Matching method of speed and altitude of unmanned aerial vehicle under accuracy condition of radioactive measurement

Abstract

The application discloses a method for matching airspeed and flight height under the condition of precision of radioactive measurement of an unmanned plane, and comprises the following steps: S1, using the unmanned plane to detect a geological body, and determining a relationship between the flight speed of the unmanned plane and the precision of radioactive measurement of the geological body; S2, determining a count rate according to the flight height of the unmanned plane and the effective detection area of a detector crystal; S3, determining a relationship between the measurement flight height of the unmanned plane, the precision of radioactive measurement and the flight speed of the unmanned plane according to the relationship between the flight speed of the unmanned plane and the precision of radioactive measurement of the geological body and the count rate, and matching the measurement flight height and the flight speed of the unmanned plane based on the set precision of radioactive measurement of the unmanned plane, the application is suitable for the technical field of unmanned planes, the flight speed of the unmanned plane is calculated according to the flight height of the unmanned plane and the precision requirement of a measurement site, the working time is reduced and the efficiency is improved while the measurement requirement is ensured, and a parameter contrast skeleton table is provided, difference calculation can be performed, and the calculation process is simplified.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of unmanned aerial vehicles, and particularly relates to a method for matching airspeed and flight height under the condition of fixed accuracy of radioactive measurement of an unmanned aerial vehicle. BACKGROUND

[0002] Unmanned aerial vehicle airborne radioactive measurement technology is derived from manned airborne radioactive measurement, and the traditional manned airborne radioactive measurement method and technical requirements comply with the Airborne Gamma Ray Spectrometry Specification. In the process of airborne radioactive measurement, the detection accuracy directly affects the data quality of the airborne measurement and the effect of geological and mineral evaluation. In view of the safety of manned airborne radioactive measurement, the detection accuracy is mainly ensured by increasing the volume of the detector and reducing the height during the production flight, and the flight speed is fixed at the minimum safe speed. However, for unmanned aerial vehicle airborne radioactive measurement, there is no unified specification, and the Airborne Gamma Ray Spectrometry Specification is still used as a guide.

[0003] Compared with the traditional manned airborne radioactive measurement, the unmanned aerial vehicle airborne radioactive measurement has the advantages of flexibility and safety of personnel, but the detector is relatively small due to the limitation of the carried load. Therefore, the airborne measurement parameters set according to the traditional manned airborne radioactive measurement specification cannot guarantee the detection accuracy of the unmanned aerial vehicle airborne radioactive measurement. SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provide a method for matching airspeed and flight height under the condition of fixed accuracy of radioactive measurement of an unmanned aerial vehicle.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The method for matching airspeed and flight height under the condition of fixed accuracy of radioactive measurement of an unmanned aerial vehicle comprises the following steps:

[0007] S1: determining the relationship between the flight speed of the unmanned aerial vehicle and the accuracy of the radioactive measurement of the geological body by using the unmanned aerial vehicle to detect the geological body;

[0008] S2: determining the count rate according to the flight height of the unmanned aerial vehicle and the effective detection area of the detector crystal;

[0009] S3: determining the relationship between the measurement flight height of the unmanned aerial vehicle and the accuracy of the radioactive measurement and the flight speed of the unmanned aerial vehicle according to the relationship between the flight speed of the unmanned aerial vehicle and the accuracy of the radioactive measurement of the geological body and the count rate, and matching the measurement flight height and the flight speed of the unmanned aerial vehicle based on the set accuracy of the radioactive measurement of the unmanned aerial vehicle.

[0010] Preferably, the step S1 comprises the following sub-steps:

[0011] S11: measuring the geological body by using the detector of the unmanned aerial vehicle, and calculating total count N of the detector and relative standard error P of nuclear radiation in the geological body;

[0012] S12: calculating total count N under current condition and time t(P) required for measurement to reach relative standard error P according to total count N of the detector and relative standard error P of nuclear radiation in the geological body;

[0013] S13: calculating the relationship between the flight speed of the unmanned aerial vehicle and the measurement accuracy of the geological body according to time t(P) required for measurement to reach relative standard error P and flight distance L.

[0014] Preferably, in the step S11, the calculation formula of total count N of the detector is:

[0015] N = nt,

[0016] wherein n represents the count rate of the measurement, and t represents the measurement time.

[0017] In the step S11, the calculation formula of relative standard error P of nuclear radiation in the geological body is:

[0018]

[0019] wherein σ represents the standard error of single measurement.

[0020] In the step S11, the calculation formula of total count N under current condition and time t(P) required for measurement to reach relative standard error P is:

[0021]

[0022] In the step S13, the calculation formula of the relationship between the flight speed of the unmanned aerial vehicle and the measurement accuracy of the unmanned aerial vehicle v(P) is:

[0023]

[0024] wherein L represents the flight distance of the unmanned aerial vehicle.

[0025] Preferably, the step S2 comprises the following sub-steps:

[0026] S21: calculating the received count rate n(l) of the detector;

[0027] S22: setting the opening angle of the receiving range of the detector, and determining the corresponding measurement radius R of the detector according to the opening angle of the receiving range of the detector;

[0028] S23: According to the receiving count rate n(l) of the detector and the measurement radius R corresponding to the detector, the count rate n(H) corresponding to the flight height of the unmanned aerial vehicle and the effective detection area of the detector crystal is calculated.

[0029] Preferably, in the step S21, the calculation formula of the receiving count rate n(l) of the detector is:

[0030] n(l) = n0e -λl η,

[0031] Wherein, n0 represents the gamma ray count rate emitted by the point source, λ represents the gamma ray line attenuation coefficient of air, l represents the distance between the detector and the point source, and η represents the detection efficiency of the detector.

[0032] In the step S23, the calculation formula of the count rate n(H) corresponding to the flight height of the unmanned aerial vehicle and the effective detection area of the detector crystal is:

[0033]

[0034] Wherein, R represents the measurement radius corresponding to the detector, and H represents the flight height of the unmanned aerial vehicle.

[0035] Preferably, in the step S3, the calculation formula of the relationship v(H, P) between the flight height of the unmanned aerial vehicle and the measurement accuracy of the radioactivity measurement and the flight speed is:

[0036]

[0037] Wherein, P represents the relative standard error of nuclear radiation in the given geological body in the measurement, H represents the flight height of the unmanned aerial vehicle, L represents the center point distance, n0 represents the gamma ray count rate emitted by the point source, η represents the detection efficiency of the detector, R represents the measurement radius corresponding to the detector, and λ represents the gamma ray line attenuation coefficient of air.

[0038] As described above, by adopting the above technical scheme, the present application has the following advantages:

[0039] In the present application, by analyzing the calculation formula of the nuclear radiation measurement accuracy, the real-time scene characteristics of the unmanned aerial vehicle measurement are introduced, and a flight speed and flight height parameter matching calculation method suitable for unmanned aerial vehicle aerial measurement is proposed. This technology overcomes the problem that the existing traditional manned aerial radioactivity measurement parameters are not suitable for unmanned aerial radioactivity measurement, and establishes the flight height and flight speed design process of the unmanned aerial vehicle.

[0040] In the present application, for the flight height and flight speed design of the unmanned aerial vehicle, a measurement parameter comparison skeleton table is formed, which is convenient for reference and difference calculation according to the actual measurement demand, simplifies the calculation process, and improves the design efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a flow chart of the present invention;

[0042] Figure 2 This is a schematic diagram of the aerial survey of the detector in the present invention. DETAILED DESCRIPTION

[0043] The following is combined with Figures 1-2 , further illustrating a specific embodiment of the method for matching the speed and altitude of a drone under a certain precision for radioactivity measurement of a drone of the present invention. The method for matching the speed and altitude of a drone under a certain precision for radioactivity measurement of a drone of the present invention is not limited to the description of the following embodiments.

[0044] Example:

[0045] This embodiment provides a specific implementation method of the method for matching the speed and altitude of a drone under a certain precision condition for radioactivity measurement. Figure 1 As shown, the following steps are included:

[0046] S1: Use UAV to detect geological bodies and determine the relationship between the UAV flight speed and the radioactivity measurement accuracy of geological bodies;

[0047] S2: Determine the counting rate based on the UAV’s flight altitude and the effective detection area of ​​the detector crystal;

[0048] S3: According to the relationship between the UAV flight speed and the radioactivity measurement accuracy of the geological body and the counting rate, the relationship between the UAV measurement flight altitude and the radioactivity measurement accuracy and the flight speed is determined, and based on the set UAV radioactivity measurement accuracy, the UAV measurement flight altitude and flight speed are matched.

[0049] Furthermore, step S1 includes the following sub-steps:

[0050] S11: Use the detector of the UAV to measure the geological body and calculate the total count N of the detector measurement and the relative standard error P of nuclear radiation in the geological body;

[0051] S12: Calculate the total count N under current conditions and the measurement time t(P) required to reach the relative standard error P based on the total count N measured by the detector and the relative standard error P of nuclear radiation in the geological body;

[0052] S13: Calculate the relationship between the UAV flight speed and the radioactivity measurement accuracy of the geological body based on the measurement time t(P) and the flight distance L required to reach the relative standard error P.

[0053] Furthermore, in step S11, the calculation formula for the total count N measured by the detector is:

[0054] N=nt,

[0055] wherein n represents the count rate of the radioactivity measurement, and t represents the measurement time;

[0056] In step S11, the formula for calculating the relative standard error P of the nuclear radiation in the geological body is:

[0057]

[0058] wherein σ represents the standard error of a single measurement;

[0059] In step S11, the formula for calculating the time t(P) required for the total count N under the current conditions to reach the relative standard error P is:

[0060]

[0061] In step S13, the formula for calculating the relationship v(P) between the flight speed of the unmanned aerial vehicle and the radioactivity measurement accuracy of the unmanned aerial vehicle is:

[0062]

[0063] wherein L represents the flight distance of the unmanned aerial vehicle.

[0064] Further, step S2 includes the following sub-steps:

[0065] S21: Calculate the received count rate n(l) of the detector;

[0066] S22: Set the opening angle of the receiving range of the detector, and determine the corresponding measurement radius R of the detector according to the opening angle of the receiving range of the detector;

[0067] S23: According to the received count rate n(l) of the detector and the corresponding measurement radius R of the detector, calculate the count rate n(H) corresponding to the flight height of the unmanned aerial vehicle and the effective detection area of the detector crystal.

[0068] Further, in step S21, the formula for calculating the received count rate n(l) of the detector is:

[0069] n(l) = n0e -λl η,

[0070] wherein n0 represents the count rate of the gamma rays emitted by the point source, λ represents the gamma ray linear attenuation coefficient of air, l represents the distance between the detector and the point source, and η represents the detection efficiency of the detector;

[0071] In step S23, the formula for calculating the count rate n(H) corresponding to the flight height of the unmanned aerial vehicle and the effective detection area of the detector crystal is:

[0072]

[0073] Among them, R represents the measurement radius corresponding to the detector, and H represents the flight altitude of the UAV.

[0074] Furthermore, in step S3, the calculation formula of the relationship between the UAV flight altitude and radioactivity measurement accuracy and flight speed v(H,P) is:

[0075]

[0076] Among them, P represents the relative standard error of nuclear radiation in a given geological body during measurement, H represents the flight altitude of the UAV, L represents the center point distance, n0 represents the gamma ray count rate emitted by the ray point source, η represents the detection efficiency of the detector, R represents the measurement radius corresponding to the detector, and λ represents the gamma ray linear attenuation coefficient of the air.

[0077] By adopting the above technical solutions:

[0078] Radioactive decay follows a Poisson distribution, while the counts of a large number of radionuclide decay measurements approximately follow a normal distribution. In order to describe the accuracy of a nuclear radiation measurement, the relative standard error P is used to represent it. During the time between two consecutive measurements by the detector, the drone's flight distance (i.e., the center point distance) L is measured. The functional relationship between the drone's flight speed v and the radioactivity measurement accuracy P is: Since the drone has a certain flight altitude when measuring geological bodies, the detector crystal can only receive radiation generated by the decay of geological bodies within a certain range. According to the radioactive measurement attenuation formula, the counting rate received by the detector can be expressed as n(l) = n0e -λl η.

[0079] like Figure 2 As shown in FIG, according to the flying height of the detector, a certain opening angle θ is selected as the solid angle of the effective receiving range of the detector, thereby corresponding to the detection range with a measurement radius R on the ground.

[0080] Assuming that the center point distance L is 40m, n0 is 300Bq, the gamma ray linear attenuation coefficient λ of air is 0.006848 / m (@1.25MeVγ), R is 2m, and η is 0.001, the relationship between the UAV measurement flight altitude and measurement accuracy and flight speed is shown in Table 1.

[0081] Table 1

[0082]

[0083] The working principle and process of the present application are as follows: firstly, the unmanned aerial vehicle is used to detect the geological body, and a relationship formula of the flight speed of the unmanned aerial vehicle and the measurement accuracy of the geological body is determined; then the flight height of the unmanned aerial vehicle and the count rate corresponding to the effective detection area of the detector crystal are determined; according to the relationship formula of the flight speed of the unmanned aerial vehicle and the measurement accuracy of the geological body, in combination with the count rate of the flight height of the unmanned aerial vehicle and the effective detection area of the detector crystal, a relationship formula of the measurement flight height of the unmanned aerial vehicle, the measurement accuracy of the radioactivity and the flight speed is determined, and based on the determined measurement accuracy of the radioactivity of the unmanned aerial vehicle, the measurement flight height of the unmanned aerial vehicle and the flight speed are matched.

[0084] The present application has the following beneficial effects:

[0085] (1) The flight speed of the unmanned aerial vehicle is calculated according to the flight height of the unmanned aerial vehicle and the accuracy requirement of the measurement site. While ensuring the measurement requirement, the working time is reduced and the efficiency is improved. Meanwhile, the parameter comparison skeleton table is given, and in specific working conditions, the difference calculation can be performed to simplify the calculation process.

[0086] (2) The method analyzes the calculation formula of the nuclear radiation measurement accuracy, introduces the real-time scene characteristics of the unmanned aerial vehicle measurement at the same time, proposes a calculation method and derivation process suitable for the unmanned aerial vehicle aerial measurement, and forms a measurement parameter list, which is convenient for checking according to the actual measurement requirement.

[0087] The above content is a further detailed description of the present application in combination with the specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, some simple deductions or substitutions can be made without departing from the concept of the present application, and all of them should be regarded as falling within the protection scope of the present application.

Claims

1. A method for matching flight speed and altitude under certain precision conditions for radioactivity measurement using unmanned aerial vehicles, characterized by: The following steps are involved: S1: Use UAV to detect geological bodies and determine the relationship between the UAV flight speed and the radioactivity measurement accuracy of geological bodies; S2: Determine the counting rate based on the UAV’s flight altitude and the effective detection area of ​​the detector crystal; S3: According to the relationship between the UAV flight speed and the radioactivity measurement accuracy of the geological body and the counting rate, the relationship between the UAV measurement flight altitude and the radioactivity measurement accuracy and the flight speed is determined, and the UAV measurement flight altitude and flight speed are matched based on the set UAV radioactivity measurement accuracy; The step S1 includes the following sub-steps: S11: Use the detector of the UAV to measure the geological body and calculate the total count N of the detector measurement and the relative standard error P of nuclear radiation in the geological body; S12: Calculate the total count N under current conditions and the measurement time t(P) required to reach the relative standard error P based on the total count N measured by the detector and the relative standard error P of nuclear radiation in the geological body; S13: Calculate the relationship between the UAV flight speed and the radioactivity measurement accuracy of the geological body based on the measurement time t(P) required to achieve the relative standard error P and the flight distance L; The step S2 includes the following sub-steps: S21: Calculate the detector's receiving count rate n(l); S22: setting the opening angle of the detector receiving range, and determining the measurement radius R corresponding to the detector according to the opening angle of the detector receiving range; S23: Calculate the count rate n(H) corresponding to the UAV flight altitude and the effective detection area of ​​the detector crystal based on the detector's receiving count rate n(l) and the corresponding measurement radius R of the detector.

2. The method for matching speed and altitude of an unmanned aerial vehicle (UAV) under constant precision radioactivity measurement conditions according to claim 1 is characterized in that: In step S11, the calculation formula for the total count N measured by the detector is: N=nt, Where n represents the counting rate of radioactivity measurement, and t represents the measurement time; In step S11, the calculation formula for the relative standard error P of nuclear radiation in the geological body is: Where σ represents the standard error of a single measurement; In step S11, the calculation formula for the measurement time t(P) required to reach the relative standard error P under the total count N under the current conditions is: In step S13, the relationship between the UAV flight speed and the UAV radioactivity measurement accuracy, v(P), is calculated as follows: Where L represents the flight distance of the drone.

3. The method for matching speed and altitude of unmanned aerial vehicle (UAV) radioactivity measurement under constant precision conditions according to claim 1, characterized in that: In step S21, the calculation formula of the detector's receiving count rate n(l) is: n(l)=n0e -λI η, Where n0 represents the gamma ray count rate emitted by the ray point source, λ represents the gamma ray linear attenuation coefficient of air, l represents the distance between the detector and the ray point source, and η represents the detection efficiency of the detector; In step S23, the calculation formula of the UAV flight altitude and the count rate n(H) of the effective detection area of ​​the detector crystal is: Among them, R represents the measurement radius corresponding to the detector, and H represents the flight altitude of the UAV.

4. The method for matching speed and altitude of an unmanned aerial vehicle (UAV) under constant precision radioactivity measurement conditions according to claim 1, characterized in that: In step S3, the calculation formula of the relationship between the UAV flight altitude and radioactivity measurement accuracy and flight speed v(H, P) is: Among them, P represents the relative standard error of nuclear radiation in a given geological body during measurement, H represents the flight altitude of the UAV, L represents the center point distance, n0 represents the gamma ray count rate emitted by the ray point source, η represents the detection efficiency of the detector, R represents the measurement radius corresponding to the detector, and λ represents the gamma ray linear attenuation coefficient of the air.

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