Filtered Split-Path Nonlinear Integrator: A Hybrid Controller for Transient Performance Improvement

Abstract

The filtered split-path nonlinear integrator (F-SPANI) is a generic nonlinear controller designed to improve the transient performance of linear (motion) systems in terms of overshoot. The main idea underlying F-SPANI is that the amplitude and phase of an integrator can be tuned using independent filters, resulting in more efficient use of the buffer of the integrator. In this article, a general description of F-SPANI is presented. In addition, a stability analysis result is presented that provides sufficient conditions in the form of linear matrix inequalities (LMIs) for closed-loop stability analysis on the basis of construction of a common quadratic Lyapunov function (CQLF). The ease of the design, implementation, and the potential of the proposed controller are illustrated both in simulations and in experiments on an industrial pick-and-place machine.

A Small-Gain Approach to Incremental Input-to-State Stability Analysis of Hybrid Integrator-Gain Systems

“…T HE IDEA of developing nonlinear control strategies that can overcome some of the fundamental limitations of linear time-invariant (LTI) control for LTI systems already dates back to the 1950's when J.C. Clegg introduced its celebrated integrator with resetting mechanism [1]. Since its introduction, the Clegg integrator has inspired many alternative strategies including generalized reset elements [2], [3], [4], [5], split-path integrators [7], [8], switching controllers [6], and hybrid integrator-gain systems (HIGS) [9], [10], [11]. HIGS recently gained much attention due to its ability to overcome fundamental limitations of linear feedback control [10] and various engineering successes were reported in industrial applications such as wafer scanners [14] and atomic force microscopes [11].…”