Calibration of MEMS Accelerometers for Vibration Sensing in CubeSat Laser Communication Terminals

Kurzfassung

Recent trends in the development of modular and compact satellite systems such as laser communication terminals include the use of commercial off-the-shelf components such as MEMS accelerometers for micro-vibration sensing due to their advantages of low cost, compactness, and light weight. This work investigates MEMS accelerometers by characterizing this sensor and comparing it with reference data to derive a system characteristic function that can be used for sensor calibration to improve sensing accuracy. High-end vibration equipment and software are used to obtain back-to-back MEMS and reference vibration data from a controlled shaker platform excitation. Excitation methods investigated include stepped sinusoidal, chirp sinusoidal, and random oscillations. Time and frequency domain processing allows direct comparison and analysis of the acceleration frequency response of the MEMS accelerometer. The test setup demonstrated the ability to generate qualitative data with satisfactory MEMS accelerometer accuracy even prior to calibration. The calibrated signal improves the correlation coefficient deviation to the reference data compared to the uncalibrated signal from about 17 % to 1 % across 98 % of the selected frequency bandwidth. The data obtained in this study supports the introduction of this type of sensor for vibration sensing in optical communication terminals, showing that it fits the broader concept of compact and modular systems and still provides sensor quality with or without calibration.