On the Design and Model-Based Validation of Flight Control System Automation for an Unmanned Coaxial Helicopter

Abstract

An existing coaxial helicopter with a maximum takeoff weight of 600 kg has been transformed into a unmanned aerial system. To enable unmanned experimental validation of novel flight control-laws in flight tests, the helicopter's flight control system has been extended by digital components. As the loss of the helicopter platform due to a failure in the experimental digital flight control system has been identified a risk for the project, contingency procedures have been considered in the system design. In this paper, we suggest a model-based and lean development approach for system automation development, which to the best of the authors knowledge, is new. Within the process we suggest to introduce Operational Sequence Diagrams that only represent procedural system behavior to describe the Design Reference Scenarios of the Concept of Operations. Thereby we enable the total exploitation of a System Architecture Behavioral model within the design process, considering the definition of procedures, the validation of architecture design and automated code generation. To validate the suggested approach, we present its application to the design of the system automation for the flight control system of the unmanned helicopter. The system has been successfully integrated and tested in caged flight tests in November 2022.