Fault-tolerant combined method of strapdown inertial integrated navigation system for underwater vehicles

The invention provides a fault-tolerant combined method of a strapdown inertia integrated navigation system for underwater vehicles. The method is composed of a strapdown inertial navigation system SINS, a terrain aided navigation system TAN, a Doppler velocity log DVL and a magnetic compass pilot MCP, and realizing an integrated navigation process through a decentralized filter structure and an intelligent fault-tolerance method. The method comprises the following steps of constructing sub-filters respectively with the SINS as a reference navigation system and the TAN, the SINS and the DVL, and the SINS and the MCP, extracting related characteristic quantities from the sub-filters to transmit them into fault diagnosis modules composed of a supporting vector machine, determining if faultsexist in the TAN, the DVL or the MCP, if the faults exist, information of the TAN, the DVL or the MCP with the faults is screened, then carrying out a system reconfiguration process, and then feedingback errors outputted from a main filter to the SINS for correction. The method can guarantee a good reliability and a high fault tolerance of a strapdown inertial integrated navigation system for underwater vehicles, especially make a support vector machine trained in small samples have a strong popularization capability, and provide a novel method for a fault diagnosis.