An Introduction to Inertial Navigation From the Perspective of State Estimation
[Focus on Education]
Abstract
Inertial navigation determines the position and attitude of a vehicle using only accelerometers and rate gyros by integrating kinematic relations. Although modern navigation systems combine inertial navigation and the Global Positioning System (GPS) in the state estimation framework to improve the accuracy of position and attitude, inertial navigation remains essential for applications where either GPS is not accessible, such as under water and under ground, as well as where GPS can be jammed or spoofed. This article focuses on strapdown inertial navigation, where the sensors are hard-mounted to the vehicle, and thus rotate as the vehicle rotates. Within this context and under simplifying assumptions, this article investigates the relevance of state estimation techniques to inertial navigation in order to highlight the special challenges of this technology. The goal of this article is to provide a foundation for the basic concepts of inertial navigation in a form that is suitable for students and instructors in systems and control.