Pearl-M – development of an unmanned aerial system platform

Puls, Tim and Vyshnevskyy Matthias
It is foreseen that there will be a future market for intelligent surveillance and superring robots, capable of discreetly penetrating confined spaces and maneuvering in those without the assistance of a human pilot tele-operating the vehicle. Thus, the development of small autonomous flying, i.e. aerial vehicles for indoor or urban applications, able to perform agile flight inside buildings, stadiums, stairwells, airports, train stations, ventilation systems, shafts, tunnels etc. is of significant importance. Such vehicles can also be used in environments where direct or remote human assistance is not feasible, e.g. in contaminated areas or in urban search and rescue operations for locating earthquake-victims inside collapse-endangered buildings. OFFIS together with industrial partners has been developing a family of prototype UAVs with different characteristics (weight, flight time, pay load) for specific applications. Core of the developments is a generic flight controller platform which can be used in both fixed- and rotary wing airframes. The flight controller uses a patented nonlinear but stable control algorithm providing the ability for the system to operate at high wind speeds of e.g. 6 bft and even to handle strong side wind boes. The current prototypes have takeoff weights between 300g and 3kg and are able to lift 300g up to 1kg for about 20 minutes. As the flight controller offers interfaces to common bus systems (CAN, RS232, I2C, PPM / PWM…) various sensors such as IR-cameras, gas- or radiation detectors can easily be attached. The entire system including payloads is operated using a graphical user interface provided by the ground control station. Remote controls as they are known from many systems are used as backup only. The system is able to take off, land and navigate autonomously even in the presence of wind using GPS waypoint navigation and barometric height control. Optical flow using cameras is available as backup, if no GPS signal is available. This disburdens the operator from piloting the UAV so that he or she can concentrate on the retrieved data.
06 / 2008