Model based verification of Electronic Control Unit (ECU) in high lift systems: Verification and validation

Aircraft flight control systems are complex systems to verify, especially considering the amount of software and hardware involved. One such flight control system is the High Lift System which provides the fundamental aircraft function of increasing wing lift. UTC Aerospace Systems provides complete "stick to surface" High Lift Actuation Systems for large commercial aircraft as well as smaller business jets. Verification of High Lift actuation Systems is a complex task, as each component has different performance, functionality and environmental requirements that need to be verified at an early stage in the lifecycle. This paper provides an overview of the method used to verify the interfaces and behaviour of a High Lift System Electronic Control Unit (ECU) with the greater system and aircraft through the use of models. The paper describes an approach to assess the functional behaviour of a system through simulation of failure conditions in a model and assessing the system response. In addition, the paper describes an approach undertaken to get visibility of the level of margin present in the Safety Monitors in the High Lift System ECU.