Design of accelerometer-based gyro-free navigation systems

Design and development of a broad class of inexpensive and compact INS that satisfy the main tactical requirements and specifications for a high dynamic environment is one of the highest priority directions in the field of design of navigation systems today. In this work we analyze the technique for designing a low-cost inertial navigation system (INS) using the accelerometer-based gyro-free approach (without any gyros).; The first aspect of this thesis is dedicated to the issues of building INS based on a distributed number of semiconductor accelerometers. It demonstrates the possibility to build accelerometer-based INS, discusses different accelerometer configuration variants, and presents the selection of the basic algorithm for calculating navigation parameters based on a distributed number of semiconductor accelerometers. Since one of the key characteristics of INS is the accuracy of calculating the main navigation parameters, the main components of the total error (systematic, noise, deterministic and non-linearity component, correspondingly) of calculation of navigation parameters using the accelerometer-based INS-algorithm are analyzed and assessed. On account of the obtained assessments, the increase of accuracy characteristics of this class of INS is considered by compensating the selected components of the total error. Thus, for each component of the total error, methods for reducing each of these components are proposed and examined. Taking into account the proposed approaches, the basic gyro-free INS algorithm is corrected and the total error is compared for compliance with the required accuracy level of modern navigation systems.; The second aspect focuses on issues of design of inexpensive navigation systems based on gyro-free INS by integrating INS with different outer information sensors, the most important of which is the GPS. It is shown that most optimal is the loosely-coupled integration of INS and GPS. At the chosen level of integration, it is considered to provide required accuracy characteristics of the navigation systems by using the following approaches: (a) attitude correction based on data from single- and multi-antenna GPS; (b) calibration of main INS parameters on the basis of data from GPS.; The third aspect is dedicated to experimental testing of the method for building gyro-free INS based navigation systems. Experimental testing was performed both at the programming level (by designing a virtual navigation system) and by building and testing experimental gyro-free INS prototypes (with different accelerometer configurations) and experimental prototypes of navigation systems realized on their basis.