• Title/Summary/Keyword: time-of -flight

Search Result 1,785, Processing Time 0.024 seconds

A Study on the Design and Validation of Switching Control Law (전환제어법칙 설계 및 검증에 관한 연구)

  • Kim, Chong-Sup
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.17 no.1
    • /
    • pp.54-60
    • /
    • 2011
  • The flight control law designed for prototype aircraft often leads to degraded stability and performance, although developed control law verify by non-real time simulation and pilot based evaluations. Therefore, the proper evaluation methods should be applied such that flight control law designed can be verified in real flight environment. The one proposed in this paper is IFS (In-Flight Simulator). Currently, this system has been implemented into the F-18 HARV (High Angle of Attack Research Vehicle), SU-27 and F-16 VISTA (Variable stability In flight Simulation Test Aircraft) programs. The IFS necessary switching control law such as fader logic and integrator stand-by mode to reduce abrupt transient and minimize the integrator effect for each flight control laws switching. This paper addresses the concept of switching mechanism with fader logic of "TFS (Transient Free Switch)" and stand-by mode of "feedback type" based on SSWM (Software Switching Mechanism). And the result of real-time pilot evaluation reveals that the aircraft is stable for inter-conversion of flight control laws and transient response is minimized.

Prediction of Possible Intercept Time by Considering Flight Trajectory of Nodong Missile

  • Lee, Kyounghaing;Oh, Kyunngwon
    • International Journal of Aerospace System Engineering
    • /
    • v.3 no.2
    • /
    • pp.14-21
    • /
    • 2016
  • This paper presents research on predicting the possible intercept time for a Nodong missile based on its flight trajectory. North Korea possesses ballistic missiles of various ranges, and nuclear warhead miniaturization tests and ballistic missile launch tests conducted last year and in previous years have made these missiles into a serious security threat for the international community. With North Korea's current miniaturization skills, the range of the nuclear capable Nodong missiles can be adjusted according to their use goals and operating environment by using a variety of adjustment methods such as payload, fuel mass, Isp, loft angle, cut-off, etc., and therefore precise flight trajectory prediction is difficult. In this regards, this research performs model simulations of the flight trajectory of North Korea's domestically developed Nodong missiles and uses these as a basis for predicting the possible intercept times for major ballistic missile defense systems such as PAC-3, THAAD, and SM-3.

Model Following flight Control System Design (준 슬라이딩 모드 제어 기법을 이용한 모델 추종 비행제어 시스템 설계)

  • Choe, Dong-Gyun;Kim, Shin;Kim, Jong-Hwan
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.6 no.12
    • /
    • pp.1133-1145
    • /
    • 2000
  • In this paper a model following flight control system design using the discrete time quasi-sliding mode control method is described. The quasi-sliding mode is represented as the sliding mode band, not as the sliding surface. The quasi-sliding mode control is composed of the equivalent control for the nominal system without uncertainties and disturbances and the additive control compensating the uncertainties and disturbances. The linearized plant on the equilibrium point is used in designing a flight control system and the stability conditions are proposed for the model uncertainties. Pseudo-state feedback control which uses the model variables for the unmeasured states is proposed. The proposed method is applied to the design of the roll attitude and pitch load factor control of a bank-to-turn missile. The performance is verified through the nonlinear six degrees of freedom flight simulation.

  • PDF

Effect of Weather, Flight, and Time Conditions on Anxiety and Time Perception of Helicopter Pilots in Flight (기상, 비행 및 시간 조건이 조종 중인 헬리콥터 조종사의 불안 및 시간지각에 미치는 영향)

  • MunSeong Kim;ShinWoo Kim;Hyung-Chul O. Li
    • Science of Emotion and Sensibility
    • /
    • v.26 no.1
    • /
    • pp.65-78
    • /
    • 2023
  • Aircraft are representative of human-machine systems. There is a delay between the human operation and the completion of the machine operation such as when the machine starts to operate and when the force is transmitted to the machine and completed. Time perception is an important component of timing tasks and is known to be affected by the anxiety associated with high arousal. This research verified the impact of weather, flight, and time conditions on the anxiety and time perception of in-service pilots in a virtual reality area. Weather conditions were divided into visual flight weather conditions and very low visibility conditions. Experiments 1 and 2 were performed with different flight and time conditions. In Experiment 1, time perception was measured by employing a button added to the control rod in the scenario of hovering and level flight with relatively little transformed in momentum and little delay. In Experiment 2, time perception was measured in the procedure of naturally taking off the helicopter by employing only the control stick in a takeoff scenario where there was a lot of transformation in momentum and a lot of delays. As a result of the experiment, it was reported that anxiety and heart rate increased in very low visibility conditions In particular, among all flight conditions in Experiments 1 and 2, it was reported that time was overestimated in the scenario of increased anxiety. This outcome can lead to overestimation of time under the impact of anxiety and failure of the timing task, which may lead to challenges in maneuvering and possibly lead to accidents.

A Study on The Spatial Disorientation of Pilots for Flight Safety (비행안전을 고려한 조종사의 비행착각에 관한 연구)

  • 강한태;윤봉수
    • Journal of the military operations research society of Korea
    • /
    • v.25 no.1
    • /
    • pp.14-28
    • /
    • 1999
  • Statistical data have shown that most of aircraft accidents attributed to the spatial disorientation result from visually restricted environments such as a flight amid clouds or a night flight, in particular during roll maneuvering. This study investigates the time necessary for a flighting pilot to recognize a sloped status as a horizontal status on the condition that the roll maneuver is operating when the visual sense is blocked In this study, aspects which affect such disorientation phenomena are examined. The result of this study shows that a pilot is rushed into a somatogyral illusion when a certain time elapses with visual sense blocked, and that as a speed of the flight increases and a bank of aircraft decreases, so a rushing time increases rapidly.

  • PDF

Characterization of a Membrane Interface for Analysis of Air Samples Using Time-of-flight Mass Spectrometry

  • Jang, Yu-Mi;Oh, Jun-Sik;Park, Chang-Joon;Yang, Sang-Sik;Jung, Kwang-Woo
    • Bulletin of the Korean Chemical Society
    • /
    • v.31 no.10
    • /
    • pp.2791-2796
    • /
    • 2010
  • In the present study, we constructed a membrane inlet assembly for selective permeation of volatile airborne organic compounds for subsequent analysis by time-of-flight mass spectrometry. The time-dependent diffusion of analytes through a $75\;{\mu}m$ thick polydimethylsiloxane membrane was measured by monitoring the ion signal after a step change in the sample concentration. The results fit well to a non-steady-state permeation equation. The diffusion coefficient, response time, and sensitivity were determined experimentally for a range of polar (halogenated) and nonpolar (aromatic) compounds. We found that the response times for several volatile organic compounds were greatly influenced by the alkyl chain length as well as the size of the substituted halogen atoms. The detection limits for benzene, ethylbenzene, and 2-propanol were 0.2 ppm, 0.1 ppm, and 3.0 ppm by volume, respectively, with a linear dynamic range greater than three orders of magnitude. These results indicate that the membrane inlet/time-of-flight mass spectrometry technique will be useful for a wide range of applications, particularly for in situ environmental monitoring.

Performance Analysis of Machine Learning Based Spatial Disorientation Detection Algorithm Using Flight Data (비행데이터를 활용한 머신러닝 기반 비행착각 탐지 알고리즘 성능 분석)

  • Yim Se-Hoon;Park Chul;Cho Young jin
    • Journal of Advanced Navigation Technology
    • /
    • v.27 no.4
    • /
    • pp.391-395
    • /
    • 2023
  • Helicopter accidents due to spatial disorientation in low visibility conditions continue to persist as a major issue. These incidents often stem from human error, typically induced by stress, and frequently result in fatal outcomes. This study employs machine learning to analyze flight data and evaluate the efficacy of a flight illusion detection algorithm, laying groundwork for further research. This study collected flight data from approximately 20 pilots using a simulated flight training device to construct a range of flight scenarios. These scenarios included three stages of flight: ascending, level, and descent, and were further categorized into good visibility conditions and 0-mile visibility conditions. The aim was to investigate the occurrence of flight illusions under these conditions. From the extracted data, we obtained a total of 54,000 time-series data points, sampled five times per second. These were then analyzed using a machine learning approach.

Experimental Verification on the Extending Flight Time of Solar Paper for Drone using Battery for Electric Vehicles (장기 체공 태양광 드론의 비행시간 연장에 관한 실험적 검증)

  • Wooram Lee
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.24 no.4
    • /
    • pp.229-235
    • /
    • 2023
  • Recently, for drones to be used for agricultural applications, it is necessary to increase the payload and extending flight time. Currently, the payload and extending flight time are limited by the battery technology for solar paper drone. In addition, charging or replacing the batteries may be a practical solution at the field that requires near continuous operation. In this paper, the procedure to optimize the main power system of an electric hybrid drone that consists of a battery and electric motor is presented. As a result, the solar paper drone flied successfully for 2-3%. The developed solar paper drone consumes and average of 55W when cruising and can receive up to 25W of energy during the day, and its extending flight time was verified through flight tests.

The Oviposition Period, Emergence Period, and Flight Activity of the African Mole Cricket(Gryllotalpa africana Palisct do Beauvois) Adult Damaging Ginseng Plants (인삼 해충, 땅강아지 ( Gryllotalpa africana Palisot do Beauvois) 성충의 산란기, 우화기 및 비산활동)

  • 김기황;김상석;손준수
    • Journal of Ginseng Research
    • /
    • v.13 no.1
    • /
    • pp.119-122
    • /
    • 1989
  • phenological study on the oviposition, emergence, and flight activity of the African mole cricket adult has been made to obtain basic information for management of pest populations in ginseng fields. The flight activity, as monitored by the blarklight trap, seemed to be initiated depending on the sunset time and lasted about 2-2.5 hours. The trap data (1984-1988) showed that the adult flight of the species occurred twice a year, from early May to late June(Spring flight) and from late August to mid October(Fall flight) during which usually more crickets were trapped than during the former period. The number of females trapped was greater than that of males regardless to the flight period, i.e., females comprised 72.2%, 83.9%, and 73.3% of the total catches in 1984, 1985, and 1986, respectively. Adults emerged from late August to mid October and laid eggs from mid May to mid July the next year, indicating that the spring and fall flights correspond to the oviposition and emergence period, respectively.

  • PDF