The Study and Design of UAV Dynamic Inversion Flight Control Law

2010 ◽  
Vol 139-141 ◽  
pp. 1757-1762
Author(s):  
Ji Lin He ◽  
Rao Bao Jiang ◽  
Bo Liu ◽  
Xin Zhao ◽  
Qing Hua He

That the dynamic model is characteristic of nonlinearity and that linear equation design approach based on small perturbations of linear system has failed to meet the design requirements cause the study of the dynamic inversion control. Integrating the dynamic inversion theory and the UAV nonlinear mathematical model, the paper, in accordance with the speed of status variable change, has designed respectively the UAV inner-loop fast variable and outer-loop slow variable controllers and thus, found the dynamic inversion flight control law applicable to UAV and conducted the simulation study. A conclusion can be drawn that the control law is satisfactory in flight control.

2011 ◽  
Vol 2011.64 (0) ◽  
pp. 115-116
Author(s):  
Koichi YONEMOTO ◽  
Hirofumi NAKASHIMA ◽  
Hiroshi KAMODA ◽  
Bruno VICTORINO SARLI

2004 ◽  
Vol 108 (1084) ◽  
pp. 319-329
Author(s):  
A. J. Steer

Abstract Modern civil transport aircraft utilise increasingly complex command and stability augmentation systems to restore stability, optimise aerodynamic performance and provide the pilot with the optimum handling qualities. Provided it has sufficient control power a second generation fly-by-wire supersonic transport aircraft should be capable of exhibiting similarly desirable low-speed handling qualities. However, successful flight control law design requires identification of the ideal command response type for a particular phase of flight, a set of valid handling quality design criteria and piloted simulation evaluation tasks and metrics. A non-linear mathematical model of the European supersonic transport aircraft has been synthesized on the final approach to land. Specific handling quality design criteria have been proposed to enable the non-linear dynamic inversion flight control laws to be designed, with piloted simulation used for validation. A pitch rate command system, with dynamics matched to the aircraft’s flight path response, will consistently provide Level 1 handling qualities. Nevertheless, pre-filtering the pilot’s input to provide a second order pitch rate response, using the author’s suggested revised constraints on the control anticipation parameter will generate the best handling qualities during the terminal phase of flight. The resulting pre-filter can be easily applied to non-linear dynamic inversion inner loop controllers and has simple and flight proven sensor requirements.


Author(s):  
Yu LI ◽  
Xiaoxiong LIU ◽  
Ruichen MING ◽  
Shaoshan SUN ◽  
Weiguo ZHANG

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.


2011 ◽  
Vol 66-68 ◽  
pp. 27-30
Author(s):  
Hai Wen Du ◽  
Xing Wei Weng ◽  
Yu Song Fu ◽  
Chuan Lin Tang

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.


1998 ◽  
Vol 120 (2) ◽  
pp. 208-215 ◽  
Author(s):  
S. A. Snell ◽  
P. W. Stout

A method of designing control laws for uncertain nonlinear systems is presented. Dynamic inversion is used to partially linearize the dynamics and then a nonlinear version of quantitative feedback theory (QFT) is applied to the resulting system which assures robustness to plant uncertainty. The design yields good performance with low bandwidth. An application to the design of flight control laws for a high performance aircraft is presented. The control laws demonstrate good performance by accurately following large angle of attack commands at flight speeds ranging from 53 to 150 m/s. Robustness is verified by including ±20 percent variations in pitching moment derivatives. The reduced bandwidth compared to a fixed-gain, linear design, leads to greatly reduced actuator transients, which should give improved reliability and longer life for the actuators and associated structure.


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