Radiation source positioning method and electronic device

Abstract

The application provides a radioactive source positioning method and an electronic device. The radioactive source positioning method comprises the following steps: obtaining measurement data of each measurement point measured by a measurement device; determining an initial value of a radioactive parameter in a relationship equation function; the relationship equation function is used to represent the relationship between the dose rate of the measurement point and the radioactive parameter and the coordinates of the measurement point; inputting the initial value of the radioactive parameter and the coordinates of each measurement point into the relationship equation function to obtain the predicted dose rate of each measurement point; adjusting the radioactive parameter by using the partial derivative function of the relationship equation function based on the dose rate loss value of the predicted dose rate of each measurement point relative to the actual dose rate, and iterating until the relationship equation function meets a convergence condition; and taking the radioactive source coordinates under the condition that the relationship equation function meets the convergence condition as target radioactive source coordinates. The technical scheme of the embodiment of the application can quickly and accurately determine the target radioactive source coordinates by using the nonlinear fitting method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear radiation monitoring, and particularly relates to a radioactive source positioning method and electronic equipment. BACKGROUND

[0002] In the related art, a scheme for determining the position of a radioactive source is generally as follows: according to measurement data returned by a detector, a remote control vehicle is controlled to follow a trajectory so as to gradually approach a high-dose-rate radioactive source center position area. Then, the position of the radioactive source is estimated according to dose rate values of all measurement points measured by the vehicle on the trajectory. However, this scheme needs a large amount of dose rate measurement work in the radioactive source center position area, and needs a long measurement time. Meanwhile, since the position of the radioactive source is estimated, the accuracy is low. SUMMARY

[0003] Embodiments of the present application provide a radioactive source positioning method and electronic equipment to solve the problems in the related art, and the technical solutions are as follows:

[0004] In a first aspect, the embodiments of the present application provide a radioactive source positioning method, including: obtaining measurement data of each measurement point measured by a measurement device; wherein the measurement data includes coordinates of each measurement point and actual dose rates of each measurement point; determining an initial value of a radioactive parameter in a relationship equation function; wherein the relationship equation function is used to represent a relationship between a dose rate of a measurement point and the radioactive parameter and coordinates of the measurement point; the radioactive parameter includes coordinates of a radioactive source and an environmental background dose rate; inputting the initial value of the radioactive parameter and the coordinates of each measurement point into the relationship equation function to obtain predicted dose rates of each measurement point; adjusting the radioactive parameter by using a partial derivative function of the relationship equation function based on dose rate loss values of the predicted dose rates of each measurement point relative to the actual dose rates, and iterating until the relationship equation function meets a convergence condition; taking the coordinates of the radioactive source under the condition that the relationship equation function meets the convergence condition as target radioactive source coordinates.

[0005] In an implementation, the obtaining of the measurement data of each measurement point measured by the measurement device includes: obtaining longitude and latitude coordinates and height coordinates of each measurement point measured by the measurement device; constructing a rectangular coordinate system and selecting a target measurement point from the plurality of measurement points as a zero point of the rectangular coordinate system; determining horizontal coordinates of each measurement point according to the longitude and latitude coordinates of the target measurement point and longitude coordinates of each measurement point; and determining vertical coordinates of each measurement point according to the latitude coordinate of the target measurement point and latitude coordinates of each measurement point.

[0006] In an embodiment, before determining the initial value of the radiation parameter in the relational equation function, further comprising: traversing the horizontal coordinate, the vertical coordinate, the height coordinate and the actual dose rate of all the measurement points to determine the maximum coordinate absolute value and the maximum dose rate value; determining a first normalization coefficient according to the maximum coordinate absolute value, and determining a second normalization coefficient according to the maximum dose rate value; multiplying the horizontal coordinate, the vertical coordinate and the height coordinate of each measurement point by the first normalization coefficient, and multiplying the actual dose rate of each measurement point by the second normalization coefficient.

[0007] In an embodiment, the radiation parameter further comprises a radiation source intensity related quantity, the radiation source intensity related quantity being proportional to the radiation source intensity; the relational equation function satisfies:

[0008]

[0009] wherein dose_rate_whole is the dose rate of the measurement point; K is the radiation source intensity related quantity; x is the horizontal coordinate of the measurement point; y is the vertical coordinate of the measurement point; z is the height coordinate of the measurement point; a is the horizontal coordinate of the radiation source; b is the vertical coordinate of the radiation source; h is the height coordinate of the radiation source; and base_dose is the environmental background dose rate.

[0010] In an embodiment, before determining the initial value of the radiation parameter in the relational equation function, further comprising: determining a data structure body of the calculation library; wherein the data structure body is used to store the measurement data of each measurement point; determining the relational equation function and the partial derivative function of the relational equation function.

[0011] In an embodiment, the radiation source positioning method further comprises: determining the distance between the target radiation source coordinate and the center position of the region measured by the measurement device; and determining that the target radiation source coordinate is valid when the distance is less than or equal to three times the radius of the coverage range of the measurement device.

[0012] In an embodiment, the convergence condition comprises: the dose rate loss value is less than a first preset threshold value, the change value of the radiation parameter is less than a second preset threshold value, and the number of iterations reaches a maximum number of iterations.

[0013] In a second aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor and a computer program stored in the memory, and the processor implements the method of any one of the embodiments of the present application when executing the computer program.

[0014] In a third aspect, an embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method of any one of the embodiments of the present application.

[0015] In a fourth aspect, an embodiment of the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the method of any of the embodiments of the present application.

[0016] The advantages or beneficial effects of the above technical solution at least include: by using the partial derivative of the relational equation function to adjust the radiation parameters based on the dose rate loss value of the predicted dose rate relative to the actual dose rate of each measurement point, and taking the radiation source coordinates under the condition that the relational equation function meets the convergence condition as the target radiation source coordinates, the target radiation source coordinates can be quickly and accurately determined by using the nonlinear fitting method, and the measurement device does not need to perform a large amount of dose rate measurement work. In addition, this method has no requirements for the measurement point positions measured by the measurement device, and each measurement point can be a measurement point in the peripheral region of the radiation source, and the measurement device does not need to enter the central region of the radiation source.

[0017] The above summary is intended to illustrate only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features will become apparent to those skilled in the art upon examination of the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0018] In the drawings, like reference numerals refer to same or similar functionalities throughout the several views. The drawings are not necessarily to scale. It is to be understood that the drawings only illustrate some embodiments in accordance with the present disclosure and should not be considered to be limiting of its scope.

[0019] Figure 1 A flowchart of a radiation source positioning method according to an embodiment of the present application is shown;

[0020] Figure 2 An application example diagram of a rectangular coordinate system according to an embodiment of the present application is shown;

[0021] Figure 3 A block diagram of an electronic device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0022] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting.

[0023] Figure 1 A flowchart of a radiation source positioning method according to an embodiment of the present application is shown. As shown in Figure 1 the radiation source positioning method comprises:

[0024] Step S101: obtaining measurement data of each measurement point measured by a measurement device; wherein, the measurement data comprises coordinates of each measurement point and actual dose rate of each measurement point.

[0025] Exemplarily, the measurement device can be a detector. The measurement device can be carried on a carrier (such as a drone). The carrier can move by itself to make the measurement device collect data at multiple different measurement points, thereby obtaining measurement data of multiple measurement points. In the description of the present application, the meaning of "multiple" is two or more.

[0026] Dose rate refers to the energy deposited by radiation per unit mass per unit time, which is used to measure the strength of radiation. The rays emitted by the radioactive source will interact with the atoms of the material when penetrating the material, mainly in the form of photoelectric effect and Compton effect. Among them, photoelectric effect refers to the interaction between rays and atoms, which transfers energy to electrons, and the rays can be completely absorbed. Compton effect refers to the collision between rays and matter, which partially loses energy and changes direction, resulting in partial attenuation of the rays. Moreover, air can also attenuate radiation rays. Therefore, the rays will be gradually absorbed or weakened in the process of propagation, so that the dose rate in the environment decreases with the increase of the distance between the radioactive source and the measurement point. In addition, due to the existence of cosmic rays and radioactive minerals in the earth, there is also a background dose rate in the environment. Therefore, the actual dose rate measured at the measurement point includes not only the dose rate contributed by the radioactive source, but also the environmental background dose rate.

[0027] Step S102: determining initial values of radioactive parameters in a relationship equation function; wherein, the relationship equation function is used to represent the relationship between the dose rate of the measurement point and the radioactive parameters and the coordinates of the measurement point; the radioactive parameters include the coordinates of the radioactive source and the environmental background dose rate.

[0028] Exemplarily, the coordinates of the measurement point and the coordinates of the radioactive source can be rectangular coordinates, including horizontal coordinates, vertical coordinates and height coordinates. In this step, by determining the initial values of the radioactive parameters in the relationship equation function, a starting point can be provided for subsequent iteration.

[0029] Step S103: inputting the initial values of the radioactive parameters and the coordinates of each measurement point into the relationship equation function to obtain the predicted dose rate of each measurement point.

[0030] In this step, based on the relationship equation function, the initial values of the radioactive parameters and the coordinates of each measurement point are inputted, and the predicted dose rate of each measurement point is outputted. The predicted dose rate of each measurement point is used to compare with the actual dose rate of each measurement point.

[0031] Step S104: based on the dose rate loss value of each measurement point's predicted dose rate relative to actual dose rate, adjust the radiation parameters using the partial derivative function of the relationship equation function, iterate until the relationship equation function meets the convergence condition.

[0032] Step S105: take the radiation source coordinates when the relationship equation function meets the convergence condition as the target radiation source coordinates.

[0033] Exemplarily, a loss function for characterizing the dose rate loss value of each predicted dose rate relative to actual dose rate can be defined. The loss function can be:

[0034]

[0035] where LOSS is the dose rate loss value of each measurement point's predicted dose rate relative to actual dose rate. n is the number of measurement points, n is an integer greater than 1. dose_rate act，i is the actual dose rate of the i-th measurement point. dose_rate pre，i is the predicted dose rate of the i-th measurement point. (dose_rate act，i -dose_rate pred，i ) 2 is the square of the difference between the actual dose rate and the predicted dose rate of the i-th measurement point (hereinafter referred to as difference square). Therefore, the "dose rate loss value of each measurement point's predicted dose rate relative to actual dose rate" described in the present application should be interpreted broadly. In this example, the dose rate loss value of each measurement point's predicted dose rate relative to actual dose rate can be obtained by summing the difference squares of all measurement points.

[0036] After inputting the initial values of the radiation parameters and the coordinates of each measurement point into the relationship equation function and obtaining the predicted dose rate of each measurement point, the predicted dose rate of each measurement point and the actual dose rate of each measurement point can be input into the loss function to obtain the dose rate loss value corresponding to the initial values of the radiation parameters. Then, based on the dose rate loss value, the partial derivative function (such as the first-order partial derivative function and the second-order partial derivative function) of the relationship equation function is used to adjust the radiation parameters. For example, the first-order partial derivative function of the relationship equation function can be used to calculate the gradient of the dose rate loss value with respect to each parameter to determine the direction of parameter adjustment; the second-order partial derivative function of the relationship equation function can be used to determine the curvature information of the loss function, dynamically adjust the step size, and combine the gradient information for more accurate parameter update, thereby improving the convergence speed and accuracy of the relationship equation function.

[0037] In the case that the relational equation function meets the convergence condition, the dose rate loss value of the predicted dose rate of each measurement point relative to the actual dose rate is minimum. That is, the error of the predicted dose rate relative to the actual dose rate is minimum under the radiation parameters when the relational equation function meets the convergence condition. Therefore, the radiation source coordinates in the case that the relational equation function meets the convergence condition are the target radiation source coordinates, so that the positioning of the radiation source can be realized.

[0038] According to the radiation source positioning method, the partial derivative function of the relational equation function is used to adjust the radiation parameters based on the dose rate loss value of the predicted dose rate of each measurement point relative to the actual dose rate, and the radiation source coordinates in the case that the relational equation function meets the convergence condition are taken as the target radiation source coordinates, so that the target radiation source coordinates can be quickly and accurately determined by using the nonlinear fitting method, and the measurement device does not need to perform a large amount of dose rate measurement work. In addition, the method has no requirement on the positions of the measurement points measured by the measurement device, and each measurement point can be a measurement point in a peripheral region of the radiation source, and the measurement device does not need to enter a central region of the radiation source.

[0039] In an embodiment, in step S101, the measurement data of each measurement point measured by the measurement device can include: acquiring the longitude and latitude coordinates and the height coordinates of each measurement point measured by the measurement device; constructing a rectangular coordinate system, and selecting a target measurement point from the plurality of measurement points as the zero point of the rectangular coordinate system; determining the horizontal coordinates of each measurement point according to the longitude and latitude coordinates of the target measurement point and the longitude coordinates of each measurement point; and determining the vertical coordinates of each measurement point according to the latitude coordinates of the target measurement point and the latitude coordinates of each measurement point.

[0040] For example, any one of the plurality of measurement points can be taken as the target measurement point, and the target measurement point is the zero point (0, 0) of the rectangular coordinate system. The horizontal coordinates and the vertical coordinates of each measurement point can be determined by the relative positions of the other measurement points and the target measurement point. For example, the longitude and latitude coordinates of the target measurement point can be set as (zero_long, zero_lat), the longitude and latitude coordinates of the i th measurement point in the plurality of measurement points can be set as (Longitude[i], Latitude[i]), and the horizontal and vertical coordinates of the i th measurement point can be set as (X[i], Y[i]). Then X[i] and Y[i] respectively satisfy:

[0041] X[i] = 111317.1 × cos(zero_lat × 2 × 3.1415926 ÷ 360) × (Longitude[i] - zero_long);

[0042] Y[i] = 110226.3 × (Latitude[i] - zero_lat).

[0043] Wherein, 111317.1 meters is the actual length corresponding to each longitude at the equator; 110226.3 meters is the length of each latitude.

[0044] Figure 2 An application example diagram of the rectangular coordinate system according to the embodiment of the present application is shown. Figure 2 The rectangular coordinate system shown is a plane rectangular coordinate system, and only the horizontal coordinate and the vertical coordinate of the measurement point are shown, and the height coordinate of the measurement point is not shown. Figure 2 Measurement point A, measurement point B and measurement point C are shown. For example, by using the above formula, the latitude and longitude coordinates (115.6°E, 39.5°N) of measurement point A can be converted into the rectangular coordinates (2.1km, 4.3km).

[0045] In the embodiment, according to the latitude and longitude coordinates of the target measurement point and the longitude coordinates of each measurement point, the horizontal coordinates of each measurement point can be determined; and according to the latitude coordinates of the target measurement point and the latitude coordinates of each measurement point, the vertical coordinates of each measurement point can be determined, so as to facilitate the calculation of the predicted dose rate and realize the rapid positioning of the radioactive source.

[0046] In one embodiment, before step S102, the radioactive source positioning method can further include: traversing the horizontal coordinates, the vertical coordinates, the height coordinates and the actual dose rates of all the measurement points to determine the maximum coordinate absolute value and the maximum dose rate value; determining the first normalization coefficient according to the maximum coordinate absolute value, and determining the second normalization coefficient according to the maximum dose rate value; multiplying the horizontal coordinates, the vertical coordinates and the height coordinates of each measurement point by the first normalization coefficient, and multiplying the actual dose rate of each measurement point by the second normalization coefficient.

[0047] It should be noted that the above-mentioned "maximum coordinate absolute value" can be understood as the maximum value among the absolute values of the horizontal coordinates, the absolute values of the vertical coordinates and the absolute values of the height coordinates of all the measurement points.

[0048] Exemplarily, first, the horizontal coordinates, the vertical coordinates and the height coordinates of all the measurement points can be traversed to determine the maximum coordinate absolute value max1; the first normalization coefficient ratio1 can be determined according to the maximum coordinate absolute value max1, for example, the first normalization coefficient ratio1 can be 100 / max1; the horizontal coordinates, the vertical coordinates and the height coordinates of each measurement point are multiplied by the first normalization coefficient ratio1. Then, the actual dose rates of all the measurement points are traversed to determine the maximum dose rate value max2; and the second normalization coefficient ratio2 is determined according to the maximum dose rate value, for example, the second normalization coefficient ratio2 can be 100 / max2; the actual dose rate of each measurement point is multiplied by the second normalization coefficient ratio2.

[0049] Thus, by multiplying the abscissa, ordinate and height coordinates of each measurement point by the first normalization coefficient, and multiplying the actual dose rate of each measurement point by the second normalization coefficient, the coordinates of each measurement point input into the relationship equation function are normalized, and the actual dose rate used for comparison with the predicted dose rate is normalized, so that in the case of adjusting the radiation parameters in the gradient descent manner, the problem of slow gradient descent caused by the large difference in the order of magnitude of various types of data can be avoided, thereby further improving the convergence speed and accuracy of the relationship equation function, and more quickly and accurately realizing positioning of the radiation source.

[0050] In an embodiment, the radiation parameters can further include a radiation source intensity related quantity, the radiation source intensity related quantity being proportional to the radiation source intensity; and the relationship equation function satisfies:

[0051]

[0052] wherein dose_rate_whole is the dose rate of the measurement point; K is the radiation source intensity related quantity; x is the abscissa of the measurement point; y is the ordinate of the measurement point; z is the height coordinate of the measurement point; a is the abscissa of the radiation source; b is the ordinate of the radiation source; h is the height coordinate of the radiation source; and base_dose is the environmental background dose rate.

[0053] The dose rate of the measurement point includes the dose rate contributed by the radiation source and the environmental background dose rate. In the above relationship equation function, is the dose rate contributed by the radiation source. Wherein x, y, z are the normalized coordinates. The normalized coordinates and dose rate values will scale the proportion on the radiation source intensity related quantity K, without affecting the calculation of the target radiation source coordinates.

[0054] In step S102, determining the initial values of the radiation parameters in the relationship equation function can include: determining the initial value of the abscissa a of the radiation source, determining the initial value of the ordinate b of the radiation source, determining the initial value of the height coordinate h of the radiation source, determining the initial value of the environmental background dose rate base_dose, and determining the initial value of the radiation source intensity related quantity K. Then the initial values of the radiation parameters (a, b, h, base_dose and K) and the coordinates (x, y, z) of each measurement point are input into the relationship equation function to obtain the predicted dose rate of each measurement point. Then the predicted dose rate of each measurement point and the actual dose rate of each measurement point are input into the loss function to obtain the dose rate loss value corresponding to the initial values of the radiation parameters. Then based on the dose rate loss value, the partial derivative functions (such as the first-order partial derivative function and the second-order partial derivative function) of the relationship equation function are used to adjust the radiation parameters, and iteration is performed until the relationship equation function meets the convergence condition.

[0055] In this embodiment, the relationship equation function satisfies The prediction of the dose rate can be achieved according to the initial value of the radiation parameter and the coordinates of each measuring point, the adjustment of the radiation parameter can be achieved based on the dose rate loss value of the predicted dose rate relative to the actual dose rate, and then the target radiation source coordinates are obtained to realize the positioning of the radiation source.

[0056] In an embodiment, before step S102, the method further comprises: determining a data structure body of a computing library; wherein the data structure body is used to store the measurement data of each measuring point; determining a relationship equation function and a partial derivative function of the relationship equation function.

[0057] For example, the computing library can be a GNU Scientific Library (GSL) library. The code of the data structure body can be:

[0058]

[0059]

[0060] Wherein, struct data is the data structure body; n is the number of measuring points; x is the horizontal coordinate of the measuring point; y is the vertical coordinate of the measuring point; z is the height coordinate of the measuring point; base_dose is the actual dose rate of the measuring point. double*x, double*y, double*z and double*dose_rate are pointers to double type data, which are used to store the horizontal coordinate, vertical coordinate, height coordinate and actual dose rate of the measuring point, respectively.

[0061] For example, after determining the data structure body, the relationship equation function expb_f can be determined. When the GSL library calculates data, the relationship between the parameters can be determined by calling the relationship equation function expb_f. When the GSL library iterates, the radiation parameters (a, b, h, base_dose and K) at the current time are input into the relationship equation function expb_f, the predicted dose rate is output, then the dose rate loss value of the predicted dose rate of each measuring point relative to the actual dose rate is obtained, and the dose rate loss value is returned to the GSL library.

[0062] After determining the relationship equation function expb_f, the first-order partial derivative function expb_df of the relationship equation function expb_f can be determined. When the GSL library calculates data, the first-order partial derivative of the relationship equation function expb_f is obtained through the first-order partial derivative function expb_df. Wherein, the first-order partial derivative of the radiation source intensity related quantity K is The first-order partial derivative of the horizontal coordinate a of the radiation source is The first-order partial derivative of the vertical coordinate b of the radiation source is The first-order partial derivative of the height coordinate h of the radioactive source is The first-order partial derivative of the environmental background dose rate base_dose is 1.

[0063] After determining the first-order partial derivative function expb_df of the relationship equation function expb_f, the second-order partial derivative function func_fvv of the relationship equation function expb_f can be determined. When the data is calculated, the GSL library can obtain the second-order partial derivative of the relationship equation function expb_f through the second-order partial derivative function func_fvv.

[0064] After determining the first-order partial derivative function expb_df and the second-order partial derivative function func_fvv of the relationship equation function expb_f, the GSL library can be used to determine the target radioactive source coordinate. First, the environment needs to be prepared, and the main data structures (such as gsl_multifit_nlinear_workspace, gsl_multifit_nlinear_fdf, gsl_multifit_nlinear_parameters, etc.) need to be instantiated. Among them, gsl_multifit_nlinear_workspace is the workspace of nonlinear fitting; gsl_multifit_nlinear_fdf is used to store the implementation of the relationship equation function and its first-order partial derivative function and second-order partial derivative; gsl_multifit_nlinear_parameters is used to control the specific behavior of the fitting algorithm, such as step size, convergence condition, etc. Set the relationship equation function, the first-order partial derivative function, and the second-order partial derivative function to expb_f, expb_df, and func_fvv, respectively. Set the trust region method to the dogleg method (gsl_multifit_nlinear_trs_dogleg). Determine the initial value of the radioactive parameter in the relationship equation function, and set the weight size. Then, use gsl_multifit_nlinear_alloc to apply the running space and initialize the related parameters.

[0065] After the environment is prepared, the iteration begins. During iteration, first, the gsl_multifit_nlinear_driver function needs to be called to start the iteration, and the maximum number of iterations (such as 200) is set. Then, it is judged whether the iteration is successful according to whether the relationship equation function meets the convergence condition. In the case that the relationship equation function does not meet the convergence condition, the trust region method (such as Gauss-Newton method or Levenberg-Marquardt method) is switched, and it is tried again. In the case that the relationship equation function meets the convergence condition, it means that the iteration is successful, and at this time the radioactive source coordinate when the relationship equation function meets the convergence condition can be taken as the target radioactive source coordinate.

[0066] In the embodiment, the data structure body of the calculation library is determined, so that the data structure body can provide input data for the relational equation function, and subsequent data processing is more concise and efficient, and the data is processed and calculated through a unified interface, so that the data is not managed in a scattered manner, and the possibility of management and access errors is reduced. By determining the relational equation function and the partial derivative function of the relational equation function, the calculation library can directly call the relational equation function and the partial derivative function of the relational equation function in the positioning process of the radiation source, which is convenient and efficient.

[0067] In an embodiment, the radiation source positioning method can further include: determining a distance between the target radiation source coordinate and a center position of a measured area of the measurement device; and determining that the target radiation source coordinate is valid when the distance is less than or equal to three times a maximum effective detection distance of the measurement device.

[0068] In the embodiment, since the dose rate decreases with the increase of the distance between the measurement device and the radiation source, that is, the farther the distance, the lower the confidence, the farther the distance between the target radiation source coordinate and the center position of the measured area of the measurement device, the lower the validity of the target radiation source coordinate. Therefore, by determining that the target radiation source coordinate is valid when the distance is less than or equal to three times the maximum effective detection distance of the measurement device, the target radiation source coordinate can be checked to ensure the validity of the target radiation source coordinate and exclude invalid data beyond the effective range.

[0069] In an embodiment, the convergence condition can include that the dose rate loss value is less than a first preset threshold, the change value of the radiation parameter is less than a second preset threshold, and the number of iterations reaches a maximum number of iterations. Thus, when the dose rate loss value is less than the first preset threshold, the error of the predicted dose rate of each measurement point relative to the actual dose rate is small enough, indicating that the adjusted radiation parameter is accurate enough, and the iteration can be stopped; when the change value of the radiation parameter is less than the second preset threshold, it indicates that the radiation parameter has tended to be stable, so as to avoid unnecessary small step adjustment and save computing resources, and the iteration can be stopped; when the number of iterations reaches the maximum number of iterations, the iteration can be stopped to prevent the algorithm from being trapped in invalid calculation.

[0070] As an implementation of the above method, the application further provides a radioactive source positioning device, which can comprise: a data acquisition module configured to acquire measurement data of each measurement point measured by a measurement device; wherein the measurement data comprises coordinates of each measurement point and actual dose rates of each measurement point; an initial value determination module configured to determine initial values of radioactive parameters in a relationship equation function; wherein the relationship equation function is used to represent a relationship between dose rates of measurement points and radioactive parameters and coordinates of measurement points; the radioactive parameters comprise coordinates of a radioactive source and an environmental background dose rate; a dose rate determination module configured to input the initial values of the radioactive parameters and the coordinates of each measurement point into the relationship equation function to obtain predicted dose rates of each measurement point; a parameter adjustment module configured to adjust the radioactive parameters by using partial derivatives of the relationship equation function based on dose rate loss values of the predicted dose rates of each measurement point relative to the actual dose rates, and iterated until the relationship equation function meets a convergence condition; and a positioning module configured to take the coordinates of the radioactive source under the condition that the relationship equation function meets the convergence condition as target radioactive source coordinates.

[0071] In an implementation, the data acquisition module is further configured to acquire longitude and latitude coordinates and height coordinates of each measurement point measured by the measurement device; construct a rectangular coordinate system and select a target measurement point from the plurality of measurement points as a zero point of the rectangular coordinate system; determine horizontal coordinates of each measurement point according to the longitude and latitude coordinates of the target measurement point and longitude coordinates of each measurement point; and determine vertical coordinates of each measurement point according to the latitude coordinates of the target measurement point and latitude coordinates of each measurement point.

[0072] In an implementation, the radioactive source positioning device can further comprise: a traversal module configured to traverse the horizontal coordinates, the vertical coordinates, the height coordinates and the actual dose rates of all the measurement points to determine a maximum coordinate absolute value and a maximum dose rate value; a coefficient determination module configured to determine a first normalization coefficient according to the maximum coordinate absolute value and a second normalization coefficient according to the maximum dose rate value; and a coordinate determination module configured to multiply the horizontal coordinates, the vertical coordinates and the height coordinates of each measurement point by the first normalization coefficient, and multiply the actual dose rates of each measurement point by the second normalization coefficient.

[0073] In an implementation, the radioactive parameters further comprise a radioactive source intensity related quantity, the radioactive source intensity related quantity is proportional to the radioactive source intensity; and the relationship equation function satisfies:

[0074]

[0075] wherein dose_rate_whole is the dose rate of the measurement point; K is the radioactive source intensity related quantity; x is the horizontal coordinate of the measurement point; y is the vertical coordinate of the measurement point; z is the height coordinate of the measurement point; a is the horizontal coordinate of the radioactive source; b is the vertical coordinate of the radioactive source; h is the height coordinate of the radioactive source; and base_dose is the environmental background dose rate.

[0076] In one embodiment, the radiation source localization device may further include: a data structure determination module for determining a data structure of a computational library; wherein the data structure is used to store measurement data of each measurement point; and a function determination module for determining the relational equation function and the partial derivative function of the relational equation function.

[0077] In one embodiment, the radiation source positioning device may further include: a distance determination module, used to determine the distance between the radiation source and the center position of the area measured by the measuring device based on the coordinates of the target radiation source; and an validity determination module, used to determine that the coordinates of the target radiation source are valid when the distance is less than or equal to three times the radius of the coverage area of ​​the measuring device.

[0078] In one implementation, the convergence conditions include: the dose rate loss value is less than a first preset threshold, the change value of the radiation parameter is less than a second preset threshold, and the number of iterations reaches the maximum number of iterations.

[0079] The functions of each module in the device of this embodiment can be found in the corresponding descriptions in the above methods, and will not be repeated here.

[0080] According to embodiments of this application, this application also provides an electronic device, a computer-readable storage medium, and a computer program product.

[0081] Figure 3 A structural block diagram of an electronic device according to an embodiment of the present invention is shown. Figure 3 As shown, the electronic device includes a memory 310 and a processor 320. The memory 310 stores a computer program that can run on the processor 320. When the processor 320 executes the computer program, it implements the radiation source localization method in the above embodiments. The number of memories 310 and processors 320 can be one or more.

[0082] The electronic device also includes:

[0083] The communication interface 330 is used to communicate with external devices and perform data exchange and transmission.

[0084] If the memory 310, the processor 320 and the communication interface 330 are implemented independently, the memory 310, the processor 320 and the communication interface 330 can be connected to each other through a bus and complete communication between each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For convenience of representation, Figure 3 Only one thick line is used to represent the bus in the figure, but it does not mean that there is only one bus or only one type of bus.

[0085] Optionally, in a specific implementation, if the memory 310, the processor 320 and the communication interface 330 are integrated on a chip, the memory 310, the processor 320 and the communication interface 330 can complete communication between each other through an internal interface.

[0086] The embodiment of the application provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the method provided in the embodiment of the application.

[0087] The embodiment of the application further provides a chip, which comprises a processor, is used for calling and running instructions stored in a memory, so that a communication device installed with the chip executes the method provided in the embodiment of the application.

[0088] The embodiment of the application further provides a chip, which comprises an input interface, an output interface, a processor and a memory, the input interface, the output interface, the processor and the memory are connected through an internal connection path, and the processor is used for executing code in the memory, and when the code is executed, the processor is used for executing the method provided in the embodiment of the application.

[0089] It is to be understood that the above-described processor can be a central processing unit (CPU), but can also be other general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic components, discrete hardware components, etc. The general purpose processor can be a microprocessor or any conventional processor, etc. It is to be noted that the processor can be an advanced RISC machine (ARM) architecture processor.

[0090] Further, the memory can include a read-only memory and a random access memory, and can further include a non-volatile random access memory. The memory can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. The non-volatile memory can include a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can include a random access memory (RAM) used as an external cache. By way of example, but not limitation, many forms of RAM can be used. For example, a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synchlink DRAM (SLDRAM), and a direct Rambus RAM (DR RAM) can be used.

[0091] In the above-described embodiments, all or part can be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed by a computer, all or part generates the processes or functions according to the present application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another computer-readable storage medium.

[0092] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0093] In addition, the terms "first", "second", etc. are used only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0094] Any process or method descriptions or descriptions in flow charts or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions or steps in the process. And the scope of the preferred embodiments of the present application includes additional implementation in which the functions can be performed in different orders, including substantially simultaneously or in reverse order, according to the functions involved.

[0095] The logic and / or steps represented in the flow chart or otherwise described herein, for example, can be considered as a list of executable instructions for implementing the logic function, which can be specifically implemented in any computer-readable medium for instruction execution system, device or equipment, such as computer-based system, system including processor or other system that can take instructions from instruction execution system, device or equipment and execute instructions, or in conjunction with these instructions execution system, device or equipment.

[0096] It should be understood that each part of the present application can be realized by hardware, software, firmware or a combination thereof. In the above embodiments, a plurality of steps or methods can be realized by software or firmware stored in a memory and executed by a suitable instruction execution system. All or part of the steps of the above-mentioned embodiment methods can be completed by a program instructing the relevant hardware, which can be stored in a computer readable storage medium and includes one or a combination of the steps of the embodiment methods when executed.

[0097] In addition, each functional unit in each embodiment of the present application can be integrated in one processing module, or each unit can be physically present separately, or two or more units can be integrated in one module. The above-mentioned integrated module can be realized in the form of hardware or in the form of a software functional module. The above-mentioned integrated module, if realized in the form of a software functional module and sold or used as an independent product, can also be stored in a computer readable storage medium. The storage medium can be a read-only memory, a magnetic disk or an optical disk, etc.

[0098] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A radioactive source positioning method characterized by, The method comprises: obtaining measurement data of each measurement point measured by a measurement device; wherein the measurement data comprises coordinates of each measurement point and actual dose rates of each measurement point; determining initial values of radiation parameters in a relationship equation function; wherein the relationship equation function is used to represent a relationship between dose rates of measurement points and radiation parameters and coordinates of measurement points; the radiation parameters comprise coordinates of a radiation source and an environmental background dose rate; inputting the initial values of the radiation parameters and the coordinates of each measurement point into the relationship equation function to obtain predicted dose rates of each measurement point; based on dose rate loss values of the predicted dose rates of each measurement point relative to the actual dose rates, adjusting the radiation parameters by using partial derivatives of the relationship equation function until the relationship equation function meets a convergence condition; taking the coordinates of the radiation source when the relationship equation function meets the convergence condition as target coordinates of the radiation source; the radiation parameters further comprise a radiation source intensity related quantity, the radiation source intensity related quantity is proportional to a radiation source intensity; the relationship equation function satisfies: ， wherein, is the predicted dose rate for the ith measurement point; K is a radiation source intensity dependent quantity; , , are the horizontal, vertical and height coordinates of the ith measurement point, respectively, a is the horizontal coordinate of the radiation source; b is the vertical coordinate of the radiation source; h is the height coordinate of the radiation source; is the environmental background dose rate.

2. The method of claim 1, wherein, obtaining measurement data of each measurement point measured by a measurement device, comprising: obtaining longitude and latitude coordinates and height coordinates of each measurement point measured by a measurement device; constructing a rectangular coordinate system and selecting a target measurement point from a plurality of measurement points as a zero point of the rectangular coordinate system; determining horizontal coordinates of each measurement point according to the longitude and latitude coordinates of the target measurement point and longitude coordinates of each measurement point; determining vertical coordinates of each measurement point according to the latitude coordinates of the target measurement point and latitude coordinates of each measurement point.

3. The method of claim 2, wherein, Before determining the initial values of the radiation parameters in the relationship equation function, further comprising: traversing the horizontal coordinates, vertical coordinates, height coordinates and actual dose rates of all measurement points to determine a maximum coordinate absolute value and a maximum dose rate value; determining a first normalization coefficient according to the maximum coordinate absolute value and a second normalization coefficient according to the maximum dose rate value; multiplying the horizontal coordinates, vertical coordinates and height coordinates of each measurement point by the first normalization coefficient and multiplying the actual dose rates of each measurement point by the second normalization coefficient.

4. The method of claim 1, wherein, The loss function of the dose rate loss value is expressed as: wherein, is the dose rate loss value, n is the number of measurement points, n is an integer greater than 1, is the actual dose rate at the i-th measurement point.

5. The method of claim 1, wherein, Before determining the initial values of the radiation parameters in the relationship equation function, further comprising: determining a data structure body of a calculation library; wherein the data structure body is used to store measurement data of each measurement point; determining a relationship equation function and partial derivatives of the relationship equation function.

6. The method of claim 1, wherein, Further comprising: determining a distance between a radiation source and a center position of a region measured by the measurement device according to the target coordinates of the radiation source; determining that the target coordinates of the radiation source are valid in a case that the distance is less than or equal to three times of a coverable range radius of the measurement device.

7. The method according to any one of claims 1 to 6, characterized in that, The convergence condition comprises that the dose rate loss value is less than a first preset threshold value, a change value of the radiation parameters is less than a second preset threshold value and an iteration number reaches a maximum iteration number.

8. An electronic device comprising: A processor and a memory storing a program, the program comprising instructions which, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 7. A processor and a memory storing a program, the program comprising instructions which, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 7.

9. A computer readable storage medium having stored therein a computer program which, when executed by a processor, implements the method of any one of claims 1-7.

10. A computer program product comprising a computer program for causing a computer to perform the method of any one of claims 1 to 7 when the computer program is executed by a processor of the computer.

Images