The Matlab/Simulink modeling and numerical simulation of an analogue capacitive micro-accelerometer. Part 1: Open loop

Abstract

The paper deal with an open loop analogue capacitive micro-accelerometer both from the point of view of mathematical modeling and through the achievement of certain numerical simulations which must confirm the mathematical models and in the same time help to establish the optimal architecture of the system. The capacitive transducer is one of differential type, with two fixed plates and one moving, which play the role of proof mass. Structure of the system contains the proper transducer and an electronic device (charge amplifier + phase-sensitive demodulator) to process the signal obtained from transducer. The accelerometer is mathematical modeled, the mathematical relation being expressed both in complex domain and in time. The mathematical modeling contains two distinct phases: the modeling of the proper accelerometer, which includes the proof mass and elastic element, and the modeling of the differential capacitive transducer for the proof mass displacements. Using these mathematical relations, the block schemas are realized for each block separately and for the full system. Starting from the numerical values of the accelerometer's parameters the numerical simulations with programming MATLAB/SIMULINK are made for each of the deduced block schemas.