High Bandwidth Stable Motion Control of Fourth and Higher Order Systems

PID is the most commonly used technique in industrial motion control. It consists of three components - lead, lag and low pass filter (LPF). PID, being a linear control method is inherently bounded by waterbed effect due to which there exists a trade-off between precision, tracking, and stability. Reset control is a nonlinear technique which shows promise in overcoming certain limitations. Despite the promise shown, the use of reset elements other than integrator within the framework of PID for improved performance has not been well investigated. This thesis work focuses on implementing reset in lead part and in LPF in order to reduce the severity of the waterbed effect in PID. Three controllers have been developed that provide improvements in bandwidth, precision, and tracking. The controllers were implemented in a Lorentz-actuated nanometer precision stage and the performance has been validated in both time and frequency domain