Safe Trajectories for Autonomous Rendezvous of Spacecraft

Abstract

Autonomous spacecraft rendezvous is an enabling technology for many future space missions, but anomalies in recent flight experiments suggest that safety considerations will play a critical role in mission success. This paper presents a method for online generation of safe, fuel-optimized rendezvous trajectories that guarantee passive collision avoidance for a large class of anomalous system behaviors. We examine the cost of imposing safety as a problem constraint and of additional constraints that guarantee infinite horizon passive collision avoidance while enabling future docking retries. A convex collision avoidance formulation was introduced and determined to provide computationally fast solutions at a small fuel expense. Several examples using both rotating and non-rotating targets are presented to demonstrate the overall benefits of incorporating these safety constraints when compared to nominal trajectory design techniques.

Model predictive control application to spacecraft rendezvous in mars sample return scenario

“…In order the predicted trajectories do not collide with the target, constraints are placed on the predicted trajectories to ensure that they do not enter a safety sphere of radius R s (t), surrounding the target. In addition, as proposed in [10], unforced drift trajectories emanating from each point in the prediction horizon are also constrained to ensure passive safety. Collision avoidance is a manifestly nonconvex constraint, but it is approximated by a half-space constraint with angle relative to the in-track direction parameterized by α (Fig.…”

Docking algorithm for flexible microsatellite mock-ups on planar air-bearing test-bench

“…Kalman filter is designed for linear mathematical models and allows the best mean-square state vector estimation. It might be adapted for any non-linear mathematical models of both dynamical system and measurements, (13) Discrete extended Kalman filter uses non-linear dynamical and measurements models for a priory estimate prediction and a posteriori correction [30]. Prediction phase is…”

“…In the last decade significant achievements have been obtained in the field of optimal docking control strategies. In the papers [12,13] the model predictive control is applied to the problem. It allows to generate the safe and fuel-optimal rendezvous trajectories that guarantee collision avoidance.…”

Safe rendezvous scenario design for geostationary satellites with collocation constraints

“…Some investigated the safety performance of the nominal trajectory, in which safety-optimal trajectories [13] or fuel-optimal trajectories with collision avoidance constraint [14,15] were designed. Some other studies investigated the safety performance considering trajectory uncertainty, in which several calculation methods of collision probability were developed [16,17] and quantitative indexes based on collision probability were defined to evaluate safety performance of rendezvous trajectories [18,19].…”