English motion-tracking specialist Vicon has furnished an eight-camera system for the European Space Agency’s Automation and Robotics Laboratory to track the motion of the robotic vehicles destined for planetary surface exploration.
A rover on a test run
“The rovers are either tele-operated or they execute autonomous navigation algorithms onboard,” said Pantelis Poulakis, a robotics systems engineer at the ESA lab. “The latter is necessary for a Mars mission scenario due to the long time it takes for signals to travel between Earth and Mars and the limited availability of communication windows.”
The system is installed in an 80-square-meter (860-square-foot) Planetary Utilization Testbed, which mimics challenging planetary surfaces such as boulder fields, sandy dunes and gravel patches. In order to ‘know’ its position on the surface of the planet and to close the loop with the navigation algorithms, the rovers are equipped with a set of sensors called a localization scheme.
“It’s a continuous learning curve for us,” said Poulakis. “The Vicon system tracks the rover navigation trajectories, thus providing an external localization reference. We then analyze that data, in order to validate the navigation algorithms and test our onboard localization scheme. In a nutshell, our aim is to narrow the difference between how we expect the rover to move and what it actually does.”