Industry Shift in Adoption
Since beginning my work as an engineer 5 years ago, I've observed the condition monitoring sector progressively adopt MEMS to replace their piezoelectric IMUs, and the widespread implementation in embedded devices as non-primary sensors. Driven by demand in consumer, automotive and UAV applications, manufacturers have iterated to produce highly-capable low-cost sensors; noise floors have decreased, compute for motion-driven power modes are integrated, and on-board temperature data enables compensation for thermal drift - a persistent source of error in MEMS. The resulting class of sensor is accurate enough for serious embedded work, packaged to fit almost anywhere, and cheap enough to fit on even the strictest BOMs.
Pushing the Envelope
Integrating a MEMS IMU is not simply a matter of reading registers. I wish I knew that at 18, spending months trying to read 10Hz at low G's. FSR switching is an effective technique, where runtime FSR configuration on modern IMUs can be leveraged to accommodate high-G events without sacrificing fidelity during periods of relative stability. Temperature compensation is often the firmware's responsibility, where utilising the temperature reading can meaningfully counteract thermal drift. Even without per-device calibration, a simple linear offset significantly improves consistency across operating temperatures.
Beyond the Primary Sensor
The more interesting shift I've observed is how lowered cost and small packaging have changed where IMUs appear in design. Due to low impact on the BOM and device footprint, designers can now include IMUs even when motion data is not a primary measurement of the device. GPS dead-reckoning is a clear example, where the IMU bridges position outages and improves low-speed and orientation accuracy when GNSS degrades. But more subtle examples exist, where portable devices use IMUs to measure inactivity for power-state management, or to determine other behaviours based on orientation, such as screen dimming when holding your phone to your ear. The IMU contributes contextual information which makes the rest of the system more intelligent, at a cost that no longer warrants rigorous justification.