Festo_BionicFlyingFox_en

Primary Secondary Angular gear unit Rack-and- pinion gear unit On-board electronics with inertial sensors Brushless DC motor 3D-milled foam body Linear drives Scissor kinematics Elastic flying membrane 02: Unique flying behaviour: the artificial flying fox moves freely like its natural role model, thanks to the elastic flying mem- brane and intelligent kinematics. 03: Sophisticated design: the on-board electronics built into the body combined with the mechanical system in the wings. BionicFlyingFox Semi-autonomous flying manoeuvres based on a natural role model The dream of flying is one of the oldest known to humankind. In this respect, we have always looked at the animal world with fas- cination – a world that shows how it is done in all sorts of ways. In the Bionic Learning Network too, flying is always a recurring theme. In association with universities, institutes and development firms, Festo has, for years now, been developing research plat- forms whose basic technical principles are derived from nature. For the BionicFlyingFox, the developers have now taken a close look at the flying fox’s special properties and technically imple- mented them in an ultra-lightweight flying object. With a wing- span of 228 cm and a body length of 87 cm, the artificial flying fox weighs just 580 g. The natural model: flying without feathers The flying fox belongs to the order Chiroptera – the only mammals that can actively fly. A particular characteristic is their fine elastic flying membrane. The membrane consists of an epidermis and der- mis and stretches from the extended metacarpal and finger bones down to the foot joints. In flight, the animals control the curvature of the flying membrane with their fingers, allowing them to move aerodynamically and agilely through the air. They thereby achieve maximum uplift, even when performing slow flying manoeuvres. Agile kinematics In order to achieve results as close to the natural flying fox as pos- sible, the wing kinematics of the BionicFlyingFox are also divided into primaries and secondaries and covered with an elastic mem- brane, which continues from the wings down to the feet. As with the biological model, all the articulation points are on one plane, meaning that the artificial flying fox can control and fold its wings together individually. So that the BionicFlyingFox is able to move semi-autonomously in a defined space, it communicates with a motion-tracking system. The installation constantly records its position. At the same time, the system plans the flight paths and delivers the necessary con- trol commands for this. A person performs the start and landing. The autopilot takes over in flight. Moving camera system for exact localisation An important part of the motion-tracking system is two infrared cameras, which rest on a pan-tilt unit. This allows them to be ro- tated and tilted in such a way that they can track the entire flight of the BionicFlyingFox from the ground. The cameras detect the flying fox by means of four active infrared markers attached to the legs and wing tips. Machine learning of the ideal flight path The images from the cameras go to a central master computer. It evaluates the data and externally coordinates the flight like an air traffic controller. In addition, pre-programmed paths are stored on the computer, which specify the flight path for the BionicFlyingFox when performing its manoeuvres. The wing move- ments required to ideally implement the intended courses are calculated by the artificial flying fox itself with the help of its on- board electronics and complex behaviour patterns. The flying fox gets the control algorithms necessary for this from the master computer, where they are automatically learnt and constantly improved. The BionicFlyingFox is thus able to optimise its behaviour during the flights and thereby follow the specified courses more precisely with each circuit flown. In this respect, the controls are governed by the movement of the legs and hence the adjustable wing area. The elastic flying mem- brane stretches over the complete back of the bionic model – from the fingertips down to the feet. This makes the wing area relatively large, allowing a low area loading. Drive with sophisticated lever mechanism The primaries and secondaries can be activated in any state so that the wings move harmoniously and almost without any shak- ing. For this purpose, the primary is coupled to the secondary and follows the latter due to forced kinematics, whereby dead centres in the movement are prevented. A nine-gram lightweight brushless DC motor in the body of the flying fox drives these flying kinematics by means of a gear ratio. The folding mechanism on the wings can be individually and infinitely adjusted using two small linear drives. 01: Latest motion-tracking system: the cameras are soon put into operation and can follow the flying object dynamically. 03 02 01 2 Festo AG & Co. KG 3 BionicFlyingFox: Ultra-lightweight flying object with intelligent kinematics