Hardware-in-the loop testing of crater navigation system for lunar landing

At the German Aerospace Center a Crater Navigation System has been developed over the last years. So far, its overall performance on challenging use-cases such as South Pole landings as well as on the real flight data from Chang’e-3 has been demonstrated. Here, we focus on showing that the algorithm provides adequate update rates when executed on flight processors. In this paper it is demonstrated that in tracking mode DLR’s Crater Navigation System provides measurements at a rate higher than 1 Hz on modern flight hardware. It is also shown that DLR’s Crater Navigation System requires less than 5 s when executed in acquisition mode. In addition this paper presents a real-time hardware-in-the-loop test of the algorithm, combining the aforementioned processor-in-the-loop setup with a real camera and a mock-up of a lunar scene. During this test it has been demonstrated that the system can successfully be operated in real-time and is capable of sustaining the favorable tracking mode during the entire test. This underlines that it is ready to be integrated in real flight systems.