Modeling and stability analysis of a hybrid docking simulator

One of the goals of performing a hardware-in-the-loop (HIL) simulation at the European Proximity Operation simulator (EPOS) is to simulate on-orbit satellite docking for verfication and validation of the docking phase. This paper presents the analytic and experimental investigations on the numerical stability of the robotic based HIL docking simulator which shall be used to identify the operational domain of the simulator. In order to identify the operational domain, we derived an analytic expression of the stable region of the simulator as a function of the contact model parameters, satellite masses and the simulator controller time delay. In addition, the paper presents an experimental validation of the robotics based HIL docking simulator developed at EPOS facility using the experimental data from an air-bearing supported zero-gravity testbed. The experimental results of robotics based HIL docking simulator comply favorably with the experimental data from air-bearing testbed, which demonstrates the validity of the simulator and increases the confidence of using the simulator for future on-orbit docking/contact algorithm validation. Finally, the stability region was also validated using the experimental data which showed consistency with the analytic expression.