Seoul, Korea

range of the gyroscope beyond the open-loop mode of operation, cation steps include bulk micromachining, wafer-to-wafer bond-ing, surface micromachining, and high aspect ratio micromachining. Each of these fabrication steps involves multiple process steps such as deposition, etching and patterning of mate-rials. In practice, small imperfections always occur during the fabrication process. Depending on the technology used, different numbers of steps may be involved in the fabrication of a MEMS gyroscope, and different fabrication tolerances can be achieved. Generally, every fabrication step contributes to imperfections in the gyroscope @2#. Fabrication imperfections that produce asym-metric structures, misalignment of actuation mechanism, and de-viations of the center of mass from the geometric center result in they still are sensitive to parameter variations such as damping, spring constant, and quadrature error variations, produce ZRO, and require tedious calibrations. The objective of this paper is to develop a new gyroscope op-eration mode and to formulate a corresponding control algorithm that is well suited for the on-line compensation of imperfections, and to operate in varying environments that affect the behavior of a MEMS gyroscope. The adaptive controlled gyroscope is self-calibrating, compensates for friction forces and fabrication imper-fections, which normally cause quadrature errors, and produces an unbiased angular velocity measurement that has no ZRO. In the next section, the dynamics of MEMS gyroscopes is de-veloped and analyzed by accounting for the effect of fabrication imperfections. The conventional operation modes such as open-loop and closed-loop modes is reviewed in Sec. III. An adaptive control approach for measuring angular rate is proposed as a new operation mode, and the convergence and resolution analysis o