Method, device and system for detecting magnetic field interference

Abstract

An unmanned aerial vehicle includes a body frame, at least two magnetometers disposed at different positions of the body frame, and a processor communicatively coupled with the at least two magnetometers. Each of the at least two magnetometers are configured to measure magnetic field information of a magnetic field in which the unmanned aerial vehicle is positioned. The processor is configured to, in response to the magnetic field information measured by the at least two magnetometers indicating that the unmanned aerial vehicle is subject to a magnetic field interference, initiate a command instructing the unmanned aerial vehicle to stop taking off or to return.

What is claimed is: 
     
         1 . An unmanned aerial vehicle comprising:
 a body frame;   at least two magnetometers disposed at different positions of the body frame, each of the at least two magnetometers being configured to measure magnetic field information of a magnetic field in which the unmanned aerial vehicle is positioned; and   a processor communicatively coupled with the at least two magnetometers and configured to, in response to the magnetic field information measured by the at least two magnetometers indicating that the unmanned aerial vehicle is subject to a magnetic field interference, initiate a command instructing the unmanned aerial vehicle to stop taking off or to return.   
     
     
         2 . The unmanned aerial vehicle of  claim 1 , wherein the processor is further configured to:
 determine magnetic difference information of the magnetic field information measured by the at least two magnetometers; and   determine whether the unmanned aerial vehicle is subject to the magnetic field interference based on the magnetic difference information.   
     
     
         3 . The unmanned aerial vehicle of  claim 2 , wherein:
 the magnetic field information includes magnetic field directions; and   the processor is further configured to:
 obtain one or more angles as the magnetic difference information, each of the one or more angles being an angle between the magnetic field directions measured by two of the at least two magnetometers; and 
 in response to a maximum angle in the one or more angles exceeding a predetermined angle threshold, determine that the unmanned aerial vehicle is subject to the magnetic field interference. 
   
     
     
         4 . The unmanned aerial vehicle of  claim 2 , wherein:
 the magnetic field information includes magnetic field vectors; and   the processor is further configured to:
 obtain a plurality of vector differences as the magnetic difference information, each of the plurality of vector differences being a difference between the magnetic field vector measured by one of the at least two magnetometers and a vector of a local magnetic field; and 
 determine whether the unmanned aerial vehicle is subject to the magnetic field interference based on the plurality of vector differences. 
   
     
     
         5 . The unmanned aerial vehicle of  claim 4 , wherein:
 the plurality of vector differences include a plurality of magnitude differences each being a difference between a magnetic field magnitude of the magnetic field vector measured by one of the at least two magnetometers and a magnitude of the vector of the local magnetic field; and   the processor is further configured to:
 in response to a maximum magnitude difference in the plurality of magnitude differences exceeding a predetermined magnitude difference threshold, determine that the unmanned aerial vehicle is subject to the magnetic field interference. 
   
     
     
         6 . The unmanned aerial vehicle of  claim 4 , wherein:
 the magnetic field vectors include magnetic field directions; and   the processor is further configured to:
 calculate a plurality of angles as the plurality of vector differences, each of the plurality of angles being an angle between the magnetic field direction measured by one of the at least two magnetometers and a direction of the local magnetic field; and 
 in response to a maximum angle in the plurality of angles exceeding an angle threshold, determine that the unmanned aerial vehicle is subject to the magnetic field interference. 
   
     
     
         7 . The unmanned aerial vehicle of  claim 2 , wherein:
 the at least two magnetometers include a first magnetometer and a second magnetometer, the first magnetometer being positioned on the unmanned aerial vehicle at a position having a distance from a local magnetic field less than a first threshold during a movement of the unmanned aerial vehicle, and the second magnetometer being positioned on the unmanned aerial vehicle at a position having a distance from the local magnetic field greater than the first threshold during the movement of the unmanned aerial vehicle; and   the processor is further configured to:
 obtain a first magnetic field vector measured by the first magnetometer and a second magnetic field vector measured by the second magnetometer; 
 calculate a first magnitude difference between a magnitude of the first magnetic field vector and a magnitude of a vector of the local magnetic field; 
 calculate a second magnitude difference between a magnitude of the second magnetic field vector and the magnitude of the vector of the local magnetic field; 
 calculate an angle between the first magnetic field vector and the second magnetic field vector; and 
 determine that the unmanned aerial vehicle is subject to the magnetic field interference in response to at least one of:
 a greater one of the first magnitude difference and the second magnitude difference exceeding a second threshold; or 
 the angle exceeding a third threshold. 
 
   
     
     
         8 . The unmanned aerial vehicle of  claim 7 , wherein
 the at least two magnetometers include three or more magnetometers; and   the first magnetometer and the second magnetometer are two magnetometers having a largest difference in height along a direction of gravity among the three or more magnetometers when the unmanned aerial vehicle is in a normal moving state.   
     
     
         9 . The unmanned aerial vehicle of  claim 2 , wherein:
 the magnetic difference information includes a plurality of magnetic differences each being a difference between the magnetic field information measured by one of the at least two magnetometers and magnetic field information of a local magnetic field; and   the processor is further configured to:
 determine a maximum magnetic difference among the plurality of magnetic differences; and 
 determine whether the unmanned aerial vehicle is subject to the magnetic field interference based on the maximum magnetic difference. 
   
     
     
         10 . The unmanned aerial vehicle of  claim 1 , wherein the processor is further configured to:
 obtain a calibration record of the at least two magnetometers; and   in response to the calibration record indicating that one or more magnetometers of the at least two magnetometers are not calibrated, calibrate the one or more magnetometers.   
     
     
         11 . The unmanned aerial vehicle of  claim 1 , wherein the processor is further configured to, in response to the magnetic field information measured by the at least two magnetometers indicating the unmanned aerial vehicle is subject to the magnetic field interference:
 obtain a current device state of the unmanned aerial vehicle; and   initiate the command according to the current device state.   
     
     
         12 . The unmanned aerial vehicle of  claim 11 , wherein the processor is further configured to:
 initiate the command instructing the unmanned aerial vehicle to stop taking off in response to the current device state indicating that the unmanned aerial vehicle is taking off; or   initiate the command instructing the unmanned aerial vehicle to return in response to the current device state indicating that the unmanned aerial vehicle is in flight.   
     
     
         13 . The unmanned aerial vehicle of  claim 1 , wherein the processor is further configured to, in response to the magnetic field information measured by the at least two magnetometers indicating the unmanned aerial vehicle is subject to the magnetic field interference:
 determine a position of a local magnetic field based on a vector of the local magnetic field; and   send an alert notification containing interference source information, the interference source information including the position of the local magnetic field.   
     
     
         14 . The unmanned aerial vehicle of  claim 1 , wherein the at least two magnetometers are disposed at different positions having different heights with respect to a top of the unmanned aerial vehicle. 
     
     
         15 . The unmanned aerial vehicle of  claim 1 , wherein the body frame includes:
 a body;   an arm coupled to the body; and   a landing gear coupled to the body.   
     
     
         16 . The unmanned aerial vehicle of  claim 15 , wherein the at least two magnetometers are provided at various positions at the body frame including at least one of the landing gear, the body, the arm, a carrier coupled to the body frame, or a load coupled to the body frame. 
     
     
         17 . An unmanned aerial vehicle comprising:
 a body frame;   at least two magnetometers disposed at different positions of the body frame, each of the at least two magnetometers being configured to measure magnetic field information of a magnetic field in which the unmanned aerial vehicle is positioned; and   a processor communicatively coupled with the at least two magnetometers and configured to, in response to the magnetic field information measured by the at least two magnetometers indicating the unmanned aerial vehicle is subject to a magnetic field interference, perform at least one of:
 automatically initiating a protection control command; or 
 sending an alert notification to a control terminal. 
   
     
     
         18 . The unmanned aerial vehicle of  claim 17 , wherein the alert notification contains interference source information, the interference source information including a position of a local magnetic field. 
     
     
         19 . The unmanned aerial vehicle of  claim 17 , wherein the processor is further configured to:
 determine magnetic difference information of the magnetic field information measured by the at least two magnetometers; and   determine whether the unmanned aerial vehicle is subject to the magnetic field interference based on the magnetic difference information.   
     
     
         20 . The unmanned aerial vehicle of  claim 17 , wherein the protection control command is configured to instruct the unmanned aerial vehicle to:
 stop taking off in response to a current device state of the unmanned aerial vehicle indicating that the unmanned aerial vehicle is taking off; or   return in response to the current device state indicating that the unmanned aerial vehicle is in flight.