• Title/Summary/Keyword: Reaction Control System

Search Result 737, Processing Time 0.027 seconds

ROBUST BOUNDARY CONTROL OF CHEMOTAXIS REACTION DIFFUSION SYSTEM

  • Ryu, Sang-Uk;Kang, Yong Han
    • Korean Journal of Mathematics
    • /
    • v.16 no.4
    • /
    • pp.457-470
    • /
    • 2008
  • This paper is concerned with the robust boundary control of the chemotaxis reaction diffusion system. That is, we show that the existence of the saddle point for the robust control problem when the control and the disturbance are given by the boundary condition.

  • PDF

Pyramidal reaction wheel arrangement optimization of satellite attitude control subsystem for minimizing power consumption

  • Shirazi, Abolfazl;Mirshams, Mehran
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.15 no.2
    • /
    • pp.190-198
    • /
    • 2014
  • The pyramidal reaction wheel arrangement is one of the configurations that can be used in attitude control simulators for evaluation of attitude control performance in satellites. In this arrangement, the wheels are oriented in a pyramidal configuration with a tilt angle. In this paper, a study of pyramidal reaction wheel arrangement is carried out in order to find the optimum tilt angle that minimizes total power consumption of the system. The attitude control system is analyzed and the pyramidal configuration is implemented in numerical simulation. Optimization is carried out by using an iterative process and the optimum tilt angle that provides minimum system power consumption is obtained. Simulation results show that the system requires the least power by using optimum tilt angle in reaction wheels arrangement.

Controller Design and Integrated Performance Tests on Nitrogen-Gas Reaction Control System of KSLV-I (나로호 질소가스 추력기시스템 자세제어기 설계 및 종합성능시험)

  • Sun, Byung-Chan;Park, Yong-Kyu;Oh, Choong-Suk;Roh, Woong-Rae
    • Aerospace Engineering and Technology
    • /
    • v.11 no.2
    • /
    • pp.195-207
    • /
    • 2012
  • This paper deals with attitude controller design and integrated performance tests on the nitrogen gas reaction control system of KSLV-I. Some major factors which are necessarily required in designing a stabilizing controller of reaction control system are investigated, and the corresponding equations are given. Experimental configurations and test conditions for system level integrated performance tests of the KSLV-I nitrogen gas reaction control system are summarized. It is shown that, based on the experimental data, operational performances of nitrogen gas reaction control system can be analyzed in terms of gas consumption, thrusting force, time delay, and specific impulse. It is also shown that a conformance of the controller to flight can be evaluated. Finally the onboard controller of KSLV-I reaction control system is shown to perform normally with enough stability margin via the first flight test result.

Propellant Consumption Estimation of Reaction Control System During Flight of KSLV-II (한국형발사체 추력기 자세제어시스템 비행 중 추진제 소모량 추정식)

  • Kang, Shin-jae;Oh, Sang-gwan;Yoon, Won-jae;Min, Byeong-joo
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.48 no.7
    • /
    • pp.529-536
    • /
    • 2020
  • Reaction Control System of the third stage of the Korean Space Launch Vehicle II conducts roll control and 3 axis control throughout third stage engine start, satellite separation, and collision and contamination avoidance maneuver. Reaction control system consumes its propellant in each thruster operation. Hence, loading of proper amount of the propellant is important for mission success. It is needed to have a rough estimation method of propellant consumption during the flight. In this paper, we developed a energy equation using pressure and temperature data which are acquired in the on-board reaction control system. We constructed a test system which is similar with the on-board reaction control system to verify the energy equation. Test results using deionized water were compared with estimated propellant consumption. We also conducted an error analysis of the energy equation. We also presented the propellant consumption result of a system level operation test.

Vibration Control of a Single-Link Flexible Manipulator Using Reaction Moment Estimator (반력모멘트 추정기를 이용한 단일 링크 유연 조작기의 진동제어)

  • Shin, Hocheol;Han, Sangsoo;Kim, Seungho
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.15 no.2 s.95
    • /
    • pp.169-175
    • /
    • 2005
  • In this paper, a novel vibration control scheme for a single-link flexible manipulator system without using a vibration feedback sensor is proposed. In order to achieve the vibration information of the flexible link, a reaction moment estimator based on the dynamic characteristics of the flexible manipulator is proposed. While the manipulator is maneuvering the reaction moment is reciprocally acting on the flexible link and the hub inertia due to the vibration of the link. A sliding mode controller based on the equivalent rigid body dynamics corresponding to the proposed flexible manipulator is then augmented with the reaction moment estimator to realize a decentralized control system. The reaction moment estimator is implemented via the first order low pass filter. The performance of the proposed control scheme is verified by computer simulation and experiment.

Development of Engineering Model for the Thruster Control Unit and Simulation system of the Reaction Control System (냉가스 추력기 시스템용 EM 제어기 및 점검 시스템 개발)

  • Jeon, Sang-Un;Kim, Ji-Hun;Jeong, Ho-Rak;Choe, Hyeong-Don
    • Aerospace Engineering and Technology
    • /
    • v.5 no.2
    • /
    • pp.188-194
    • /
    • 2006
  • This paper deals with the development of Engineering Model for the TCU( Thruster Control Unit) and simulation system of the reaction control system using cold gas. TCU communicates with TLM(Telemetry) and ground control console so that it transmits monitoring data of pressures and temperatures for reaction control system. The cpu/communication board performs MIL-STD-1553B communication, RS-422 communication, data input/output processing and program loading to EEPROM. We applied Intel 80386DX Microprocessor, 256Kbytes EEPROM and 256Kbytes SRAM for program storage and execution. Also, we developed the direct access interface circuit to EEPROM and simulation system for TCU.

  • PDF

Development of a Biological Reaction and Measurement Control System for Rapid Detection of the Insecticide Imidacloprid Residues (살충제 Imidacloprid 잔류물의 신속한 측정을 위한 생물반응 및 계측제어 시스템 개발)

  • Lim J. K.;Cho H. K.
    • Journal of Biosystems Engineering
    • /
    • v.30 no.2 s.109
    • /
    • pp.114-120
    • /
    • 2005
  • In this study, a biological reaction and measurement control system was developed to rapidly measure the insecticide imidacloprid residues in agricultural products. The biological reaction part of the system was designed to include micro-pumps and valves for fluid transport, and a polystyrene covet as a reaction chamber. The measurement control part of the system consisted of a photodiode with a light-emitting diode for optical density measurement, and a control microcomputer to implement assay. Signal output was read as the rate of change in optical density at 645 nm. The sensitivity of the system was 2.2 ng/mL ($IC_50$). The system could execute a measurement cycle in about 19 minutes. Research will be continued to develop an automatic sampler fur imidacloprid residues from agricultural products.

Sliding Mode Control of Spacecraft with Actuator Dynamics

  • Cheon, Yee-Jin
    • Transactions on Control, Automation and Systems Engineering
    • /
    • v.4 no.2
    • /
    • pp.169-175
    • /
    • 2002
  • A sliding mode control of spacecraft attitude tracking with actuator, especially reaction wheel, is presented. The sliding mode controller is derived based on quaternion parameterization for the kinematic equations of motion. The reaction wheel dynamic equations represented by wheel input voltage are presented. The input voltage to wheel is calculated from the sliding mode controller and reaction wheel dynamics. The global asymptotic stability is shown using a Lyapunov analysis. In addition the robustness analysis is performed for nonlinear system with parameter variations and disturbances. It is shown that the controller ensures control objectives for the spacecraft with reaction wheels.

Performance of Excessive Mental-workload under Limited Reaction Time (제한된 반응시간에서 과도한 정신부하작업의 수행도에 관한 연구)

  • Oh Young-Jin;Kim Che-Soong
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.10 no.2
    • /
    • pp.21-25
    • /
    • 2005
  • Human performance of system control under excessive mental-workload may differ from stable situation. In this study, design guidelines of secondary control system were introduced to enhance performance of safety control system. Under urgent situation, the first performance criterion is not a reaction time but safe control reaction that prevents system disaster. Therefore it is important to find out the facts that are mainly related system safety. Experimental results show performance of primary task didn't reflect whole system influence within a limited short reaction time. In this situation, the secondary task is more sensitive to system influence that varied with some factors of urgent status. Therefore, when a system proceeds to abnormal and unsafe status, and even more the reaction time is limited within a very short time to control the system, the estimation of human performance is more sensitive using secondary task performance then primary task performance. Those results mean it is required to develop various secondary tasks to design safety control systems preventing disaster, And also require many studies of estimation methods human performances especially when system status varies dangerous and/or unsafe situation.

  • PDF