Designing a Control Failure Survival System for High Speed Transport Aircraft Using Eigenvalue Assignment Method

2012 ◽  
Author(s):  
Zairil A. Zaludin
Keyword(s):  
Control System ◽  
Flight Control ◽  
High Speed ◽  
Control Surface ◽  
Longitudinal Motion ◽  
State Variables ◽  
Flight Control System ◽  
Short Period ◽  
Control Failure ◽  
Eigenvalue Assignment

Jika kerosakan berlaku kepada permukaan kawalan penerbangan, tujuan “Sistem Pereka Bentuk Kawalan Penerbangan” ialah untuk membahagi dan menyelaras usaha kawalan antara permukaan-permukaan kawalan yang masih aktif untuk tujuan mengekalkan mutu penerbangan yang diingini. Tugas utama ‘Sistem Pereka Bentuk Kawalan Penerbangan’ adalah untuk menyelaraskan unit kawalan semasa kerosakan berlaku ataupun menukar unit kawalan kepada sistem kawalan yang lebih sesuai untuk tujuan membaiki kerosakan tersebut. Dalam kertas ini, cara yang kedua dipertimbangkan. Reka bentuk “Sistem Keselamatan Kegagalan Kawalan” untuk pesawat hipersonik dibentangkan. Cara tersebut adalah berdasarkan cara penetapan nilai eigen dan teori pengatur kuadratik linear. Terdapat tiga masukan kawalan ke pesawat tersebut. Jika cara yang dibentangkan di dalam kertas ini digunakan, keputusan analisis yang dibentangkan menunjukkan bahawa sistem kawalan penerbangan untuk pesawat ini boleh direka bentuk sehingga kestabilan pesawat tersebut dicapai semula apabila salah satu ataupun gabungan permukaan kawalan gagal berfungsi pada masa yang sama. Didapati juga gerakan tabii pesawat yang mengalami kerosakan dapat dibaik pulih seperti sebelum kerosakan berlaku. Satu contoh disertakan dalam kertas ini menggunakan model matematik pesawat hipersonik. Kata kunci: dinamik penerbangan; penerbangan hipersonik; kawalan optimal; penetapan nilai eigen; Teori LQR In the event of a control surface failure, the purpose of a reconfigurable flight control system is to redistribute and coordinate the control effort among the aircraft’s remaining effective surfaces such that satisfactory flight performance is retained. A major task in control reconfiguration deals with adjusting the controller gains on-line or switching to a different control law to compensate for the failure. In this paper, the former option is considered. The design of a Control Failure Survival System (CFSS) for a hypersonic transport (HST) aircraft is presented. The method is based on eigenvalue assignment which was developed using Linear Quadratic Regulator theory. There are three control inputs available on board the HST; the change in the flaps deflection, the change in the propulsion diffuser area ratio and the change in the total temperature across combustor. Using the method discussed in this paper, the results showed that it was possible to reconfigure the flight control system such that the aircraft stability is regained when either a single or a combination of, control failures occurred simultaneously. In addition, the natural motion characteristics (i.e short period, phugoid and height motion) of the aircraft before the failure occurred are conserved and the transient response of the aircraft state variables after failure was almost the same as before failure occurred. An example is included in this paper using the mathematical model of the longitudinal motion of the HST. Key words: Aircraft dynamics; hypersonic flight; optimal control; eigen value assignment; LQR Theory

Design of sliding mode flight control system for a flexible aircraft

2021 ◽  
pp. 095441002110455
Author(s):  
Majeed Mohamed ◽  
Madhavan Gopakumar
Keyword(s):  
Control System ◽  
Rigid Body ◽  
Flight Control ◽  
High Speed ◽  
Sliding Mode ◽  
Flight Mechanics ◽  
Frequency Separation ◽  
Flight Control System ◽  
Flexible Aircraft ◽  
Aircraft Dynamics

The evolution of large transport aircraft is characterized by longer fuselages and larger wingspans, while efforts to decrease the structural weight reduce the structural stiffness. Both effects lead to more flexible aircraft structures with significant aeroelastic coupling between flight mechanics and structural dynamics, especially at high speed, high altitude cruise. The lesser frequency separation between rigid body and flexible modes of flexible aircraft results in a stronger interaction between the flight control system and its structural modes, with higher flexibility effects on aircraft dynamics. Therefore, the design of a flight control law based on the assumption that the aircraft dynamics are rigid is no longer valid for the flexible aircraft. This paper focuses on the design of a flight control system for flexible aircraft described in terms of a rigid body mode and four flexible body modes and whose parameters are assumed to be varying. In this paper, a conditional integral based sliding mode control (SMC) is used for robust tracking control of the pitch angle of the flexible aircraft. The performance of the proposed nonlinear flight control system has been shown through the numerical simulations of the flexible aircraft. Good transient and steady-state performance of a control system are also ensured without suffering from the drawback of control chattering in SMC.

Modeling, control design, and influence analysis of catapult-assisted take-off process for carrier-based aircrafts

2017 ◽  
Vol 232 (13) ◽  
pp. 2527-2540 ◽  
Author(s):  
Ziyang Zhen ◽  
Ju Jiang ◽  
Xinhua Wang ◽  
Kangwei Li
Keyword(s):  
Control System ◽  
Flight Control ◽  
Control Design ◽  
Control Surface ◽  
Flight Control System ◽  
Influence Analysis ◽  
Surface Ship ◽  
Lateral Channel ◽  
And Performance ◽  
Longitudinal Channel

This paper addresses the problems of modeling, control design, and influence analysis of the steam catapult-assisted take-off process of the carrier-based aircrafts. The mathematical models of the carrier-based aircraft, steam catapult, landing gears, and the environmental factors including deck motion and bow airflow have been established to express the aircraft dynamics in the take-off process. An engineering method based automatic flight control system has been designed, which is divided into the longitudinal channel and lateral channel. The influences of the preset control surface, ship deck motion, ship bow airflow, and automatic flight control system system are tested by a series of simulations. The simulation results show that the elevator angle preset is necessary in the stage of accelerated running on the ship deck and the deck motion is the most important factor for safe take-off, while the ship bow airflow is beneficial for climbing up of the aircraft. The automatic flight control system gives the guarantee of safety and performance in the take-off process of the carrier-based aircraft.

Sensor Fault Diagnosis for an UAV Control System Based on a Strong Tracking Kalman Filter

2014 ◽  
Vol 687-691 ◽  
pp. 270-274 ◽  
Author(s):  
Feng Tian ◽  
Jian Yang Zheng ◽  
Tong Zhang
Keyword(s):  
Kalman Filter ◽  
Control System ◽  
Fault Diagnosis ◽  
Real Time ◽  
Flight Control ◽  
Joint Estimation ◽  
Filter Method ◽  
State Variables ◽  
Flight Control System ◽  
Sensor Fault

The fault diagnosis of unmanned aerial vehicle (UAV) flight control system is an important research of UAV in health management. The sensor is the link which easiest to have problems of the flight control system. Making timely and accurate prediction of its faults is particularly important. A strong tracking Kalman Filter method for the sensor fault diagnosis of UAV flight control system was presented in this paper. The parameters of the system were extended to the state variables, the sensor fault observer was constructed, and the joint estimation of states and parameters of flight control system were gotten. The method can be used to real-time estimate the unmeasured states and time-varying parameters. The results of simulation experiments show that the method has a good real-time and accuracy in the sensor fault diagnosis of flight control system.

scholarly journals Structural Coupling and Whirl-Flutter Stability with Pilot-in-the-Loop

2021 ◽  
Author(s):  
Vincenzo Muscarello ◽  
Giuseppe Quaranta
Keyword(s):  
Control System ◽  
Flight Control ◽  
High Speed ◽  
Sensitivity Analyses ◽  
Critical Parameters ◽  
Flight Control System ◽  
Structural Coupling ◽  
Yaw Control ◽  
Whirl Flutter ◽  
Biodynamic Model

This paper investigates structural coupling problems for tiltrotors, considering not only the interaction of the flight control system with the flexible structure but also the potentially adverse effects on the aeroservoelastic stability that may be caused by the pilot's involuntary, high-frequency, biodynamic response. The investigation is focused on the analysis of the side effects that could appear at high speed in the airplane flight regime, where the whirl flutter boundaries may be significantly reduced. A detailed tiltrotor model, representative of the Bell XV-15 and of a flight control system has been built and joined with a pilot biodynamic model acting on the power-lever and on the center stick, available in the literature. Additionally, a modified version of the XV-15 using differential collective pitch for yaw control in airplane mode instead of rudder has been investigated to show the effect of different yaw control designs.The stability analyses presented demonstrate that the structural coupling analysis and the flutter boundaries for tiltrotors must be evaluated not only considering the closed loop created by the flight control system but also the effect of involuntary pilot response. Sensitivity analyses examine the most critical parameters impacting tiltrotor aeroservoelastic stability. Finally, the employment of notch filters as a means of prevention is discussed.

Effect of Control Surface Responses on Flight Control System Based on Hierarchical Dynamic Inversion

2019 ◽  
Vol 2019.72 (0) ◽  
pp. C23
Author(s):  
Kazuki KISHIWADA ◽  
Koichi YONEMOTO ◽  
Takahiro FUJIKAWA ◽  
Kento SHIRAKATA ◽  
Takahiro MATSUKAMI
Keyword(s):  
Control System ◽  
Flight Control ◽  
Control Surface ◽  
Dynamic Inversion ◽  
Flight Control System

scholarly journals Simulating actuator energy consumption for trajectory optimisation

2017 ◽  
Vol 232 (11) ◽  
pp. 2178-2192
Author(s):  
Michael Cooper ◽  
Craig Lawson ◽  
Amir Zare Shahneh
Keyword(s):  
Control System ◽  
Flight Control ◽  
High Speed ◽  
Electrical Energy ◽  
Guidance System ◽  
Control Surface ◽  
Aerodynamic Load ◽  
Actuation System ◽  
Heading Control ◽  
Trajectory Optimisation

This work aims to construct a high-speed simulation tool which is used to quantify the dynamic actuator power consumption of an aircraft in flight, for use within trajectory optimisation packages. The purpose is to evaluate the energy penalties of the flight control actuation system as an aircraft manoeuvre along any arbitrary trajectory. The advantage is that the approximations include major transient properties which previous steady state techniques could not capture. The output can be used to provide feedback to a trajectory optimisation process to help it compute the aircraft level optimality of any given flight path. The tool features a six degree of freedom dynamic model of an aircraft which is combined with low frequency functional electro-mechanical actuator models in order to estimate the major transient power demands. The actuator models interact with the aircraft using an aerodynamic load estimator which generates load forces on the actuators that vary as a function of flight condition and control surface demands. A total energy control system is applied for longitudinal control and a total heading control system is implemented to manage the lateral motion. The outer loop is closed using a simple waypoint following guidance system with turn anticipation and variable turn radius control. To test the model, a simple trajectory analysis is undertaken which quantifies a heading change executed with four different turn rates. The tool shows that the actuation system requires 12.8 times more electrical energy when performing a 90° turn with a radius of 400 m compared to 1000 m. A second test is performed to verify the model’s ability to track a longer trajectory under windy conditions.

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