Control Synthesis for an Underactuated Cable Suspended System Using Dynamic Decoupling
This work addresses a challenging control problem for a novel underactuated system, but the results are incremental as they extend existing decoupling and backstepping methods to a specific configuration.
The paper presents a control strategy for stabilizing an underactuated cable-suspended plate with a freely moving mass, using dynamic decoupling and partial feedback linearization. The approach achieves horizontal stabilization at a desired height with bounded velocities.
This article studies the dynamics and control of a novel underactuated system, wherein a plate suspended by cables and with a freely moving mass on top, whose other ends are attached to three quadrotors, is sought to be horizontally stabilized at a certain height, with the ball positioned at the center of mass of the plate. The freely moving mass introduces a 2-degree of underactuation into the system. The design proceeds through a decoupling of the quadrotors and the plate dynamics. Through a partial feedback linearization approach, the attitude of the plate and the translational height of the plate is initially controlled, while maintaining a bounded velocity along the $y$ and $x$ directions. These inputs are then synthesized through the quadrotors with a backstepping and timescale separation argument based on Tikhonov's theorem.