Flight Mechanics, Flight Control and Aeroelasticity

LAPAZ II - Luft-Arbeits-Plattform für die Allgemeine Zivilluftfahrt II

LAPAZ II is a two-and-a-half-year (Oct. 1, 2010 - Dec. 31, 2013) project funded under the National Aeronautics Research Program (LUFO IV) to develop an automatic flight control system for aerial workhorses.

 

Introduction

There is a worldwide market for powerful and efficient aerial work and research aircraft in the STEMME S15 class. In the LAPAZ project, an automatic flight control system was developed for the S15, which will be further developed in this follow-up project to enable the aircraft to take off and land automatically and to perform measurement flights as a stabilized measurement platform even in turbulence.

 

Objectives

The aim of the research project is to further develop the highly reliable, automatic flight control system for the Stemme S15 aerial workhorse developed in the LAPAZ project. On the one hand, it is to be expanded to include the gust load reduction function so that the most stable platform possible is available for measurement tasks. Secondly, it should be possible to completely automate take-off and landing so that difficult missions can also be carried out unmanned.

With a view to later certification as a working aircraft, development processes for complex, safety-critical aviation systems and complex, safety-critical software for aircraft systems (SAE ARP 4754, SAE ARP 4761, RTCA DO-178B) will be established and software development will be oriented as closely as possible to these guidelines.

Project Plan

AP1000Definitions and RequirementsDevelopment of all higher-level specifications at the aircraft and system levels.
AP2000Stability and ControlDevelopment of the flight mechanical model of the elastic aircraft; design and test of control algorithms; development of a hardware-in-the-loop flight simulator.
AP3000AFCS PlatformIntegration and verification of control software.
AP4000Integrated overall systemFlight measurement system for integration in the test vehicle
AP5000TestingTests with the hardware-in-the-loop flight simulator to achieve flight clearance and training of the pilot in the use of the control system
AP6000EvaluationDocumentation of the evaluation and analysis
AP7000Approval procedureDevelopment of a procedure for the qualification of the flight controller software as well as its integration into the overall "working aircraft" system.

Task of the TU Berlin

The Flight Mechanics, Flight Control and Aeroelasticity department is involved in the concept for adapting the system architecture to the new functions. For flight simulation and controller design, the existing flight mechanical model of the aircraft is extended by a model containing the aeroelastic degrees of freedom. This model is used to design the flight controller laws for the gust load reduction and automatic takeoff and landing modes. Another important task is to create an efficient, automated process chain for controller design and testing, as well as to build a cost-effective process chain for generating qualifiable, safety-critical software.The flight controller operating and display unit (AFCP) developed in LAPAZ will be extended to include the new functions. The flight controller algorithms will be coded into software and their correct functionality verified in the SEPHIR research simulator. A hardware-in-the-loop (HIL) simulator will be set up to perform controller integration tests on the aircraft and to prepare flight tests. The department supports the project partners in the development of their test facilities, in the integration tests on the aircraft and in the testing of the flight controller on the ground (tests with SEPHIR and HIL simulator) and in the air. For the controller development it provides the research flight simulator SEPHIR and for the flight testing it provides its flight measurement facility.

 

Project Partners

  • STEMME AG
  • Institut für Luftfahrtsysteme (ILS) der Universität Stuttgart
  • Institut für Luft- und Raumfahrttechnik (ILR) der TU Berlin

Funding