| Author | Singanamala, Dinesh |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Mechatronics |
| Publisher | Asian Institute of Technology |
| Abstract | This thesis work studies the influence of space debris that causes vibration to the tether that effects on an orbital position of a microsatellite with a single elastic tether system at Low Earth Orbit using Lyapunov based MIMO-MRAC algorithm. Considering Two cube microsatellites together with a cable typed tether joining between them form a Tethered satellite system (TSS). Due to the presence of disturbances to tether, it causes elastic tether vibrations which perturbs the orbital position of microsatellite. An analysis on the
microsatellite dynamics using classical Keplerian orbital elements (CKOE) given by Gauss variational Equations (GVE) is made and compared with modified Equinoctial Orbital Elements (EOE) using Lagrange Perturbation equations (LPE) to verify the microsatellite dynamics. For this case, non-spherical harmonic gravitational perturbation term given by the
Earth’s gravitational field is applied as a disturbance. To validate the tether dynamics, an analysis on suspended cable dynamics is made by the combination of Finite Element Method (FEM) to obtain first-order discretized ordinary differential equations (ODE) and 14th order
Runge-Kutta method (RK14) is used. For both validation models, Linear and Non-Linear control of the proposed algorithm are applied, and the results are almost identical. A Linear analysis on the orbit deviation of TSS due to the influence of elastic tether vibrations is been made using GVEs and RK 14. A Linear control of proposed algorithm is established to maintain orbital position of TSS and to control the vibration of the tether simultaneously. A simulation result shows the good orbital tracking convergence of the TSS in which its perturbed orbit follows a predicted reference orbit precisely by reducing the disturbances. |
| Keyword | Classical Keplerian Orbital elements; Equinoctial Orbital Elements; Gauss
variational Equations; Lagrange Perturbation equations; Tethered microsatellite
system; FEM; MIMO; MRAC; 14th order explicit Runge-Kutta method; Direction
Cosine Matrices. |
| Year | 2019 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Industrial Systems Engineering (DISE) |
| Academic Program/FoS | Industrial Systems Engineering (ISE) |
| Chairperson(s) | Song Weon Keun; |
| Examination Committee(s) | Abeykoon, A. M. Harsha S. ;Huynh Trung Luong; |
| Scholarship Donor(s) | AIT Fellowship; |