Flight Test Approach for Modeling and Control Law Validation for Unmanned Aircraft

2022 ◽  
Author(s):  
James L. Gresham ◽  
Jean-Michel W. Fahmi ◽  
Benjamin M. Simmons ◽  
Jeremy W. Hopwood ◽  
Wade Foster ◽  
...  
1998 ◽  
Vol 120 (1) ◽  
pp. 221-227 ◽  
Author(s):  
C. D. Rahn ◽  
S. Joshi

This paper introduces models for electrorheological (ER) structures based on visco-elasticity and sandwich beam theory. The partial differential equations describing the dynamics of an ER sandwich beam are derived and a modal analysis is performed. Feedback controllers, derived using Lyapunov theory, ensure stability of all modes of the beam. Feedback from an axial velocity sensor to the applied ER beam voltage provides an implementable approximation to the control law. Simulations of a cantilevered ER beam show the stable response and improved transient decay provided by the control system.


2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
Yifei Wu ◽  
Zhihong Wang ◽  
Yuanyuan Li ◽  
Wei Chen ◽  
Renhui Du ◽  
...  

A novel approach for modeling and control of servo systems with backlash and friction is proposed based on the characteristic model. Firstly, to deal with friction-induced nonlinearities, a smooth Stribeck friction model is introduced. The backlash is modeled by a continuous and derivable mathematical function. Secondly, a characteristic model in the form of a second-order slowly time-varying difference equation is established and verified by simulations. Thirdly, a composite controller including the golden-section adaptive control law and the integral control law is designed and the stability of the closed-loop system is analyzed. The simulation and experimental results show that the proposed control scheme is effective and can improve the steady-state precision and the dynamic performance of the servo system with backlash and friction.


2013 ◽  
Vol 01 (01) ◽  
pp. 41-58 ◽  
Author(s):  
Andrew N. Kopeikin ◽  
Sameera S. Ponda ◽  
Luke B. Johnson ◽  
Jonathan P. How

A multi-UAV system relies on communications to operate. Failure to communicate remotely sensed mission data to the base may render the system ineffective, and the inability to exchange command and control messages can lead to system failures. This paper describes a unique method to control network communications through distributed task allocation to engage under-utilized UAVs to serve as communication relays and to ensure that the network supports mission tasks. This work builds upon a distributed algorithm previously developed by the authors, CBBA with Relays, which uses task assignment information, including task location and proposed execution time, to predict the network topology and plan support using relays. By explicitly coupling task assignment and relay creation processes, the team is able to optimize the use of agents to address the needs of dynamic complex missions. In this work, the algorithm is extended to explicitly consider realistic network communication dynamics, including path loss, stochastic fading, and information routing. Simulation and flight test results validate the proposed approach, demonstrating that the algorithm ensures both data-rate and interconnectivity bit-error-rate requirements during task execution.


Author(s):  
Byungchan Jung ◽  
Henryk Flashner ◽  
Jill McNitt-Gray

A model of a wheeled platform that includes slipping is formulated. Slipping is modeled by adopting the LuGre friction model. This is a dynamic friction model that can reproduce realistic friction phenomena not present in static friction models. Using the backstepping approach, tracking controllers for non-slipping and slipping cases are developed and compared via simulation. The proposed control law is designed to be robust with respect to the change in system parameters such as the platform’s mass and moment inertia. Simulation results show good performance for point stabilization in specific destination postures, as well as for tracking.


2013 ◽  
Vol 58 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Christina M. Ivler ◽  
Mark B. Tischler

Flight control design and analysis requires an accurate flight dynamics model of the bare airframe and its associated uncertainties, as well as the integrated system model (block diagrams), across the frequency range of interest. Frequency response system identification methods have proven to efficiently fulfill these modeling requirements in recent rotorcraft flight control applications. This paper presents integrated system identification methods for control law design with flight-test examples of the Fire Scout MQ-8B, S-76, and ARH-70A. The paper also looks toward how system identification could be used in new modeling challenges such as large tilt-rotors and uniquely configured unmanned aircraft.


2021 ◽  
Vol 229 ◽  
pp. 01061
Author(s):  
Said Mahfoud ◽  
Aziz Derouich ◽  
Najib El Ouanjli ◽  
Taoussi Mohammed ◽  
Ahmed Hanafi

This article presents a modeling and control of the Doubly Fed Induction Motor (DFIM), associated with two inverters controlled through the Pulse Width Modulation technique (PWM), the control of the DFIM is carried out by the approach of Rotor Flux Oriented Control (RFOC) according to the direct axis. In this approach, regulation is done by classic PI regulators, the latter having undesirable overruns and static errors in non-linear systems, for that the introduction of the control by sliding mode in place of the classic PI speed regulator, that is in the form of a control law based on this type of controller since it is invariant to the non-linearity of the system and precise, stable, simple and has a good response time, in order to validate the objectives of improving the DFIM behavior in front of the reference parameters, such as the speed and the torque imposed on the machine. The results of the proposed approach are validated by its implementation on the Matlab/Simulink environment.


1989 ◽  
Vol 12 (2) ◽  
pp. 195-200 ◽  
Author(s):  
P. K. A. Menon ◽  
R. A. Walker ◽  
E. L. Duke

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