# Reset Control for Vibration Disturbance Rejection

## TL;DR

This paper explores advanced reset control strategies to improve vibration disturbance rejection in high-precision positioning systems, surpassing traditional PID limitations and addressing higher order harmonic effects.

## Contribution

It introduces and compares two reset control strategies, demonstrating that phase compensation outperforms band-pass phase lag reduction in vibration rejection.

## Key findings

- Phase compensation yields better vibration suppression.
- Reset control strategies outperform PID in disturbance rejection.
- Higher order harmonic effects can be mitigated with phase compensation.

## Abstract

The high tech industry which requires fast stable motion with nanometer precision continues to mainly use PID which is limited by fundamental linear control limitations. Floor vibrations as disturbance significantly affect performance and their rejection is particularly affected by these limitations. Reset control has provided a promising alternative to surpass these, while simultaneously allowing the use of industry standard loop-shaping during design. However, the reset action introduced higher order harmonics can induce unwanted dynamics and negatively influence performance. This paper investigates two reset control strategies namely (1) band-pass phase lag reduction and (2) phase compensation to reduce the negative effects of higher order harmonics. The strategies are tested on a precision positioning stage for vibration rejection and the results show that phase compensation provides better performance compared to other tested strategies.