OPTIMIZATION-BASED CALIBRATION OF MEMS NAVIGATION SYSTEM

Abstract

Technologies of autonomous wheeled robotic systems are becoming more and more in demand lately. A separate type of application of such technology is an autonomous unmanned ground vehicle. Unlike other types of transport (air, water), ground vehicles need to periodically operate in full autonomy - when external communication with the infrastructure and other agents of the transport network is inaccessible. In such circumstances, the issue of autonomous navigation comes out on top, and increased requirements are imposed on positioning accuracy, especially in an anthropogenic environment, for example, when driving in an urban environment, along narrow mountain roads, and tunnels. One of the components of autonomous navigation is often an inertial assembly consisting of several accelerometers, gyroscopes, and magnetometers. To obtain a high-precision navigation solution based on an inertial assembly, it is required to properly calibrate it. A separate issue is automation and its cost for further scaling necessary for mass production. The article presents the theory and methodology for automated calibration of an inertial navigation system based on MEMS sensors by solving an optimization problem. The proposed technique does not require high-precision calibration equipment. The aim of the presented work is to develop methods and theory for the calibration of inertial navigation units. The article formulates general measurement models of sensors included in the inertial assembly, and proposes methods for calibrating the parameters of accelerometers and gyroscopes fixed relative to each other. The method of automation of the calibration process is presented, which does not require high-precision equipment. The results of the application of the developed methods for the calibration of a real inertial assembly are presented. A stand for automated calibration is presented.