• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.88-92
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• 2009

Total pressure recovery ratio in intake is crucial factor to the operational characteristics of supersonic propulsion system because it does not compress inlet air mechanically by compressor, but does compress inlet air by ram compression. As the result of that the dynamic characteristic analysis of engine was performed before the controller was designed, it could be ascertained when the AoA of flight vehicle increases, the buzz margin decreases so that the shock wave produced outside intake in the specified area according to flight operation's characteristics. Therefore the PID control algorithm was designed to be controlled buzz margin that the characteristic of shock wave could meet the requirement of performance in intake. The PID controller was designed that the buzz margin value is being positive number using the control variables; fuel flow and nozzle throat area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.339-342
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• 2007

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot inputs the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller RPM. The manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever arm(PLA) angle according to the variation of flight altitude and speed. These data provide a guide for the engine control in manual mode operation.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.1
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• pp.40-47
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• 2010

In this study, basic research on the thrust control by controling oxidizer mass flow rate of a $GO_2$/PE hybrid rocket is presented. For this purpose, hybrid rocket system including oxidizer flow control system and data acquisition system was developed. To control oxidizer mass flow rate, we used needle valve with stepping motor which was controled by LabVIEW program. During the fundamental experiments, this system managed to follow the pre-programmed (20 N - 10 N - 20 N - 0 N) thrust level.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.9-16
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• 2015

The control law for simultaneous pressure and thrust control of solid DACS(Divert Attitude Control System) is suggested. To regulate the two variables effectively, the control structure of sequential loop closer is applied to the system considering the physical characteristics of each variable and the weighted pseudo-inverse method is suggested to allocate effective command for indeterminate system. Also, the pressure guidance law for safe and high acceleration is applied to the homing stage to verify the effectiveness of the command distribution.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.42-47
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• 2008

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot adjusts the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller rotational speed. The electronic engine controller(EEC) of PW206C engine developed for helicopter is not fit for the power control concept of Smart UAV, and therefore the manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever angle(PLA) according to the variation of engine output shaft speed, flight altitude and flight speed. These data provide a guide for the PLA control in manual mode operation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.368-373
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• 2017

Control method for DACS with variable burning area is designed and the performance of the control method is analyzed by doing simulation at various conditions. DACS, which got solid propellant on board, is designed as end-burning type typically. End-burning type DACS has the merit of controlling pressure and thrust, but it discharges the combustion gas which does not using for getting thrust. Therefore, optimal design of propellant grain and burning area changes over time as a result. Variable burning area can be assumed as a disturbance and adaptive control method is useful for pressure control of DACS effected by disturbance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.139-141
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• 2017

By modulating the flow rate of $N_2O$ into a HR motor assembly, a control valve of a hybrid rocket engine plays a role to increase or decrease the thrust. In this study, the control valve has been designed to meet the requirements which are response speed(${\leq}$ about 1 second) and torque(${\geq}$ about $36N{\cdot}m$). Then, when analog signal 0~10V is applied, the situation where the valve is opened and closed has to be realized. To do this, the data values have to be entered into the actuator. Finally, the performance evaluation of the control valve has been performed to validate this product.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1127-1134
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• 2017

Gas turbine engine control was originated from a single hydro-mechanical governor for fuel metering and changed to 1970s' DEEC and then today's centralized FADEC. In order to attain the goal of improvement of control performance, application of PHM technology, and reduction of system weight, it is necessary to make a transition to distributed engine control. This paper describes the concept and roadmap of distributed control, collaborative efforts of government and industry for successful development of the system, and technical challenges for the system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.11a
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• pp.97-104
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• 1996

DYGABCD 프로그램을 이용해 선형모델의 구성에 필요한 시스템 행렬을 구하고 최소자승법을 이용하여 실시간 선형모사를 행한 후 DYNGEN 프로그램을 이용한 비선형 모사와 비교하여 그 타당성을 입증하였다. 그리고 가제어성과 가안정성을 시험하여 시스템에 대해 제어기설계가 가능한지 확인하고 엔진의 성능과 직결되는 터빈입구 온도의 Overshoot 제어를 위해 고전적 제어기법인 PI제어기와 현대적 최적제어기법인 LQR 제어기를 설계하여 각각의 성능을 비교해 보았다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.35-35
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• 1999

최근 미사일 및 차세대 비행체에는 초기 고기동이나 무수한 제어력의 특성을 지닌 TVC 시스템이 많이 사용되고 있다. 기존의 공력 조타에 의한 비행 자세 제어방법은 속도의 2승에 비례하는 제어력을 발생하지만, TVC(Thrust Vector Control)를 이용하면 추력 방향을 변경하여 제어력을 얻음으로써 방향 제어에 보다 월등한 성능을 발휘할 수 있기 때문이다. TVC를 이용한 방향제어는 저속도 경우와 공기가 희박한 고 고도에서도 충분한 제어력을 얻을 수 있다. 그러나 그 우수성에 비추어 국내에서는 아직 그 성능에 대해 충분한 자료가 없는 실정이다.