Sliding Mode Proximate Time-Optimal Servomechanism

Author:	Lee Seung-Hi, Samsung Adv. Inst. of Tech., Korea, Republic of
Topic:	2.1 Control Design
Session:	Nonlinear Control Systems II
Keywords:	Servomechanism, Variable structure systems, Discrete time systems, Digital control, Disk drives

Abstract

A discrete-time sliding mode proximate time-optimal servomechanism is developed using nonlinear sliding mode tangent to a reference velocity profile. Instead of a strong nonlinear function causing control chattering in discrete-time, a linear control is designed around the sliding surface. The resulting servomechanism delivers a bounded motion about the sliding surface even in the presence of plant uncertainties. Application results demonstrate accurate reference velocity tracking and uniformly excellent seek performance regardless of seek length via enforced sliding mode.