Software and Simulation Architecture for an Experimental Unmanned Rotorcraft Platform

Abstract

The DLR Institute of Flight Systems is developing a multi-purpose Vertical Takeoff and Landing UAV test platform, to be used in bio-inspired vision experiments, development of advanced flight controls, and guidance stragtegies. The ARTIS (Autonomous Rotorcraft Testbed for Intelligent Systems) features an experimental modular avionics system, adaptable to multiple airframes, and is mainly composed of Commercial-Off-The-Shelf components. All flight critical guidance and control loops are executed on a single onboard computer. The real-time software on this computer has been implemented in the C programming language in a multi-threaded architecture, that is optimized towards the requirements of the multi-sensor platform in combination with the necessary sensor fusion techniques. This paper describes the software development setup within the ARTIS research project including the necessary simulation environment. As Simulink is the most popular tool, it was not only used for a Software-In-The-Loop Simulation of the complete UAV system but also to create the simulation code of a Hardware-In-The-Loop Simulator that runs in real time. Pieces of the onboard software, that need to be tested, are being included into the Simulink simulation and can be evaluated separately. These proven chunks of the onboard code can then be added to the onboard flight code architecture. Flight control code can be hand coded or generated automatically and can be tested using the aforementioned methods. In the summary, results from the applied development approach are presented and the methodology is once again reevaluated and necessary improvements will be pointed out.