Abstract: To address the problem that the initial directional error is large with the short self aiming time under the condition of mobile launch of hypersonic vehicle, an on line identification method of initial directional error based on terrain matching is proposed. Two terrain matching results of the adjacent two terrain matching areas are fused and an on line identification model of initial directional error is established based on the analysis of the navigation error model of inertial system with initial alignment and attitude control. The adaptability of the identification model is discussed from two aspects of the instrument errors of the inertial system and the terrain matching error. The simulation environment is established with the CAV H hypersonic vehicle as the research object, and the identification effect of the initial directional error is tested by the Monte Carlo method. The simulation results show that the average value of the initial directional residual deviation is 8.42″ and the maximum is 34.65″ under the condition that the terrain matching positioning error is 173.88 m (3σ), which can effectively improve the navigation accuracy of inertial system. This model is helpful to shorten the launch preparation time and improve the survivability of weapon system.

Key words: Hypersonic vehicle, Terrain matching, Initial orientation, Error identification, Mobile launch