Robust Second-Order Sliding Mode Control Law Design and Realization for Nonlinear Mechanical Systems
Published in National Cheng Kung University, Department of Aeronautics and Astronautics, Master Thesis, 2021
The master thesis focuses on the robust control law design for the nonlinear mechanical systems. Including the motion control of the DC motor systems, single-axis reaction wheel positioning, and spacecraft attitude control via multiple reaction wheels.
DC Motor Positioning Control
The following videos demo the positioning control of a DC motor using the proportional-integral-derivative (PID) control and the super-twisting control (STC). It can be found that both controllers can track the desired trajectory well.
PID Controller
STC Controller
DC Motor Positioning Control with External Disturbance Input
However, when the system is subjected to unknown external disturbances, the PID controller cannot perfectly track the desired command, whereas the STC can. In the following demo, the exogenous PWM signal is imposed as the disturbance source. The experiment results reveal that the STC has superior robust performance compared to PID.
PID Controller
STC Controller
Single-Axis Reaction Wheel Positioning Control
This video demonstrates the positioning control of the single-axis reaction wheel platform via the super-twisting controller.