Development of a Robotics-based Satellites Docking Simulator

摘要: The European Proximity Operation Simulator (EPOS) is a hardware-in-the-loop (HIL) system aiming, among other objectives, at emulating on-orbit docking of spacecraft for verification and validation the phase. This HIL simulator set-up essentially consists interfaces, simulating servicing satellite called chaser satellite, serviced target sensor forces torques during contact, two industrial robots that hold control satellites motion relative position attitude. Furthermore, EPOS includes real-time controller interface linked to computer-based numerical orbital attitude dynamics. A key feature this feedback loop closed on real force sensed interfaces contact. That used as driving input dynamics simulation. simulation concept has unique advantage using measured contact torques, but it presents significant challenges. high stiffness yields bandwidth impact and, thus, very short time durations. These times might be shorter than inherent delay robot controllers. leads physical inconsistency in variables. also causes stability issue may cause catastrophic damages robots. Additional problems need addressed are characterization domain operation, compensation non-contact such due gravity effect. Finally, thesis addresses task identifying dynamic behavior end-effectors. above mentioned challenges solutions towards stable safe operation facility. First, order mitigate problem, introduces novel idea based hybrid model. method, developed thesis, combination passive compliance introduced end-effector virtual model allows operator vary parameters which can gain. method solve problem coming from end-effector. For control, new device designed fairly known properties softer stiffness. Second, analysis proposed via adaptation pole location dead-time systems. linearized design dynamics; linearization performed around geometrical configuration. work first an single dimensional case, then extended dimensions. highlight development physically intuitive state-space easily unveil modes application resulting second-order characteristics polynomial straight forward. contribution closed-form relationship, associated plots, system's parameter, i.e., satellite's masses, damping coefficient parameters, delay, geometry. In addition, supported passivity valid three Third, force-torque presented, classical weighted least-squares estimation technique suggested identification torque measurement. utilize LEICA laser tracker, positioning measurement system, identify end-effectors behaviors natural frequency ratio. accompanying envisioned tool flexible operations. shall allow emulation desired any within region without recurring modification hardware. experimental results robotics comply with data air-bearing testbed was independently by author Space Robotics Laboratory Tohoku University. It demonstrates validity operations increases confidence approach future docking/contact algorithm validation,