The Centaur Hardware-in-the-Loop Simulator (HILSim) at Aurora Flight Sciences, a Boeing company, has been upgraded to enhance the testing and refinement of new flight technology before physical flight tests.
This ground-based testing allows for a smoother transition to flight testing in the company’s Centaur optionally piloted aircraft (OPA). The Centaur OPA can function as a surrogate uncrewed system, enabling flight testing of autonomous capabilities within the National Airspace System (NAS), controlled from a ground station while carrying an on-board safety pilot.
The Centaur HILSim includes a complete Centaur airframe, incorporating the identical hardware and software used in the actual aircraft, allowing engineers to accurately predict the aircraft’s in-flight behavior.
Erica Powers, Software Engineer at Aurora Flight Sciences, commented, “The Centaur HILSim gives us a nearly complete picture of how hardware and software interact under realistic flight conditions. It allows us to uncover integration issues early and resolve challenges faster and more efficiently while still on the ground.”
Aurora’s flight test team recently concluded a HILSim test campaign to validate a key connection between the aircraft’s mission management system (MMS) and Aurora’s autonomy framework. By simulating flight-like conditions, the team could observe data flow across the network and test the MMS’s response to situations like corrupted or delayed messages. The results confirmed that the system maintained stable communication and proper coordination among nodes, even under demanding circumstances.
Powers continued, “Validating the MMS to our autonomy interface in simulation gave us a level of confidence that would have taken weeks of flight time to achieve. We confirmed message integrity, timing, and fault recovery in a fully controlled environment – all before the hardware ever left the ground.”
With this validation, a standardized interface for autonomy testing is now accessible across Aurora’s SKIRON-X small UAS, including its HILSim and foam-constructed surrogate air vehicle, as well as the Centaur HILSim and aircraft. Engineering teams developing new autonomous capabilities can begin testing with Group 1 and 2 drones and subsequently advance to testing with an optionally piloted twin-engine aircraft in the Group 4 class.
HIL simulation has become a vital component of Aurora’s flight test process. By validating the behavior of software, hardware, and interfaces early, HILSim lowers flight risk and shortens test schedules by providing essential insight before the aircraft reaches the flight line. “It’s important to note that HIL simulation doesn’t replace flight testing,” Powers explained. “HILSim ensures that when an aircraft moves from ground to flight testing, system behaviors are well understood, and the flight tests can focus more on refinement rather than troubleshooting.”
