A Nonlinear Navigation Observer Using IMU and Generic Position Information

TL;DR

This paper introduces a nonlinear observer for full state estimation of vehicles in 3D space using IMU data and various position sensors, demonstrating stability and effectiveness through simulations and experiments.

Contribution

A novel semi-globally exponentially stable nonlinear observer that estimates vehicle states and biases using diverse position measurements.

Findings

Observer achieves accurate state estimation in simulations.

Experimental results confirm robustness and stability.

Effective with various sensor configurations.

Abstract

This paper deals with the problem of full state estimation for vehicles navigating in a three dimensional space. We assume that the vehicle is equipped with an Inertial Measurement Unit (IMU) providing body-frame measurements of the angular velocity, the specific force, and the Earth's magnetic field. Moreover, we consider available sensors that provide partial or full information about the position of the vehicle. Examples of such sensors are those which provide full position measurements (e.g., GPS), range measurements (e.g., Ultra-Wide Band (UWB) sensors), inertial-frame bearing measurements (e.g., motion capture cameras), or altitude measurements (altimeter). We propose a generic semi-globally exponentially stable nonlinear observer that estimates the position, linear velocity, linear acceleration, and attitude of the vehicle, as well as the gyro bias. We also provide a detailed observability analysis for different types of measurements. Simulation and experimental results are provided to demonstrate the effectiveness of the proposed estimation scheme.