Modeling and control of high density microcantilever systems

Multivariable Control;Structured Singular Value;H infinity Control;Distributed Controller;Microcantilever Dynamics;Finite Element Method

Mehmet, Berkem ; Voulgaris ; Petros G.

关键词: Multivariable Control;    Structured Singular Value;    H infinity Control;    Distributed Controller;    Microcantilever Dynamics;    Finite Element Method;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/30892/Mehmet_Berkem.pdf?sequence=1&isAllowed=y

美国|英语

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

【 摘 要 】

In this thesis we build on our earlier work on the control of high density, electrostatically actuated microcantilever arrays and present simple statefeedback controllers that can achieve reasonable performance. These controllers are localized, spatially distributed and yield tracking performances comparable to the performance of the more complex H infinity controller that takes disturbances and couplings into account, for reference frequencies as high as3000 rad/sec. These simpler structures come with the cost of worse performance at higher frequencies, relatively inferior robustness to phase shifts anda state availability requirement. Therefore, they can be effectively used for relatively lower bandwidth applications where the states are measurable. TheH infinity controller on the other hand operates quite well at higher, spatially varyingfrequencies despite having a limited output information. This can befirst demonstrated by developing a centralized controller for an array consistingof afinite number of cantilevers in order to have a benchmark. Using infinite abstraction methods however a localized and spatially distributed controller on par with the centralized control can be developed for the infinite cantilever array. Instead of regarding only the cantilever tip as if the cantilever was a pointmass the above results can be further verified by using a multimodal model of the cantilever system. The FEM model, as a typical multimodal method,views the cantilever as a more complex structure by cutting it into segments and taking the dynamics of each segment into calculation. Hence thismethodology yields a more accurate idea about the control of high density microcantilever systems.