• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1103-1111
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• 2014

The results of control law design for a tilt-rotor unmanned aerial vehicle that has a nacelle mounted wing extension (WE) are presented in this paper. It consists of a control surface mixer, stability and control augmentation system (SCAS), hold mode for altitude / speed / heading, and a guidance mode for preprogram and point navigation which includes automatic take-off and landing. The conversion corridor and the control moments derivatives between the original tilt-rotor and its variant of the nacelle mounted WE were compared to show the effectiveness of the WE. The nacelle conversion of the original tilt-rotor starts when the airspeed is greater than 30 km/h but its WE variant starts at 0 km/h in order to reduce the drag caused by the high incidence angle of the WE. The stability margins of the inner loop are presented with the optimization approach. The outer loops for the hold mode are designed with trial and error methods with linear and nonlinear simulation. The main control parameter for altitude control of the helicopter mode is thrust command and it is transferred to the pitch attitude command in airplane mode. Otherwise, the control parameter for the speed of the helicopter mode is the pitch attitude command and it is transferred to the thrust command in airplane mode. Therefore the speed and altitude hold mode are coupled to each other and are engaged at the same time when an internal pilot engages any of the altitude or speed hold modes. The nonlinear simulation results of the guidance control for the preprogrammed mode and point navigation are also presented including automatic take-off and landing in order to prove the full control law.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.1-9
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• 2009

The ground integration test of Smart UAV has been performed according to the flight test plan. The flight test of full scaled model will be performed followed by 4 DOF ground rig test and a tethered hover test. Smart UAV is the first indigenous tiltrotor aircraft which can fly with fast cruise speed and take off or land vertically. In order to prove the flight control law of Smart UAV, the 40% scaled airplane was developed and have been tested. During flight test of small scaled model, many unique and unexpected problems occurred. After clearing these problems, fully automatic flight test was performed successfully. The experiences about many trouble shooting and resolving the problems would be basic material to avoid the unexpected but similar flight test problems hidden behind of the full scaled Smart UAV. This paper presents the detailed procedures of trouble shootings to solve the unique problems which occurred during the flight test of small scaled tiltrotor UAV.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.10
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• pp.805-812
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• 2013

The operational flight program(OFP) which has the functions of I/O processing with avionics, flight control logic calculation, fault diagnosis and redundancy mode is embedded in the flight control computer of Smart UAV. The OFP was developed in the environment of PowerPC 755 processor and VxWorks 5.5 real-time operating system. The OFP consists of memory access module, device I/O signal processing module and flight control logic module, and each module was designed to hierarchical structure. Memory access and signal processing modules were verified from bench test, and flight control logic module was verified from hardware-in-the-loop simulation(HILS) test, ground integration test, tethered test and flight test. This paper describes development environment, software structure, verification and management method of the OFP.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.2
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• pp.133-139
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• 2017

Flight control computer of tiltrotor UAV was designed by redundancy system with primary and secondary channels to improve reliability. The redundancy functions consist of channel switching and data recovery. The channel switching function consists of software method by using cross channel data link and hardware method by using watchdog timer. The data recovery is the function to maintain flight condition when the flight control computer is restarted exceptionally in operation. The redundancy system was verified by flight control computer bench test, system integration test and HILS test. This paper describes the redundancy function of tiltrotor UAV flight control computer and test-verification method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.731-738
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• 2014

The mission of UAV has been expanded from a land to an ocean based on an enhancement of its technologies. Korea Aerospace Research Institute (KARI) also tries to expand the mission of tilt rotor UAV to an ocean, in which the shipboard landing of UAV is required. However the environment of an oceanic operation is severer than that of land due to salty, fogy, and windy condition. The landing point for automatic landing is not fixed due to movement of shipboard in roll, pitch, and heave. It makes the oceanic operation and landing of UAV difficult. In order to conduct an oceanic operation of tilt rotor UAV, this paper presents that the sea wave modeling according to the sea state is conducted and the shipboard landing of tilt rotor UAV under the sea wave is tested and evaluated through the flight simulator for UAV.

• Journal of Aerospace System Engineering
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• v.11 no.1
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• pp.14-21
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• 2017

A Linear parameterized Sigma-Pi neural network (SPNN) is applied to a tilt-duct unmanned aerial vehicle (UAV) which has a very large longitudinal stability ($C_{L{\alpha}}$). It is uncontrollable by a proportional, integral, derivative (PID) controller due to heavy stability. It is shown that the combined inner loop and outer loop of SPNN controllers could overcome the sluggish longitudinal dynamics using a method of dynamic inversion and pseudo-control to compensate for reference model error. The simulation results of the way point guidance are presented to evaluate the performance of SPNN in comparison to a PID controller.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.1-8
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• 2010

The tilt-rotor Smart UAV(Unmanned Air Vehicle) has been developed by KARI(Korea Aerospace Research Institute) for civil purposes. In order to prove the reliabilities of total system of Smart UAV, the series of ground tests were performed including system interface test, aircraft HILS(Hardware In the Loop Simulation) Test, ground power test, 4-DOF (Degrees of Freedom)rig test, and tethered hover test. Many unexpected problems occurred at each ground test. With clearing these problems, the total Smart UAV systems were matured and the airworthiness was proven enough. After complete of additional ground test proposed by FRRB(Flight Readiness Review Board), the first flight test will be performed in this year. This paper presents the procedures and the analysis results of the ground tests for the tilt-rotor Smart UAV.

• Aerospace Engineering and Technology
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• v.12 no.1
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• pp.22-31
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• 2013

Flight tests on flight control performance of helicopter, conversion and airplane mode for the Smart UAV were completed. Automatic take-off and landing, automatic return home as well as automatic approach to hover were performed in helicopter mode. Climb/descent, left/right turn using speed and altitude hold mode were performed in each $10^{\circ}$ tilt angle in conversion mode. The rotor speed in airplane mode was reduced to 82% from 98% RPM in order to increase rotor efficiency with reducing Mach number at tip of rotors. It reached to the designed maximum speed, $V_{TAS}$=440 km/h at 3 km altitude. This paper presents the flight test result on full envelopment of Smart UAV. Detailed test plan and test data on control performance were also presented to prove that all data meets the flying qualities requirement.

• Journal of Korean Physical Therapy Science
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• v.4 no.1
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• pp.315-327
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• 1997

The purpose of this thesis is to investigate the application of a medical cure with a mixture of the merit of a hydrotherapy, as a kind of a physical therapy, and the remedy efficacy of mugwort, which uses in a chinese medical treatment in order to remove an unpleasant smell of HOT Pack and its tube to use in hospital. The usability of mugwort and the degree of its preference was obtained through question naires sent to 120 students including 50 students of the department of physical therapy. And the feeling, at the moment a HOT Pack Tube was opened, was investigated through 74-physical therapists. This research is to investigate the effect of the remedy to add a mugwort-pack in a HOT Pack tube using already in hospital. The results of this study are as following : The efficacy of a mugwort-pack to get rid of an unpleasant smell got better than that of a HOT Pack and its tube. As most of physical therapy laboratory lies to a basement of a hospital, the efficacy to remove a particular offensive smell of a basement got better than that of a HOT Pack using in a common hospital. Also, the degree of patients' preference on a HOT Pack to add with mugwort got to be higher and increased gradually. I can't see the definite difference of a medical remedy, but, I suppose that the visible feeling was of much help for the effect of patients's remedy.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.436_437
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• 2009

이 논문은 MW-MVAr mile 법에 의한 요금제를 배전계통에 대하여 적용하며, 배전손실에 의한 비용과의 비교를 목표로 하였다. 특히 분산전원이 배전계통에 투입되는 경우에 있어서 투입되는 부하점에 따라 배전 손실 내지 배전요금이 변할 수 있음을 확인하였고, 배전손실이 최소가 되는 지점과 배전요금이 최저가 되는 지점이 반드시 일치하지는 않음을 알 수 있었다. 8모선의 배전계통에서 시뮬레이션이 이루어졌으며, 각 배전선로 별로 임피던스, 길이, 용량, 연간 필요 수입액등을 정하였다. 논의의 간소화를 위하여 분산전원은 상시 정격 출력하는 것으로 가정하였다.