Development and calibration of low cost MEMS IMU for UAV applications

In this paper, an affordable and reliable low-cost inertial measurement unit (IMU) is designed using commercial off-the-shelf (COTS) components. Micro electro-mechanical systems (MEMS) accelerometers and rate-gyros are used, and a methodology for calibrating the resulting IMU is developed when the precise orientation of the IMU is unknown. The proposed methodology requires no precise mechanical platform for the accelerometer while as simple rotating table is utilized for the rate-gyros calibration. The proposed calibration methods utilize the fact that ideally the norm of the measured output of the accelerometer and gyro cluster is equal to the magnitude of applied force and rotational velocity, respectively. Least squares method is used to evaluate the accelerometers and gyros model coefficients.