880 research outputs found
Survey on Aerial Multirotor Design: a Taxonomy Based on Input Allocation
This paper reviews the impact of multirotor aerial vehicles designs on their abilities in terms of tasks and system properties. We propose a general taxonomy to characterize and describe multirotor aerial vehicles and their design, which we apply exhaustively on the vast literature available. Thanks to the systematic characterization of the designs we exhibit groups of designs having the same abilities in terms of achievable tasks and system properties. In particular, we organize the literature review based on the number of atomic actuation units and we discuss global properties arising from their choice and spatial distribution in the designs. Finally, we provide a discussion on the common traits of the designs found in the literature and the main future open problems
Voliro: An Omnidirectional Hexacopter With Tiltable Rotors
Extending the maneuverability of unmanned areal vehicles promises to yield a
considerable increase in the areas in which these systems can be used. Some
such applications are the performance of more complicated inspection tasks and
the generation of complex uninterrupted movements of an attached camera. In
this paper we address this challenge by presenting Voliro, a novel aerial
platform that combines the advantages of existing multi-rotor systems with the
agility of omnidirectionally controllable platforms. We propose the use of a
hexacopter with tiltable rotors allowing the system to decouple the control of
position and orientation. The contributions of this work involve the mechanical
design as well as a controller with the corresponding allocation scheme. This
work also discusses the design challenges involved when turning the concept of
a hexacopter with tiltable rotors into an actual prototype. The agility of the
system is demonstrated and evaluated in real- world experiments.Comment: Submitted to Robotics and Automation Magazin
Mechanical Design, Modelling and Control of a Novel Aerial Manipulator
In this paper a novel aerial manipulation system is proposed. The mechanical
structure of the system, the number of thrusters and their geometry will be
derived from technical optimization problems. The aforementioned problems are
defined by taking into consideration the desired actuation forces and torques
applied to the end-effector of the system. The framework of the proposed system
is designed in a CAD Package in order to evaluate the system parameter values.
Following this, the kinematic and dynamic models are developed and an adaptive
backstepping controller is designed aiming to control the exact position and
orientation of the end-effector in the Cartesian space. Finally, the
performance of the system is demonstrated through a simulation study, where a
manipulation task scenario is investigated.Comment: Comments: 8 Pages, 2015 IEEE International Conference on Robotics and
Automation (ICRA '15), Seattle, WA, US
Swashplateless-elevon Actuation for a Dual-rotor Tail-sitter VTOL UAV
In this paper, we propose a novel swashplateless-elevon actuation (SEA) for
dual-rotor tail-sitter vertical takeoff and landing (VTOL) unmanned aerial
vehicles (UAVs). In contrast to the conventional elevon actuation (CEA) which
controls both pitch and yaw using elevons, the SEA adopts swashplateless
mechanisms to generate an extra moment through motor speed modulation to
control pitch and uses elevons solely for controlling yaw, without requiring
additional actuators. This decoupled control strategy mitigates the saturation
of elevons' deflection needed for large pitch and yaw control actions, thus
improving the UAV's control performance on trajectory tracking and disturbance
rejection performance in the presence of large external disturbances.
Furthermore, the SEA overcomes the actuation degradation issues experienced by
the CEA when the UAV is in close proximity to the ground, leading to a smoother
and more stable take-off process. We validate and compare the performances of
the SEA and the CEA in various real-world flight conditions, including
take-off, trajectory tracking, and hover flight and position steps under
external disturbance. Experimental results demonstrate that the SEA has better
performances than the CEA. Moreover, we verify the SEA's feasibility in the
attitude transition process and fixed-wing-mode flight of the VTOL UAV. The
results indicate that the SEA can accurately control pitch in the presence of
high-speed incoming airflow and maintain a stable attitude during fixed-wing
mode flight. Video of all experiments can be found in
youtube.com/watch?v=Sx9Rk4Zf7sQComment: 8 pages, 13 figure
BogieCopter: A Multi-Modal Aerial-Ground Vehicle for Long-Endurance Inspection Applications
The use of Micro Aerial Vehicles (MAVs) for inspection and surveillance
missions has proved to be extremely useful, however, their usability is
negatively impacted by the large power requirements and the limited operating
time. This work describes the design and development of a novel hybrid
aerial-ground vehicle, enabling multi-modal mobility and long operating time,
suitable for long-endurance inspection and monitoring applications. The design
consists of a MAV with two tiltable axles and four independent passive wheels,
allowing it to fly, approach, land and move on flat and inclined surfaces,
while using the same set of actuators for all modes of locomotion. In
comparison to existing multi-modal designs with passive wheels, the proposed
design enables a higher ground locomotion efficiency, provides a higher payload
capacity, and presents one of the lowest mass increases due to the ground
actuation mechanism. The vehicle's performance is evaluated through a series of
real experiments, demonstrating its flying, ground locomotion and wall-climbing
capabilities, and the energy consumption for all modes of locomotion is
evaluated.Comment: This paper has been accepted for publication at the IEEE
International Conference on Robotics and Automation (ICRA), London, 202
An Omnidirectional Aerial Platform for Multi-Robot Manipulation
The objectives of this work were the modeling, control and prototyping of a new fully-actuated
aerial platform. Commonly, the multirotor aerial platforms are under-actuated vehicles, since the
total propellers thrust can not be directed in every direction without inferring a vehicle body rotation.
The most common fully-actuated aerial platforms have tilted or tilting rotors that amplify
the aerodynamic perturbations between the propellers, reducing the efficiency and the provided
thrust. In order to overcome this limitation a novel platform, the ODQuad (OmniDirectional
Quadrotor), has been proposed, which is composed by three main parts, the platform, the mobile
and rotor frames, that are linked by means of two rotational joints, namely the roll and pitch
joints. The ODQuad is able to orient the total thrust by moving only the propellers frame by
means of the roll and pitch joints.
Kinematic and dynamic models of the proposed multirotor have been derived using the Euler-
Lagrange approach and a model-based controller has been designed. The latter is based on two
control loops: an outer loop for vehicle position control and an inner one for vehicle orientation
and roll-pitch joint control. The effectiveness of the controller has been tested by means of numerical
simulations in the MATLAB
c SimMechanics environment. In particular, tests in free motion
and in object transportation tasks have been carried out. In the transportation task simulation, a
momentum based observer is used to estimate the wrenches exchanged between the vehicle and
the transported object.
The ODQuad concept has been tested also in cooperative manipulation tasks. To this aim, a
simulation model was considered, in which multiple ODQuads perform the manipulation of a
bulky object with unknown inertial parameters which are identified in the first phase of the simulation.
In order to reduce the mechanical stresses due to the manipulation and enhance the system
robustness to the environment interactions, two admittance filters have been implemented: an external
filter on the object motion and an internal one local for each multirotor.
Finally, the prototyping process has been illustrated step by step. In particular, three CAD
models have been designed. The ODQuad.01 has been used in the simulations and in a preliminary
static analysis that investigated the torque values for a rough sizing of the roll-pitch joint
actuators. Since in the ODQuad.01 the components specifications and the related manufacturing
techniques have not been taken into account, a successive model, the ODQuad.02, has been designed.
The ODQuad.02 design can be developed with aluminum or carbon fiber profiles and 3D
printed parts, but each component must be custom manufactured. Finally, in order to shorten the
prototype development time, the ODQuad.03 has been created, which includes some components
of the off-the-shelf quadrotor Holybro X500 into a novel custom-built mechanical frame
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