Improved Strapdown Inertial Measurement Unit Calibration Procedures
Paul G. Savage, Strapdown Associates, Inc.
Location: Big Sur
This article describes an improved strapdown rotation test (SRT) for calibrating the compensation coefficients in a strapdown inertial measurement unit (IMU). The SRT consists of a set of IMU rotation sequences and processing routines that enable precision determination of IMU gyro/accelerometer misalignment, gyro/accelerometer scale factor, and accelerometer bias calibration errors, all without requiring precision rotation fixtures and IMU mounting setup. The improved SRT is compatible with a broad range of IMU types from aircraft accuracy inertial navigation systems to low cost micro-machined electronic module systems (MEMS). This article describes the general theory for the improved rotation tests, rotation test operations, data collection during test, post-test data processing, rotation test fixture requirements, and an analysis of SRT accuracy in determining IMU sensor errors.