SIMULATION OF TWO-AXIS MICROMECHANICAL GYROSCOPE-ACCELEROMETER

Abstract

Modeling a MEMS gyroscope accelerometer with the use of SIMULINK. For modeling,
a 2-axis accelerometer is used, developed as part of patent No. 2683810. When linear acceleration
occurs along an axis located in the plane of the semiconductor substrate, the inertial masses under
the action of inertia begin to move along the X axis in the plane of the semiconductor substrate,
due to the bending of elastic beams, which are rigidly connected at one end to the moving electrodes
of capacitive displacement transducers and the other with supports, respectively, of elastic
beams and "P"-shaped systems of elastic beams that are rigidly connected at one end to the movable
electrodes of the capacitive transducer of movements, and others - with supports. The voltage
difference generated by the capacitive displacement transducers formed by the fixed electrodes of
the capacitive displacement transducers and the movable electrodes of the capacitive displacement
transducers, respectively, due to a change in the gap between them, characterizes the magnitude of
the linear acceleration. When electrostatic drives with comb structures of alternating voltages,
1800 phase-shifted relative to each other, are applied to the stationary electrodes relative to the
movable electrodes, an electrostatic interaction occurs between them, which leads to the appearance
of out-of-phase oscillations of the moving electrodes in the plane of the semiconductor substrate
along the X axis due to bending elastic beams. Oscillations are transmitted by the stiffening
plates of the elastic suspension 86, 87, which causes out-of-phase oscillations of inertial masses in
the plane of the semiconductor substrate along the Y axis. The voltage difference generated by the
capacitive displacement transducers formed by the stationary electrodes of the capacitive displacement
transducers and the moving electrodes of the capacitive displacement transducers,
respectively, due to changes in the gap between them, characterizes the amount of displacement of
inertial masses under the influence of electrostatic human forces. Thus, in comparison with similar
devices, the proposed integrated micromechanical gyroscope-accelerometer reduces the substrate
area used for the placement of measuring elements of the angular velocity and linear acceleration,
since for measuring linear acceleration along the X and Y axes located mutually perpendicular to
the plane the substrate, and the Z axis directed perpendicular to the plane of the substrate, and the
angular velocity along the X axis located in the plane of the substrate, and the Z axis directed per
Pendicular to the plane of the substrate, only one integrated micromechanical sensor is used. For
mathematical modeling of such systems, it is customary to use HAMSTER, but in our work we
preferred SIMULINK to it. Simulink is a graphical simulation environment that allows using block
diagrams in the form of directed graphs to build dynamic models, including discrete, continuous
and hybrid, nonlinear and discontinuous systems. Simulink interactive environment allows you to
use ready-made library libraries for modeling electric power, mechanical and hydraulic systems,
as well as apply the developed model-oriented approach to the development of control systems,
digital communications and real-time devices. A relevant topic for research is the development of
the design of a MEMS accelerometer of high accuracy and noise immunity. Previously, mathematical
modeling of the movement of the micromechanical accelerometer was performed, but the output
result needed to be adjusted. This article demonstrates the adjustment of the mathematical
model by introducing the transfer function into it.