Globally exponentially stable attitude and gyro bias estimation with application to GNSS/INS integration

This paper deals with the construction of nonlinear observers for navigation purposes. We first present a globally exponentially stable observer for attitude and gyro bias, based on gyro measurements and two or more pairs of vector measurements. We avoid the well-known topological obstructions to global stability by not confining the attitude estimate to SO(3), but rather estimating a full rotation matrix with nine degrees of freedom. We also show how the attitude can be estimated under a relaxed persistency-of-excitation condition, with a single vector measurement as a special case. Next, we use the attitude observer to construct a globally exponentially stable observer for gnss/ins integration, based on accelerometer, gyro, andmagnetometer measurements, as well as gnssmeasurements of position and (optionally) velocity. We verify the stability properties of the design using experimental data from a light fixed-wing aircraft. © 2014 Elsevier Ltd. All rights reserved.