Date of Award

Summer 6-24-2024

Access Type

Thesis - Open Access

Degree Name

Master of Science in Aerospace Engineering

Department

Aerospace Engineering

Committee Chair

Dongeun Seo

First Committee Member

Dongeun Seo

Second Committee Member

Sergey V. Drakunov

Third Committee Member

Richard Prazenica

College Dean

James W. Gregory

Abstract

Sliding Mode Control is a powerful nonlinear control methodology that can handle parametric uncertainties and external disturbances. However, the discontinuous and high-frequency switching nature of the control law introduces the chattering phenomenon, which leads to potential actuator degradation, alterations to the desired response characteristics and, sometimes, instability during control implementation. The main objective of this thesis is to study Sliding Mode Control with chattering reduction. The Sliding Mode Control law involves an equivalent control component and a discontinuous control component. A disturbance estimation is performed based on Lyapunov analysis and adaptive control techniques and then included in the control law along with the equivalent control term. As a result, the Sliding Mode Control gain can be set to a smaller constant value so as to reduce chattering. The modified controller is tested on a simulation model of the rotational dynamics of a small satellite experiencing constant disturbances using quaternion kinematics and Euler’s equations of rotational motion. Furthermore, a Conventional Sliding Mode Controller and an Adaptive Controller are also designed using Lyapunov analysis. The error quaternion and angular velocities are driven towards the identity quaternion and zero respectively using all three control methods and a comparative analysis of the results obtained is conducted.

Download

Share

COinS