PMI based nonlinear H∞ estimation of unknown sensor error for INS/GPS integrated system

This paper deals with the problem of robust estimation for time-varying sensor errors of inertial navigation system (INS) and global positioning system integration. A nonlinear strapdown INS error model is established to describe the behavior of the the integrated system. Under assumptions of time-varying bias and noise being L2norm bounded, a robust H∞nonlinear estimator by Krein space theory is proposed and, based on this, a proportional and multi-integral H∞estimator is developed for simultaneous estimation of the navigation states and sensor errors. Finally, a flight experiment is implemented to show the effectiveness of the proposed method.