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The recent development on micro aerial vehicles (MAV), especially the unmanned quadrotor proposes increased requirements on reference generation. This paper proposed a dynamically feasible, state constrained and smooth trajectory generation method using B-spline. The reference can be shown to satisfy the dynamics of the quadrotor and accurate tracking performance is guaranteed. The algorithm can be...
This paper presents a model based robust control scheme for tail-sitter hybrid Unmanned Aerial Vehicles (UAVs) in forward transition phase. To tackle the problem from high nonlinearity and uncertainties in transition dynamics, a comprehensive model form is constructed, and a so-called Robust Perfect Tracking (RPT) control method is utilized in attitude tracking. Experiment results are given to demonstrate...
This paper presents a systematic control synthesis method in order to achieve auto-transition for KH-Lion, a tail-sitter hybrid UAV. Although there are huge potentials in various applications of the hybrid tail-sitter UAVs, the transition between vertical take-off and landing mode and cruise mode is still a challenge now. Due to the complex behaviour that the transition can generate, it is very difficult...
A nonlinear model of a flapping-wing micro aerial vehicle (MAV) is built in which the load acceleration and equivalent moment are formulated linearly in the body frame. The aerodynamic force and moment are not considered directly because the mass and moment of inertia of the flapping-wing MAV are too tiny. The visual measurement system (VMS) is taken to measure the flight data such as the position...
This paper presents a comprehensive modeling approach for tail-sitter hybrid UAVs featured by vertical take-off and landing (VTOL) and cruise flight capabilities. The modeling approach includes all essential components, such as full angle of attack envelope wing and fuselage aerodynamics, sideslip wind effect and actuator dynamics. A unified formulation comprising all model components is derived to...
In this paper, we present a novel hybrid UAV, U-Lion, which has autonomous VTOL and cruise flying capabilities. The reconfigurable wings are designed so that the structure of U-Lion is aerodynamically efficient in both flying modes. Vectoring thrust and the multiple control surfaces tail are implemented to increase the controllability for better maneuverability and stronger rejection to wind gust...
This paper presents a systematic design approach for an unconventional UAV, J-Lion. J-Lion is a UAV featured by its hybrid flight capability in both VTOL and fixed-wing modes. Besides, a morphing wing concept is also realized by the extensible wing design. To reduce the development cycle, our approach takes into account the common factors systematically in the conceptual design phase, including overall...
In this work, we provide a nonlinear mathematical model identification methodology of an autonomous micro quadrotor, and the design of its orientation and position controllers. In the model identification, we specifically focus on the brushed D.C. motor dynamics, which further breaks down into three different segments: voltage generation, motor dynamics, and force/torque generation. Test bench experiments...
This paper presents a navigation system that enables small-scale unmanned aerial vehicles to navigate autonomously in foliage environment without GPS using a 2D laser range finder. The navigation framework consists of real-time onboard motion estimation and trajectory smoothing using pose graph optimization, real-time dual layer control. In particular, onboard real-time motion estimation is achieved...
The recent development of small yet sophisticated sensors has led to the development of smaller unmanned aerial vehicles, especially in the form of quadrotor. When it is limited by the availability of the reverse propellers, the conventional quadrotor will no longer be realizable, and thus introducing the 4-standard-propeller (4SP) quadrotor design. This paper presents a comprehensive nonlinear modeling...
Hierarchical dynamic inversion (HDI) is proposed together with newly developed variant-factor and recursive control techniques to design autonomous flight control (AFC) laws for fixed-wing aircraft. HDI is applicable to control design of some non-affine nonlinear systems to which dynamic inversion is not applicable. The AFC law designed with HDI at the nominal flight condition is applicable to other...
The objective of the paper is to design the control system of following a predefined 3D path while maintaining a specified flight speed and considering the timing constraint. This can be accomplished by a cascaded solution framework based on theoretical dynamic error modeling. The controller for each loop can thus be designed separately so that the design problem is simplified and the control system...
We document in this article a general introduction to modern miniature unmanned rotorcraft systems. More specifically, we present a fairly detailed overview on the hardware configuration, software integration, aerodynamic modeling, automatic flight control system, and computer vision system involved in forming an unmanned rotorcraft system.
We present in the paper the comprehensive design procedure of a mini UAV helicopter, called BabyLion. The hardware construction, along with the selection of all of necessary components, will be introduced. Since the system identification method is only partially suitable for the self-built BabyLion, we propose a more suitable parameter identification approach which combines both system identification...
LabVIEW has become a popular environment to develop data acquisition and control systems in aerospace simulation facilities such as those found at the aerodynamics laboratory of the National Research Council of Canada. These programs are usually developed as structured programs but with time evolve into ad hoc programs. object oriented programming (OOP) is a well established technique that has many...
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