General Aviation Data Framework

The Flight Research Services Directorate at the NASA Langley Research Center (LaRC) provides development and operations services associated with three general aviation (GA) aircraft used for research experiments. The GA aircraft includes a Cessna 206X Stationair, a Lancair Colombia 30 0X, and a Cirrus SR22X. Since 2004, the GA Data Framework software was designed and implemented to gather data from a varying set of hardware and software sources as well as enable transfer of the data to other computers or devices. The key requirements for the GA Data Framework software include platform independence, the ability to reuse the framework for different projects without changing the framework code, graphics display capabilities, and the ability to vary the interfaces and their performance. Da ta received from the various devices is stored in shared memory. This paper concentrates on the object oriented software design patterns within the General Aviation Data Framework, and how they enable the construction of project specific software without changing the base classes. The issues of platform independence and multithreading which enable interfaces to run at different frame rates are also discussed in this paper. I. Introduction HE Flight Research Services Directorate at the NASA Langley Research Center (LaRC) provides design, development, implementation, and testing services for simulation and flight aerospace experiments. This support enables researchers to develop and test research ideas to enhance aviation safety, aviation capacity, and the ope rational needs of the national airspace system 1 . FRSD develops, operates, and maintains three general aviation (GA) research airplanes: Cessna 206H Stationair, Lancair Columbia 300, and Cirrus SR22X in addition to several other types of airplanes to suppor t flight experiments. FRSD designed and built a GA baseline research system for these GA research airplanes at LaRC. The Flight Simulation and Software Branch (FSSB) of the FRSD developed a Generic Aviation Data Framework for the GA baseline research syste m in order to support experiments performed in all three of these research GA airplanes. The Generic Aviation Data Framework is designed to operate on both Windows and Linux platforms to gather data from hardware devices for use by experimental equipment, data gathering and analysis, and graphics display. The goal of the GA research system is "to provide a generic research system for the three NASA GA aircraft using as many common features/components as possible to minimize the specific hardware and softwar e necessary for experiments envisioned within the next three to five years." 2 Various objectives within this goal include minimizing the costs and time in reconfiguring aircraft between experiments and the ability to use interchangeable research system co mponents between the aircraft. 3 The framework should reuse LaSRS++ components, and be designed with the long -term benefits of re -usability, portability, testability, and maintainability. The original requirements included the hardware, software, and vario us other components of the planes. Derived requirements were written to detail software design goals that include the ability to vary the interfaces, use the software on both Windows and Linux platforms, use both mouse and bezel button inputs to communicat e with the system, check the status of interfaces, view the data received by the various interfaces and display graphics.