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.

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.

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.

A Linear Quadratic Integral Design Approach for the Automatic Control System of a Launch Vehicle

2015 ◽  
Vol 772 ◽  
pp. 410-417 ◽  
Author(s):  
Adrian Mihail Stoica ◽  
Cristian Emil Constantinescu ◽  
Silvia Nechita
Keyword(s):  
Control System ◽  
Flight Control ◽  
Launch Vehicle ◽  
Design Approach ◽  
Flight Control System ◽  
Linear Quadratic ◽  
Atmospheric Disturbances ◽  
Modeling Uncertainties ◽  
Quadratic Integral ◽  
The Stability

This paper presents a design approach for the automatic flight control system of a launch vehicle using a linear quadratic integral technique together with a fixed gain Kalman filter. Its purpose is to analyse the stability and tracking robustness performances of the control system designed via this approach when atmospheric disturbances, modeling uncertainties and structural flexible modes of the launcher are taken into account.

Design and Verification the Simulation System of UAS Flight Control Considering the Effects of Time Delay

2013 ◽  
Vol 278-280 ◽  
pp. 1746-1753
Author(s):  
Sheng Yi Yang ◽  
Sheng Jing Tang ◽  
Chao Liu ◽  
Jie Guo
Keyword(s):  
Control System ◽  
Time Delay ◽  
Real Time ◽  
Flight Control ◽  
Simulation System ◽  
Unmanned Aircraft ◽  
Flight Control System ◽  
The Real ◽  
The Stability ◽  
Hil Simulation

It had not been explored which real-time magnitude can meet the requirement of the simulation object in computer simulation system. Taking time delay into consideration, the influence of time delay on the stability of the low-altitude and low-speed small Unmanned Aircraft Systems (UAS) flight control system had been analyzed and the real-time magnitude of the miniature hardware-in-loop (HIL) simulation system was determined. Then a miniature HIL simulation system of the UAS flight control system was designed to prove the real-time magnitude feasibility. The result shows the real-time magnitude by time delay analysis can meet the requirements of flight control system.

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