Navigation method of low-cost long-endurance autonomous underwater robot

The invention provides a navigation method of a low-cost long-endurance autonomous underwater robot. Task stages needing to be executed for realizing the navigation algorithm comprise a water surface cruising stage, a diving stage, an underwater cruising stage and a floating stage. The surface flow velocity estimation module only works in a water surface cruising stage of the underwater robot and is used for estimating water flow velocity information of a seawater surface reference layer. The deep flow velocity recursion module works in the diving, underwater cruising and floating stages of the underwater robot and is used for calculating water velocity information of the underwater robot in different depth environments. The absolute speed calculation module is applied to the diving, underwater cruising and floating stages of the underwater robot, and is mainly used for calculating the current absolute speed of the underwater robot. The absolute speed of the underwater robot without the influence of the water