On motor velocity control by using only position measurements: Two case studies

Velocity control by using only position measurements consists of finding a control algorithm that reconstructs the motor shaft velocity from the position measurements of the shaft encoder. The aim of this paper is to present the problem of velocity control in a linear description of a motor as paradigm in the application of the basic concepts of an introductory course in control systems; namely, transfer function, characteristic equation, stability, and Routh-Hurwitz criterion. Experiments have been carried out on a motor illustrating the performance of the velocity control algorithms discussed in this paper.