Autonomous-Calibration of Micro Inertial Sensors by On-chip Physical Stimulus and Position Sensing

Achieving long-term scale factor and bias stability in micro inertial sensors is critical to unlock their potential in high precision navigation applications. Recently, electronic self-calibration methods are reported based on creating a virtual Coriolis force to mimic an external reference rate. As an alternative approach, this project aims to integrate a micro motion stage into the inertial sensor package, and provide controlled on-chip physical stimulus for in situ measurement and recalibration of signal drifts. In addition, the introduced microsystem can provide integrated sensing of applied stimulus, compensation of undesired vibrations, and electrostatic lock-down for shock protection. The platform can excite a dual-axis MEMS gyroscope up to 300°/sec rate, while providing a sensing signal to determine the applied rate with a precision of ~1°/sec. The estimated scale factor of the gyroscope has only 0.8% deviation from rate-table measurements. This demonstration is the first step to achieve the ambitious goal of on-chip self-calibration of a multi-axis IMU with 1 ppm estimation error in a tiny system of 30 mm3.

Related Publications:

E. E. Aktakka, J.-K. Woo, D. Egert, R. Gordenker, K. Najafi, “A micro actuation and sensing platform with active lockdown for in situ calibration of scale factor drift in dual axis gyroscopes,” IEEE/ASME Transactions on Mechatronics, vol. 20, pp. 934-943, 2015. [PDF]

E. E. Aktakka, J.-K. Woo, D. Egert, R. Gordenker, K. Najafi, “A micro vibratory stage for on chip physical stimulation and calibration of MEMS gyroscopes,” Proc. IEEE Int. Symposium on Inertial Sensors and Systems (ISISS), pp. 151-152, Laguna Beach, CA, Feb. 2014. [PDF]

B. Edamana, Y.Chen, D. Slavin, E. E. Aktakka, K. R. Oldham, “Control and estimation with threshold sensing for gyroscope calibration using a piezoelectric microstage,” IEEE Trans. Control Systems Technology, vol. 23, pp. 1943-1951, 2015. [PDF]

B. Edamana, D. Slavin, E. E. Aktakka, K. R. Oldham, “Control and estimation with threshold sensing for inertial measurement unit calibration using a piezoelectric microstage,” American Control Conference (ACC), pp. 3686-3691, Portland, OR, June 2014. [PDF]