After being neglected during many decades, airships are experiencing a new interest, specially the stratospheric lighter than air vehicle. This paper presents a nonlinear motion control method of a dirigible in a high constant altitude flight, for path tracking. We use the property that the system is input/output linearizable. In path generation, we use the cubic spiral while the polynomial app...

Beginning in the mid-1980s, the phenomenon of capital flight from developing countries received considerable attention in the economics literature. Capital flight destroys the domestic macroeconomic environment and decreases transparency and accountability. It restricts financial resources when a country is looking for economic growth and development. The purpose of this article is to measure t...

The present paper compares the effect of different waypoint parameters on the flight performance of a special autonomous indoor UAV (unmanned aerial vehicle) fusing ultrasonic, inertial, pressure and optical sensors for 3D positioning and controlling. The investigated parameters are the acceptance threshold for reaching a waypoint as well as the maximal waypoint step size or block size. The eff...

Tracking moving ground targets using unmanned air vehicles (UAVs) has important applications in several areas. Keeping a close line of sight from a UAV to a target in a densely populated area is a challenging task because of many constraints. An algorithm for several UAVs to track a moving target cooperatively is proposed. From random samples on the ground and obstacles, a cost inversely propor...

This paper describes a system for landing a vertical take-off and landing vehicle on a moving deck using a monocular vision system and inertial measurement unit. Data from the vision system and IMU are used to compute an estimate of relative deck position, and a touchdown trajectory generator based on tau-guidance is used to compute a path to landing. A trajectory-following controller follows t...

A velocity selector is described which is designed for measurement of the total collision cross section of electrons in the energy region below one volt. The system determines the distributions of times of flight of single electrons over a measured path at selected pressures of a specimen gas. The electrons are generated by repetitive illumination of a photo-emitter by a spark gap, pass over a ...