  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.
