Improved Analysis for Intrinsic Properties of Triaxial Accelerometers to Reduce Calibration Uncertainty

Area of Science:

• Metrology
• Sensor Technology
• Instrumentation

Background:

• Accurate characterization of intrinsic properties is crucial for triaxial accelerometers.
• Existing measurement protocols may suffer from reproducibility issues, especially with consumer-grade components.
• Inter-laboratory comparisons highlight the need for robust and reliable calibration procedures.

Purpose of the Study:

• To present a modified measurement-analysis protocol for determining triaxial accelerometer intrinsic properties.
• To improve the reproducibility and accuracy of accelerometer calibration using MEMS devices.
• To investigate and identify sources of error in low-cost sensor-rotation table systems.

Main Methods:

• Utilized a protocol based on stepwise angular rotation in Earth's gravitational field.
• Employed MEMS triaxial accelerometers co-integrated in wireless microsensors.
• Conducted measurements on low-cost rotation tables across different laboratories and countries.
• Applied a previously described calibration-uncertainty metric for error analysis.

Main Results:

• Identified an unacceptably large error in one microsystem and low-cost rotation table combination.
• A simple modification to the analysis protocol significantly improved reproducibility for all tested systems.
• The modified protocol successfully validated with a high-performance accelerometer and expensive rotation table.
• Discovered unidentified defects in a microsystem and rotation table that caused significant errors with the old protocol.

Conclusions:

• The modified measurement-analysis protocol offers substantial improvements in the reproducibility of triaxial accelerometer characterization.
• The study highlights the importance of robust protocols in identifying and mitigating errors, especially in inter-laboratory comparisons.
• Unforeseen interactions between specific microsystems and rotation tables can lead to significant measurement errors, which the new protocol addresses.