밀폐형 공압회로 내 정밀압력제어를 위한 기계 구동식 가스 압력제어기의 제어특성 평가

박청용,정욱철 한국정밀공학회 2023 한국정밀공학회지 Vol.40 No.4

In this work, precise gas pressure control based on a closed pneumatic circuit was achieved with a mechanically driven gas pressure controller (MDGPC), consisting of a variable-volume bellows chamber and linear actuator. The linear actuator was employed to change an axial dimension of the bellows chamber with the proportional (P) and proportional-integral (PI) controls for fast, stable, and precise pressure control of the gas inside the bellows chamber. The pressure control stability and resolution of the MDGPC were approximately 1.5 Pa and 10 Pa for the P control and 1 Pa and 5 Pa for the PI control, respectively. Despite the more stable and precise control characteristics of the PI control method, overshoots and undershoots observed during the set-point pressure changes and recoveries from pressure disturbances rendered it unsuitable for the MDGPC control method. In contrast, the MDGPC operated under the P control did not show any significant overshoots or undershoots when the set-point pressure abruptly changed or when the MDGPC was exposed to pressure disturbances. Therefore, it was concluded that a fast, precise, and stable gas pressure control in a closed manner was attainable with the MDGPC under the P control.

Pressure Control Design by Fieldbus System for the Pressure Gauge Calibration

Chatchaval Pornpatkul,Wipawan Suksathid 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

This paper presented the pressure control by Fieldbus system for the pressure gauge calibration. The data in control is standard communication. The programs for control system are classified into 2 parts, the one for controlling the external element and the other for creating the graphic display. The result of control can be monitor. The program for control can be create the function to computer and send the result to control external element. The program for creating graphic and monitor the result of control can be setting the method of monitoring and the result of control. We can be control the both of the programs for control the external element and the program for create graphic and monitor the result of the control system. Finally, the pressure gauge calibration using air pressure gauge as an intermediary is presented in this paper. The standard pressure gauge is calibrated in the working standard commonly used in the industry. The calibration method of DAkkS-DKD-R 6-1 standard guide line is deployed, where the error margin in measuring the pressure of the pressure gauge does not exceed the accuracy value to set by the factory manufacturers throughout the measurement range (±0.5% of span). At least seven uncertainties are determined. It is found that the value of expanded uncertainty is significantly affected by some certain variables. The experimental result of the UUC studied in this paper show that the maximum error value of measurement is +0.008 kg/㎠ at 2.0 kg/㎠, which is in the range of accuracy value specified by the manufacturer (±0.5% of span = ± 0.02 kg/㎠). Moreover, when combining the maximum error value of the measurement obtained from the experiment with the expanded uncertainty (Uexp) = ± 4.672×10-3 kg/㎠, it is also found that the result is still in the accuracy value specified by the manufacturer. Therefore, a calibration certificate of UUC can be issued for UUC utilization.

Robust Common Rail Pressure Control for Diesel Engines using a Quantitative Feedback Theory

Jaewook Shin,Seungwoo Hong,Inseok Park,Minkwang Lee,Myoungho Sunwoo 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

This paper proposes a common rail pressure controller for passenger car diesel engines. The common rail system of diesel engine has some difficulties to control rail pressure. The rail pressure is influenced by interaction between a metering unit (MeUn) and a pressure control valve (PCV). The interaction increases complexity of control algorithm. In order to solve this problem, we present a common rail pressure controller based on the quantitative feedback theory (QFT). For the controller design, a plant model of the common rail system is approximated by a first order transfer function, and the PCV driving current and the rail pressure are used as input/output variables of this model. The rail pressure variation by MeUn is represented as parametric uncertainty. Then, requirement specifications for stability and reference tracking are defined, and the control algorithm is designed to satisfy these requirements using the QFT method. In order to validate the proposed controller, engine experiments are performed. The QFT based rail pressure controller successfully satisfies the tracking performance. Furthermore, the control robustness is evaluated when the MeUn driving current is abruptly changed.

비례제어 릴리프 밸브의 압력제어시스템의 동특성 해석

박재필(Jaepill Park),이대섭(Daesuep Lee),최종민(Jongmin Choi),김현욱(Hyunwook Kim),진식(Sik Jin) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

Hydraulic press is the mechanism which causes plastic-deformation for materials using by hydraulic. The method of control can be classified by pressure, displacement and speed control. Among these methods, it is focus on the analysis of pressure characteristics for the pressure control system in this paper. To control pressure of cylinder, a general relief valve, a proportional control relief valve and a servo valve are used in general. But, the general relief valve is impossible for feedback control and the servo valve is not a economical control system. Therefore, in this paper, the proportional control relief valve which is a comparable price and excellent for pressure control is used for pressure control. In this paper, it is identified the characteristic of pressure control system by AMESim, and it has been confirmed the usefulness of AMESim modeling by comparison between AMESim simulation results and experimental results.

High Precision Pressure Control of a Pneumatic Chamber using a Hybrid Fuzzy PID Controller

Liu, Hao,Lee, Jae-Cheon,Li, Bao-Ren Korean Society for Precision Engineering 2007 International Journal of Precision Engineering and Vol.8 No.3

A hybrid fuzzy PID controller for a pneumatic chamber is proposed in this paper. First, a mathematical model of a pneumatic pressure servocontrol system was developed where separate implementations of a PID controller and a fuzzy controller were made. The experimental results using a step input signal revealed that the PID controller accurately controlled the steady-state pressure but did not robustly handle parameter variations in the system while the fuzzy controller provided a fast rise time and low overshoot of the pressure in the system. In order to attain the advantages of both the fuzzy and PID controllers, a hybrid control scheme was developed. The experimental results show that the hybrid fuzzy PID controller proposed in this study does indeed possess the advantages of both PID and fuzzy controllers. Hence, it can be concluded that the hybrid fuzzy PID controller is suited for high-precision control of pressure in a pneumatic chamber.

통합 제연시스템의 컨트롤러 개발에 관한 연구

이동명 한국화재소방학회 2006 한국화재소방학회논문지 Vol.20 No.1

This study defined engineering mechanism and compensation method to establish reference pressure of smoke control zone with atmospheric pressure that is compensated for temperature. The reliable controller of integration smoke control was developed by establishing the specifications, algorithms and constructing engineering data. The development of controller for integration smoke control can cut down number of processes, manufacturing and installation cost by removing pressure measurement pipe established separately for non smoke control zone, and improve the accuracy of pressure differential by embedding pressure measurement ports for non smoke control zone. More correct and reliable pressure differentials can be obtained by the central control from controller of integration smoke control rather than the existent individual control. This will provide the basics and the flexibility to the integral smoke control system and accordingly improve the performance of disaster prevention. 본 연구에서는 온도가 보상된 압력을 제연구역의 기준압력으로 설정하기 위한 공학적인 메커니즘과 보 상방법을 정립하였고, 통합 제연시스템의 컨트롤러의 개발을 위한 프로세스, 알고리즘 확립과 엔지니어링 데이터의 구축으로 신뢰성이 확보된 통합 제연시스템의 컨트롤러를 개발하였다. 컨트롤러를 개발함으로서 비제연구역의 압력측정을 위해서 별도로 설치되는 압력측정관을 생략할 수 있어 제작단가와 설치비용 및 작업공수를 줄일 수 있고, 층별 제연구역의 차압측정을 위한 비제연구역의 압력측정포트를 시스템에 일체 화함으로서 차압의 정밀도를 향상시킬 수 있다. 기존의 개별제어 방식에서 통합 제연시스템의 컨트롤러로 부터 중앙집중식 통합관리를 함으로서 보다 정확하고 신뢰성 있는 차압을 얻을 수 있으며, 제연시스템에 유연성을 부과시킬 수 있을 것으로 본다. 또한 통합 제연시스템의 기틀을 마련하고 제연의 유연성을 주며 방재성능을 향상시킬 것으로 본다.

차량의 전복 방지 및 조향 안정성 향상을 위한 VDC 시스템의 제어기 개발

유승진(Seungjin Yoo),조준상(Joon-Sang Jo),유승한(Seung-Han You),이교일(Kyo Il Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper presents the design of modularized controller for the VDC(Vehicle Dynamics Control). With this design scheme, the controller can be decomposed in the following two parts : vehicle dynamics controller and brake pressure controller. For vehicle dynamics controller, sliding mode controllers are designed that are activated in the order of priority to prevent rollover, excessive body sideslip angle, as well as understeer/oversteer of the vehicle. While, the brake pressure controller is designed to make brake pressures in each wheel track the desired pressures calculated in the vehicle dynamics controller. A feedback controller as well as a brake pressure estimator is designed based on the developed mathematical model for VDC hydraulic system. The results of the HILS(Hardware In the Loop Simulation) show that the roll angle, body sideslip angle and yaw rate responses of the vehicle are improved in the several driving scenarios.

유압 서보 시스템의 압력제어에 관한 연구

문봉호,양경욱,김현태 여수대학교 1999 論文集 Vol.14 No.2

In this study, a control scheme of a repetitive pressure control of hydraulic system using proportional control valve in electro-hydraulic system has been suggested. The repetitive pressure control of hydraulic cylinder was carried out using a system consisting of a proportional type valve with a built in overlaptype 3-way valve, one pressure sensor and personal computer. For the repetitive pressure control by using proportional pressure control valve, we adopted a preview controller and learning controller. Because the Preview -Learning controller has merit of the preview controller and learning controller, the control performance of a repetitive pressure for the hydraulic system which is to be unstable easily is excellent. Through numerical simulation results of the hydraulic system with the preview- learning controller, the validity of this control method has been confirmed.

과학기술위성3호 홀 추력기용 제어기 개발

이성호,유준,명로훈 제어로봇시스템학회 2009 제어로봇시스템학회 각 지부별 자료집 Vol.2009 No.12

Science and Technology Satellite-3 (STSAT-3) has been developed including a 300W Hall effect thruster and scheduled to be launched in 2010. The Hall thruster Propulsion System (HPS) has been developed with a flow control accuracy of less than 3% over the pressure range from 100bar to 2bar. HPS consists of Xenon Feeding System (XFS), Propulsion Control Module(PCM), Hall Thruster (HT) and Power Processing Module (PPM). PCM has the two stage structure: pressure control and flow control. The pressure control system controls the pressure to low using Proportional Flow Control Valve (PFCV) and the low pressure transducer. The flow control system regulates the flow rate using PFCV and the anode current telemetry of HT. PCM uses the control parameter simulated by the Matlab software. Also the control performance of PCM is verified and tuned by the performance test of HPS. Related design informations as well as results of the development test conducted at Satellite Technology Research Center (SaTReC) are gliven.

A Study on the Design of Back Pressure for Automotive Scroll Compressor

구인회,이건호 대한설비공학회 2009 International Journal Of Air-Conditioning and Refr Vol.17 No.1

The optimum design of back pressure chamber is one of the most important factors in designing scroll compressors because it has a great influence on the efficiency and other design parameters. The design process can be divided into 2 parts. One is obtaining the optimum pressure of the chamber and keeping it in constant value. The other is finding out the minimum inflow rate of medium with which back pressure chamber is filled. In this study we are focused on the first step. At first we added a simple structure that can change back pressure without reassembling compressor. It makes possible to obtaining optimum back pressure. Then we designed an equipment that the back pressure control valve assembly could be independently tested with. Spring was redesigned to decrease stiffness variation. Also sealing mechanism of back pressure control valve was improved to more effective way. As a result, it was verified that in a real mode test back pressure variation could be retained in 2.3 % with discharge pressure and operating frequency varied. In addition the integrated structure of back pressure control valve is expected to contribute to effective manufacturing process. The optimum design of back pressure chamber is one of the most important factors in designing scroll compressors because it has a great influence on the efficiency and other design parameters. The design process can be divided into 2 parts. One is obtaining the optimum pressure of the chamber and keeping it in constant value. The other is finding out the minimum inflow rate of medium with which back pressure chamber is filled. In this study we are focused on the first step. At first we added a simple structure that can change back pressure without reassembling compressor. It makes possible to obtaining optimum back pressure. Then we designed an equipment that the back pressure control valve assembly could be independently tested with. Spring was redesigned to decrease stiffness variation. Also sealing mechanism of back pressure control valve was improved to more effective way. As a result, it was verified that in a real mode test back pressure variation could be retained in 2.3 % with discharge pressure and operating frequency varied. In addition the integrated structure of back pressure control valve is expected to contribute to effective manufacturing process.