Second Order Sliding Mode Control of a DC drive with uncertain parameters and load conditions

The Higher Order Sliding Mode (HOSM) is considered as a generalization of standard sliding modes that attenuates the chattering phenomenon. The main problem in implementation of the HOSM is the increasing information demand. In this work we implement two recent non-linear robust control schemes on a DC drive emphasizing their ability to tackle realistic situations in which the drive parameters are subject to variation, in addition to a time varying load constraint. Namely, we consider the Twisting algorithm which requires the first time derivative of the sliding variable to be known. In addition to that, we use the Super Twisting algorithm, which unlike other HOSM algorithms merely requires measurements of the sliding variable. Simulation results are given to support the approach.