Hardware-In-The-Loop – an Essential Part of the Development Process for the Automatic Flight Control System of a Utility Aircraft

Based on a powered sailplane STEMME S15, an automatic flight control system is designed for high-precision automatic control of a utility aircraft. The LAPAZ project is funded by the German National Aviation Research Program (LUFO IV). LAPAZ is a German acronym for an Air-Working Platform for the General Civil Aviation. To test the automatic flight control system, a ground test facility in the form of a hardware-in-the-loop (HIL) simulator was built. The correct integration of the flight control system in the aircraft (STEMME S15 prototype) is checked by this system. In addition, the functions of the flight control laws are verified. HIL simulation is part of a cost-effective development process for safety-critical systems, which will be established as part of this project. The present report gives an overview of the development process and describes the concept, the functional principle and the construction of the HIL simulator. As an example to validate the HIL-simulator flight test and simulation data of the first automatic landing of the STEMME S15 are compared.