Rendezvous in cislunar halo orbits: Hardware-in-the-loop simulation with coupled orbit and attitude dynamics

in Acta Astronautica (2023), 211

Space missions to Near Rectilinear Halo Orbits (NRHOs) in the Earth-Moon system are upcoming. A rendezvous technique in cislunar space is proposed in this investigation, one that leverages coupled orbit ... [more ▼]

Space missions to Near Rectilinear Halo Orbits (NRHOs) in the Earth-Moon system are upcoming. A rendezvous technique in cislunar space is proposed in this investigation, one that leverages coupled orbit and attitude dynamics in the Circular Restricted Three-body Problem (CR3BP). An autonomous Guidance, Navigation, and Control (GNC) technique is demonstrated in which a chaser spacecraft approaches a target spacecraft in a sample southern 9:2 synodic-resonant L2 NRHO, one that currently serves as the baseline for NASA's Gateway. A two-layer guidance and control approach is contemplated. First, a nonlinear optimal controller identifies an appropriate baseline rendezvous path for guidance, both in position and orientation. As the spacecraft progresses along the pre-computed baseline path, navigation is performed through optical sensors that measure the relative pose of the chaser relative to the target. A Kalman filter processes these observations and offers state estimates. A linear controller compensates for any deviations identified from the predetermined rendezvous path. The efficacy of the GNC technique is tested by considering a complex scenario in which the rendezvous operation is conducted with an uncontrolled tumbling target. Hardware-in-the-loop laboratory experiments are conducted as a proof-of-concept to validate the guidance algorithm, with observations supplemented by optical navigation techniques. [less ▲]

Towards incremental autonomy framework for on-orbit vision-based grasping

in Proceedings of the International Astronautical Congress, IAC-2021 (2021, October 29)

This work presents a software-oriented autonomy framework that enables the incremental development of high robotic autonomy. The autonomy infrastructure in space applications is often cost-driven and ... [more ▼]

This work presents a software-oriented autonomy framework that enables the incremental development of high robotic autonomy. The autonomy infrastructure in space applications is often cost-driven and built for a narrow time/complexity domain. In domains like On-orbit Servicing Assembly and Manufacturing (OSAM), this prevents scalability and generalizability, motivating a more consistent approach for the incremental development of robotic autonomy. For this purpose, the problem of vision-based grasping is described as a building block for high autonomy of dexterous space robots. Subsequently, the need for a framework is highlighted to enable bottom-up development of general autonomy with vision-based grasping as the starting point. The preliminary framework presented here comprises three components. First, an autonomy level classification provides a clear description of the autonomous behavior of the system. The stack abstraction provides a general classification of the development layers. Finally, the generic execution architecture condenses the flow of translating a high-level task description into real-world sense-planact routines. Overall, this work lays down foundational elements towards development of general robotic autonomy for scalablity in space application domains like OSAM. [less ▲]