Calibration of the DQI (Digital Quartz Inertial Measurements Unit)

The DQI is a low-cost tactical grade Inertial Measurement Unit based on quartz gyro and accelerometer technology. The DQI is in pilot production at Rockwell's El Paso production facility. Achieving performance over the military temperature range of -54C to +71C requires accurate calibration of temperature dependent bias, scale factor and input axis models. Cost considerations require this to be done in the minimum amount of time. A calibration technique will be described, which estimates the instrument model coefficients from data obtained while simultaneously applying rate table motions and slewing the temperature through the full range. Estimates of the calibration accuracy will be shown, along with data showing representative calibration residuals and IMU performance results. The calibration is currently implemented on the DQI production test equipment at Rockwell El Paso.