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    Control effectiveness investigation of a ducted-fan aerial vehicle using model predictive controller

    , Article International Conference on Advanced Mechatronic Systems, ICAMechS ; 2014 , pp. 532-537 Banazadeh, A ; Emami, S. A ; Sharif University of Technology
    Special attention is given to vertical takeoff and landing air vehicles due to their unique capabilities and versatile missions. The main problem here is control effectiveness at low flight speeds and transition maneuvers because of the inherent instability. RMIT is a small sized tail-sitter ducted fan air vehicle with a particular configuration layout, multiple control surfaces, low weight, and high-speed flight capability. In the current study, a comprehensive nonlinear model is firstly developed for RMIT, followed by a validation process. This model consists of all parts including aerodynamic forces and moments, control surfaces term together with the gravity and driving fan forces.... 

    Multi-objective trade-off analysis of an integrated cold gas propulsion system

    , Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 227, Issue 8 , 2013 , Pages 1233-1250 ; 09544100 (ISSN) Banazadeh, A ; Gol, H. A ; Sharif University of Technology
    The overall design of cold gas propulsion systems is pretty complicated when considering the mission requirements, operating constraints and functional limitations imposed by the mechanical components. To address this complication, a precise design process is proposed, which attempts to optimize the cost of operation as well as to minimize the waste volume and weight by using multi-objective trade-off analysis. This analysis is based on a set of ordinary differential equations that are solved iteratively to describe the optimal behavior of the system. Therefore, a numerical code is being developed to give insight on the design sensitivity with respect to uncertainties on the design... 

    Neural network-based flight control systems: Present and future

    , Article Annual Reviews in Control ; Volume 53 , 2022 , Pages 97-137 ; 13675788 (ISSN) Emami, S.A ; Castaldi, P ; Banazadeh, A ; Sharif University of Technology
    Elsevier Ltd  2022
    As the first review in this field, this paper presents an in-depth mathematical view of Intelligent Flight Control Systems (IFCSs), particularly those based on artificial neural networks. The rapid evolution of IFCSs in the last two decades in both the methodological and technical aspects necessitates a comprehensive view of them to better demonstrate the current stage and the crucial remaining steps towards developing a truly intelligent flight management unit. To this end, in this paper, we will provide a detailed mathematical view of Neural Network (NN)-based flight control systems and the challenging problems that still remain. The paper will cover both the model-based and model-free... 

    Robust attitude control of an agile aircraft using improved Q-Learning

    , Article Actuators ; Volume 11, Issue 12 , 2022 ; 20760825 (ISSN) Zahmatkesh, M ; Emami, S. A ; Banazadeh, A ; Castaldi, P ; Sharif University of Technology
    MDPI  2022
    Attitude control of a novel regional truss-braced wing (TBW) aircraft with low stability characteristics is addressed in this paper using Reinforcement Learning (RL). In recent years, RL has been increasingly employed in challenging applications, particularly, autonomous flight control. However, a significant predicament confronting discrete RL algorithms is the dimension limitation of the state-action table and difficulties in defining the elements of the RL environment. To address these issues, in this paper, a detailed mathematical model of the mentioned aircraft is first developed to shape an RL environment. Subsequently, Q-learning, the most prevalent discrete RL algorithm, will be... 

    PID controller design for micro gas turbines using experimental frequency-response data and a linear identification technique

    , Article International Journal of Advanced Mechatronic Systems ; Volume 5, Issue 6 , 2013 , Pages 353-364 ; 17568412 (ISSN) Banazadeh, A ; Gol, H. A ; Ramazani, H ; Sharif University of Technology
    E-flow Inderscience  2013
    This paper discusses the identification process of engine dynamics and presents derived transfer function models including; thrust, shaft speed, compressor exit pressure and turbine exit temperature in relation to the fuel flow. Model identification approach, presented in this paper, is the first to consider frequency-sweep signals to excite dynamics, as well as to utilise windowing and smoothing techniques to reduce random errors in the spectral estimates. Here, frequency sweep provides a fairly uniform spectral excitation and chirp-z transform warrants the exact determination of the frequency responses that are robust to the uncertainties. The identified models are also validated with the... 

    Effect of RGO/Zn:XCd1- xS crystalline phase on solar photoactivation processes

    , Article RSC Advances ; Volume 6, Issue 52 , 2016 , Pages 46282-46290 ; 20462069 (ISSN) Moradlou, O ; Tedadi, N ; Banazadeh, A ; Naseri, N ; Sharif University of Technology
    Royal Society of Chemistry  2016
    A series of reduced graphene oxide/ZnxCd1-xS (RGO/ZnxCd1-xS) nanocomposites (0 < x < 1) with different ratios of Zn/Cd were synthesized via a facile hydrothermal route under optimized experimental conditions and were carefully characterized by various techniques. Because very little is known about the morphology, specific surface area, and crystal phase effects of RGO/ZnxCd1-xS crystals on their photoresponsivity, field-emission scanning electron microscopy (FE-SEM), BET surface area analysis and X-ray diffraction (XRD) data were studied to investigate their effects on photoactivity. Based on the results, a crystal phase transition from a cubic phase in RGO/Zn0.9Cd0.1S to a hexagonal... 

    Adaptive Controller Design for Ducted Fans in Vertical Plane Phases

    , M.Sc. Thesis Sharif University of Technology Fadaeian, Ehsan (Author) ; Banazadeh, Afshin (Supervisor)
    Ducted fan vertical take-off and landing (VTOL) aerial vehicles have drawn many attentions in the world because of their capability to offer high power to weight ratio for a certain vehicle diameter relative to open rotors or helicopters. However, due to inherent uncertainties in dynamics and inefficient and poor quality responses, significant control challenges are still unsolved and exciting fields for research. In the current study, a nonlinear dynamic model is proposed for the controller design purpose. This model is validated against simulation by performing several standard scenarios. An adaptive control method, named model reference (MRAC), is utilized to design a perfect controller... 

    Trajectory Optimization of Micromechanical Flying Insect

    , M.Sc. Thesis Sharif University of Technology Firouzbakht, Shahriar (Author) ; Banazadeh, Afshin (Supervisor)
    In this work, A new hybrid approach is presented to optimize a trajectory of Micromechanical Flying Insect in an obstacle reach environment. Here, a singleobjective Evolutionary Algorithm is utilize for finding solutions corresponding to multiple conflicting goals, which include minimizing the length of the path while maximizing safety margin by avoiding hard and non-moving obstacles. On the other hand, dynamic constraints of Micromechanical Insect such as maximum and minimum attitude angles and speed should be taken into account. In order to reduce the computational cost, a novel hybrid two-layer procedure is suggested for trajectory optimization. In the first layer, the algorithm generates... 

    Captive System Identification of Coanda-Effect Aerial Vehicle in Hover

    , M.Sc. Thesis Sharif University of Technology Behroo, Mahan (Author) ; Banazadeh, Afshin (Supervisor)
    Identification of dynamic behavior and extraction of mathematical model for aerial vehicle is important in design, test and evaluation processes. Due to explosion of unmanned vehicles industry in recent years, many innovative aerial concepts is introduced. Coanda-effect air vehicle is one of these novel ideas which is similar to flying saucers. In this study, an experimental scale model of this air vehicle is designed, built and tested with purpose of identifying the linear dynamic model of the vehicle, using the frequency domain identification methods. Performing the system Identification in hover requires a stable hovering capability in the vehicle. Given the inherent instabilities of... 

    Codification of Reliability Evaluation Software in UAVs Industry

    , M.Sc. Thesis Sharif University of Technology Mirzaei, Payman (Author) ; Banazadeh, Afshin (Supervisor)
    In every modern society, the engineers and technical managers are in charge of planning, designing, manufacturing and utilizing the simplest products to the most complex systems. This shows the importance of reliability management in engineering systems. Inattention to the reliability of such systems leads to the difficulty or even impossibility in planning or utilizing them. Malfunction of products and systems results in disruption in different levels and can be regarded as a severe threat to society and environment.
    Therefore, consumers and general public expect products and systems to be durable, reliable and safe. Thus, the main question is how safe and how reliable the system will... 

    A computational and analytical study into the use of counter-flow fluidic thrust vectoring nozzle for small gas turbine engines

    , Article Applied Mechanics and Materials ; Vol. 629, issue , 2014 , pp. 97-103 ; ISSN: 16609336 Banazadeh A ; Banazadeh, F ; Sharif University of Technology
    This paper provides an understanding of counter-flow fluidic thrust vectoring, in the presence of the secondary air vacuum, applied to the exhaust nozzle of a micro-jet engine. An analytical and numerical study is performed here on a divergent collar surface adjacent to the cylindrical exhaust duct system. The vectoring angle is controlled by manipulating the momentum flux through a vacuum gap that is located on a circle concentric to the main nozzle. Three dimensional numerical simulations are conducted by utilizing a computational fluid dynamics model with two-equation standard k-ε turbulence model to study the pressure and velocity distribution of internal flow and nozzle geometry.... 

    Dynamic Model Identification of a 4th Generation Turbojet Engine’s FCU Using Parametric Frequency Response Analysis

    , M.Sc. Thesis Sharif University of Technology Yazdani, Amin (Author) ; Banazadeh, Afshin (Supervisor)
    In this thesis, dynamics of a turbojet’s fuel control unit is studied for the nature and the range of its inputs and outputs. Then, inputs and outputs involved in the system identification process are determined. Tools needed for the application of the input and the signal data sampling are recognized, and henceforth, with the appropriate input applied and the frequency-domain system identification process carried out, desired linear transformation functions representing dynamics of the fuel control unit are found. Using these transformation functions, the fuel control unit is simulated to be converted to an electronic control unit  

    Nonlinear dynamic modeling and simulation of an insect-like flapping wing

    , Article Applied Mechanics and Materials ; Vol. 555, issue , 2014 , p. 3-10 Banazadeh, A ; Taymourtash, N ; Sharif University of Technology
    The main objective of this paper is to present the modeling and simulation of open loop dynamics of a rigid body insect-like flapping wing. The most important aerodynamic mechanisms that explain the nature of the flapping flight, including added mass, rotational lift and delayed stall, are modeled. Wing flapping kinematics is described using appropriate reference frames and three degree of freedom for each wing with respect to the insect body. In order to simulate nonlinear differential equations of motion, 6DOF model of the insect-like flapping wing is developed, followed by an evaluation of the simulation results in hover condition  

    Adaptive Attitude and Position Control of a Rigid Body Insect-Like Flapping Wing

    , M.Sc. Thesis Sharif University of Technology Taymourtash, Neda (Author) ; Banazadeh, Afshin (Supervisor)
    In this study, adaptive control of attitude and position of a rigid body insect-like flapping wing is investigated. For this purpose, a non-linear dynamic and time varying modeling and simulation is carried out initially with six degrees of freedom, and then the accuracy of the simulation is evaluated during different test cases. In order to design the controller, non-linear and time varying dynamic is transformed into non-linear and time-invariant dynamic using theory of averaging. Then, a non-linear controller is designed based on Lyapunov stability theory. Due to the inefficiency of the aforementioned controller under disturbances and unknown uncertainties in the model, an adaptive... 

    Minimum-Distance Collision-Free Trajectory Generation for Formation Flying Satellites Using a Hybrid Path-Planning Algorithm

    , M.Sc. Thesis Sharif University of Technology Behzadpour, Saniya (Author) ; Banazadeh, Afshin (Supervisor)
    The formation flight of satellites corresponds to a group of small satellites, performing the mission of a presumed larger and more expensive satellite. Usually mission designers tend to put these satellites in such orbital configurations that their trajectories do not intersect. Although a stable configuration in a certain collision-free orbit is desirable for long term purposes, most of the missions including maneuvers like forming or changing a configuration and inserting new satellites need to be planned using a proper path planning algorithm. In this thesis, a path planning algorithm is suggested that acquires the optimal and impact-free trajectories for a group of satellites for... 

    Development of an Optimal Path Planning Algorithm for Aerial Robots Based on GPOPS Program

    , M.Sc. Thesis Sharif University of Technology Pakro, Farhad (Author) ; Banazadeh, Afshin (Supervisor)
    In this thesis the problem of path planning for aerial robots,specifically the UAVs, is studied. Some software packs aiming to perform optimal path planning are already published worldwide. In this thesis, these software are investigated and UAV path planning is done by them. In UAV path planning using these software, due to the high number of equations, number of constraints in solution increases and even in a simple problem, the process of solving becomes difficult for software. Among introduced software packs, “GPOPS”, which uses pseudospectral methods, is chosen as the best. Avoiding obstacles in different problems is checked. Obstacle avoidance and waypoint tracking at the same time,... 

    Adaptive attitude and position control of an insect-like flapping wing air vehicle

    , Article Nonlinear Dynamics ; Volume 85, Issue 1 , 2016 , Pages 47-66 ; 0924090X (ISSN) Banazadeh, A ; Taymourtash, N ; Sharif University of Technology
    Springer Netherlands  2016
    This study describes an adaptive sliding mode technique for attitude and position control of a rigid body insect-like flapping wing model in the presence of uncertainties. For this purpose, a six-degrees-of-freedom nonlinear and time-varying dynamic model of a typical hummingbird is considered for simulation studies. Based on the quasi-steady assumptions, three major aerodynamic loads including delayed stall, rotational lift and added mass are presented and analyzed, respectively. Using the averaging theory, a time-varying system is then transformed into the time-invariant system to design the adaptive controller. The controller is designed so that the closed-loop system will follow any... 

    Development, instrumentation, and dynamics identification of a Coanda air vehicle

    , Article IEEE Aerospace and Electronic Systems Magazine ; Volume 30, Issue 10 , October , 2015 , Pages 4-12 ; 08858985 (ISSN) Banazadeh, A ; Behroo, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015

    Efficiency Analysis of Principal Soft Computing Techniques for Noise Cancellation

    , M.Sc. Thesis Sharif University of Technology Ebrahimi, Naeim (Author) ; Banazadeh, Afshin (Supervisor)
    In this thesis, LMS, NLMS, RLS, ADALINE and ANFIS as five adaptive noise removal methods have been studied with a software application approach. The aim of this study is to obtain the best method to remove noise in terms of signal to noise ratio (SNR) improvement as well as the speed of convergence. In this regard, firstly by applying a frequency sweep input, which is contaminated with white noise, the performance of these algorithms are investigated. Then, an audio signal is utilized as the target input, and the performance of the corresponding algorithms have been analyzed in aspect of filter order and learning coefficient. The results show that by increasing the order of filter and... 

    Optimal control of an aerial tail sitter in transition flight phases

    , Article Journal of Aircraft ; Volume 53, Issue 4 , Volume 53, Issue 4 , 2016 , Pages 914-921 ; 00218669 (ISSN) Banazadeh, A ; Taymourtash, N ; Sharif University of Technology
    American Institute of Aeronautics and Astronautics Inc  2016
    The main purpose of this study is to generate optimal transition trajectories for an aerial tail sitter that uses cross-coupled thrust-vectoring control. A transition maneuver is most challenging for such configurations due to coupling of the forces and moments with instability in the most critical low-speed flight phases. Based on the classical Cauchy method, an improved gradient-based algorithm is developed in a collaborative process in order to find transition trajectories and increase the convergence rate. The cost function is defined in terms of minimum time in transition from hover to cruise and minimum altitude variations from cruise to hover. In addition, physical constraints are...