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This paper is dedicated to the study and improvement of the aerodynamic properties of the feeder airship in the context of MAAT project. FP7 MAAT project is based on the concept of two different types of airships (the cruiser and the feeder) working together as a transportation system. The current feeder concept includes unconventional shape changing envelope. Two problems are considered in this paper. The first problem is to find a condition of the effective vertical ascent for the feeder (from the ground to the altitude of the cruiser). A series of CFD simulations were carried out for the top flow for a range of altitudes from 0 to 16 km and velocities between 2 and 10 m/s. The results confirm the appearance of some negative effects, including high drag during the vertical ascent, especially, at low altitudes. The second problem is to study and reduce the side wind effects on the ascending feeder airship.

In this paper a control system design for robotic airship is developed. The nonlinear multilinked mathematic model of airship is considered. The results of aerodynamic analysis, parametric and structure disturbances estimation, nonlinear control algorithms are presented. Airship motion simulator is developed and successfully applied. Airship is implemented on experimental robotic mini-airship.

Functional and energetic issues of control of feeder-airship of MAAT system are considered in the paper. MAAT (Multibody Advanced Airship for Transport) [1,2] is an environmentally friendly system for transportation of passengers and cargos. It consists of cruiser and a few feeders. Cruiser flies in stratosphere at almost fixed altitude. Feeder acts like an elevator, it delivers passengers and cargos from airport to cruiser and in opposite direction. Paper shows, that wide altitude range feeder flies through, strong and dynamic wind loads at various tropospheric and stratospheric altitudes, makes definition of control strategies and energy requirements for control a nontrivial task. That is why this work pays much attention to assessment and mathematical description of feeder flight environment, existing and potential wind profiles, essentially influencing at feeder flight trajectory. Energy efficiency increase is considered in the paper.

In this paper we consider one of the problems in the development of control system for the feeder for MAAT transportation system. This problem is connected with estimation of inboard energy requirements. Traditionally such estimation is made on the basis of static relations. They allow assessing the power required to move a solid body with a constant air speed. However a contribution from aerodynamic forces and moments can vary depending on a regime of motion (value of linear and angular accelerations, angle of attack, etc). Because of that fact, this work investigates the estimation of the total required inboard energy and contribution of aerodynamic forces and moments to it in specified feeder motion regimes. The method of assessment is based on the feeder model, which is built on the equations of the rigid body. This paper contains general structure of feeder mathematical model, which includes equations of statics, dynamics and control mechanisms.

The paper describes methods for control of docking of two moving stratospheric airships. One of them (cruiser) implements cruising flight at the defined altitude with defined velocity. The other one (feeder) fulfills the mission of chasing the cruiser with following docking operations. Mathematical model of exact airships are used in the work. Instances of structural and algorithmic implementation are based on position-trajectory controller. Simulation of docking control was accomplished with proposed methods.

The aim of this paper is to develop a new concept of unconventional airship based on morphing a lenticular shape while preserving the volumetric dimension. Lenticular shape is known to have relatively poor aerodynamic characteristics. It is also well known to have poor static and dynamic stability after the certain critical speed. The new shape presented in this paper is obtained by extending one and reducing the other direction of the original lenticular shape. The volume is kept constant through the morphing process. To improve the airship performance, four steps of morphing, starting from the lenticular shape, were obtained and compared in terms of aerodynamic characteristics, including drag, lift and pitching moment, and stability characteristics for two different operational scenarios. The comparison of the stability was carried out based on necessary deflection angle of the part of tail surface.

This paper looks into with the aerodynamic properties and stability of the feeder airship in the framework of MAAT project. FP7 MAAT project is based on the concept of two different types of airships (the cruiser and the feeder) working together as a transportation system. The feeder considered in this paper is a rigid airship with an unconventional envelope shape. Aerodynamic forces and moments acting on the airship during the horizontal and vertical flight modes are of special interest in this study, because the aerodynamic performance of the aircraft directly influences its general dynamic behavior and, thus, its in-flight stability. A set of CFD simulations was conducted for vertical and horizontal flights of the feeder airship. Drag and lift forces and pitching moment together with their coefficients, were obtained for different altitudes and velocities from the proposed operational ranges of the airship.

In this paper, we study a problem of control system design for small-scale helicopter that has been applied to a robotic helicopter project. The structure of the mathematical models of single-rotor helicopter and the description of its constituent elements are presented. The general mathematical model of a helicopter is a complex multivariable system. This model consists of nonlinear differential equations of the helicopter dynamics, the kinematics and auxiliary equations. The control forces and moments, and also the external disturbances, that affecting on helicopter flight, are in the right side of the dynamic equations. It is necessary to have experimental data for helicopter flight parameters to get adequate auxiliary equations. Those equations have been applied to associate the control forces and moments, to control positions of actuators. In this paper we present the experimental results, estimation algorithms and data-processing.