• Title, Summary, Keyword: flight control

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An Adaptive Flight Control Law Design for the ALFLEX Flight Control System

  • Imai, Kanta;Shimada, Yuzo;Uchiyama, Kenji
    • 제어로봇시스템학회:학술대회논문집
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    • pp.148.5-148
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    • 2001
  • In this report, an adaptive flight control law based on a linear-parameter-varying (LPV) model is presented for a flight control system. The control system is designed to track an output of a vehicle to a reference signal from the guidance system, which generates a reference flight path. The proposed adaptive control law adjusts the controller gains continuously on line as flight conditions change. The obtained adaptive controller guarantees global stability over a wide flight envelope. Computer simulation involving six-degree-of-freedom nonlinear flight dynamics is applied to Japan´s automatic landing flight experimental vehicle (ALFLEX) to examine the effectiveness of the proposed adaptive flight control law.

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Development of Flight Control Laws for the T-50 Advanced Supersonic Jet Trainer

  • Kim, Chong-Sup;Hur, Gi-Bong;Hwang, Byung-Moon;Cho, In-Je;Kim, Seung-Jun
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.1
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    • pp.32-45
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    • 2007
  • The T-50 advanced supersonic jet trainer employs the Relaxed Static Stability (RSS) concept to improve the aerodynamic performance while the flight control system stabilizes the unstable aircraft and provides adequate handling qualities. The T-50 flight control laws employ a proportional-plus-integral type controller based on a dynamic inversion method in longitudinal axis and a proportional type controller based on a blended roll system with simple roll rate feedback and beta-betadot feedback system. These control laws are verified by flight tests with various maneuver set flight envelopes and the control laws are updated to resolve flight test issues. This paper describes several concepts of flight control laws used in T-50 to resolve those flight test issues. Control laws for solving the roll-off problem during pitch maneuver in asymmetric loading configurations, improving the departure resistance in negative angle of attack conditions and enhancing the fine tracking performance in air-to-air tracking maneuvers are described with flight test data.

Analysis on Flight Test Results of Reconfiguration Flight Control System (재형상 비행제어 시스템의 비행시험 결과 분석)

  • Min, Byoung-Mun;Kim, Seong-Pil;Kim, Bong-Ju;Kim, Eung-Tai;Tahk, Min-Jea
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.12
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    • pp.1244-1252
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    • 2008
  • This paper presents the analysis results obtained by the flight test of reconfiguration flight control system for an aircraft. The reconfiguration flight control system was designed by using control allocation scheme that automatically distributes the demanded control moments determined by control law to each actual control surface. In this paper, some control allocation algorithms for reconfiguration control of general aircraft with redundant control surfaces are summarized and their performance evaluation results through nonlinear simulation and Hardware-In-the-Loop-Simulation (HILS) test are shown. Also, Unmanned Aerial Vehicle (UAV) system adopted as a platform for the flight test of reconfiguration flight controller and the implementation procedure of reconfiguration flight controller into real-time UAV system were introduced. Finally, flight test results were analyzed.

A Study on the Design of Software Switching Mechanism for Develops the Flight Control Law (제어법칙 개발을 위한 소프트웨어 전환장치 설계에 관한 연구)

  • Kim, Chong-Sup;Cho, In-Je;Ahn, Jong-Min;Shin, Ji-Hwan;Park, Sang-Seon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.11
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    • pp.1130-1137
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    • 2006
  • Relaxed Static Stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, the flight control systems are necessary to stabilizes the unstable aircraft and provides adequate handling qualities. The initial production flight control system are verified by flight test and it's always an elements of danger because of flight-critical nature of control law function and design error due to model base design method. These critical issues impact to flight safety, and it could be lead to a loss of aircraft and pilot's life. Therefore, development of an easily modifiable RFCS(Research Flight Control System) capable of reverting to a PFCS(Primary Flight Control System) of reliable control law must be developed to guarantee the flight safety. This paper addresses the concept of SSWM(Software Switching Mechanism) using the fader logic such as TFS(Transient Free Switch) based on T-50 flight control law. The result of the analysis based on non-real time simulation in-house software using SSWM reveals that the flight control system are switching between two computers without any problem.

Flight Control System Design and Verification Process (비행제어시스템 설계 및 검증 절차)

  • Kim, Chong-Sup
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.824-836
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    • 2008
  • Relaxed static stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, flight control systems are necessary to stabilize an unstable aircraft, and provides adequate handling qualities and achieve performance enhancements. Standard FCSDVP (Flight Control System Design and Verification Process) is provided to reduce development period of the flight control system. In addition, if this process is employed in developing flight control system, it reduces the trial and error for development and verification of flight control system. This paper addresses the flight control system design and verification process for the RSS aircraft utilizing design goal based on military specifications, linear and nonlinear system design and verification based on universal software, handling quality test based on HILS(Hardware In-the-Loop Simulator) environment, and ground and flight test results to verify aircraft dynamic flight responses.

Development of Low-Cost Automatic Flight Control System for Unmanned Target Drone

  • Lee, Jang-Ho;Ryu, Hyeok;Kim, Jae-Eun;Ahn, Iee-Ki
    • 제어로봇시스템학회:학술대회논문집
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    • pp.367-371
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    • 2004
  • This paper describes development of automatic flight control system for an unmanned target drone which is operated by Korean army as for anti-air gun shooting training. Current target drone is operated by pilot control of on-board servo motor via remote control system. Automatic flight control system for the target drone greatly reduces work load of ground pilot and can increase application area of the drone. Most UAVs being operated now days use high-priced sensors as AHRS and IMU to measure the attitude, but those are costly. This paper introduces the development of low-cost automatic flight control system with low-cost sensors. The integrated automatic flight control system has been developed by integrating combining power module, switching module, monitoring module and RC receiver as an one module. The performance of automatic flight control system is verified by flight test.

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In Flight Simulation for Flight Control Law Evaluation of Fly-by-Wire Aircraft (I)

  • Ko, Joon-Soo;Lee, Ho-Keun
    • 제어로봇시스템학회:학술대회논문집
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    • pp.2560-2565
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    • 2003
  • The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The control law was designed for the most unstable aircraft configuration flight regime for the target aircraft (FBWA). The ground based simulation including math-model, real-time pilot-in-the-loop and iron bird simulation were used for validation of the control law before the experimental in-flight simulation on the IFS (In.Flight-Simulator) aircraft. The flight tests results showed that Level 1 handling qualities for the most unstable flight regime were achieved.

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Design of a Variable Stability Flight Control System

  • Park, Sung-Su;Ko, Joon-Soo
    • International Journal of Aeronautical and Space Sciences
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    • v.9 no.1
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    • pp.162-168
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    • 2008
  • A design objective for variable stability flight control system is to develop a controller of in-flight simulation capability that forces the aircraft being flown to follow the dynamics of other aircraft. This paper presents a model-following variable stability control system (VSS) for in-flight simulation which consists of feedforward and feedback control laws, the aircraft dynamic model to be simulated, and switching and fader logics to reduce the transient effect between two aircraft dynamics. The separate design techniques for feedforward and feedback control law proposals are based on model matching and augmented linear quadratic (LQ) techniques. The system allows pilots to select and engage VSS mode, and when deselected, the aircraft reverts to the baseline flight control system. Both the baseline flight control laws and VSS control laws are computed continuously during flight. Initialization of the state values are necessary to prevent instability, since VSS control laws have integrators and filters in longitudinal, and lateral/directional axes. This paper demonstrates and validates the effectiveness and quality of VSS with F-16 models embedded in T-50 in-flight simulation aircraft.

Recent trends in advanced flight control

  • Kanai, Kimio
    • 제어로봇시스템학회:학술대회논문집
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    • pp.24.1-24
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    • 1996
  • The development of future aircraft that involves the expanded flight envelop will place increased performance requirements on the design of the flight control system. Maneuvering areas are expanding into flight envelopes characterized by significantly larger levels of modeling uncertainty than encountered in present flight control designs. Conventional flight control techniques that ignore the effects of large parameter variations, modeling uncertainties and nonlinearities, will likely produce designs with poor performance and robustness. Recent advances in modern control theories called advanced control theories, most notably the H$\_$.inf./ synthesis technique, adaptive control and neural network application, offer the promise of a design technique that can produce both high performance and robust controllers for next generation aircraft. This special lecture will survey the recent development in advanced flight control and review the possible application of advanced control theories.

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A Flight Mechanics-Centric Review of Bird-Scale Flapping Flight

  • Paranjape, Aditya A.;Dorothy, Michael R.;Chung, Soon-Jo;Lee, Ki-D.
    • International Journal of Aeronautical and Space Sciences
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    • v.13 no.3
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    • pp.267-281
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    • 2012
  • This paper reviews the flight mechanics and control of birds and bird-size aircraft. It is intended to fill a niche in the current survey literature which focuses primarily on the aerodynamics, flight dynamics and control of insect scale flight. We review the flight mechanics from first principles and summarize some recent results on the stability and control of birds and bird-scale aircraft. Birds spend a considerable portion of their flight in the gliding (i.e., non-flapping) phase. Therefore, we also review the stability and control of gliding flight, and particularly those aspects which are derived from the unique control features of birds.