Information fusion robust guaranteed cost Kalman estimators with uncertain noise variances and missing measurements

For multisensor systems with uncertain noise variances and missing measurements, it can be converted into one only with uncertain noise variances by introducing fictitious measurement white noises. According to the minimax robust estimation principle and parameterisation representation of perturbances of uncertain noise variances, based on the worst-case system with conservative upper bounds of uncertain noise variances, the two classes of guaranteed cost robust weighted fusion Kalman estimators with matrix weights, diagonal matrix weights, scalar weights, and covariance intersection fusion matrix weights are presented. One class is the construction of a maximal perturbance region of uncertain noise variances, in which for all admissible perturbances, the accuracy deviations are guaranteed to remain within the prescribed range. The other class is the finding of minimal upper bound and maximal lower bound of accuracy deviations over the given perturbance region of uncertain noise variances. Two problems can be converted into the optimisation problems with constraints. Their optimal analytical solutions can simply be found respectively by the Lagrange multiplier method and the linear programme method. The guaranteed cost robustness is proved by the Lyapunov equation approach. A simulation example applied to the mass-spring system is provided to demonstrate the correctness and effectiveness of the proposed results.