ON-GROUND TESTING OPTICAL NAVIGATION SYSTEMS FOR EXPLORATION MISSIONS

Abstract

In response to a growing demand for the test of optical navigation sensors and systems the Institute of Space Systems of the German Aerospace Center (DLR) has developed in the last years the Testbed for Robotic Optical Navigation (TRON). This facility is a special simulator to create realistic scenes which would be encountered by optical sensors during exploration missions. TRON has been applied for breadboard tests of the absolute optical navigation method for ESA’s Lunar Lander mission, the EU project Small Integrated Navigator for PLanetary EX- ploration (SINPLEX) - an integrated miniaturized navigation system [2], and the EU project Flash Optical Sensor for Terrain Relative Navigation (FOSTERNAV) - a flash lidar breadboard [1]. The main elements of the facility are 3D terrain models of celestial bodies and two robots to position the sensor (camera) and a light simulating the sun. Since the tests are carried out with downscaled models special care has to be taken to ensure the accuracy of the ground truth in order to provide a representative test environment. This applies to the manufacturing and verification of the 3D models as well as to the positioning accuracy of the sensor with respect to the target models. Recently DLR also invested in the development of a TRON-complementary test bench offering the possibility of high-speed and long-range tests. The Test Environment for Navigation Systems On airfield Runway (TENSOR) facility was used for testing of the flash lidar developed in the frame of the FOSTERNAV project. This paper shows the layout and operation of the TRON test facility and also gives an introduction to TENSOR. Methods and measures taken to ensure a high accuracy of the ground truth data are presented and discussed. [1] Pollini A. FLASH OPTICAL SENSORS FOR GUIDANCE, NAVIGATION AND CONTROL SYSTEMS. American Astronautical Society, February 2012. AAS 12-075. [2] Stephen R Steffes and et. al. Target Relative Navigation Results from Hardware-in-the-Loop Tests Using the SINPLEX Navigation System. In 37th Annual AAS Guidance and Control Conference , Breckenridge, Colorado, February 2014. AAS. AAS 14-402.