Lyapunov-based estimation and control of velocity and load in rotating machines via Luenberger globally-convergent observer

This paper presents the design of a Lyapunov-based Luenberger-like observer to simultaneously estimate the non-available angular velocity and the unknown constant load torque of rotating machines. This proposal assumes that the only measurable output is the rotor angle, which is considered to be defined in the circle, its natural topology. This provides nonlinear dynamics where the Lyapunov-based Luenberger-like observer globally converges. Moreover, a trajectory tracking controller for the motor angular velocity is also designed by feeding back the observer estimations. Convergence analysis of the observer-controller system is performed using Lyapunov-like theory. The effectiveness and performance of the system are validated through tests performed on an experimental platform.