Dynamik och reglering av rendezvous och dockning av obemannade rymdfarkoster

This paper presents a study on spacecraftRendezvous and Docking (RvD) through a comprehensiveliterature review, in addition to investigate the main phases andpossible control methods during the space rendezvous and docking.It presents a study of different energy efficient far rangerendezvous (e.g. Hoffman, bi-elliptic, phasing maneuver etc.). Aset of formation flying models (i.e. relative navigation) for twospacecraft operating in close proximity are examined. Oneapproach to depict the relative orbit’s dynamics model for closeproximity operations is to mathematically express it by thenonlinear equations of relative motion (NERM), that present thehighest accuracy and are valid for all types of orbit eccentricitiesand separations. Another approach is the Hill-Clohessy-Wiltshire(HCW). This method is only valid for two conditions, when thetarget satellite orbit is near circular and the distance between thechaser and target is small. The dynamics models in this paperdescribe the spacecraft formation flying in both unperturbed andperturbed environment, where only the Earth oblatenessperturbations are being treated.Furthermore, this paper presents a design of a control, guidance,and navigation (GNC) based on the aforementioned dynamicmodel. This will enable the chaser satellite to autonomouslyapproach towards the target satellite during the close proximitynavigation using some control techniques such Linear QuadraticRegulation (LQR) and Linear Quadratic Gaussian (LQG). Thesecontrol techniques aim to reduce both the duration and the ΔVcost of the entire mission.I denna rapport utreds olika faser avrymdfarkosters rendezvous och docknings manövrar (RvD) samtundersöks en rad matematiska modeller för formationsflygning,nämligen de icke-linjära ekvationerna av relativ rörelse (NERM)och Hill-Clohessy-Wiltshire-ekvationer (HCW). Dessa dynamiskasystemmodeller beskriver formationsflygningen i både ostörd ochstörd omgivning. Vidare undersöks alternativa reglermetoder ochen filtreringsmetod såsom Linjär Kvadratisk Regulator (LQR),Linjär Kvadratisk Gaussisk (LQG) och utökad Kalman filtrering(EKF), för att reducera både tid och ΔV-kostnaden för hela rymduppdraget.Målen med dessa reglermetoder är att rymdfarkostensjälvständigt skall kunna utföra rendezvous och dockning