On the use of impact-induced nonlinearities in limit switch design

limit switch;dynamical systems;bifurcation;electromechanical coupling;microelectromechanical systems (MEMS)

Wilcox, Bryan R.

关键词: limit switch;    dynamical systems;    bifurcation;    electromechanical coupling;    microelectromechanical systems (MEMS);   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/24228/Wilcox_Bryan.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This dissertation explores the use of grazing bifurcations inimpacting mechanical systems as a useful means of creatingfast-acting limit switches. Using analytical, numerical, andexperimental techniques, the transient and asymptotic responses ofseveral example vibro-impacting systems undergoing the onset oflow-relative-velocity contact are investigated. It is argued thatthe rapid transients and distinct asymptotic dynamics distinguishingpre- and post-grazing attractors provides an advantageous mechanismon which to base a limit switch design. Further, it is shown thatthese changes, which originate due to the mechanical interactions,can be detected in coupled electrical systems through bothelectromagnetic and electrostatic coupling mechanisms. Thedissertation concludes with a realization in a prototypemicroelectromechanical systems (MEMS) design in which a grazingbifurcation may trigger snap-through in a parallel plate capacitiveactuator. The results of these studies indicate that a switch basedon the proposed nonsmooth fold scenario would outperform one thatrelies on a smooth bifurcation, such as the cyclic-fold bifurcation,in terms of switching speed and sensitivity.