The objective of this work is to achieve real time tracking of power conductors using a Quadrotor Unmanned Air Vehicle (UAV). Two solutions are proposed. For the first solution, the control is directly solved in the 2D image space. The link between image features and the kinematics of the vehicle is achieved using an Image Based Visual Servoing (IBVS) formulation, combined with a Linear Quadratic Servo (LQ-Servo) approach. In the second solution, a partial pose of the vehicle with respect to (wrt) the lines is estimated. Then, a position controller designed in the Cartesian space is used to drive the vehicle to the desired configuration. Experimental results are provided to validate the two approaches.
2015),"Evaluation of torque as a means of in-process sensing of tool wear in friction stir welding of metal matrix composites", If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information.
About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation.
AbstractPurpose -This paper aims to present a new vision-based approach for both the identification and the estimation of the relative distance between the unmanned aerial vehicle (UAV) and power pylon. Autonomous power line inspection using small UAVs, has been the focus of many research works over the past couple of decades. Automatic detection of power pylons is a primary requirement to achieve such autonomous systems. It is still a challenging task due to the complex geometry and cluttered background of these structures. Design/methodology/approach -The identification solution proposed, avoids the complexity of classic object recognition techniques. Instead of searching the whole image for the pylon template, low-level geometric priors with robust colour attributes are combined to remove the pylon background. The depth estimation, on the other hand, is based on a new concept which exploits the ego-motion of the inspection UAV to estimate its distance from the pylon using just a monocular camera.Findings -An algorithm is tested on a quadrotor UAV, using different kinds of metallic power pylons. Both simulation and real-world experiments, conducted in different backgrounds and illumination conditions, show very promising results. Research limitations/implications -In the real tests carried out, the Inertial Navigation System (INS) of the vehicle was used to estimate its ego-motion. A more reliable solution should be considered for longer distances, by either fusing INS and global positioning system data or using visual navigation techniques such as visual odometry. Originality/value -A simple yet efficient solution is proposed that allows the UAV to reliably identify the pylon, with still a low processing cost. Considering a monocular solution is a major advantage, given the limited payload and processing power of such small vehicles.
Quadrotor helicopters have been the focus of many research works during the last decade. Thanks to their numerous appealing features, their applications are increasingly reported in the literature. Their main limitation, however, is their lightweight which makes them sensitive to external disturbances. The aim of this paper is to achieve robust trajectory following for a Quadrotor UAV, in the presence of wind disturbances. Two nonlinear controllers are designed and discussed, the first controller is based on Feedback Linearisation, while the second is designed using a Backstepping approach. Numerical simulations are provided to support the controllers design and assess their robustness to wind gust disturbances.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.