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This paper describes a navigation algorithm for small fixed-wing airplanes so as to perform path following. The wind gusts need to be taken into account as they play a key role in small prototypes, being the main disturbance when flights are performed. To solve this issue, we use an algorithm known in the literature as carrot-chasing, which includes wind estimates. A Lyapunov stability based control...
The distributed cooperative tracking control problem for a group of quadrotors in a three-dimensional space is addressed in this paper. The controller design is divided in two stages. In the first stage, local distributed controllers for the translational dynamics are designed, forcing the quadrotor to asymptotically track the desired trajectory with the required separation and therefore a specific...
The work is devoted to development of software complex for simulation of artillery shot, which includes calculation module, input and output data, modules of scientific graphics and 3D visualization. Mathematical models of internal and external ballistics of artillery shot are shown. Developing toolkit for software complex and its functionality are described in the paper.
This paper tackles the problem of trajectory tracking problem of a quadrotor. A sliding mode block control algorithm based on the super twisting algorithm using unit quaternion feedback is applied to the dynamic model of the quadrotor helicopter. The derivative of the virtual control inputs are obtained using exact first order differentiator, and the aerodynamic forces and moments acting on the quadrotor...
We consider the problem of system identification of helicopter dynamics. Helicopters are complex systems, coupling rigid body dynamics with aerodynamics, engine dynamics, vibration, and other phenomena. Resultantly, they pose a challenging system identification problem, especially when considering non-stationary flight regimes. We pose the dynamics modeling problem as direct high-dimensional regression,...
This paper presents a nonlinear control based on sliding mode control (SMC) for the position and the attitude tracking control of a small coaxial-rotor UAV subjected to uncertainties and aerodynamic disturbances. The dynamical motion equations are obtained through the Newton-Euler formalism. Firstly, the dynamical model is divided into a fully actuated subsystem and an underactuated subsystem. Secondly,...
In this work, we present the application of a neural network (NN) based adaptive control scheme for the purpose of trajectory tracking of an air-to-air missile. The nonlinear dynamic model of such missiles contain numerous aerodynamic coefficients. It is well known that uncertainty in these coefficients can cause degradation of control performance. In this work, we explore the feasibility of applying...
This paper presents a two-loops structured control system design for quadrotor's position/attitude trajectory tracking. The aim of the outer loop is to provide the roll/pitch tilting commands to the inner loop, which in turns generates the quadrotor's tilting angles required to control the horizontal CG position. To fulfill that purpose, the outer loop utilizes Generalized Dynamic Inversion of a prescribed...
In this paper we propose a framework combining techniques from sampling-based motion planning, machine learning, and trajectory optimization to address the kinodynamic motion planning problem in real-time environments. This framework relies on a look-up table that stores precomputed optimal solutions to boundary value problems (assuming no obstacles), which form the directed edges of a precomputed...
This paper presents an algorithm for aerial vehicle trajectory generation based on the optimal Rapidly-exploring Random Tree (RRT*). The trajectory generation for the aerial vehicle is a complex path planning problem since the vehicle flies in a heterogeneous environment. The vehicle must also avoid some obstacles or inaccessible zones such as buildings, mountains and even radar detection zones depending...
The realization and utilization of multimodal locomotion to enable robots to accomplish useful tasks is a significantly challenging problem in robotics. Related to the challenge, it is crucial to notice that the locomotion dynamics of the robots is a result of interactions between a particular control structure and its body-environment dynamics. From this perspective, this paper presents a simple...
The prominent maneuverability of flapping flight is enabled by rapid and significant changes in aerodynamic forces, which is a result of surprisingly subtle and precise changes of wing kinematics. The high sensitivity of aerodynamic forces to wing kinematic changes demands precise and instantaneous control of the flapping wing trajectories, especially in the presence of various types of uncertainties...
In this paper, a non linear autopilot for a missile pitch axis is designed over a wide flight envelope. The controller is obtained by a Linear Parametrically Varying (LPV) synthesis applied to the H¥/loop-shaping criterion. The resulting controller depends on the angle of attack, the Mach number and the altitude. Robust stability and performance are firstly checked by means of linear analysis and...
The requirements, design and simulation of a control system for a precision tracking task, called a Pitch-rate Control Augmentation System (CAS), for the F-16 fighter aircraft model, is considered. This control system is designed over the entire flight envelope using one of the nonlinear Model Based Predictive Control techniques (MBPC), which is called Non-linear Generalized Predictive Control (NLGPC)...
This work focuses on the nonlinear control of helicopters. Our global interest is a general model (7-DOF) to be used on the autonomous forward-flight of helicopters. However, in this paper we present a reduced-order model (3-DOF) representing a scale model helicopter mounted on an experimental platform. In this system the vertical flight of the helicopter can be studied. Although simplified, this...
This paper is concerned with obstacle avoidance of robots moving on a plane, based on a fluid mechanical principle known as the Circle Theorem. Considering the motion region as a fictitious fluid environment surrounding the obstacles, fluid streamlines are calculated which correspond to unique smooth paths that a mobile robot can follow without colliding with the obstacles. The design and analysis...
This paper proposes data-driven Model-Free Control (MFC) algorithms for Multi Input-Multi Output (MIMO) twin rotor aerodynamic systems. A discrete-time formulation of the algorithms is given in the framework of a MIMO control system structure with azimuth and pitch position control loops. An optimal design approach of the MIMO MFC algorithms is proposed using a Linear Quadratic Regulator formulation...
This paper presents a mixed variable variational algorithm to the optimal atmospheric ascent guidance problem of launch vehicles subject to path constraints and final condition constraints. The optimal three-dimension ascent problem is transformed into a Hamiltonian boundary value problem. And the solving algorithm is a symplectic numerical method based on the dual variational principle, which transforms...
This paper describes a 3D reference trajectory generation and tracking control method for a quadcopter. The flying trajectory is a piecewise curve that passes through viapoints at specified times or speeds and has constant acceleration within each interval. The path is first represented as the third degree polynomials, and to overcome demerits of the C-splines, a numeric algorithm is suggested and...
A conceptual design approach has been described for a back-packable, hand-launched miniature unmanned aerial vehicle. The design space has been segregated into different areas that are analyzed separately in detail. The initial design phase involves an intellectual process and requires a number of design iterations to be performed. Therefore, low fidelity analyses tools are mostly employed to acquire...
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