Method for geomagnetically detecting submarine cable

A method for geomagnetically detecting a submarine cable, applied to detection control terminals, comprising steps of:

• step S01, performing a preliminary detection by controlling an underwater robot equipped with a proton magnetometer;
• and then determining a preliminary direction and a preliminary location of the cable based on preliminary detection information;
• the preliminary detection information comprising underwater positioning data and a general geomagnetic field;
• step S02, performing a route detection by controlling the underwater robot equipped with the proton magnetometer and two fluxgate magnetometers to launch into the water, according to preliminary location information;
• then, controlling the underwater robot to travel over the cable and determining specific location information of the cable, based on the general geomagnetic field measured by the proton magnetometer during the route detection;
• and, controlling a heading of the underwater robot to move along the preliminary direction of the cable, based on an X-axis component gradient value obtained by the two fluxgate magnetometers;
• and
• step S03, performing a patrol detection by controlling the underwater robot equipped with the proton magnetometer and the two fluxgate magnetometers to launch into the water, according to the specific location information;
• then, determining whether a fault in the submarine cable occurs and a location of a fault point, based on Z-axis components and launching depth data of the underwater robot measured by the two fluxgate magnetometers;
• where the proton magnetometer is installed in front of the underwater robot, and the two fluxgate magnetometers are installed on both sides of the underwater robot;
• wherein the step S02 comprises:
• step S21, determining a launching location of the underwater robot equipped with the proton magnetometer and the two fluxgate magnetometers, according to the preliminary location information;
• step S22, controlling the underwater robot to launch at the launching location, and controlling the underwater robot to travel to hover right over the cable;
• step S23, controlling the underwater robot to translate along the preliminary direction of the cable according to the preliminary direction of the cable, and adjusting a translation direction of the underwater robot according to a change of the general geomagnetic field measured by the proton magnetometer;
• determining the location hover right over the cable at a peak of the general geomagnetic field after adjusting the translation direction several times, and determining the specific location information of the cable;
• and
• step S24, controlling the underwater robot to travel, and controlling the heading of the underwater robot to move along the preliminary direction of the cable, based on the X-axis component gradient value obtained by the two fluxgate magnetometers during a travelling process.