Stable and Robust Discrete-time Tracking Control of Unmanned Vehicles
Using a Finite-Time Stable Disturbance Observer
Abstract
This work provides an asymptotically stable and robust tracking control
scheme using a finite-time stable disturbance observer in the feedback
loop, for an unmanned vehicle modeled as a rigid body. The dynamics of
the system is discretized using a Lie group variational integrator in
the form of a “gray box” dynamics model that also accounts for unknown
additive disturbance force and torque. These disturbance terms are
estimated using the finite-time stable disturbance observer in real-time
and then compensated by the control scheme. The stability analysis for
translational and rotational motions is carried out separately. It is
shown that the discrete-time control laws achieve asymptotically stable
tracking of the reference position and attitude trajectories.