Method of Analyzing Dynamic Characteristics of MEMS Gyroscopes in Test Measurement Mode

The work deals with the problem of enhancing the measurement accuracy of MEMS gyroscopes integrated circuits by means of digital filters and built-in self test techniques. Digital filters help minimize noise whereas test measurement techniques are intended for reduction of the time instability of the measurement track. Test measurement techniques consist in formation of periodical displacements of a preset magnitude inside inertial parts of MEMS structures. The work is aimed at development of an investigation procedure into the dynamic characteristics in test modes of MEMS gyroscopes comprising IMU modules. The subject of study is L3G4200D, a gyroscope integrated into the IMU module GY-80. We have formulated basic requirements for investigation procedures needed for examining the parameters of gyroscopes and other components of IMUs. Upon the formulated requirements we have developed a hardware-software tool IMUTester. Experiments have shown that the transition time and pulse shape of test signals depend significantly on the measurement frequency and frequency band of the filter being used, and averaging of test measurement results should be done taking into account the measuring circuit relaxation.