Radiation standard detection system and positioning control method thereof

Abstract

This invention provides a radiation standard detection system and its positioning control method. The radiation standard detection system includes a radiation source, a position adjustment device for adjusting the position of the detection device in the radiation beam exit direction, a positioning laser, and a control device. The positioning control method includes a first positioning control step, in which, for a first positioning distance, a moving platform is moved to a first reference working position and a first calibration working position, and the first positioning distance, the first reference position information, and the first calibration position information are recorded; a second positioning control step, in which, for a given second positioning distance, the moving platform is controlled to move in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. Using this invention, the detection device at different positions in the radiation beam exit direction can be easily and accurately positioned.

Description

Technical Field

[0001] This invention relates to radiation standard detection systems (e.g., X-ray standard detection systems), and more particularly to improvements in the measurement and positioning control of radiation fields in radiation standard detection systems. Background Technology

[0002] X-ray standard testing systems are used for the verification, calibration, and testing of X-ray radiation instruments, as well as in industrial non-destructive testing. When testing an instrument, the beam-limiting aperture must be precisely positioned at the exit point of the X-ray beam, requiring precise adjustments in the X, Y, and Z axes.

[0003] Existing X-ray standard testing systems, such as the X-ray standard testing system disclosed in Chinese invention patent No. 104964992B, disclose the following technical content. The X-ray standard testing system includes an X-ray generating device, a filtering device, and a guide rail platform. The guide rail platform is located on one side of the X-ray beam exit direction and includes: a guide rail parallel to the X-ray beam exit direction and a measurement and calibration platform that moves parallel to the guide rail. The measurement and calibration platform is adjusted so that the center of the object to be inspected, placed on the platform, coincides with the center of the X-ray beam. Specifically, the object to be inspected is placed on the measurement and calibration platform, and then the platform is adjusted in x, y, z, and r dimensions to position the crosshair laser at the center of the object to be inspected, thereby ensuring that the object to be inspected is in the optical path at the center of the X-ray beam. Summary of the Invention

[0004] The technical problem to be solved by this invention

[0005] The radiation intensity of an X-ray beam decreases with increasing distance from the X-ray source. In X-ray standard testing systems, the measurement and calibration range of the ionization chamber is controlled by changing the distance between the ionization chamber (the measuring device) and the X-ray source. During measurement, it is crucial not only to ensure that the center of the object under test (AUT) placed on the measurement and calibration platform coincides with the center of the X-ray beam, but also to accurately acquire the distance information between the sensitive center of the AUT (e.g., the beam-limiting aperture of the instrument under test) and the X-ray source at different locations. This requires accurate positioning of the AUT moving parallel to the X-ray beam exit direction on a guide rail. Especially in X-ray standard testing systems with a reference ionization chamber and a ionization chamber to be calibrated, calibration of the ionization chamber requires acquiring detection data from both chambers at the same distance.

[0006] However, existing standard X-ray inspection systems, such as the X-ray standard inspection system disclosed in 104964992B, still have room for improvement in how to accurately locate the object under inspection at different positions along the X-ray beam exit direction.

[0007] To address the technical problems existing in current X-ray standard detection systems, this invention proposes a X-ray standard detection system and its positioning control method, which can easily and accurately position the detection device at different locations along the X-ray beam exit direction.

[0008] Technical means to solve technical problems

[0009] To achieve the above objectives, the present invention provides a radiation standard measurement system, comprising:

[0010] A radiation source that produces a beam of radiation that radiates in a first horizontal direction;

[0011] A position adjustment device includes: at least two first linear guides extending along a first direction; a moving platform, which is mounted on the first linear guides by a slider and is movable along the first linear guides, the moving platform having two second linear guides extending along a horizontal second direction, the second direction being perpendicular to the first direction; and a measuring platform, which is mounted on the second linear guides by a slider and is movable along the second linear guides, the measuring platform having a first platform for placing a reference ionization chamber and a second platform for placing an ionization chamber to be calibrated arranged side by side along the second direction.

[0012] A positioning laser, positioned to the side of the first linear guide rail and at a first positioning distance from the exit port of the ray source in the first direction, is capable of emitting a positioning laser beam along the second direction; and

[0013] The control device controls the operation of the X-ray standard measurement system.

[0014] The radiation source is positioned at one end of the first linear guide rail in the first direction.

[0015] A magnetic scale or optical scale is installed along the first linear guide rail, and a sensor is installed on the moving platform to read the position data of the magnetic scale or optical scale.

[0016] For the first positioning distance, the control device can control the moving platform to move along the first linear guide rail in the first direction to the first reference working position and the first calibration working position, and record the first positioning distance, the first reference position information of the first reference working position in the first direction, and the first calibration position information of the first calibration working position in the first direction. Specifically, at the first reference working position, the positioning laser beam is aligned with the sensitive center of the reference ionization chamber, positioning the sensitive center of the reference ionization chamber at the first positioning distance from the exit port of the radiation source. At the first calibration working position, the positioning laser beam is aligned with the sensitive center of the ionization chamber to be calibrated, positioning the sensitive center of the ionization chamber to be calibrated at the first positioning distance from the exit port of the radiation source. The first reference position information and the first calibration position information are read by the sensor from the magnetic grating ruler or optical grating ruler.

[0017] Furthermore, for a given plurality of second positioning distances, the control device can control the movement of the mobile platform along the first linear guide in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. At the second reference working position, the sensitive center of the reference ionization chamber is located at the second positioning distance from the exit port of the radiation source, and at the second calibration working position, the sensitive center of the ionization chamber to be calibrated is located at the second positioning distance from the exit port of the radiation source.

[0018] Preferably, in the above-mentioned X-ray standard measurement system, the at least two first linear guide rails are respectively arranged on at least two support beams extending along the first direction, a rack is fixed on one of the support beams, a first drive motor and a transmission gear are installed on the moving platform, the transmission gear meshes with the rack, and can rotate forward and backward under the drive of the first drive motor to realize the forward and backward movement of the moving platform. The first drive motor is a servo motor, and the control device can perform feedback control on the first drive motor based on the position information read by the sensor, so that the moving platform moves along the first linear guide rail to a specified position.

[0019] Preferably, in the above-mentioned X-ray standard measurement system, a lead screw and a second drive motor are installed on the moving platform. The lead screw is parallel to the second linear guide rail, one end of which is connected to the second drive motor, and the other end is rotatably fixed to the moving platform. The lead screw passes through a nut-shaped component fixed to the lower surface of the measurement platform, thereby driving the lead screw to rotate through the second drive motor to move the measurement platform in the second direction. The second drive motor is a servo motor, and the control device can provide feedback control to the second drive motor to move the measurement platform along the second linear guide rail to a specified position.

[0020] Preferably, in the above-mentioned radiation standard measurement system, the first platform and the second platform are fixed at their bottoms on the plane of the measurement platform, and the distance between the two platforms is fixed. The first platform has pitch, height, and torsion fine adjustment functions to ensure that the reference ionization chamber can be parallel to the radiation field beam direction. The second platform has electric lifting and angle adjustment functions to adapt to ionization chambers of different structures and sizes to be calibrated.

[0021] Preferably, in the above-mentioned radiation standard measurement system, the radiation source includes: an X-ray generating device that generates an X-ray beam radiating in the first horizontal direction; and an X-ray filtering device that filters the X-ray beam generated by the X-ray generating device, the X-ray filtering device being disposed between the X-ray generating device and the position adjustment device in the first direction.

[0022] Furthermore, this invention provides a positioning control method for a radiation standard measurement system.

[0023] The radiation standard measurement system includes:

[0024] A radiation source that produces a beam of radiation that radiates in a first horizontal direction;

[0025] A position adjustment device includes: at least two first linear guides extending along a first direction; a moving platform, which is mounted on the first linear guides by a slider and is movable along the first linear guides, the moving platform having two second linear guides extending along a horizontal second direction, the second direction being perpendicular to the first direction; and a measuring platform, which is mounted on the second linear guides by a slider and is movable along the second linear guides, the measuring platform having a first platform for placing a reference ionization chamber and a second platform for placing an ionization chamber to be calibrated arranged side by side along the second direction.

[0026] A positioning laser, disposed to the side of the first linear guide and located at a first positioning distance from the emission port of the ray source in the first direction, is capable of emitting a positioning laser beam along the second direction; and

[0027] The control device controls the operation of the X-ray standard measurement system.

[0028] The radiation source is positioned at one end of the first linear guide rail in the first direction.

[0029] A magnetic scale or optical scale is installed along the first linear guide rail, and a sensor is installed on the moving platform to read the position data of the magnetic scale or optical scale.

[0030] The positioning control method includes the following steps:

[0031] In the first positioning control step, for the first positioning distance, the control device controls the moving platform to move along the first linear guide rail in the first direction to the first reference working position and the first calibration working position, and records the first positioning distance, the first reference position information of the first reference working position in the first direction, and the first calibration position information of the first calibration working position in the first direction. Specifically, at the first reference working position, the positioning laser beam is aligned with the sensitive center of the reference ionization chamber, positioning the sensitive center of the reference ionization chamber at the first positioning distance from the emission port of the radiation source; at the first calibration working position, the positioning laser beam is aligned with the sensitive center of the ionization chamber to be calibrated, positioning the sensitive center of the ionization chamber to be calibrated at the first positioning distance from the emission port of the radiation source. The first reference position information and the first calibration position information are read by the sensor.

[0032] In the second positioning control step, for a given second positioning distance, the control device controls the movement of the mobile platform along the first linear guide rail in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. At the second reference working position, the sensitive center of the reference ionization chamber is positioned at the second positioning distance from the exit port of the radiation source. At the second calibration working position, the sensitive center of the ionization chamber to be calibrated is positioned at the second positioning distance from the exit port of the radiation source.

[0033] The second positioning control step is repeated to perform positioning control on the reference ionization chamber and the ionization chamber to be calibrated for multiple given second positioning distances.

[0034] Preferably, in the above positioning control method, the at least two first linear guide rails are respectively arranged on at least two support beams extending along the first direction, a rack is fixed on one of the support beams, a first drive motor and a transmission gear are installed on the moving platform, the transmission gear meshes with the rack, and can rotate forward and backward under the drive of the first drive motor to realize the forward and backward movement of the moving platform. The first drive motor is a servo motor. In the first positioning control step and the second positioning control step, the first drive motor is fed back and controlled based on the position information read by the sensor, so that the moving platform moves along the first linear guide rail to a specified position.

[0035] Preferably, in the above-described positioning control method, after the first positioning control step and the second positioning control step, there are a first radiation detection step and a second radiation detection step, respectively. In the first radiation detection step, the radiation beam from the radiation source is detected and the detection data is recorded at the first reference working position and the first calibration working position using the reference ionization chamber and the ionization chamber to be calibrated, respectively. In the second radiation detection step, the radiation beam from the radiation source is detected and the detection data is recorded at the second reference working position and the second calibration working position using the reference ionization chamber and the ionization chamber to be calibrated, respectively. The second positioning control step and the second radiation detection step are repeated to perform radiation beam detection and detection data recording for multiple given second positioning distances.

[0036] Preferably, in the above positioning control method, a lead screw and a second drive motor are installed on the moving platform. The lead screw is parallel to the second linear guide rail, one end of which is connected to the second drive motor, and the other end is rotatably fixed to the moving platform. The lead screw passes through a nut-shaped component fixed to the lower surface of the measuring platform, thereby driving the lead screw to rotate through the second drive motor to achieve the movement of the measuring platform in the second direction. The second drive motor is a servo motor. In the first and second X-ray detection steps, the control device performs feedback control on the second drive motor to move the measuring platform along the second linear guide rail to a predetermined position, so that the sensitive center of the reference ionization chamber and the sensitive center of the ionization chamber to be calibrated are respectively aligned with the X-ray beam for X-ray beam detection.

[0037] Preferably, in the above positioning control method, the radiation source includes: an X-ray generating device that generates an X-ray beam radiating in a first horizontal direction; and an X-ray filtering device that filters the X-ray beam generated by the X-ray generating device. The X-ray filtering device is disposed between the X-ray generating device and the position adjustment device in the first direction and can obtain multiple different radiation qualities by changing the parameters of the X-ray filtering device. In the first radiation detection step and the second radiation detection step, for each radiation quality, the radiation beam from the radiation source is detected and the detection data is recorded.

[0038] Invention Effects

[0039] According to the X-ray standard detection system and its positioning control method of the present invention, the detection device at different positions along the X-ray beam exit direction can be easily and accurately positioned. Furthermore, since only one precise positioning is required for each instrument to be calibrated using a positioning laser, subsequent positioning distances can be determined using the recorded positioning information to obtain the target position information (i.e., the first direction coordinates of the moving platform). This allows control of the drive device to move the moving platform to the target position. Therefore, control software can be used to control the entire system to perform X-ray measurements at various positioning distances. In other words, operators can complete X-ray measurements at various target positions without entering the X-ray measurement area, enabling remote control and precise positioning even in radioactive radiation fields. Attached Figure Description

[0040] Figure 1 This is a schematic diagram illustrating the overall structure of a radiation standard detection system according to one embodiment of the present invention.

[0041] Figure 2 This is a block diagram illustrating the positioning control method of a radiation standard measurement system according to one embodiment of the present invention.

[0042] Figure 3 The diagram illustrates a radiation source and position adjustment device in a radiation standard detection system according to an embodiment of the present invention, wherein (a) is a front view and (b) is a top view. Detailed Implementation

[0043] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0044] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0045] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0046] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0047] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the content disclosed in the embodiments of this application. It should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this application indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing technical features and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention unless they conflict with the context. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance unless they conflict with the context.

[0048] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0049] The specific embodiments and examples of the present invention will now be described with reference to the accompanying drawings.

[0050] Figure 1This is a schematic diagram illustrating the overall structure of a radiation standard detection system according to one embodiment of the present invention. This radiation standard detection system is a multi-detector calibration system that can perform measurements at the same working position by switching the positions of the ionization chamber to be calibrated and the reference ionization chamber.

[0051] like Figure 1 As shown, an embodiment of the X-ray standard measurement system 1 of the present invention includes a X-ray source 10 that generates X-rays along a first horizontal direction (…). Figure 1 The device includes: a beam of radiation radiating in the left-right direction; a position adjustment device 20, comprising: at least two first linear guide rails 21 extending along a first direction; a moving platform 22, movable along the first linear guide rails 21 by means of a slider, the moving platform 22 having two second linear guide rails 23 extending in a horizontal second direction, the second direction being perpendicular to the first direction; a measuring platform 24, movable along the second linear guide rails 23 by means of a slider, the measuring platform 24 having a first platform 25 for placing a reference ionization chamber arranged side-by-side along the second direction. A second platform 26 for placing the ionization chamber to be calibrated; a positioning laser 30, located to the side of the first linear guide 21 and at a first positioning distance from the exit port of the X-ray source 10 in the first direction, capable of emitting a positioning laser beam along the second direction; and a control device 40 for controlling the operation of the X-ray standard measurement system 1, wherein the X-ray source 10 is located at one end of the first linear guide 21 in the first direction, a magnetic grating ruler or optical grating ruler (not shown) is provided along the first linear guide 21, and a sensor (not shown) is provided on the moving platform to read the position data of the magnetic grating ruler or optical grating ruler.

[0052] The apparatus for mounting and positioning the laser 30 can, for example, employ the laser adjustment device disclosed in 104199082B. This laser adjustment device has a translation stage, a lifting stage, a rotary stage, and an angular displacement stage, enabling precise adjustment of the laser's position and angle. The first positioning distance between the positioning laser 30 and the exit port of the radiation source in a first direction can be precisely determined, for example, using a laser interferometer.

[0053] exist Figure 1The specific structure and function of the control device 40 are not shown in detail here. It can be implemented through a combination of hardware and software. An example of its specific structure will be described in detail in the embodiments below. The control device 40 can control the moving platform 22 to move along the first linear guide rail 21 in the first direction to the first reference working position and the first calibration working position, and record the first positioning distance, the first reference position information of the first reference working position in the first direction, and the first calibration position information of the first calibration working position in the first direction. Specifically, at the first reference working position, the positioning laser beam is aligned with the sensitive center of the reference ionization chamber, positioning the sensitive center of the reference ionization chamber at the first positioning distance from the emission port of the radiation source 10. At the first calibration working position, the positioning laser beam is aligned with the sensitive center of the ionization chamber to be calibrated, positioning the sensitive center of the ionization chamber to be calibrated at the distance from the emission port of the radiation source 10. The position of the first positioning distance, the first reference position information, and the first calibration position information are read by the sensor from the magnetic grating ruler or optical grating ruler. For a given plurality of second positioning distances, the control device 40 can control the movement of the mobile platform 22 along the first linear guide rail 21 in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. At the second reference working position, the sensitive center of the reference ionization chamber is located at the second positioning distance from the exit port of the radiation source 10. At the second calibration working position, the sensitive center of the ionization chamber to be calibrated is located at the second positioning distance from the exit port of the radiation source.

[0054] In the X-ray standard detection system 1, the measurement and calibration range of the ionization chamber is achieved by changing the distance between the ionization chamber (which serves as the measuring device) and the X-ray source 10. That is, the ionization chamber needs to be moved in the first direction to position it at a specified distance relative to the X-ray source 10. This movement is achieved through… Figure 1 The position adjustment is performed by a device consisting of a first linear guide rail 21, a moving platform 22, etc. Furthermore, precise positioning of the ionization chamber, which has been moved to multiple locations, is required to enable measurement and calibration of the ionization chamber at specified distances.

[0055] Because the sizes of calibrated instruments vary greatly, precise positioning of instruments of various sizes is difficult, especially when precisely locating the sensitive center of the ionization chamber (e.g., the entrance aperture). Therefore, in one embodiment of the present invention, the X-ray standard detection system 1 is equipped with a positioning laser 30, which is positioned in the second direction (…). Figure 1 The laser beam is emitted in the vertical direction to position it at the sensitive center of the ionization chamber.

[0056] However, since precise positioning of ionization chambers that have been moved to multiple locations is required, it is difficult to perform positioning operations on ionization chambers located in different locations if the positioning laser 30 is placed at only one fixed location. One possible solution is to set the positioning laser 30 to be located at different locations in the first direction or to set multiple positioning lasers 30. However, this would complicate the overall system structure, and since positioning using the positioning laser 30 usually requires manual observation and operation, this would increase the complexity of the positioning operation, especially in radioactive radiation fields, making remote control difficult.

[0057] To address this, the present invention employs a technical solution where a positioning laser 10 is positioned at a fixed location (the first positioning distance from the radiation source 10 in the first direction is precisely measured beforehand, for example, 1000 mm). Under the control of a controller and combined with manual observation, this laser is used to position the reference ionization chamber and the ionization chamber to be calibrated, and the first position information of the reference ionization chamber and the ionization chamber to be calibrated in the position adjustment device is recorded (precisely measured by a magnetic or optical grating ruler). Subsequently, for a given number of second positioning distances (e.g., 2000 mm, 3000 mm, etc.), the first positioning distance and the first position information of the reference ionization chamber and the ionization chamber to be calibrated in the position adjustment device can be used to calculate the second position information corresponding to the second positioning distance, thereby accurately moving the reference ionization chamber and / or the ionization chamber to be calibrated in the position adjustment device to the corresponding second working position, thus completing the positioning at any second positioning distance.

[0058] By employing the above technical solution, it is possible to easily and accurately locate detection devices such as ionization chambers at different positions along the beam exit direction. Furthermore, since only one precise positioning using a positioning laser is required for each instrument to be calibrated, subsequent positioning distances can be determined using the recorded positioning information to obtain the target position information (i.e., the first direction coordinates of the moving platform). This allows control of the drive device to move the moving platform 22 to the target position. Therefore, control software can be used to control the entire system to perform X-ray measurements at various positioning distances. In other words, operators can complete X-ray measurements at various target positions without entering the X-ray measurement area, enabling remote control and precise positioning even in radioactive radiation fields.

[0059] Preferably, in the above-mentioned X-ray standard measurement system 1, the at least two first linear guide rails 21 are respectively arranged on at least two support beams extending along the first direction. A rack is fixed on one of the support beams. The moving platform 22 is equipped with a first drive motor and a transmission gear. The transmission gear meshes with the rack and can rotate forward and backward under the drive of the first drive motor to realize the forward and backward movement of the moving platform 22. The first drive motor is a servo motor. The control device 40 can perform feedback control on the first drive motor based on the position information read by the sensor, so that the moving platform 22 moves along the first linear guide rail 21 to a specified position.

[0060] The servo motor is a closed-loop control system with an internal encoder. It can adjust the motor's speed and direction in real time based on control signals, achieving continuous and precise control. In this invention, the control device 40 can perform feedback control on the first drive motor based on the position information read by the magnetic scale / optical scale from the sensor, causing the moving platform 22 to move along the first linear guide 21 to a predetermined position. Using the magnetic scale / optical scale allows direct measurement of the position of the moving platform 22, avoiding transmission errors caused by the encoder being mounted on the motor shaft, thus resulting in higher positioning accuracy. Simultaneously, the magnetic scale / optical scale typically has higher resolution, suitable for applications requiring high precision, enabling more accurate servo control. This allows the servo motor to drive a rack and pinion mechanism to achieve the forward and backward movement of the moving platform, precisely moving the moving platform 22 to the predetermined position.

[0061] Preferably, in the above-mentioned X-ray standard measurement system 1, a lead screw and a second drive motor are installed on the moving platform 22. The lead screw is parallel to the second linear guide rail 23, one end of which is connected to the second drive motor, and the other end is rotatably fixed to the moving platform 22. The lead screw passes through a nut-shaped component fixed to the lower surface of the measurement platform 24, thereby driving the lead screw to rotate through the second drive motor to realize the movement of the measurement platform in the second direction. The second drive motor is a servo motor, and the control device 40 can provide feedback control to the second drive motor to move the measurement platform 24 along the second linear guide rail 23 to a specified position.

[0062] Figure 1 The radiation standard detection system 1 shown is a multi-detector simultaneous position calibration system, capable of achieving measurements at the same working position by switching the positions of the ionization chamber to be calibrated and the reference ionization chamber. For this purpose, measurements are taken on the measurement platform 24 along the second direction (…). Figure 1The measuring platform 24 is arranged side-by-side in the vertical direction of the measuring platform 24, with a first platform 25 for placing the reference ionization chamber and a second platform 26 for placing the ionization chamber to be calibrated. The measuring platform 24 needs to be moved in the second direction to switch the positions of the ionization chamber to be calibrated and the reference ionization chamber. A servo motor is used as the second drive motor to drive the lead screw, and the control device 40 can provide feedback control to the second drive motor, enabling the measuring platform 24 to be precisely moved to a specified position along the second linear guide 23.

[0063] Preferably, in the above-mentioned X-ray standard measurement system 1, the first platform 25 and the second platform 26 are fixed at their bottoms on the plane of the measurement platform 24, and the distance between the two platforms is fixed. The first platform 25 has pitch, height, and torsion fine adjustment functions to ensure that the reference ionization chamber can be parallel to the direction of the radiation field beam. The second platform 26 has electric lifting and angle adjustment functions to adapt to ionization chambers of different structures and sizes to be calibrated.

[0064] The first platform 25 is used to mount the reference ionization chamber. This platform has fine-tuning functions such as pitch, elevation, and yaw. Pitch and yaw can be achieved, for example, by using a rotating bearing and an adjusting handwheel. The bearing is the center of the rotation radius. By rotating the handwheel, pitch and yaw can be adjusted to ensure that the reference ionization chamber is perfectly parallel to the optical path, avoiding unnecessary corrections due to non-parallelism. The second platform 26 is used to place the ionization chamber to be calibrated. This platform has electric lifting and angle adjustment functions, facilitating the testing of the angle response or other performance of the instrument to be calibrated, and can be adapted to ionization chambers of different structures and sizes.

[0065] The electric lifting function of the second platform 26 can, for example, adopt the structure disclosed in 106548919B. Specifically, the electrically controlled lifting device includes a first fixed base, a second fixed base, a lifting platform, and a calibration equipment platform. Electric lifting is achieved by using a servo motor to drive the lead screw rotation, enabling the lifting platform and the calibration equipment platform to move up and down synchronously.

[0066] Furthermore, the stage for the calibrated equipment can be equipped with a first-direction translation structure, a second-direction translation structure, an electrically driven rotation structure, and a fixture for the calibrated equipment. The specific structure of the fixture for the calibrated equipment can, for example, adopt the structure disclosed in 104091748B.

[0067] Preferably, in the above-described radiation standard measurement system 1, the radiation source 10 includes: an X-ray generating device that generates an X-ray beam radiating in the first horizontal direction; and an X-ray filtering device that filters the X-ray beam generated by the X-ray generating device, the X-ray filtering device being disposed between the X-ray generating device and the position adjustment device in the first direction.

[0068] In this invention, the X-ray source 10 is equipped with an X-ray generating device and an X-ray filtering device. The former generates an X-ray beam, and the latter filters the X-ray beam to allow X-rays of a specific radiation quality to pass through. X-ray radiation quality refers to the ability of X-rays to penetrate matter, which is determined by the energy distribution of the X-rays, including parameters such as maximum energy, minimum energy, average energy, and resolution. Using the above structure, X-rays of a specific radiation quality can be measured using the X-ray standard measurement system 1 of this invention, and the ionization chamber can be calibrated.

[0069] Below, refer to Figure 2 The positioning control method of the X-ray standard measurement system 1 according to one embodiment of the present invention will be described. Figure 2 This is a block diagram illustrating the positioning control method of a radiation standard measurement system 1 according to one embodiment of the present invention.

[0070] In the positioning control method of the X-ray standard measurement system according to one embodiment of the present invention, the method used is... Figure 1 The radiation standard measurement system 1 shown includes a radiation source 10 that generates radiation along a first horizontal direction ( Figure 1 The device includes: a beam of radiation radiating in the left-right direction; a position adjustment device 20, comprising: at least two first linear guide rails 21 extending along a first direction; a moving platform 22, movable along the first linear guide rails 21 by means of a slider, the moving platform 22 having two second linear guide rails 23 extending in a horizontal second direction, the second direction being perpendicular to the first direction; and a measuring platform 24, movable along the second linear guide rails 23 by means of a slider, the measuring platform 24 having a first flat surface for placing a reference ionization chamber arranged side-by-side along the second direction. The system includes a platform 25 and a second platform 26 for placing the ionization chamber to be calibrated; a positioning laser 30, located to the side of the first linear guide rail 21 and at a first positioning distance from the exit port of the X-ray source 10 in the first direction, capable of emitting a positioning laser beam along the second direction; and a control device 40 for controlling the operation of the X-ray standard measurement system 1, wherein the X-ray source 10 is located at one end of the first linear guide rail 21 in the first direction, a magnetic grating ruler or an optical grating ruler is provided along the first linear guide rail 21, and a sensor for reading the position data of the magnetic grating ruler or the optical grating ruler is provided on the moving platform 22.

[0071] like Figure 2 As shown, the positioning control method of the X-ray standard measurement system according to one embodiment of the present invention includes a first positioning control step S1 and a second positioning control step S2.

[0072] In the first positioning control step S1, for the first positioning distance, the control device 40 controls the moving platform 22 to move along the first linear guide rail 21 in the first direction to the first reference working position and the first calibration working position, and records the first positioning distance, the first reference position information of the first reference working position in the first direction, and the first calibration position information of the first calibration working position in the first direction. Specifically, at the first reference working position, the positioning laser beam is aligned with the sensitive center of the reference ionization chamber, positioning the sensitive center of the reference ionization chamber at the first positioning distance from the exit port of the radiation source 10. At the first calibration working position, the positioning laser beam is aligned with the sensitive center of the ionization chamber to be calibrated, positioning the sensitive center of the ionization chamber to be calibrated at the first positioning distance from the exit port of the radiation source 10. The first reference position information and the first calibration position information are read by the sensor.

[0073] In the second positioning control step S2, for a given second positioning distance, the control device 40 controls the movement of the mobile platform 22 along the first linear guide rail 21 in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. At the second reference working position, the sensitive center of the reference ionization chamber is located at the second positioning distance from the exit port of the radiation source 10. At the second calibration working position, the sensitive center of the ionization chamber to be calibrated is located at the second positioning distance from the exit port of the radiation source 10. For multiple different second positioning distances, the second positioning control step is repeated to implement positioning control of the reference ionization chamber and the ionization chamber to be calibrated for multiple given second positioning distances.

[0074] By employing the above technical solution, it is possible to easily and accurately locate detection devices such as ionization chambers at different positions along the beam exit direction. Furthermore, since only one precise positioning using a positioning laser is required for each instrument to be calibrated, subsequent positioning distances can be determined using the recorded positioning information to obtain the target position information (i.e., the first direction coordinates of the moving platform). This allows control of the drive device to move the moving platform 22 to the target position. Therefore, control software can be used to control the entire system to perform X-ray measurements at various positioning distances. In other words, operators can complete X-ray measurements at various target positions without entering the X-ray measurement area, enabling remote control and precise positioning even in radioactive radiation fields.

[0075] Preferably, in the above-described positioning control method, after the first positioning control step and the second positioning control step, there are a first radiation detection step and a second radiation detection step, respectively. In the first radiation detection step, the radiation beam from the radiation source 10 is detected and the detection data is recorded at the first reference working position and the first calibration working position using the reference ionization chamber and the ionization chamber to be calibrated, respectively. In the second radiation detection step, the radiation beam from the radiation source 10 is detected and the detection data is recorded at the second reference working position and the second calibration working position using the reference ionization chamber and the ionization chamber to be calibrated, respectively. The second positioning control step and the second radiation detection step are repeated to perform radiation beam detection and detection data recording for multiple given second positioning distances.

[0076] As an example of a radiation standard measurement system 1, an X-ray standard detection system is used for the verification, calibration, and testing of X-ray radiation instruments. Therefore, in the positioning control method of this invention, after the first positioning control step and the second positioning control step, there are respectively a first radiation detection step and a second radiation detection step. This allows for the detection and recording of radiation beams from the radiation source 10 using the reference ionization chamber and the ionization chamber to be calibrated, respectively, based on precise positioning of the reference ionization chamber and the ionization chamber to be calibrated, thereby achieving the calibration of the ionization chamber to be calibrated.

[0077] Preferably, in the above positioning control method, a lead screw and a second drive motor are installed on the moving platform. The lead screw is parallel to the second linear guide rail 23, one end of which is connected to the second drive motor, and the other end is rotatably fixed to the moving platform. The lead screw passes through a nut-shaped component fixed to the lower surface of the measuring platform 24, thereby driving the lead screw to rotate through the second drive motor to move the measuring platform 24 in the second direction. The second drive motor is a servo motor. In the first X-ray detection step and the second X-ray detection step, the control device 40 performs feedback control on the second drive motor to move the measuring platform 24 along the second linear guide rail 23 to a specified position, so that the sensitive center of the reference ionization chamber and the sensitive center of the ionization chamber to be calibrated are respectively aligned with the X-ray beam for X-ray beam detection.

[0078] As mentioned above, Figure 1 The radiation standard detection system 1 shown is a multi-detector simultaneous calibration system, capable of measuring values ​​at the same working position by switching the positions of the ionization chamber to be calibrated and the reference ionization chamber. For this purpose, along the second direction on the measurement platform (… Figure 1A first platform 25 for placing a reference ionization chamber and a second platform 26 for placing an ionization chamber to be calibrated are arranged side-by-side in the vertical direction. The measuring platform 24 needs to be moved in the second direction to switch the positions of the ionization chamber to be calibrated and the reference ionization chamber. A servo motor is used as the second drive motor to drive the lead screw to rotate. In the first X-ray detection step S1 and the second X-ray detection step S2, the control device 40 provides feedback control to the second drive motor, causing the measuring platform 24 to move along the second linear guide rail 23 to a predetermined position, so that the sensitive centers of the reference ionization chamber and the ionization chamber to be calibrated are respectively aligned with the X-ray beam for X-ray beam detection.

[0079] As one way to align the sensitive center of the ionization chamber with the X-ray beam, the positioning method disclosed in 104964992B can be used, for example. Specifically, an end laser can be placed at the end of the first linear guide 21 (i.e., the other end of the first linear guide 21 in the first direction), so that the laser beam emitted by it is parallel to the first direction and overlaps with the center of the X-ray beam emitted by the X-ray source 10. That is, the laser beam emitted by the end laser is used instead of the X-ray beam to position the ionization chamber. For example, when it is necessary to align the sensitive center of the reference ionization chamber with the X-ray beam, the second drive motor drives the lead screw to rotate, thereby moving the measuring platform in the second direction (the sensitive center of the reference ionization chamber has been pre-positioned at the height of the laser beam in the height direction) until the laser beam emitted by the end laser irradiates the sensitive center of the reference ionization chamber. Then the end laser is turned off and the X-ray source is turned on, so that the reference ionization chamber can detect the X-ray beam.

[0080] Preferably, in the above positioning control method, the radiation source 10 includes: an X-ray generating device that generates an X-ray beam radiating in a first horizontal direction; and an X-ray filtering device that filters the X-ray beam generated by the X-ray generating device. The X-ray filtering device is disposed between the X-ray generating device and the position adjustment device 20 in the first direction and can obtain multiple different radiation qualities by changing the parameters of the X-ray filtering device. In the first radiation detection step S1 and the second radiation detection step S2, for each radiation quality, the radiation beam from the radiation source 10 is detected and the detection data is recorded.

[0081] As mentioned above, X-ray radiation quality refers to the ability of X-rays to penetrate matter, which is determined by the energy distribution of X-rays, including parameters such as maximum energy, minimum energy, average energy, and resolution. In this invention, multiple different radiation qualities can be obtained by changing the parameters of the X-ray filtering device. For multiple radiation qualities, repeated detection and data recording are performed until all standardized measurements are completed. The measurement data of the reference ionization chamber and the ionization chamber to be calibrated are processed to assign a calibration factor to the ionization chamber to be calibrated based on the reference value, thus completing the calibration work.

[0082] The following reference Figure 3 An embodiment of the X-ray standard measurement system 1 of the present invention is described.

[0083] Figure 3 The figure shows a radiation source 10 and a position adjustment device 20 in a radiation standard detection system 1 according to an embodiment of the present invention, wherein (a) is a front view and (b) is a top view.

[0084] (1) X-ray source 10 in the embodiment

[0085] The X-ray source 10 includes a tungsten target X-ray machine, manufactured by YXLON GmbH, Germany, model MG325, which has a higher energy range and dose rate range compared to medical diagnostic X-ray machines. It also includes an X-ray filtering device. Specifically, the X-ray filtering device includes two filter discs symmetrically arranged in a partially overlapping manner, centered on the X-ray beam. Although in Figure 3 The structure is not shown in detail. Each filter disk has multiple filter holes along its circumference. Each filter hole contains an X-ray filter that can output a specific radiation quality. By rotating the two filter disks, any one of the filter holes of each of the two filter disks can be aligned with the X-ray beam at the same time, so that the X-ray beam can be emitted after passing through the two overlapping filters.

[0086] This dual-disc filtration structure greatly increases the quantity of radioactive material, meeting the laboratory's long-term plan to establish multiple series of radioactive materials.

[0087] (2) Position Adjustment System of the Embodiment

[0088] In this embodiment, three first linear guide rails are fixed to the foundation structure. The length of the first linear guide rail in the first direction (X direction) is increased to 5m. The first linear guide rail is supported by three support beams, equipped with a magnetic scale to ensure positioning accuracy, and has more than ten feet for easy leveling during installation. For each first linear guide rail 21, at least two sliders are provided on the moving platform 22 along the first direction. In this embodiment, three sliders are provided on the moving platform 22 for each first linear guide rail 21, thereby ensuring that the moving platform is stably supported and that the platform surface direction remains unchanged when moving along the first linear guide rail 21. The length of the second linear guide rail 23 is increased to 1.5m, which meets the requirements of the larger measuring platform 24, that is, ensuring the required stroke for its movement along the second direction even with the larger measuring platform 24.

[0089] On the measurement platform 24, along the direction perpendicular to the optical path, i.e., the second direction, there are two platforms. The first platform 25 is a dedicated platform for the reference ionization chamber (e.g., a free air ionization chamber). This platform has fine-tuning functions such as pitch, height, and yaw (pitch and yaw are both composed of rotating bearings and adjusting handwheels, with the bearings being the center of the rotation radius. The yaw and pitch can be adjusted by rotating the handwheels) to ensure that the free air ionization chamber is completely parallel to the optical path and to avoid unnecessary corrections due to non-parallelism. The second platform 26 is the platform for the instrument to be calibrated. This platform has electric lifting and electric rotation functions to facilitate the testing of the angle response or other performance of related instruments and equipment, and can be adapted to calibrated instruments (ionization chambers to be calibrated) of different structures and sizes.

[0090] The transmission mechanism for moving the mobile platform 22 in the first direction adopts a rack and pinion system. A drive motor (servo motor) is located on the mobile platform, driving the mobile platform 22 to move in the first direction (X-axis direction) via the servo motor. This ensures smooth movement and accurate positioning. The drive motor is controlled to rotate forward and backward, realizing the forward and backward movement of the mobile platform 22 in the first direction. The servo motor is a Panasonic MHMF082L1A1 servo motor, and the rack is a helical precision-milled rack of model CHTM02020-DIN8.

[0091] The measurement platform 24 moves in the second direction (Y-axis direction, perpendicular to the X-ray beam and parallel to the ground) using a lead screw drive, which is driven by a servo motor to rotate the lead screw and achieve movement. The second platform 26 includes an electrically controlled lifting device and a stage for the equipment being calibrated. Its movement in the height direction (Z-axis direction, perpendicular to the X-ray beam and the ground) uses an electrically controlled lifting device, which is driven by a servo motor to rotate the lead screw and achieve electric lifting.

[0092] The guide rail positioning characteristic test involves aligning a laser interferometer with the platform under test (the interferometer's reflector is placed against the platform, with the interferometer facing the reflector; the accuracy of the moving distance is measured based on the laser signals emitted and received by the interferometer; the interferometer is manufactured by Kede CNC Co., Ltd.) and fixing it stationary. The platform is then allowed to move forward a certain distance and return, and the distance between the returning platform and its original position is measured, thus obtaining the return error. A measuring rod (manufactured by Chengdu Chengliang Tools Group Co., Ltd.) is placed at the zero position of each axis of the guide rail. After the platform reaches the zero limit and returns, the distance between the returned position and the original position is measured, thus obtaining the guide rail positioning return error. The measurement results are shown in Table 2-1.

[0093] Table 2-1 Return difference of each guide rail (mm)

[0094] Serial Number X-axis Y-axis Z-axis 1 -0.003 -0.008 -0.011 2 -0.014 -0.005 -0.021 3 -0.008 -0.008 -0.032 4 -0.022 -0.015 -0.015 5 -0.021 -0.017 -0.003 Range 0.019 0.012 0.029

[0095] Based on the above measurement results, it can be seen that the average distance error caused by the guide rail backlash difference in the tested working section is less than 0.03mm.

[0096] Repeatedly measure the positioning point distance between zero and 1400mm along the X-axis at 200mm intervals; repeatedly measure the positioning point distance between zero and 350mm along the Y-axis; and repeatedly measure the positioning point distance between zero and 150mm along the Z-axis. Calculate the repeatability accuracy according to the following formula.

[0097]

[0098] in:

[0099] RDP stands for Repeatability Precision.

[0100] X i This represents the result of the i-th positioning measurement;

[0101] X m This represents the average value of the location measurement results;

[0102] n represents the number of measurements.

[0103] The repeatability measurement results of the X-axis and Y-axis are shown in Tables 2-2 and 2-3. The repeatability of the X-axis is better than 0.01 mm, and the repeatability of the Y-axis is better than 0.02 mm.

[0104] Table 2-2 Measurement Results of X-axis Repeatability Accuracy

[0105]

[0106] Table 2-3 Measurement Results of Y-axis Repeatability Accuracy

[0107]

[0108] (3) Positioning laser in the embodiment

[0109] Custom-designed red dot laser, model: DZJLK-16, diameter 16mm, laser line thickness adjustable to below 1mm at any position.

[0110] (4) Control device of the embodiment

[0111] The control device 40 adopts a hardware plus software structure, mainly including an industrial computer and a control cabinet. The industrial computer can communicate with a host computer, which issues commands to control the operation of the entire system.

[0112] Specifically, the industrial control computer consists of a monitor, host computer, keyboard, and mouse. It communicates with the host computer, displays the system's operating interface, and allows users to input commands and access the interface via the mouse and keyboard. The industrial control computer sends control instructions to the motion control card in the control cabinet based on these instructions and reports the system's motion status. The control cabinet mainly includes the motion control card, servo drivers, stepper drivers, control power supply, and various I / O interfaces. Red buttons, green buttons, and an emergency stop switch are all mounted on the front of the control cabinet.

[0113] The automatic positioning function in the first direction is achieved by issuing tasks to the servo motor through control software. For example, in the second positioning control step, for a given second positioning distance (e.g., 2000mm), the second reference position (1821mm) and the second calibration position (1723mm) corresponding to the second positioning distance are first calculated based on the first positioning distance (e.g., 1000mm), the first reference position information (e.g., 821mm), and the first calibration position information (e.g., 723mm). Then, the control software issues tasks to the servo motor to move the mobile platform to the second reference position and the second calibration position respectively. During the movement, the servo motor is controlled by feedback based on the position signal read by the magnetic scale, so that the mobile platform can accurately reach the second reference position and the second calibration position.

[0114] The control software is not only used for servo motor control, but also manages the entire X-ray standard inspection system, including position signal feedback and system coordination. The control software drives the PLC, which in turn controls the servo motors and other equipment, thereby achieving real-time control and improving system response speed and stability.

[0115] According to the X-ray standard detection system and its positioning control method of the present invention described above, the detection device at different positions along the X-ray beam exit direction can be easily and accurately positioned. Furthermore, since only one precise positioning using a positioning laser is required for each instrument to be calibrated, subsequent positioning distances can be determined using the recorded positioning information to obtain the target position information (i.e., the first direction coordinates of the moving platform). This allows control of the drive device to move the moving platform to the target position. Therefore, control software can be used to control the entire system to perform X-ray measurements at various positioning distances. In other words, operators can complete X-ray measurements at various target positions without entering the X-ray measurement area, enabling remote control and precise positioning even in radioactive radiation fields.

[0116] The above describes one embodiment of the X-ray standard detection system and its positioning control method of the present invention. However, the X-ray standard detection system and its positioning control method of the present invention are not limited to the above embodiment. They can be modified and altered, and additional components can be added.

[0117] As a variation, this paper describes an implementation method for error compensation of position measurement data to further improve the positioning accuracy of the position adjustment system.

[0118] In the actual operation of the X-ray standard inspection system, for example, the mobile platform needs to travel a distance of 5000 mm. However, during the travel process, due to the cumulative error of the mechanical system and the influence of other factors, the actual travel distance may deviate.

[0119] In a modified example, to eliminate this deviation, the displacement of the mobile platform is compensated based on the error value obtained from previous tests. As the mobile platform moves from its initial position to the target position (e.g., from 0 mm to 5000 mm), the displacement is compensated in real time using the previously measured error data.

[0120] Specifically, in the initial stage of equipment use, a laser interferometer is used to perform high-precision displacement measurements at designated measurement points, such as 500 measurement points between 0 mm and 5000 mm (i.e., one measurement point every 10 mm). Through the high resolution and high sensitivity of the laser interferometer, the error value between the theoretical position and the actual position of each measurement point is obtained. The error data for each position point is recorded (stored) and used in subsequent error compensation processes.

[0121] This error compensation method is implemented using a linear function. Specifically, the relationship between the actual walking distance and the theoretical distance is represented as a linear function, and the error at each step point is calculated and compensated using linear interpolation. When the mobile platform moves from the initial position of 0 mm to the target position of 5000 mm, for example, for every 1 mm traveled, the error value of each measurement point (10 mm per step) is proportionally distributed to each 1 mm, thereby achieving precise control over the overall error.

[0122] As described above, precise measurements are taken at multiple locations using a laser interferometer during the initial use of the equipment. Then, in subsequent use, the displacement is compensated in real-time based on the measured error data. This further improves the system's positioning accuracy and reduces the impact of accumulated errors, making it suitable for high-precision positioning and motion control applications. Through progressively accumulated error compensation and linear function interpolation, the accuracy of each step position is ensured, thereby achieving precise control of the overall displacement.

Claims

1. A radiation standard measurement system, characterized in that, include: A radiation source that produces a beam of radiation that radiates in a first horizontal direction; A position adjustment device includes: at least two first linear guides extending along a first direction; a moving platform, which is mounted on the first linear guides by a slider and is movable along the first linear guides, the moving platform having two second linear guides extending along a horizontal second direction, the second direction being perpendicular to the first direction; and a measuring platform, which is mounted on the second linear guides by a slider and is movable along the second linear guides, the measuring platform having a first platform for placing a reference ionization chamber and a second platform for placing an ionization chamber to be calibrated arranged side by side along the second direction. A positioning laser, positioned to the side of the first linear guide rail and at a first positioning distance from the exit port of the ray source in the first direction, is capable of emitting a positioning laser beam along the second direction; and The control device controls the operation of the X-ray standard measurement system. The radiation source is positioned at one end of the first linear guide rail in the first direction. A magnetic scale or optical scale is installed along the first linear guide rail, and a sensor is installed on the moving platform to read the position data of the magnetic scale or optical scale. For the first positioning distance, the control device can control the moving platform to move along the first linear guide rail in the first direction to the first reference working position and the first calibration working position, and record the first positioning distance, the first reference position information of the first reference working position in the first direction, and the first calibration position information of the first calibration working position in the first direction. Specifically, at the first reference working position, the positioning laser beam is aligned with the sensitive center of the reference ionization chamber, positioning the sensitive center of the reference ionization chamber at the first positioning distance from the exit port of the radiation source. At the first calibration working position, the positioning laser beam is aligned with the sensitive center of the ionization chamber to be calibrated, positioning the sensitive center of the ionization chamber to be calibrated at the first positioning distance from the exit port of the radiation source. The first reference position information and the first calibration position information are read by the sensor from the magnetic grating ruler or optical grating ruler. Furthermore, for a given plurality of second positioning distances, the control device can control the movement of the mobile platform along the first linear guide in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. At the second reference working position, the sensitive center of the reference ionization chamber is located at the second positioning distance from the exit port of the radiation source, and at the second calibration working position, the sensitive center of the ionization chamber to be calibrated is located at the second positioning distance from the exit port of the radiation source.

2. The X-ray standard measurement system according to claim 1, characterized in that: The at least two first linear guide rails are respectively mounted on at least two support beams extending along the first direction. A rack is fixed to one of the support beams, and a first drive motor and a transmission gear are mounted on the moving platform. The transmission gear meshes with the rack and can rotate forward and backward under the drive of the first drive motor to realize the forward and backward movement of the moving platform. The first drive motor is a servo motor, and the control device can perform feedback control on the first drive motor based on the position information read by the sensor, so that the mobile platform moves along the first linear guide rail to a specified position.

3. The radiation standard measurement system according to claim 1 or 2, characterized in that: The mobile platform is equipped with a lead screw and a second drive motor. The lead screw is parallel to the second linear guide rail, with one end connected to the second drive motor and the other end rotatably fixed to the moving platform. The lead screw passes through a nut-shaped component fixed to the lower surface of the measuring platform, thereby enabling the measuring platform to move in the second direction by rotating the lead screw via the second drive motor. The second drive motor is a servo motor, and the control device can perform feedback control on the second drive motor to move the measuring platform along the second linear guide to a specified position.

4. The X-ray standard measurement system according to claim 1 or 2, characterized in that: The first platform and the second platform are fixed at their bottoms to the plane of the measuring platform, and the distance between the two platforms is fixed. The first platform has pitch, elevation, and torsion fine-tuning functions to ensure that the reference ionization chamber is parallel to the direction of the radiation field beam. The second platform has electric lifting and angle adjustment functions to adapt to ionization chambers of different structures and sizes to be calibrated.

5. The X-ray standard measurement system according to claim 1 or 2, characterized in that: The radiation source includes: an X-ray generating device that generates an X-ray beam radiating along the first horizontal direction; and an X-ray filtering device that filters the X-ray beam generated by the X-ray generating device. The X-ray filtering device is disposed between the X-ray generating device and the position adjustment device in the first direction.

6. A positioning control method for a radiation standard measurement system, characterized in that, The radiation standard measurement system includes: A radiation source that produces a beam of radiation that radiates in a first horizontal direction; A position adjustment device includes: at least two first linear guides extending along a first direction; a moving platform, which is mounted on the first linear guides by a slider and is movable along the first linear guides, the moving platform having two second linear guides extending along a horizontal second direction, the second direction being perpendicular to the first direction; and a measuring platform, which is mounted on the second linear guides by a slider and is movable along the second linear guides, the measuring platform having a first platform for placing a reference ionization chamber and a second platform for placing an ionization chamber to be calibrated arranged side by side along the second direction. A positioning laser, disposed to the side of the first linear guide and located at a first positioning distance from the emission port of the ray source in the first direction, is capable of emitting a positioning laser beam along the second direction; and The control device controls the operation of the X-ray standard measurement system. The radiation source is positioned at one end of the first linear guide rail in the first direction. A magnetic scale or optical scale is installed along the first linear guide rail, and a sensor is installed on the moving platform to read the position data of the magnetic scale or optical scale. The positioning control method includes the following steps: In the first positioning control step, for the first positioning distance, the control device controls the moving platform to move along the first linear guide rail in the first direction to the first reference working position and the first calibration working position, and records the first positioning distance, the first reference position information of the first reference working position in the first direction, and the first calibration position information of the first calibration working position in the first direction. Specifically, at the first reference working position, the positioning laser beam is aligned with the sensitive center of the reference ionization chamber, positioning the sensitive center of the reference ionization chamber at the first positioning distance from the emission port of the radiation source; at the first calibration working position, the positioning laser beam is aligned with the sensitive center of the ionization chamber to be calibrated, positioning the sensitive center of the ionization chamber to be calibrated at the first positioning distance from the emission port of the radiation source. The first reference position information and the first calibration position information are read by the sensor. In the second positioning control step, for a given second positioning distance, the control device controls the movement of the mobile platform along the first linear guide rail in a first direction based on the first positioning distance, the first reference position information, and the first calibration position information, so that it is located at the second reference working position and / or the second calibration working position. At the second reference working position, the sensitive center of the reference ionization chamber is positioned at the second positioning distance from the exit port of the radiation source. At the second calibration working position, the sensitive center of the ionization chamber to be calibrated is positioned at the second positioning distance from the exit port of the radiation source. The second positioning control step is repeated to perform positioning control on the reference ionization chamber and the ionization chamber to be calibrated for multiple given second positioning distances.

7. The positioning control method according to claim 6, characterized in that: The at least two first linear guide rails are respectively mounted on at least two support beams extending along the first direction. A rack is fixed to one of the support beams, and a first drive motor and a transmission gear are mounted on the moving platform. The transmission gear meshes with the rack and can rotate forward and backward under the drive of the first drive motor to realize the forward and backward movement of the moving platform. The first drive motor is a servo motor. In the first positioning control step and the second positioning control step, the first drive motor is controlled by feedback based on the position information read by the sensor, so that the mobile platform moves to the specified position along the first linear guide rail.

8. The positioning control method according to claim 6 or 7, characterized in that: Following the first positioning control step and the second positioning control step, there are respectively a first X-ray detection step and a second X-ray detection step. In the first radiation detection step, the radiation beam from the radiation source is detected and the detection data is recorded at the first reference working position and the first calibration working position using the reference ionization chamber and the ionization chamber to be calibrated, respectively. In the second radiation detection step, the radiation beam from the radiation source is detected and the detection data is recorded at the second reference working position and the second calibration working position using the reference ionization chamber and the ionization chamber to be calibrated, respectively. The second positioning control step and the second ray detection step are repeatedly performed to detect the ray beam and record the detection data for multiple given second positioning distances.

9. The positioning control method according to claim 8, characterized in that: The mobile platform is equipped with a lead screw and a second drive motor. The lead screw is parallel to the second linear guide rail, with one end connected to the second drive motor and the other end rotatably fixed to the moving platform. The lead screw passes through a nut-shaped component fixed to the lower surface of the measuring platform, thereby enabling the measuring platform to move in the second direction by rotating the lead screw via the second drive motor. The second drive motor is a servo motor. In the first and second X-ray detection steps, the control device performs feedback control on the second drive motor, causing the measurement platform to move along the second linear guide to a specified position, so that the sensitive center of the reference ionization chamber and the sensitive center of the ionization chamber to be calibrated are respectively aligned with the X-ray beam for X-ray beam detection.

10. The positioning control method according to claim 8, characterized in that: The radiation source includes: an X-ray generating device that generates an X-ray beam radiating in a first horizontal direction; and an X-ray filtering device that filters the X-ray beam generated by the X-ray generating device, the X-ray filtering device being disposed between the X-ray generating device and the position adjustment device in the first direction. Multiple different radiation qualities can be obtained by changing the parameters of the X-ray filtering device. In the first and second radiation detection steps, for each radiation source, the radiation beam is detected and the detection data is recorded.

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