In this example, Architect is employed to build a fully parametric, 3-D model of the gyroscope using plates, beams, electrodes and comb-finger elements from the Parameterized Electromechanical (PEM) parts library. Figure 2 shows the Architect schematic of the gyroscope.
Figure 2: Architect schematic of dual mass gyroscope
The perforated proof masses are modeled using components labeled "Rigid Plate". Similarly, the electrodes beneath the proof masses, which sense the proof mass motion, are modeled by components labeled "Electrode". The comb drives on either side of the two proof masses are modeled by "Straight Comb" components. The suspension elements for the proof masses are modeled using a combination of "Box-beam" and "Beam" components. Note that the Architect PEM parts library has a variety of beam-like suspensions structures, and a single "Box-Beam" element could therefore be used instead of using four rectangular "Straight" beams.
Figure 3a shows the simulated displacement of the proof mass in the x and z direction over a period of 50ms. Figure 3b shows the first 5ms only. The simulation starts from the steady state, computed with a small signal AC analysis. The excitation voltages applied to the comb-drives vibrates the proof masses in the x direction at a frequency of 16.987 KHz. Angular velocity applied about y direction, after 1ms, induces a Coriolis force that causes proof mass motion in the z direction. This motion is sensed by measuring the difference in capacitance, "Delta Cap" in the output plot, between the two sensing electrodes. After 25ms the rotation rate about the y axis returns to zero, and the output signal decreases to a steady-state value. In this simulation modal (Rayleigh) damping models are used for the beam and velocity damping values used for the plate. The fully coupled electro-mechanical 50ms simulation takes about 1 hr to run on a 2 GHz processor.
Nombre: Lenny D. Ramirez C.
Ver blogg: http://lennyramirez-crf3.blogspot.com/