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A system of small unmanned aerial vehicles (SUAV) that can coordinate and assist multiple teams of first responders (FR) is proposed. Initially the system assesses the situation using information available from onboard sensors and human operator input. It then uses this assessment to predict energy, time, and entropy costs for specific combinations of possible responses that are allowed by constraints...
A unified approach to cooperative and non-cooperative Sense-and-Avoid (SAA) is presented that addresses the technical and regulatory challenges of Unmanned Aircraft Systems (UAS) integration into non-segregated airspace. In this paper, state-of-the-art sensor/system technologies for cooperative and non-cooperative SAA are reviewed and a reference system architecture is presented. Automated selection...
In this paper we present our ongoing efforts to build a heavy lift multirotor platform capable of lifting over 50kg of payload. Such a system requires a paradigm shift in the design of the UAV. Therefore we propose using miniature two stroke internal combustion engines to supply the necessary lift and endurance and combine them with a novel control concept based on the variations of the center of...
These days we demand Unmanned Aerial Systems (UASs) fly autonomously and be able to physically interact with their environment executing prescribed tasks. An excellent example of that are the Aerial Manipulators (AMs) i.e. UASs formed by the join of an Unmanned Aerial Vehicle (UAV) and a Robot Manipulator (RM). Moreover, the lack of structured workspaces in outdoor operations is challenging for the...
This paper investigates the stand-off measurement of atmospheric pollutant concentrations and air quality parameters around industrial complexes. The theoretical investigation considers a robust, accurate and inexpensive measurement system based on tuneable Light Detection and Ranging (LIDAR), calibrated reflectors and imaging systems. The equipment is deployed in two non-collocated components. The...
In this paper, a robust altitude control scheme is proposed for a mini-Quadrotor UAV system based on sliding mode controller with an integral action to eliminate the steady-state error induced by the boundary layer in order to achieve asymptotic convergence to the desired altitude with continuous control input. The proposed integral sliding mode controller is chosen to ensure the stability and robustness...
We propose to estimate steady and turbulent wind velocities and aerodynamic coefficients of a fixed-wing Unmanned Aerial Vehicle (UAV) by using frequency separation as well as kinematic, aerodynamic and wind models combined in an Extended Kalman Filter (EKF). With these estimates it is possible to calculate the angle of attack and the magnitude of the airspeed. Avoiding the need for prior knowledge...
Vision-based sky segmentation and horizon line detection can be extremely useful to perform important tasks onboard Unmanned Aerial Vehicles (UAVs), such as pose estimation and collision avoidance. Most of the existing vision-based solutions use traditional image processing methods to identify the horizon line. This results in good overall accuracy and fast computation times. However, difficult environmental...
This paper presents the design and simulation of an energy-based control strategy to stabilize a quadrotor described with unit quaternions and their axis-angle representation. The mathematical model is based on Euler-Lagrange formulation using a logarithmic mapping in the quaternion space. The proposed solution introduces a new approach: a quaternion-energy-based control, which introduces an energy...
This work presents the modeling and control of an aerial manipulator based on a quadrotor with a robotic arm using the dual quaternion approach. First the kinematic model of the complete system is obtained using dual quaternions to represent multiple rotations and translations, then the dynamic model is developed via the Newton-Euler formalism. A position control law is used to stabilize the vehicle...
To simplify the usage of the Unmanned Aerial Systems (UAS), extending their use to a great number of applications, fully autonomous operation is needed. There are many open-source architecture frameworks for UAS that claim the autonomous operation of UAS, but they still have two main open issues: (1) level of autonomy, being in most of the cases limited and (2) versatility, being most of them designed...
Unmanned Air Vehicles (UAVs), which have been popular in the military context, have recently attracted attention of many researchers because of their potential civilian applications. However, before UAVs can fly in civilian airspace, they need to be able to navigate safely to its goal while maintaining separation with other manned and unmanned aircraft during the transit. Algorithms for autonomous...
To accelerate research and development of the autonomous capabilities of micro aerial vehicles we have developed flight control framework, ROSflight, as a research tool. ROSflight makes development of autopilot code easier and more efficient by minimizing the use of embedded systems, incorporating the Robot Operating System and using off-the-shelf and open-source hardware and software. Motivation...
A cooperative track-before-detect algorithm for multiple ground targets is presented for fixed-wing Unmanned Air Vehicles (UAVs) with a finite field of view. The road network forms a graph whose nodes indicate the target likelihood ratio. Target observations are assimilated by a Bayesian likelihood ratio tracker in which likelihood diffuses according to the graph Laplacian of the road network. Using...
This paper presents a novel human robot interaction system that can be used for real-time 3D environment exploration with an unmanned aerial vehicle (UAV). The method creates a mixed reality environment, in which a user can interactively control a UAV and visualize the exploration data in real-time. The method uses a combination of affordable sensors, and transforms the control and viewing space from...
This paper investigates forest monitoring and fire detection strategies using a team of unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs). UAVs have great advantages in forest fire detection and fighting. However they have limited running time and payload capabilities, therefore UGVs are paired with UAVs to avoid their demerits. First, UGVs are used to transport the UAVs to the nearest...
Our objective is to design a consensus based control law for a multi-agent system to track a desired trajectory in the presence of a constant input delay. The agents of the multi-agent system are modeled as double integrator. The communication topology is represented by a fixed and weakly connected digraph. The controller works in conjugation with an estimator to help the agents track the desired...
Several approaches can be identified in the literature for area decomposition: Grid based methods, Cellular decomposition and Boustrophedon (or Morse) decomposition. This paper proposes a novel discretization method for the area based on computational geometry approaches. By using a Constrained Delaunay Triangulation, a complex area is segmented in cells which have the size of the projected field...
This paper presents an active fault-tolerant control scheme for a quadrotor unmanned helicopter with velocity sensor faults. A two-level control scheme is designed to guarantee the trajectory following of the quadrotor when there are no faults. The control scheme consists of an external-loop Proportion Differentiation (PD) control law and an internal-loop Proportion Integration Differentiation (PID)...
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