A Fusion Method and Fusion System for UAV Heading Angle Measurement Data

Abstract

The present invention provides a method and system for fusing drone heading angle measurement data, aiming to solve the problem that in areas with complex interference conditions in the prior art, the drone navigation cannot accurately measure the heading. The fusion method obtains the heading angle through positioning heading, obtains the heading angle through magnetic heading, and obtains the heading angle through IMU integrated heading. According to the signal quality of the heading angle itself and the deviation between the heading angle change rate and the heading angle change rate, it is judged whether the fixed heading angle is credible; when it is determined that the heading angle is credible, it is directly output as the heading result; and the magnetic heading angle is corrected based on the fixed heading angle; when it is determined that the heading angle is not credible, it is judged whether the magnetic heading angle is credible according to the deviation between the magnetic heading angle change rate and the fixed heading angle change rate; when it is determined that the magnetic heading angle is credible, the increment is added to the result output in the previous cycle as the heading result output in this cycle; when it is determined that the magnetic heading angle is not credible, the magnetic heading angle is output as the heading result.

Description

Technical Field

[0001] The present invention belongs to the technical field of UAV navigation, and particularly relates to a method and system for fusing UAV heading angle measurement data. Background Technique

[0002] The heading of an unmanned aerial vehicle (UAV) is the basis for attitude solution, speed, and position control. Usually, the magnetic heading is obtained by measuring the triaxial geomagnetic flux using a magnetometer, or the true north heading is measured using a GPS dual antenna. However, the data obtained by these two methods has poor reliability and is easily interfered with. For magnetic heading measurement, it is mainly very susceptible to interference from ferromagnetic objects on the aircraft and in the flight environment, as well as the influence of the Earth's magnetic field itself, resulting in inaccurate or even incorrect measurements. For the method of measuring the heading using a GPS or other satellite positioning system's dual antenna, it is affected by the quality of the positioning satellite signal, directly affecting the heading measurement result, such as cloud cover, building or mountain blockage, electromagnetic interference, etc. There is also a method of using a high-precision gyro for measurement, which is costly, large in weight and volume, and is often not suitable for UAVs; while the low-cost rate gyro has serious drift and cannot obtain the heading for a long time.

[0003] The above single measurement methods cannot effectively obtain reliable heading measurement values. The satellite navigation system has high positioning and orientation accuracy and can directly measure true north, but the satellite navigation signal is easily blocked, shielded, and interfered with; the magnetic heading data is smooth and has a fast response, but it is also easily interfered with and has poor accuracy; the inertial device has a fast response and is not easily interfered with, and the dynamic results within a short time are reliable, but it cannot measure the absolute heading and has a drift problem over a long time. Summary of the Invention

[0004] The present invention provides a method and system for fusing UAV heading angle measurement data, aiming to solve the problem that in areas with complex interference conditions in the prior art, UAV navigation cannot accurately measure the heading.

[0005] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0006] In a first aspect, the present invention provides a method for fusing UAV heading angle measurement data, including step S200:

[0007] S201. Obtain the heading angle and the rate of change of the heading angle; obtain the heading angle and the rate of change of the heading angle through the magnetic heading, and obtain the heading angle and the rate of change of the heading angle by integrating the heading through the IMU; and the rate of change of the heading angle;

[0008]

[0008] S202. Judge the heading angle Whether the signal quality of itself meets the threshold judgment condition; and judge the heading angle Rate of change and heading angle Whether the deviation between the rates of change exceeds the threshold; if the heading angle The signal quality of itself exceeds the threshold judgment condition and the heading angle Rate of change and heading angle If the deviation between the rates of change does not exceed the threshold, then judge the heading angle To be credible, otherwise judge the heading angle To be not credible;

[0009] When it is judged that the heading angle Is credible, directly use the heading angle As the heading result output; and use the heading angle As a reference to correct the heading angle For correction;

[0010] S203. When it is judged that the heading angle Is not credible, judge the heading angle Rate of change and heading angle Whether the deviation between the rates of change exceeds the threshold. If it does not exceed the threshold, then judge the heading angle Is credible, otherwise judge the heading angle To be not credible;

[0011] When it is judged that the heading angle Is credible, calculate the increment of the heading angle During this period Add the increment to the result output in the previous period As the heading result output for this period;

[0012] S204. When it is judged that the heading angle Is not credible, use the heading angle As the heading result output.

[0013] Further improved scheme: Before step S201, it further includes step S100 of geomagnetic field measurement and calibration:

[0014] The unmanned aerial vehicle collects magnetic heading acquisition data covering 360 degrees on the ground and performs calibration in each different direction;

[0015] The unmanned aerial vehicle collects magnetic heading acquisition data covering 360 degrees in the air and performs calibration in each different direction.

[0016] Since the method of data acquisition and calibration on the ground is easily interfered by the surrounding environment, the present invention adopts a method of data acquisition and calibration combining the ground and the air, and the calibration is more accurate.

[0017] Further improved solution: In step S100, an elliptical or ellipsoidal correction method is adopted for the magnetic heading calibration method.

[0018] Further improved solution: After obtaining the heading result output through step S200, the heading result output is then combined with the kinematic equation of the UAV, the measurement equation of the heading angle, or the Kalman filter for integrated navigation solution to obtain the final heading angle.

[0019] Further improved solution: In step S202, when calibrating the heading angle as a reference for the heading angle a polynomial correction method is adopted for correction. Adopting the polynomial correction method for correction can reduce the consumption of computing resources of the on-board computer. During large-scale flight, the above online real-time calibration method can effectively correct the change of the earth's magnetic field.

[0020] Further improved solution: When the UAV is on the ground and the heading measurement device in the UAV is powered on and running, wait for a certain time until the heading angle is reliable, and use the reliable heading angle as the initial value of the heading angle ;

[0021] When the UAV is on the ground, if a reliable heading angle or a reliable heading angle cannot be obtained within the set time, a heading measurement warning signal can be output.

[0022] Further improved solution: When the UAV is in the air and the heading measurement device in the UAV is powered on and restarted, when the heading angle is reliable within the set time, use the reliable heading angle as the initial value of the heading angle ; when the heading angle is not reliable within the set time, first use the heading angle as the initial value of the heading angle until the heading angle is reliable, and then use the reliable heading angle as the initial value of the heading angle ;

[0023] Further improved solution: When obtaining the heading angle through the positioning system, two-point position measurement and orientation are adopted; when obtaining the heading angle through the magnetic heading, local three-axis geomagnetic flux measurement is adopted; when obtaining the heading angle through IMU integrated heading, inertial device angular velocity measurement is adopted.

[0024] Further improved solution: The positioning system is a global positioning system or a radio positioning system.

[0025] Further improved solution: Obtain the heading angle through the positioning system When doing so, use two-point position measurement for orientation, and calculate the change rate through the two nearest adjacent heading angles When obtaining the heading angle through the magnetic heading, use local three-axis geomagnetic flux measurement, and calculate the change rate through the two nearest adjacent heading angles When obtaining the heading angle through the IMU integrated heading, use the angular velocity measurement of inertial devices.

[0026]

[0027] Second aspect, the present invention provides a fusion system for unmanned aerial vehicle heading angle measurement data, including:

[0027] Heading angle data acquisition unit: Obtain the heading angle through the positioning system and the heading angle change rate; obtain the heading angle through the magnetic heading and the heading angle change rate, and obtain the heading angle through the IMU integrated heading and the heading angle change rate;

[0028] Positioning system output unit: Judge whether the signal quality of the heading angle itself meets the threshold judgment condition; and judge whether the deviation between the heading angle change rate and the heading angle change rate exceeds the threshold; if the signal quality of the heading angle itself exceeds the threshold judgment condition and the deviation between the heading angle change rate and the heading angle change rate does not exceed the threshold, then determine that the heading angle is credible, otherwise determine that the heading angle is not credible;

[0029] When it is determined that the heading angle is credible, directly output the heading angle as the heading result; and use the heading angle as a reference to correct the heading angle ;

[0030] Magnetic heading output unit: When it is determined that the heading angle is not credible, judge whether the deviation between the heading angle change rate and the heading angle change rate exceeds the threshold. If it does not exceed the threshold, then determine that the heading angle If it is reliable, otherwise determine the heading angle is unreliable;

[0031] When determining the heading angle is reliable, calculate the increment of the heading angle in this period Add the increment to the result output in the previous period and output it as the heading result of this period;

[0032] IMU integrated heading output unit: When determining that the heading angle is unreliable, use the heading angle as the heading result output.

[0033] The beneficial effects of the present invention are:

[0034] In the method for fusing UAV heading angle measurement data in the present invention, it can still have a good navigation effect in a relatively chaotic and complex area where the magnetic heading is interfered, the positioning system (GPS heading) is interfered, and both are interfered at the same time; in the present invention, the reliable heading angle of the positioning system is used as a reference benchmark to real-time correct the heading angle of the magnetic heading When the positioning system is not interfered, use the reliable heading angle as the heading result output; when the positioning is interfered and the magnetic heading is not interfered, the reliable heading angle can be temporarily used as the heading result output; when both the positioning and the magnetic heading are interfered, the heading angle can be temporarily used as the heading result output. When the heading angle is interfered or fails, it can provide an accurate heading value for a short time to ensure that the UAV has time to get out of the interference.

[0035] In the present invention, it does not completely rely on one of the navigation methods. Using the reliable heading angle as a reference benchmark, the heading angle can be real-time corrected. The corrected heading angle and the heading angle can also temporarily play the role of precise navigation when the heading angle is unreliable. The three navigation methods support each other, are sufficient to cope with various chaotic and complex areas with interference, and still have good accuracy.

[0036] Taking the change rate of the heading angle of the IMU integrated heading as a reference benchmark, it can accurately judge whether the heading angle and the heading angle are reliable, and at the same time can judge whether the current positioning system and magnetic heading are interfered; in the present invention, using the reliable heading angle and the heading angle Taking the change rates as double benchmarks, mutual feedback information is formed to create an intelligent and accurate navigation applicable to complex areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can be obtained based on these drawings.

[0038] Figure 1 It is a schematic flowchart of a data fusion method for measuring the heading angle data of an unmanned aerial vehicle applicable to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0040] Embodiment 1:

[0041] Referring to Figure 1 , this embodiment provides a fusion method for measuring the heading angle data of an unmanned aerial vehicle, including:

[0042] S100: The unmanned aerial vehicle collects magnetic heading acquisition data covering 360 degrees on the ground and calibrates in each different direction;

[0043] The unmanned aerial vehicle collects magnetic heading acquisition data covering 360 degrees in the air and calibrates in each different direction.

[0044] Among them, the magnetic heading calibration method can adopt the ellipse or ellipsoid correction method.

[0045] S201. Obtain the heading angle and the change rate of the heading angle through the positioning system; obtain the heading angle and the change rate of the heading angle through the magnetic heading; obtain the heading angle and the change rate of the heading angle through the IMU integrated heading;

[0046] S202. Judge the heading angle Whether the signal quality of itself meets the threshold judgment conditions (such as the number of satellites is greater than 7, the position accuracy index is less than 2.5, and the speed accuracy index is less than 0.2); and judge the heading angle change rate and the heading angle Whether the deviation between the change rates exceeds the threshold; if the heading angle The signal quality of itself exceeds the threshold judgment conditions and the heading angle change rate and the heading angle If the deviation between the change rates does not exceed the threshold, it is determined that the heading angle is credible, otherwise it is determined that the heading angle is not credible;

[0047] When it is determined that the heading angle is credible, directly output the heading angle as the heading result; and use the heading angle as the reference to correct the heading angle ;

[0048] S203. When it is determined that the heading angle is not credible, judge whether the deviation between the heading angle change rate and the heading angle change rate exceeds the threshold. If it does not exceed the threshold, it is determined that the heading angle is credible, otherwise it is determined that the heading angle is not credible;

[0049] When it is determined that the heading angle is credible, calculate the increment of the heading angle in this period Add the increment to the result output in the previous period as the heading result of this period;

[0050] S204. When it is determined that the heading angle is not credible, output the heading angle as the heading result.

[0051] S300. Combine and navigate and solve the heading result output according to the kinematic equation of the UAV, the measurement equation of the heading angle, or using Kalman filtering to obtain the final heading angle.

[0052] On the basis of the above scheme, when the UAV is on the ground and the heading measurement device in the UAV is powered on and running, wait for a certain time until the heading angle is credible, and use the credible heading angle as the initial value of the heading angle ;

[0053] When the UAV is on the ground, if a credible heading angle cannot be obtained within the set time limit or a reliable heading angle When this occurs, a heading measurement warning signal can be output

[0054] When the UAV is in the air and the heading measurement device in the UAV is powered on and restarted, when the heading angle is reliable within a set duration, the reliable heading angle is used as the initial value of the heading angle ; when the heading angle is not reliable within the set duration, first the heading angle is used as the initial value of the heading angle until the heading angle is reliable, and then the reliable heading angle is used as the initial value of the heading angle .

[0055] Based on the above solution, when obtaining the heading angle through the positioning system, two-point position measurement orientation is adopted, and the change rate is calculated through the two nearest adjacent heading angles obtained; when obtaining the heading angle through the magnetic heading, local three-axis geomagnetic flux measurement is adopted, and the change rate is calculated through the two nearest adjacent heading angles obtained; when obtaining the heading angle through IMU integrated heading, inertial device angular velocity measurement is adopted (i.e., the change rate of the heading angle φ3).

[0056] Based on the above solution, the positioning system is a global positioning system or a radio positioning system

[0057] Figure 1 In this case, measuring the angular velocity through the IMU can verify whether the GPS heading and the magnetic heading are reliable; and when both the GPS heading and the magnetic heading are not reliable, by measuring the angular velocity through the IMU, the IMU integrated heading can be used as the temporary heading. When in the GPS heading, the magnetic heading can be corrected

[0058] Embodiment 2:

[0059] This embodiment provides a fusion system for UAV heading angle measurement data, including:

[0060] Heading angle data acquisition unit: Obtain the heading angle and the heading angle change rate through the positioning system; obtain the heading angle and the heading angle change rate through the magnetic heading, and obtain the heading angle and the heading angle change rate through IMU integrated heading;

[0061] Positioning system output unit: Determine the heading angle Whether its own signal quality meets the threshold judgment condition; and determine the heading angle Rate of change and heading angle Whether the deviation between the rates of change exceeds the threshold; if the heading angle Its own signal quality exceeds the threshold judgment condition and the heading angle Rate of change and heading angle If the deviation between the rates of change does not exceed the threshold, then determine the heading angle Is credible, otherwise determine the heading angle Is not credible;

[0062] When it is determined that the heading angle Is credible, directly use the heading angle As the heading result output; and use the heading angle As a reference to correct the heading angle For correction;

[0063] Magnetic heading output unit: When it is determined that the heading angle Is not credible, determine the heading angle Rate of change and heading angle Whether the deviation between the rates of change exceeds the threshold. If it does not exceed the threshold, then determine the heading angle Is credible, otherwise determine the heading angle Is not credible;

[0064] When it is determined that the heading angle Is credible, calculate the increment of the heading angle During this cycle Add the increment to the result output in the previous cycle As the heading result output for this cycle;

[0065] IMU integrated heading output unit: When it is determined that the heading angle Is not credible, use the heading angle As the heading result output.

[0066] The present invention is not limited to the above optional implementation manners. Anyone can obtain other various forms of products under the inspiration of the present invention. However, no matter what changes are made in its shape or structure, as long as the technical solutions fall within the scope defined by the claims of the present invention, they all fall within the protection scope of the present invention.

Claims

1. A method for fusing the heading angle measurement data of an unmanned aerial vehicle, characterized in that, Including: Step S200: S201. Obtain the heading angle through the positioning system and the change rate of the heading angle; obtain the heading angle through the magnetic heading and the change rate of the heading angle, obtain the heading angle through the IMU integrated heading and the change rate of the heading angle ; obtain the heading angle through the IMU integrated heading and the change rate of the heading angle ; S202. Determine the heading angle Whether the signal quality of itself meets the threshold judgment condition; and determine the heading angle The change rate and the heading angle Whether the deviation between the change rates exceeds the threshold; if the signal quality of the heading angle Itself exceeds the threshold judgment condition and the heading angle The change rate and the heading angle The deviation between the change rates does not exceed the threshold, then determine that the heading angle Is credible, otherwise determine that the heading angle Is not credible; When it is determined that the heading angle is reliable, directly output the heading angle as the heading result; and use the heading angle as a reference to correct the heading angle ; S203. When it is determined that the heading angle is not credible, determine whether the deviation between the change rate of the heading angle and the change rate of the heading angle exceeds the threshold. If it does not exceed the threshold, determine that the heading angle is credible; otherwise, determine that the heading angle is not credible. When it is determined that the heading angle is reliable, calculate the increment of the heading angle in this period Add the increment to the result output in the previous period and output it as the heading result of this period; S204. When it is determined that the heading angle is not credible, use the heading angle as the heading result for output.

2. The fusion method of the heading angle measurement data of an unmanned aerial vehicle according to claim 1, characterized in that: Before step S201, it also includes step S100 for geomagnetic field measurement and calibration: The drone collects magnetic heading acquisition data covering 360 degrees on the ground and performs calibration in various different directions; The drone collects magnetic heading acquisition data covering 360 degrees in the air and performs calibration in various different directions.

3. The fusion method of the heading angle measurement data of an unmanned aerial vehicle according to claim 2, wherein: In step S100, the elliptical or ellipsoidal correction method is adopted for the magnetic heading calibration method.

4. A method for fusing the measured data of the heading angle of an unmanned aerial vehicle according to claim 1, characterized in that: After obtaining the heading result output through step S200, the heading result output is then combined with the drone kinematic equation, the heading angle measurement equation, or Kalman filtering for integrated navigation solution to obtain the final heading angle.

5. A method for fusing the heading angle measurement data of an unmanned aerial vehicle according to claim 1, characterized in that: In step S202, when calibrating the heading angle as a reference for the heading angle , a polynomial correction method is used for correction.

6. A method for fusing the heading angle measurement data of an unmanned aerial vehicle according to claim 1, characterized in that: When the drone is on the ground and the heading measurement device in the drone is powered on and running, wait for a certain period of time until the heading angle is reliable, and use the reliable heading angle as the initial value of the heading angle ; When the drone is on the ground and cannot obtain a reliable heading angle within the set duration or a reliable heading angle output a heading measurement warning signal.

7. A method for fusing the measured data of the heading angle of an unmanned aerial vehicle according to claim 6, characterized in that: When the drone is in the air and the heading measurement device in the drone is powered on and restarted, if the heading angle is credible within a set duration, then the credible heading angle is used as the initial value of the heading angle ; if the heading angle is not credible within the set duration, then first the heading angle is used as the initial value of the heading angle until the heading angle becomes credible, and then the credible heading angle is used as the initial value of the heading angle .

8. A method for fusing the measured data of the heading angle of an unmanned aerial vehicle according to claim 1, characterized in that: Obtain the heading angle through the positioning system When doing so, use two-point position measurement for orientation and calculate the change rate through the two nearest adjacent heading angles obtained When obtaining the heading angle through the magnetic heading, use local three-axis geomagnetic flux measurement and calculate the change rate through the two nearest adjacent heading angles obtained When doing so When obtaining the heading angle through IMU integrated heading, use the angular velocity measurement of inertial devices When doing so 9. A method for fusing the heading angle measurement data of an unmanned aerial vehicle according to claim 1 or 8, characterized in that: The positioning system is a global positioning system or a radio positioning system.

10. A fusion system for measuring data of the heading angle of an unmanned aerial vehicle, characterized in that, Including: Heading angle data acquisition unit: Obtain the heading angle through the positioning system and the heading angle change rate; Obtain the heading angle through the magnetic heading and the heading angle change rate, and obtain the heading angle through IMU integrated heading and the heading angle change rate; Positioning system output unit: Determine the heading angle Whether its own signal quality meets the threshold judgment condition; and determine the heading angle The change rate and the heading angle Whether the deviation between the change rates exceeds the threshold; if the heading angle Its own signal quality exceeds the threshold judgment condition and the heading angle The change rate and the heading angle The deviation between the change rates does not exceed the threshold, then determine the heading angle is credible, otherwise determine the heading angle is not credible; When it is determined that the heading angle is reliable, directly output the heading angle as the heading result; and use the heading angle as a reference to correct the heading angle ; Magnetic heading output unit: When it is determined that the heading angle is not credible, judge the heading angle change rate and the heading angle whether the deviation between the change rates exceeds the threshold. If it does not exceed the threshold, it is determined that the heading angle is credible, otherwise it is determined that the heading angle is not credible; When it is determined that the heading angle is reliable, calculate the increment of the heading angle in this period Add the increment to the result output in the previous period and output it as the heading result of this period; IMU integrated heading output unit: When it is determined that the heading angle is not credible, the heading angle is used as the heading result output.

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