13 research outputs found
Continuum Deformation of a Multiple Quadcopter Payload Delivery Team without Inter-Agent Communication
This paper proposes continuum deformation as a strategy for controlling the
collective motion of a multiple quadcopter system (MQS) carrying a common
payload. Continuum deformation allows expansion and contraction of inter-agent
distances in a 2D motion plane to follow desired motions of three team leaders.
The remaining quadcopter followers establish the desired continuum deformation
only by knowing leaders positions at desired sample time waypoints without the
need for inter-agent communication over the intermediate intervals. Each
quadcopter applies a linear-quadratic-Gaussian (LQG) controller to track the
desired trajectory given by the continuum deformation in the presence of
disturbance and measurement noise. Results of simulated cooperative aerial
payload transport in the presence of uncertainty illustrate the application of
continuum deformation for coordinated transport through a narrow channel
Flexible collaborative transportation by a team of rotorcraft
We propose a combined method for the collaborative transportation of a
suspended payload by a team of rotorcraft. A recent distance-based
formation-motion control algorithm based on assigning distance disagreements
among robots generates the acceleration signals to be tracked by the vehicles.
In particular, the proposed method does not need global positions nor tracking
prescribed trajectories for the motion of the members of the team. The
acceleration signals are followed accurately by an Incremental Nonlinear
Dynamic Inversion controller designed for rotorcraft that measures and resists
the tensions from the payload. Our approach allows us to analyze the involved
accelerations and forces in the system so that we can calculate the worst case
conditions explicitly to guarantee a nominal performance, provided that the
payload starts at rest in the 2D centroid of the formation, and it is not under
significant disturbances. For example, we can calculate the maximum safe
deformation of the team with respect to its desired shape. We demonstrate our
method with a team of four rotorcraft carrying a suspended object two times
heavier than the maximum payload for an individual. Last but not least, our
proposed algorithm is available for the community in the open-source autopilot
Paparazzi.Comment: ICRA 2019, 6+1 page
Energy distribution in dual-UAV collaborative transportation through load sharing
In this paper, a novel dual-UAV collaborative aerial transport strategy based on energy distribution and load sharing is proposed. This paper presents the first experimental demonstration of dual-UAV collaborative aerial transport while distributing power consumption. The demonstration is performed while distributing the power consumption between two drones sharing a load based on their battery state of charge. A numerical model of the dual-hex-rotor-payload is used to validate the proposed strategy. Numerical and hardware tests were conducted to demonstrate the load distribution using multiple UAV with certain spatial configurations. Finally, collaborative aerial transport test scenarios are performed numerically and experimentally. The simulation and experimental results show the effectiveness and applicability of the proposed strategy
A review of aerial manipulation of small-scale rotorcraft unmanned robotic systems
Small-scale rotorcraft unmanned robotic systems (SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years (2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem, trends, and challenges are described from three aspects. Conclusions of the paper are presented, and the future of SRURSs is discussed to enable further research interests
Robust global exponential stabilization on the n-dimensional sphere with applications to trajectory tracking for quadrotors
In this paper, we design a hybrid controller that globally exponentially stabilizes a system evolving on the n-dimensional sphere, denoted by Sn. This hybrid controller is induced by a “synergistic” collection of potential functions on Sn. We propose a particular construction of this class of functions that generates flows along geodesics of the sphere, providing convergence to the desired reference with minimal path length. We show that the proposed strategy is suitable to the exponential stabilization of a quadrotor vehicle