Aiming at the problem that the traditional electromagnetic underground pipeline trajectory detection is susceptible to the external environment

an underground pipeline trajectory detection system based on rotary inertial measurement unit（ IMU） is designed. The system uses combination of single-axis fiber-optic gyroscope

accelerometer and Hall sensor

and uses the Euler angle rotation matrix principle to design the algorithm and mathematics platform. The hardware part uses the SINS/PINS hybrid architecture design to track the change of attitude angle using inertial measurement methods

which is not affected by the external environment and pipeline material

and the detection continuity is strong. The software part uses C language to write the program

and solves the relative coordinates of the pipeline; using Python to draw the coordinates into a three-dimensional trajectory map

which can more intuitively present the pipeline space trajectory. Through a large number of experimental tests

the system can accurately measure the pipeline trajectory data. After comparing with other actual measurement methods

the compliance rate is high

indicating that the system can meet the engineering requirements.