으로 연구하는데 있다.

• 드라이브 ㆍ 컨트롤
• /
• 제16권4호
• /
• pp.93-100
• /
• 2019

Nuclear and thermal power plants must provide the turbines with an appropriate degree of high temperature and high pressure steam, to produce the optimum electricity. Additionally, in the event of system and power system failure during electrical production, the steam is immediately disabled, to protect the turbines and generators rotating at high speed. The plant thus uses a special steam control valve system for turbine control, which is opened by force of the hydraulic servo actuator and closed by a large steel spring force. In this study, the causes of failure of the turbine control valve system, a key device of the power plants, were analyzed, and the causes of failure were improved relative to reliability of the equipment.

• 한국정밀공학회지
• /
• 제17권10호
• /
• pp.162-169
• /
• 2000

A Direct Drive Valve(DDV) hydraulic actuation system which is commonly used as an aircraft's control surface driving actuator has multi-loop control structure to ensure its safety operation. However, because of not perfect matching of one self channel characteristics with the others, the servo valve driving current of each channel can be widely different. Therefore, the long-time use of DDV actuator without any correction of these channel current offsets will cause the problem of performance or life expectancy degradation due to unwanted heats in the linear motor. A current equalization loop structure which can minimizes current offsets between channels is introduced and designed. The performance of the current equalization loop is investigated and verified through the analytic and experimental ways.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
• /
• pp.54-59
• /
• 1994

In this study, a high-speed servo valve with no outer leakage is developed, which is used to drive flexible hydraulic actuators (FHA) for extreme environments. In the valve, multilayered PZT devices are used to drive a spool directly and quickly. A bellows is also used to prevent outer leak from the clearance between the spool and the sleeve. Employing a disturbance observer, the lack of the system damping of the valve is improved by feeding back the estimated velocity of the spool, as well as the estimated disturbance is fed back to eliminate effectively the hysteresis between input voltage and output displacement of the PZT devices.