Slow-Axis Control for an Electrostatic Scanning Micromirror
| Autor: | Lin, Heng, 林 恆 |
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| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 This thesis proposes to design a slow-axis trajectory control system for an capacitively transduced scanning micromirror to achieve robust performance. To design a controller, we first establish the mathematical model of the plant that includes the behavior of capacitances versus rotation angles simulated by Coventorware. The complete plant model is obtained following polynomial fitting in Matlab and combined with the second-order mechanical system. Then we linearize the plant model and build the Bode diagram, as a design reference of the controller. Finally, we perform time-domain analysis of the control system by using Simulink to confirm system stability, followed by implementation of the control circuits. In the measurement, we successfully use the same electrode for capacitive driving and sensing. The controller’s frequency response is consistent with the simulation. Although we fail to get the desired results during closed-loop control, we still try to find and solve the problem. We think that the nonlinearity of electrostatic driving negatively impacts the feedback control system. Non-idealities, such as noise and DC offset, are likely to be the reasons to cause instability. We try to add additional DC offset, as a temporary command, before applying the real command. The system is still not stable. The effect of uncertainties is beyond expectation. At the end, we lower the system’s gain and successfully close the loop. The result confirms the reliability of our simulation and the feasibility of the system. Keywords：micromirror, electrostatic, trajectory control |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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