Abstract:
In the past decade, there has been increasing interest in underactuated mechanical
systems. These systems have many practical and diverse applications in modern
science and engineering. The broad application areas of underactuated systems
include robotics, industry, and aerospace systems. This thesis presents a simple
stabilizing control algorithm for a class of underactuated mechanical systems with
n degrees of freedom (n DOF). The methodology is based on adaptive sliding mode
control. Firstly, the system is transformed into a special structure through input
transformation, containing nominal part plus some unknown term. The unknown
term is computed adaptively. Later the transformed system is stabilized using
adaptive sliding mode control. The adapted laws are derived in such a way that the
time derivative of a Lyapunov function becomes strictly negative. The effectiveness
of the proposed method is applied to different underactuated systems with 2 DOF
and 3DOF: Inverted pendulum, TORA system, The Pendubot and Acrobot, Ball
and Beam system and double inverted pendulum. Computer simulation results
show the effectiveness of the proposed control algorithm on these systems.
