scholarly journals Robust dynamic inversion control of flight control system based on L1 adaptive structure

2021 ◽  
Vol 39 (5) ◽  
pp. 995-1004
Author(s):  
Yu LI ◽  
Xiaoxiong LIU ◽  
Ruichen MING ◽  
Shaoshan SUN ◽  
Weiguo ZHANG
Keyword(s):  
Control System ◽  
Flight Control ◽  
Dynamic Performance ◽  
Dynamic Inversion ◽  
Control Law ◽  
Flight Control System ◽  
Parameter Uncertainties ◽  
Strong Robustness ◽  
Adaptive Structure ◽  
The Stability

Nonlinear Dynamic Inversion(NDI) control has excellent rapidity and decoupling ability, unfortunately it lacks the essential robustness to disturbance. From the perspective of enhancing the robustness, an adaptive NDI method based on L1 adaptive structure is proposed. The L1 adaptive structure is introduced into the NDI control to enhance its robustness, which also guarantees the stability and expected dynamic performance of the system suffering from the disturbance influence. Secondly, the flight control law of the advanced aircraft is designed based on the present method to improve the robustness and fault tolerance of the flight control system. Finally, the effectiveness of the flight control law based on the present approach is verified under the fault disturbance. The results showed that the flight control law based on L1 adaptive NDI has excellent dynamic performance and strong robustness to parameter uncertainties and disturbances.

Design UCAV Flight Control Law Based on Jamming Observer

2011 ◽  
Vol 66-68 ◽  
pp. 27-30
Author(s):  
Hai Wen Du ◽  
Xing Wei Weng ◽  
Yu Song Fu ◽  
Chuan Lin Tang
Keyword(s):  
Control System ◽  
Flight Control ◽  
System Stability ◽  
Good Stability ◽  
Dynamic Inversion ◽  
Control Law ◽  
Flight Control System ◽  
System A ◽  
Simulation Results

In order to study the nonlinear jamming problem in UCAV’s flight control system, a method of using observer to check the system’s jamming was designed, constructed robust dynamic inversion control law based on jamming observer. The simulation results show that the robust dynamic inversion control law based on jamming observer, make UCAV’s flight control system have good stability and robustness, it’s a great convenience analyzing the system stability.

scholarly journals An adaptive dynamic inversion control method based on improved piecewise constant for flight control system

2021 ◽  
Vol 39 (1) ◽  
pp. 167-174
Author(s):  
Yu Li ◽  
Xiaoxiong Liu ◽  
Qizhi He ◽  
Weiguo Zhang ◽  
Tianpeng Huang
Keyword(s):  
Control System ◽  
Flight Control ◽  
Present Method ◽  
Control Method ◽  
Controller Design ◽  
Dynamic Performance ◽  
Sudden Change ◽  
Dynamic Inversion ◽  
Piecewise Constant ◽  
The Stability

To overcome the lack of robustness of the nonlinear dynamic inversion (NDI) control, a simple and practical adaptive NDI control method based on an improved piecewise constant is proposed in this paper to enhance its robustness to disturbances and improve the accuracy of response tracking. Firstly, reasonable assumptions and analyses are made for the system with the influence of disturbance. Secondly, an improved piecewise constant adaptive NDI control method suitable for general flight control systems is proposed. The stability of the control system with disturbance and the error convergence range of the improved piecewise constant adaptive control are proved and analyzed theoretically. Finally, taking into account the fighter actual control requirements, the angular rates control strategy is given, and the proposed method is applied to the angular rates flight controller design. Matlab simulations are carried out under the disturbance of the actuator failure and the sudden change of the center of gravity, and the robustness and dynamic performance of the controller designed based on the present method is compared and verified. The results illustrate that our present method has stronger robustness and higher control accuracy.

Integrated Aircraft Modeling Research for Accurate Flight Control System Design

2013 ◽  
Vol 791-793 ◽  
pp. 658-662
Author(s):  
Chao Zhang ◽  
Yi Nan Liu ◽  
Jian Hui Xu
Keyword(s):  
Control System ◽  
System Design ◽  
Flight Control ◽  
Time Delays ◽  
Flight Dynamics ◽  
Control System Design ◽  
Control Law ◽  
Flight Control System ◽  
Aircraft Model ◽  
Simulation Results

In order to realize accurate flight control system design and simulation, an integrated scheme of aircraft model which consists of flight dynamics, fly-by-wire (FBW) platform and flight environment is proposed. Flight environment includes gravity, wind, and atmosphere. And the actuator and sensors such as gyroscope and accelerometer models are considered in the FBW platform. All parts of the integrated model are closely connected and interacted with each other. Simulation results confirm the effectiveness of the integrated aircraft model and also indicate that the (Flight Control Law) FCL must be designed with robustness to sensor noise and time delays with the FBW platform in addition to the required robustness to model uncertainty in flight dynamics.

scholarly journals Impacts of Deflection Nose on Ballistic Trajectory Control Law

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bo Zhang ◽  
Shushan Wang ◽  
Mengyu Cao ◽  
Yuxin Xu
Keyword(s):  
Control System ◽  
Motion Control ◽  
Flight Control ◽  
Calculation Model ◽  
Trajectory Control ◽  
Control Law ◽  
Flight Control System ◽  
Theory Of Motion ◽  
Ballistic Trajectory ◽  
Exterior Ballistics

The deflection of projectile nose is aimed at changing the motion of the projectile in flight with the theory of motion control and changing the exterior ballistics so as to change its range and increase its accuracy. The law of external ballistics with the deflectable nose is considered as the basis of the design of a flight control system and an important part in the process of projectile development. Based on the existing rigid external ballistic model, this paper establishes an external ballistic calculation model for deflectable nose projectile and further establishes the solving programs accordingly. Different angle of attack, velocity, coefficients of lift, resistance, and moment under the deflection can be obtained in this paper based on the previous experiments and emulation researches. In the end, the author pointed out the laws on the impaction of external ballistic trajectory by the deflection of nose of the missile.

PID Control Based Missile Sub-Channel Simulation

2012 ◽  
Vol 433-440 ◽  
pp. 7011-7016 ◽  
Author(s):  
Chao Bo Chen ◽  
Bing Liu ◽  
Ning He ◽  
Song Gao ◽  
Quan Pan
Keyword(s):  
Control System ◽  
Real Time ◽  
Flight Control ◽  
Pid Control ◽  
Pid Controller ◽  
Channel Model ◽  
Control Method ◽  
Flight Control System ◽  
Aerodynamic Control ◽  
The Stability

The accuracy and real-time of modern missile flight control system of traditional aerodynamic can not be satisfied. In this paper a new method is presented to improve the accuracy and real-time of missiles under this condition. First of all, a missile sub-channel model of the dynamic equations and steering gear is established, then based on the established model, using PID controller to control steering gear and three channels of missile pitch, yaw, roll respectively which is called missile sub-channel PID control method, and finally making use of MATLAB/Simulink to complete the simulation. Simulation results show that compared with traditional aerodynamic control system, this method can reduce the response time of aerodynamic missile and enhance the stability of the control system obviously.

LQG-Based Robustifying Flight Control System

2003 ◽  
Author(s):  
D. Griffin ◽  
A. G. Kelkar
Keyword(s):  
Control System ◽  
Flight Control ◽  
Controller Design ◽  
Second Step ◽  
Flight Control System ◽  
Robust Controller ◽  
Fighter Aircraft ◽  
Stability Robustness ◽  
Uncertainty Model ◽  
The Stability

This paper presents a robust controller design for an automatic flight control system (AFCS) for a fighter aircraft model with eight inputs and seven outputs. The controller is designed based on McFarlane-Glover robustifying technique using a simple baseline LQG design. Controllers designed purely based on traditional LQG techniques are known to have no guaranteed robustness margins. The McFarlane-Glover technique can be used to enhance the stability robustness of the baseline LQG design using a two-step design process. In the first step, an LQG controller is designed which is optimized only for performance without any consideration to robustness. In the second step, the performance optimized LQG design is rendered robust using McFarlane-Glover procedure. The robustifying procedure uses a coprime factor uncertainty model and H∞ optimization. An important advantage of this procedure is that no problem dependent uncertainty modelling or weight selection is required in the second step of the process. The robustifying procedure also yields the quantitative estimate of the robustness.

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