A New Contact Dynamics Model Tool for Hardware-In-The-Loop Docking Simulation

Abstract

One of the goals of performing a hardware-in-the-loop (HIL) simulation at the European Proximity Operation simulator (EPOS 2.0) is to simulate on-orbit docking for verification and validation of the docking phase. However, this closed-loop docking simulation is influenced by the response time delay of the EPOS 2.0 controllers and by the high stiffness of the EPOS 2.0 robots. The high stiffness causes an unrealistic high impact force which puts the safety of the facility at risk and increases the position error in the docking simulator. In addition, the controller time delay destabilizes the HIL simulation by adding energy to the system. The paper presents a new contact dynamics model tool the development of which is based on a combination of a passive and active compliance and that can be used for analysis in a hybrid simulation. This method is validated experimentally using the EPOS 2.0 facility and a standard contact dynamics model. In addition, this paper presents the effect of parameters like time delay, stiffness, damping and mass on the stability of the HIL simulation, both analytically and experimentally.