METHOD OF DETERMINING ERRORS OF AN INERTIAL UNIT OF SENSITIVE ELEMENTS ON A BIAXIAL ROTARY TABLE Russian patent published in 2020 - IPC G01C25/00 

FIELD: instrument engineering.

SUBSTANCE: invention relates to navigation instrument-making and is intended for evaluation of main characteristics of the strap down inertial navigation system inertial measurement unit containing at least three single-type uniaxial accelerometers with non-coplanar measuring axes and three single-type uniaxial gyroscopic meters with noncoplanar measuring axes. Method of estimating errors of main characteristics of an inertial measurement unit on a biaxial rotary table consists in the fact that at the first stage, a multi-position scheme of turns of the seating surface of a two-axis rotary table with an inertial measurement unit rigidly installed on it is implemented. Rotation scheme includes nine stationary positions set by a given sequence of eight single turns around one of two (outer and inner) axes of rotation of the rotary table with another rotation axis fixed. At the second stage, errors in the main characteristics of the accelerometers are evaluated using a scalar method by processing the recorded accelerometric measurement information in stationary positions using the reference value of the module of the free fall acceleration vector at the place of testing. Estimation results are used to update accelerometer measurement information. At the third stage, for each group of paired turns, the direction of the rotation axis and the turns in the associated coordinate system are determined using the accelerated metric information refined at the second step in those stationary positions, which are realized by the considered group of paired turns, including stationary positions at the beginning and end of the given group. Then, values of rotations determined for each group of paired turns are specified by taking into account calculated components due to rotation of the Earth. At the fourth stage, errors of the main characteristics of the gyroscopic meters are evaluated by combined processing of the registered gyroscopic measurement information in the stationary positions of the inertial measurement unit using reference values of the modulus of the angular velocity of rotation of the Earth and the geographical latitude of the test location and on sections of paired turns using the directions of the rotation axis and the values of turns determined at the third stage for each group of paired turns.

EFFECT: high accuracy of estimating main characteristics of an inertial measurement unit by associating the angular position of the sensitivity axes of accelerometers and gyroscopic meters to a single design orthogonal coordinate system associated with a unit of inertial meters.

1 cl, 1 dwg, 1 tbl