Underground pipeline three-dimensional trajectory measurement method based on integrated navigation system

The invention relates to an underground pipeline three-dimensional track measurement method based on an integrated navigation system, belongs to the technical field of non-excavation, and solves the problem of poor measurement precision of an underground pipeline three-dimensional track in the prior art. The method comprises the following steps: step 1, establishing an error model of an MEMS gyroscope and an accelerometer; step 2, establishing an error equation of speed, position and attitude; step 3, determining a state variable and a state equation according to the motion characteristics of the pipeline measuring instrument, the MEMS sensor error model and the speed, position and attitude error equation; 4, an MEMS magnetometer, an odometer and quasi zero velocity information are used as external quantity measurement, and a measurement equation of Kalman filtering is established; 5, discretizing the Kalman filtering continuous system; and step 6, carrying out Kalman filtering equation solution, compensating