Implementation, calibration and testing of GFINS models based on six-accelerometer cube

Gyro-Free Inertial Navigation Systems (GFINS) models have been developed in the past to remove gyroscopes and rely only on accelerometers in computing the motions of objects. However, most of the research done in this area essentially focused on analyzing the models using simulated data. The present work is concerned with the implementation and testing of a GFINS hardware prototype based on the conventional six-accelerometer cubic arrangement. The system has been calibrated in three stages; sensors calibration, compensation for sensors misalignments and overall system calibration. The system was used to validate different types of models which describe the outputs of the accelerometers in the GFINS cube. The performance of the GFINS prototype has been studied by testing the system both under rotational and linear motions. Results obtained from the sensors of the prototype have convincingly demonstrate that gravity factor should be included while modeling the outputs of the accelerometers. Testing results of the prototype under rotational and linear motions show that the system can accurately measure accelerations. However, when displacements are computed by integrating the accelerations, any initial small error gets accumulated over time.