Abstract:

The observation equations of the current extended Kalman filter (EKF) describe the linear relationship between state vector and bearings measurement, which only exerts weak constraint on state vectors without the support of relative range measurement. To solve the problem, the observation equations are rebuilt by the improved Laplace method in a creative way, which considers both the geometry and orbit restrictions. Simulation results show that the convergent performance is dramatically improved by this method compared with the current EKF with the same measurement precision.