Automatic landing on aircraft carrier by visual servoing

International audienceThe landing on carrier is a very difficult task even for trained pilots. This paper presents a method to land automatically using aircraft sensors and three visual features inspired by visual cues used by pilots. These features whose link with the aircraft state is established, are introduced in a control scheme using a linearized aircraft model. The control law demonstrates a large convergence domain using simulated visual features and a 3D tracker applied on synthetic images

Potential of legume-based grassland - livestock systems in Europe: a review

European grassland-based livestock production systems face the challenge of producing more meat and milk to meet increasing world demands and to achieve this using fewer resources. Legumes offer great potential for achieving these objectives. They have numerous features that can act together at different stages in the soil-plant-animal-atmosphere system, and these are most effective in mixed swards with a legume proportion of 30-50%. The resulting benefits include reduced dependence on fossil energy and industrial N-fertilizer, lower quantities of harmful emissions to the environment (greenhouse gases and nitrate), lower production costs, higher productivity and increased protein self-sufficiency. Some legume species offer opportunities for improving animal health with less medication, due to the presence of bioactive secondary metabolites. In addition, legumes may offer an adaptation option to rising atmospheric CO2 concentrations and climate change. Legumes generate these benefits at the level of the managed land-area unit and also at the level of the final product unit. However, legumes suffer from some limitations, and suggestions are made for future research to exploit more fully the opportunities that legumes can offer. In conclusion, the development of legume-based grassland-livestock systems undoubtedly constitutes one of the pillars for more sustainable and competitive ruminant production systems, and it can be expected that forage legumes will become more important in the future

UNI-Copter: A portable single-rotor-powered spherical unmanned aerial vehicle (UAV) with an easy-to-assemble and flexible structure

This paper presents the design and modeling of the UNI-Copter, a portable spherical unmanned aerial vehicle (UAV) that is powered by a single rotor. This type of single-rotor spherical UAV has many advantages over other types of multi-rotor UAVs, but the spherical external structure takes up more volume, thereby reducing its portability. We focus on designing and building the UNI-Copter to provide ease of assembly and portability while taking advantage of the existing spherical structure. This paper explains our design concepts and the development process of improving the performance through various prototypes. We also verify flight stability of our new design by conducting several flight tests. To do so, a mathematical model of the UNI-Copter is derived in detail, and then we implement a state feedback controller for hovering flight. As a result, the indoor flight tests show stable performance, and the outdoor flight tests show that stable performance could also be achieved provided that the wind speed is low