On one approach to the use of redundant information in attitude determination from two vector observations

Abstract

The paper summarizes the results of developing an approach to the use of informational redundancy in a widely met problem of attitude determination from two vector observations. This approach is based on using the relationship that should be met by all 12 vectors’ components. In the known publications this scalar relation was used for the sensor outputs checking only. Meanwhile it could be used for either (1) sensor errors calibration or (2) reconstruction of one component of one vector (in the case of incomplete composition of sensors or for the period when the input of one sensor is distorted, say, by a vehicle maneuver) as well. In the paper the usefulness of such approach for the sensor calibration purposes is illustrated as applied to the gimbaled ESG-based (ESG — electrostatically suspended gyro) INS (inertial navigation system). It is shown that with this additional relation in hand it became possible to determine all reasonable gyro drift model coefficients as well as the mechanical misalignments. To demonstrate the advantages of using this approach for the reconstruction of one vector component the results of treating two attitude determination problems are presented. One refers to airplane attitude determination by means of accelerometers and magnetometers and the other to borehole attitude determination using gyro inclinometer which has no sensor measuring the axial angular rate component.