CALIBRATION OF AN INERTIAL MEASUREMENT UNIT AT CHANGING TEMPERATURE WITH SIMULTANEOUS ESTIMATION OF TEMPERATURE VARIATION COEFFICIENTS: A CASE STUDY ON BINS-RT

摘要

The work aims to present the results of the application of previously developed calibration technique that allows conducting calibration experiments at changing temperature with simultaneous estimation of temperature variation coefficients, to an inertial measurement unit of navigation grade, namely BINS-RT of JSC "Inertial Technologies of Technocomplex". The whole dataset obtained from the inertial sensors in calibration experiment is processed by a single estimation algorithm, i.e. Kalman filter, there is no requirement for some strict sequence of operations to be carried out during the calibration experiment, and the estimates for calibration accuracy are computed along with calibration parameters. The absence of stringent requirements on the experiment makes the method easy to transfer between different manufacturers, IMU designs and bench equipment configurations. The experiment must simply provide some static period for the conventional initial alignment of the IMU, followed by some rotation around each instrumental axis set nearly to the horizon without a special rotation profile, but with the magnitude of the angular rate close to a real IMU application. Simultaneous changing of temperature strong enough for the temperature variations of inertial sensor errors to manifest itself is also expected in the experiment, with no wait for the thermal equilibrium inside the IMU. A case study on BINS-RT shows that calibration experiments can go under the continuous changing of temperature inside the desired temperature range, to halve the time required for the whole calibration process compared to traditional temperature profile.