NASA Marshall Space Flight Center Robot Verification

Abstract

The NASA Marshall Space Flight Center (MSFC) has developed a unique avionics simulation capability through the integration of several MSFC avionics test beds. This integrated test bed consists of three separate facilities interconnected by fiber-optic networks for real-time data exchange. The three facilities that support this capability are the Marshall Avionics System Testbed (MAST), Flight Robotics Laboratory (FRL) and Contact-Dynamics Simulation Laboratory (CDSL). MSFC wanted the robots in the FRL and CDSL to be verified using dynamic measurements with six degrees of freedom to determine how accurately the robots responded to commanded moves. Contact-Dynamics Simulation Laboratory (CDSL) CDSL was developed in response to the need to evaluate the Earth-orbit dynamic response of the interfacing mechanisms. This facility allows engineers to simulate how a docking or berthing mechanism would behave in Earth orbit under a variety of conditions. In the CDSL, one component is attached to a motion-base, while the other component is mounted to a force and torque sensor fixed in the support structure above the motion-base, as seen in figure 1. The motion-base is a hydraulically driven CAE-LINK Stewart platform that is used to simulate the relative motion of the berthing and docking mechanisms in six degrees of freedom. The motion-base is commanded by an Alliant FX-80 parallel super computer, which runs a simulation program modeling two vehicles in Earth orbit.