Bias Drift in Consumer MEMS IMUs After 500 Thermal Cycles

Abstract

Datasheet bias-stability figures are quoted at room temperature on fresh parts, which is not how industrial equipment ages. We cycled forty six-axis IMUs from four manufacturers between minus 40 and plus 85 degrees Celsius for 500 cycles and re-characterised bias, scale factor and cross-axis sensitivity after each 100. Gyroscope bias degraded three to eleven times faster than the accelerometer channel, and the ranking between manufacturers changed after cycle 200, so a selection made on fresh-part data can be wrong within a year of field service.