A temperature compensation procedure for performance improvement of mass-produced MEMS gyroscopes based on direct parameter measurement.

摘要

Micro Electro Mechanical Systems gyroscopes are an enabling technology for many rate sensing applications that require low cost, mass and volume, including the class of spacecraft known as nano- or pico-satellites. The weakness of these types of gyroscopes to date has been limited performance capabilities, especially over a varying temperature range. This thesis presents a methodology for correcting the gyroscope output signal for variations over temperature based on measurements of specific internal gyro parameters, namely, drive and sense axis resonant frequency, and off-axis electrostatic forcing function.;The thesis presents the development of the full analytical equations of motion for a translating type MEMS gyro. The equations are simplified, numerically validated, and decomposed for gyro scale factor and bias expressions. Employing gyroscope parameters obtained from open literature sources as a function of temperature, a reference model of gyro scale factor and bias voltage as a function of temperature is developed.;The research also includes the empirical testing of two types of gyro, and ten total individual devices, including eight ADXRS150 automotive grade gyroscopes from Analog Devices. Device outputs at temperatures from -35°C to +75°C and across a range of rotation rate were measured and processed to calculate individual gyro scale factor and bias. Data from all gyros were analyzed using a principal component methodology to extract the dominant structures in the gyro behavior.;The final correction model is individualized for each gyro using ambient scale factor and bias data from that gyro. This model is used to compensate the individual raw gyro output taken during testing. Compositing the compensated output from all gyro provides a final rate estimate, which can be compared against the known testing inputs. The results demonstrate considerable improvement over manufacturer-provided scale factor and bias correction values. With the linkage between the performance over temperature and the internal parameters established, the gyro output may be compensated using the ambient data only without the need for prior calibration over the full temperature range.