Maximum-Tilt Control of Electromagnetic Micromirrors with Embedded Piezoresistive Sensor

This study introduces a novel closed-loop control system specifically engineered for scanning micromirrors. This system strategically incorporates a piezoresistive sensor, an inclusion aimed at substantially reducing the physical space typically demanded by an optical position sensor. In our approach, we endeavor to transcend the constraints presented by traditional driving methods, primarily by integrating a feedback controller tasked with the regulation of amplitude-modulated tilt angles, thereby enabling effective control over scan patterns. An essential feature of this system lies in its capacity to track the resonant frequency automfatically, thereby achieving the maximum tilt angle. This tracking is facilitated by continual monitoring of the phase difference existing between the input voltage and the tilt angle. The performance and efficacy of this proposed system have been rigorously examined through experiments involving a 6.25-kHz electromagnetic micromirror. The results obtained offer robust validation for the system, revealing its capability to facilitate precise control over an array of scan patterns.