Award Date


Degree Type


Degree Name

Master of Science (MS)


Electrical and Computer Engineering

First Committee Member

Sahjendra N. Singh

Number of Pages



This thesis presents control systems design for control of rigid and flexible spacecraft in the presence of parameter uncertainty and disturbance inputs. Two kinds of control systems are designed for the control of rigid spacecraft. For the design of the first controller, Rodrigues parameters and modified Rodrigues parameters are used to describe the orientation of spacecraft. A dynamic decoupling attitude control law is derived for the tracking of reference attitude trajectories. The singular perturbation theory is used for the stability analysis of the closed-loop system. For the synthesis of the control law, only the attitude error is required. The second control law for rigid spacecraft is derived choosing Euler angles as output variables, and using a similar design procedure as used for the first controller. Finally, based on the variable structure model reference adaptive control (VS-MRAC) theory, a new control system for the control of an orbiting flexible spacecraft is designed. For the derivation of control law, it is assumed that the parameters and the structure of the nonlinear functions in the model are unknown. It is shown that in the closed-loop system including the VS-MRAC system designed using bounds on uncertain functions, the pitch angle tracks given reference trajectory and the vibration is suppressed.


Adaptive Control; Dynamic; Feedback; Flexible; Rigid; Robust; Spacecraft; Structure; Variable

Controlled Subject

Electrical engineering; Aerospace engineering

File Format


File Size

2058.24 KB

Degree Grantor

University of Nevada, Las Vegas




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