유압모터 구동용 동기제어 시스템 제안

양경욱(Kyong-Uk Yang) 전남대학교 수산과학연구소 2019 수산과학연구소논문집 Vol.28 No.-

In this paper, we study the synchronous control of hydraulic system with two hydraulic motors in the hydraulic system. A hydraulic motor use for a rotary motion in hydraulic system. As the external load force in the hydraulic system increases, the hydraulic power can not be generated by only one hydraulic motor, therefore it is used to generate the hydraulic power by connecting two hydraulic motors. At this time, the same external load must be applied to two hydraulic motors depending on the external load, so a stable hydraulic system can be provided. The power acting on the hydraulic motor is controlled using the hydraulic control valve installed at the inlet side of the hydraulic motor. Therefore, the hydraulic motors must be controlled and synchronized using the hydraulic control valve. The method for synchronizing is to use the control algorithm we proposed, the synchronization target is set to the rotation number of the hydraulic motors, and to perform the modeling of the hydraulic system. We propose a synchronization method for the hydraulic motor and verify the usefulness of the proposed method through simulation results in this study.

Hydraulic Control System Using a Feedback Linearization Controller and Disturbance Observer - Sensitivity of System Parameters -

김태형,이일영,장지성 사단법인 유공압건설기계학회 2019 드라이브·컨트롤 Vol.16 No.2

Hydraulic systems have severe nonlinearity inherently compared to other systems like electric control systems. Hence, precise modeling and analysis of the hydraulic control systems are not easy. In this study, the control performance of a hydraulic control system with a feedback linearization compensator and a disturbance observer was analyzed through experiments and numerical simulations. This study mainly focuses on the quantitative investigation of sensitivity on system uncertainties in the hydraulic control system. First, the sensitivity on the system uncertainty of the hydraulic control system with a Feedback Linearization - State Feedback Controller (FL-SFC) was quantitatively analyzed. In addition, the efficacy of a disturbance observer coupled with the FL-SFC for the hydraulic control system was verified in terms of overcoming the control performances deterioration owing to system uncertainty.

다축 유압 시스템을 위한 동기 위치 기반 제어 알고리즘 개발

조성진,윤성수,전재욱 제어로봇시스템학회 2010 제어로봇시스템학회 합동학술대회 논문집 Vol.2010 No.12

Many industrial motion systems use electronic motors. However, big power systems that make automobile frames, roll blending machines and many other systems can’t use electronic motors due to relatively small power. Thus, hydraulic systems are used in press machines and industrial heavy machines. Hydraulic systems use many control methods such as open-loop control method and the close-loop control method. Among hydraulic systems, we focus on the control hydraulic press system; particularly, the hydraulic press system that operates with vertical movement and has big weight. In this case, if the close-loop method is applied to the hydraulic press system, then vibration and noise problems will occur due to the inertia of the press system. Also, the hydraulic press systems use many axes so these systems require synchronization control. In this paper, we propose PDC(Position Dependent Control) Synchronization algorithm between the open-loop controller and the close-loop controller with a variety of interpolation methods in the close-loop controller in order to efficiently control the hydraulic press system.

Hydraulic Control System Using a Feedback Linearization Controller and Disturbance Observer - Sensitivity of System Parameters -

Kim, Tae-hyung,Lee, Ill-yeong,Jang, Ji-seong The Korean Society for Fluid Power and Constructio 2019 드라이브·컨트롤 Vol.16 No.2

Hydraulic systems have severe nonlinearity inherently compared to other systems like electric control systems. Hence, precise modeling and analysis of the hydraulic control systems are not easy. In this study, the control performance of a hydraulic control system with a feedback linearization compensator and a disturbance observer was analyzed through experiments and numerical simulations. This study mainly focuses on the quantitative investigation of sensitivity on system uncertainties in the hydraulic control system. First, the sensitivity on the system uncertainty of the hydraulic control system with a Feedback Linearization - State Feedback Controller (FL-SFC) was quantitatively analyzed. In addition, the efficacy of a disturbance observer coupled with the FL-SFC for the hydraulic control system was verified in terms of overcoming the control performances deterioration owing to system uncertainty.

Energy Efficiency and Dynamic Analysis of a Novel Hydraulic System with Double Actuator

Mengdi Gao,Lei Li,Qingyang Wang,Conghu Liu 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.3

At present, increased attention has been given to energy effi ciency promotion and energy saving of manufacturing equipment and systems. Hydraulic system is widely used in engineering machinery industries; however, the high energy consumption and low energy effi ciency of which limit its development and application. On the basis of previous research on hydraulic system, an energy-effi cient hydraulic system with double actuator is proposed in this study. This hydraulic system can reduce the energy consumption by reusing the potential energy loss of the system. In this novel hydraulic system, the chambers of two actuators are connected with rod by pipes and valves. During the operating processes, the falling operation of one cylinder and the returning operation of the other are synchronized. That is, one actuator remains at the top point performing the demanded operation, whereas the other one remains at the bottom performing the corresponding operation. System models are developed to address the energy consumption and dynamic performance of the proposed hydraulic system. This hydraulic system is applied into a press to study its energy-saving mechanism and dynamic performance during transient under various working conditions. On the basis of the simulation and experimental results, energy and production effi ciency are compared and discussed. Results show that in comparison with the energy and time consumption of the original 630 kN hydraulic press, the energy-saving potential has reached 17.34%, and the production effi ciency can be improved by 18.85%.

Hydraulic Control System Using a Feedback Linearization Controller and Disturbance Observer - Sensitivity of System Parameters -

Tae-hyung Kim,Ill-yeong Lee,Ji-seong Jang 유공압건설기계학회 2019 드라이브·컨트롤 Vol.16 No.2

Hydraulic systems have severe nonlinearity inherently compared to other systems like electric control systems. Hence, precise modeling and analysis of the hydraulic control systems are not easy. In this study, the control performance of a hydraulic control system with a feedback linearization compensator and a disturbance observer was analyzed through experiments and numerical simulations. This study mainly focuses on the quantitative investigation of sensitivity on system uncertainties in the hydraulic control system. First, the sensitivity on the system uncertainty of the hydraulic control system with a Feedback Linearization - State Feedback Controller (FL-SFC) was quantitatively analyzed. In addition, the efficacy of a disturbance observer coupled with the FL-SFC for the hydraulic control system was verified in terms of overcoming the control performances deterioration owing to system uncertainty.

Modeling and Characteristics Analysis of Single-Rod Hydraulic System Using Electro-Hydrostatic Actuator

오주영,정규홍,이근호,박영준,송창섭 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Typical hydraulic system, although it is widely applied in industry because of its high energy density, its actual operational efficiency is only 23%–25% owing to very high energy losses, such as pressure loss and fluid dynamics loss, caused by the hydraulic system. An electro-hydrostatic actuator (EHA) system is a compact system in which an electric motor and hydraulic pump are incorporated into a cylinder, which results in greater energy efficiency than conventional hydraulic systems. The EHA system also suffers from relatively less leakage than valve-operated systems. This system consists of a bidirectional pump and a hydraulic cylinder operated by an electric motor, which adjusts the discharge flow rate of the pump by controlling the speed in both directions and changes the forward or backward direction and speed of the hydraulic cylinder accordingly. In this study, the characteristics of a single-rod cylinder load operation system, an EHA hydraulic circuit, and an electric motor are analyzed using mathematical models, and the performance of a closed-loop hydraulic control system incorporating an EHA with a rotation angle of a base plate controller is investigated.

Maglev(UTM-02) Brake System Change from Pneumatic Bake System to Hydraulic Brake System

Kinam Kim,Sungwoon Hwang,Heekwon Jeon 한국철도학회 2015 International Journal of Railway Vol.8 No.1

The Maglev(UTM-02) project is leading by Korea Institute of Machinery & Materials and financially supported from the ministry of Commerce, Industry and Energy. The early development stagy of Maglev(UTM-02) was adopted the general urban railway pneumatic brake system due to the Korea domestic industrial environment. Currently there is two commercial operation Light Railway Train(LRT) system in Korea. One is U-Line in Uijungbu, and the other is Everline in Yongin. Both LRT systems are adopting high performance light weight hydraulic brake system. But those design and manufacturing core technology of the brake system is came from a major brake system companies located from aboard. Currently various studies have been continued to increase practical application and to improve competitiveness on performance for each sub-system of Maglev. Also in case of brake system, developing competitive hydraulic brake system is required. In this study, we have introduced the development process and performance evaluation of the new hydraulic brake system of Maglev.

Maglev(UTM-02) Brake System Change from Pneumatic Bake System to Hydraulic Brake System

Kim, Kinam,Hwang, Sungwoon,Jeon, Heekwon The Korean Society for Railway 2015 International Journal of Railway Vol.8 No.1

The Maglev(UTM-02) project is leading by Korea Institute of Machinery & Materials and financially supported from the ministry of Commerce, Industry and Energy. The early development stagy of Maglev(UTM-02) was adopted the general urban railway pneumatic brake system due to the Korea domestic industrial environment. Currently there is two commercial operation Light Railway Train(LRT) system in Korea. One is U-Line in Uijungbu, and the other is Everline in Yongin. Both LRT systems are adopting high performance light weight hydraulic brake system. But those design and manufacturing core technology of the brake system is came from a major brake system companies located from aboard. Currently various studies have been continued to increase practical application and to improve competitiveness on performance for each sub-system of Maglev. Also in case of brake system, developing competitive hydraulic brake system is required. In this study, we have introduced the development process and performance evaluation of the new hydraulic brake system of Maglev.

유압식 굴삭기 효율 향상을 위한 HPM 시스템 개발

권용철,이경섭,김성훈,구병국 사단법인 유공압건설기계학회 2019 드라이브·컨트롤 Vol.16 No.4

The HPM (High-speed Power Matching) system is an electro-hydraulic control system. It directly controls the swash plate of the pump by selecting four-loop logic based on joystick signals, pump flow, and pressure signal to improve the efficiency and controllability of construction machines. In the NFC (Negative Flow Control) system, a typical pump control system using conventional open center type MCV, the loss is continuously generated by flow through the center bypass line even when the excavator is not in operation. Also, due to the slow response of the pump that indirectly controls the flow rate using the pressure regulator, peak pressure occurs at the start or stop of the operation. Conversely, the HPM system uses an MCV without center-by-pass flow path and the swash plate of a pump for the HPM is controlled by a high-speed proportional flow control valve. As a result, the HPM system minimizes energy loss in standby state of the excavator and enables peak pressure control through rapid electro-hydraulic control of a pump. In this paper, the concept of the HPM system algorithm is introduced and the hydraulic system efficiency is compared with the NFC system using the excavator SAT (System Analysis Tool).