Implementation and Testing of Adaptive Augmentation Techniques on a 2-DOF Helicopter

2013 ◽  
Author(s):  
Pavan Nuthi ◽  
Kamesh Subbarao
Keyword(s):  
Flight Control ◽  
High Performance ◽  
Reference Model ◽  
Mimo System ◽  
Design Procedure ◽  
Linear Quadratic ◽  
Test And Evaluation ◽  
Modeling Uncertainties ◽  
Augmentation Techniques ◽  
Model Tuning

This paper presents the design procedure and experimental results of a high performance adaptive augmentation technique applied to a controller derived based on linear quadratic methods. The Quanser 2-DOF helicopter was chosen as the experimental platform on which these controllers were implemented. The paper studies the implementation of each of these controllers stand-alone as well as in the augmented scheme, and discusses its performance and robustness for cases with parametric uncertainties, and unmodeled dynamics. An attempt is made to combine linear quadratic tracker’s reliability with the adaptive augmentation’s robustness towards modeling uncertainties. It is found that appropriate tuning of parameters in the adaptive framework is key to its performance and thus the process of choosing the parameters is elaborated along with guidelines for choosing a reference model. Tuning considerations for controller implementation on the experimental setup as compared to the same on the numerical model are also addressed. The experiments performed on this nonlinear MIMO system serve as a suitable research test and evaluation basis for robotics and flight control applications.

Experimental Verification of Linear and Adaptive Control Techniques for a Two Degrees-of-Freedom Helicopter

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Pavan Nuthi ◽  
Kamesh Subbarao
Keyword(s):  
Flight Control ◽  
High Performance ◽  
Degrees Of Freedom ◽  
Reference Model ◽  
Design Procedure ◽  
Linear Quadratic ◽  
Two Degrees Of Freedom ◽  
Test And Evaluation ◽  
Modeling Uncertainties ◽  
Model Tuning

This paper presents the design procedure and experimental results of a high performance adaptive augmentation technique applied to a controller derived based on linear quadratic methods. The Quanser two degrees-of-freedom (2DOF) helicopter was chosen as the experimental platform on which these controllers were implemented. The paper studies the implementation of each of these controllers standalone as well as in the augmented scheme, and discusses its performance and robustness for cases with parametric uncertainties, and unmodeled dynamics. An attempt is made to combine linear quadratic tracker's reliability with the adaptive augmentation's robustness toward modeling uncertainties. It is found that appropriate tuning of parameters in the adaptive framework is key to its performance and thus the process of choosing the parameters is elaborated along with guidelines for choosing a reference model. Tuning considerations for controller implementation on the experimental setup as compared to the same on the numerical model are also addressed. The experiments performed on this system serve as a suitable research test and evaluation basis for robotics and flight control applications.

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.

scholarly journals SDRE and LQR Controls Comparison Applied in High-Performance Aircraft in a Longitudinal Flight

2021 ◽  
Vol 1 (2) ◽  
pp. 131-144
Author(s):  
Guilherme P. Dos Santos ◽  
Adriano Kossoski ◽  
Jose M. Balthazar ◽  
Angelo Marcelo Tusset
Keyword(s):  
Nonlinear Model ◽  
Flight Control ◽  
High Performance ◽  
Large Range ◽  
Angle Of Attack ◽  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
State Dependent ◽  
Stall Angle ◽  
Difficult Situations

This paper presents the design of the LQR (Linear Quadratic Regulator) and SDRE (State-Dependent Riccati Equation) controllers for the flight control of the F-8 Crusader aircraft considering the nonlinear model of longitudinal movement of the aircraft.  Numerical results and analysis demonstrate that the designed controllers can lead to significant improvements in the aircraft's performance, ensuring stability in a large range of attack angle situations. When applied in flight conditions with an angle of attack above the stall situation and influenced by the gust model, it was demonstrated that the LQR and SDRE controllers were able to smooth the flight response maintaining conditions in balance for an angle of attack up to 56% above stall angle.  However, for even more difficult situations, with angles of attack up to 76% above the stall angle, only the SDRE controller proved to be efficient and reliable in recovering the aircraft to its stable flight configuration.

Investigation of Grouted Coupler Connection Details for Accelerated Bridge Construction

2021 ◽  
pp. 036119812199939
Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson
Keyword(s):  
Crack Width ◽  
High Performance ◽  
Static Load ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Load Testing ◽  
Test And Evaluation ◽  
Load Tests ◽  
Precast Elements

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.

Research of the 3-DOF Helicopter System Based on Adaptive Inverse Control

2013 ◽  
Vol 389 ◽  
pp. 623-631 ◽  
Author(s):  
Xiu Yan Wang ◽  
Ying Wang ◽  
Zong Shuai Li
Keyword(s):  
Neural Network ◽  
Flight Control ◽  
Fuzzy Inference ◽  
Reference Model ◽  
Back Propagation ◽  
Back Propagation Algorithm ◽  
Actual System ◽  
Adaptive Inverse Control ◽  
Inverse Control ◽  
Network Connection

For the flight control problem occurred in 3-DOF Helicopter System, reference adaptive inverse control scheme based on Fuzzy Neural Network model is designed. Firstly, fuzzy inference process of identifier and controller is achieved by using the network structure. Meanwhile, the neural network connection weights are used to express parameters of fuzzy inference. Then, back-propagation algorithm is adopted to amend the network connection weights in order to automatically identify the fuzzy model and adjust its membership functions and parameters, so that the actual system output of adaptive inverse controller control which is adjusted can track the reference model output. Finally, the simulation result of 3-DOF Helicopter System based on the scheme shows that the method is effective and feasible.

High-Sideslip Model Reference Adaptive Flight Control for Aileron Locked Aircraft

2014 ◽  
Vol 651-653 ◽  
pp. 751-756
Author(s):  
Peng Fei Cheng ◽  
Cheng Fu Wu ◽  
Yue Guo
Keyword(s):  
Flight Control ◽  
Control Method ◽  
Reference Model ◽  
Sideslip Angle ◽  
Model Reference ◽  
Control Scheme ◽  
Adaptive Flight Control ◽  
Random Initialization ◽  
Model Reference Adaptive ◽  
The Given

This paper develops a high-sideslip flight control scheme based on model reference adaptive control (MRAC) to stabilize aircraft under aileron deadlock of one side. Firstly, the cascaded flight control scheme for high-sideslip straight flight is presented and how the control signals transfer is also analyzed. After that, the control structure and laws of MRAC for attitude inner-loop connected with sideslip command are designed. Finally, the control scheme is verified under a nonlinear aircraft model in conditions of no fault and one side aileron deadlock respectively. The simulation results show that when one side aileron deadlock occurs in accompany with the plant’s aerodynamic data perturbation and random initialization of controller parameters, this control method could utilize operation points of no-fault aircraft to force the faulty aircraft following the given reference model responses and finally tracking given sideslip angle command without static error robustly.

scholarly journals Design of a PID-Lead Compensator for a Twin Rotor Aerodynamic System (TRAS)

2021 ◽  
Vol 27 (1) ◽  
pp. 79-88
Author(s):  
Rafal Fawzi Faisal ◽  
Omar Waleed Abdulwahhab
Keyword(s):  
Frequency Response ◽  
Rise Time ◽  
Performance Index ◽  
Closed Loop ◽  
Mimo System ◽  
Design Procedure ◽  
Absolute Error ◽  
Root Locus ◽  
Lead Compensator ◽  
Twin Rotor

This paper deals with a Twin Rotor Aerodynamic System (TRAS). It is a Multi-Input Multi-Output (MIMO) system with high crosscoupling between its two channels. It proposes a hybrid design procedure that combines frequency response and root locus approaches. The proposed controller is designated as PID-Lead Compensator (PIDLC); the PID controller was designed in previous work using frequency response design specifications, while the lead compensator is proposed in this paper and is designed using the root locus method. A general explicit formula for angle computations in any of the four quadrants is also given. The lead compensator is designed by shifting the dominant closed-loop poles slightly to the left in the s-plane. This has the effect of enhancing the relative stability of the closed-loop system by eliminating the oscillation in its transient part but at the expense of greater rise time. However, for some applications, long rise time may be an allowable price to get rid of undesired oscillation. To demonstrate the proposed hybrid controller's performance numerically, a new performance index, designated by Integral Reciprocal Time Absolute Error (IRTAE), is defined as a figure to measure the oscillation of the response in its transient part. The proposed controller enhances this performance index by 0.6771%. Although the relative enhancement of the performance index is small, it contributes to eliminating the oscillation of the response in its transient part. Simulation results are performed on the MATLAB/Simulink environment.

scholarly journals Return Flight

1999 ◽  
Vol 121 (12) ◽  
pp. 62-64 ◽  
Author(s):  
Peggy Chalmers
Keyword(s):  
Flight Control ◽  
High Performance ◽  
Development Work ◽  
Flight Control System ◽  
Complex Interactions ◽  
System A ◽  
Physical Testing ◽  
Fluid Properties ◽  
Computational Fluid Dynamics Cfd ◽  
Thrust Control

This article focuses on the fact that using computational fluid dynamics (CFD) and design of experiments (DOE) software, researchers are in pursuit of aircraft fluidics thrust control without moving component parts. Fluidics’ performance is dictated by complex interactions among approximately two dozen geometric and fluid properties. These complex interactions probably proved overwhelming to early researchers seeking a stable, reliable rocket flight control system. A major advantage of DOE is that it allows all the parameters to vary simultaneously. A single permutation, on the other hand, varies one parameter at a time and cannot deal with interactions among the fixed parameters. There is still more development work to be done, but indications are that CFD and DOE are leading Lockheed Martin to a promising design. Physical testing reinforces the belief that a fluidic nozzle can achieve the performance levels required. The technology that never got off the ground in the early rocket era may find itself flying high in the next generation of high-performance tactical aircraft.

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