Angular velocity nonlinear observer from vector measurements

TL;DR

This paper introduces a nonlinear observer that estimates a rigid body's angular velocity directly from vector measurements without relying on attitude data or rate gyros, ensuring exponential convergence.

Contribution

It presents a novel high-gain nonlinear observer that directly filters vector measurements to estimate angular velocity, avoiding the use of attitude or gyroscope data.

Findings

The observer guarantees local uniform exponential convergence.

Simulation results validate the effectiveness of the proposed method.

Abstract

The paper proposes a technique to estimate the angular velocity of a rigid body from vector measurements. Compared to the approaches presented in the literature, it does not use attitude information nor rate gyros as inputs. Instead, vector measurements are directly filtered through a nonlinear observer estimating the angular velocity. Convergence is established using a detailed analysis of the linear-time varying dynamics appearing in the estimation error equation. This equation stems from the classic Euler equations and measurement equations. A high gain design allows to establish local uniform exponential convergence. Simulation results are provided to illustrate the method.