A synchronous scanning system and a synchronous scanning method

Abstract

The present application provides a synchronous scanning system and a synchronous scanning method. The synchronous scanning system provided by the present application includes an accelerator, a lifting platform, a linear array detector, a motion controller, a field programmable gate array FPGA and a data processing unit. The scanning system provided by the present application can accurately control the starting position, sampling position and end position of the sampling during each scanning process, can avoid the sampling inconsistency problem caused by speed changes or pulse triggering errors, ensure the sampling position, accelerator beam output and linear array detector acquisition are strictly synchronized, and ensure the position accuracy and consistency of multiple scans. Furthermore, on this basis, the synchronous scanning method provided by the present application can ensure the consistency of the position of multiple scans during multiple object scanning processes. By micro-moving the linear array detector and multiple scans, the originally large detector channel spacing can be indirectly greatly reduced to generate a higher resolution scan image.

Description

Technical Field

[0001] The present application relates to the technical field of non-destructive testing digital scanning and imaging, and in particular to a synchronous scanning system and a synchronous scanning method. Background Art

[0002] With the rapid development of science and technology and the continuous improvement of automation level, synchronous scanning systems have been widely used in the field of industrial digital non-destructive testing. For example, synchronous scanning systems can be used to detect internal defects of workpieces. Through synchronous scanning systems, not only can strict control of product quality be achieved, but also detection efficiency can be improved.

[0003] In recent years, in order to further improve the inspection quality, it is often necessary to scan the product multiple times and conduct a comprehensive evaluation of the product based on the data obtained from multiple scans. When performing multiple scans, in order to ensure the position accuracy and synchronization of multiple sampling scans, it is necessary to ensure that the starting position and the ending position of each scan are completely consistent. Therefore, the development and optimization of related technologies are attracting more and more attention from researchers and engineers. Summary of the invention

[0004] In view of this, the present application provides a synchronous scanning system and a synchronous scanning method to ensure that the starting position and the ending position of each object scanning are completely consistent. Furthermore, on this basis, the purpose of improving the resolution is achieved through multiple scanning.

[0005] Specifically, the present application is implemented through the following technical solutions:

[0006] The first aspect of the present application provides a synchronous scanning system, which includes an accelerator, a lifting platform, a linear array detector, a motion controller, a field programmable gate array FPGA and a data processing unit; wherein,

[0007] The motion controller is used to control the lifting platform to accelerate from rest to a preset speed, and to set the sampling enable signal to 0 before reaching the preset speed; the motion controller is also used to record the sampling starting position after reaching the preset speed, and to set the sampling enable signal to 1 to indicate the entry into the sampling phase; the motion controller is also used to control the lifting platform to move at a constant speed at the preset speed for a first preset distance and then reach the end position during the sampling phase; the motion controller is also used to set the sampling enable signal to 0 after reaching the end position to indicate the end of sampling, and to control the lifting platform to decelerate to stop after the end of sampling, thereby completing a load scanning process;

[0008] The motion controller is further used to generate an initial pulse signal for synchronously triggering the accelerator to emit beams and the linear array detector to collect data each time the lifting platform moves a second preset distance during a scanning sampling process;

[0009] The FPGA is used to generate a first synchronization pulse signal for driving the accelerator and a second synchronization pulse signal for driving the linear array detector according to a sampling enable signal and an initial pulse signal from the motion controller; wherein, when the sampling enable signal is at a low level, the FPGA generates a target pulse signal by itself, and uses the target pulse signal as the first synchronization pulse signal of the accelerator, so as to control the accelerator to generate rays in advance and achieve stability, and control the linear array detector not to perform sampling at this stage; when the sampling enable signal is at a high level, the FPGA switches to use the initial pulse signal as both the first synchronization pulse signal and the second synchronization pulse signal, so as to control the accelerator to generate rays continuously and the linear array detector starts synchronous acquisition; wherein, the target pulse signal and the initial pulse signal generated by the FPGA by itself have the same frequency, so as to ensure that the rays of the accelerator remain stable;

[0010] The linear array detector is used to perform photoelectric conversion and analog-to-digital conversion on the collected signals, and transmit the converted data to the data processing unit; the data processing unit is used to generate a frame of scanned image according to the converted data.

[0011] A second aspect of the present application provides a synchronous scanning method, the synchronous scanning method comprising:

[0012] For a workpiece to be scanned, use any one of the synchronous scanning systems provided in the first aspect of the present application to perform a load scanning;

[0013] The linear array detector is fine-moved once according to a preset fine-movement distance; wherein the preset fine-movement distance is equal to L / (n+1); L is the spacing of the linear array detector channels, n is the number of encrypted sampling times, and n is a positive integer;

[0014] The linear array detector performs another object scan based on the micro-motion;

[0015] When the total number of object scanning times does not reach n+1 times, the step of fine-moving the linear array detector once according to the preset fine-movement distance is performed again until the total number of object scanning times reaches n+1 times;

[0016] The n+1 frames of scanned images obtained by the n+1 object scans are interpolated to obtain a final scanned image.

[0017] The scanning system provided by the present application, on the one hand, uses a motion controller to accurately control the movement of the lifting platform, and outputs a sampling enable signal to the FPGA during the acceleration, uniform speed and deceleration stages of the lifting platform, so that the FPGA can accurately control when to sample based on the sampling enable signal, thereby ensuring that the starting position and ending position of each sampling are consistent; on the other hand, during the sampling stage, the FPGA can divide the initial pulse signal generated by the motion controller into two paths as synchronous pulse signals for the accelerator and the linear array detector, thereby ensuring that the accelerator beam is synchronized with the detector acquisition, thereby ensuring that during each sampling period, the ray generation and detection are accurately corresponded, and further, by generating an initial pulse signal every time the lifting platform moves a second preset distance, the consistency of each sampling position during the scanning process can be ensured; in summary, the scanning system can accurately control the starting position of the sampling during each scanning process, thereby avoiding the problem of inconsistent sampling positions due to speed changes or pulse triggering errors, thereby ensuring the position accuracy and consistency of multiple scans.

[0018] The scanning method provided in the present application, for the workpiece to be scanned, performs a load scan once by using the above scanning system, and micro-moves the linear array detector once according to a preset micro-movement distance, and then performs another load scan based on the linear array detector after micro-movement, and when the total number of load scans does not reach n+1 times, the step of micro-moving the linear array detector once according to the preset micro-movement distance is performed again until the total number of load scans is equal to n+1 times, and finally interpolates the n+1 frames of scanned images obtained by the n+1 load scans to obtain the final scanned image. Among them, the preset micro-movement distance is equal to L / (n+1); the L is the spacing of the linear array detectors, so that by micro-moving the linear array detector and multiple scans, the originally large detector channel spacing can be indirectly greatly reduced to generate a higher resolution scanned image. In addition, the method has relatively low requirements for the linear array detector, and the resolution of the final scanned image can be improved by the method without significantly increasing the hardware cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a scanning system shown as an exemplary embodiment of the present application;

[0020] Figure 2 This is a working timing diagram of a scanning system according to an exemplary embodiment of the present application;

[0021] Figure 3 The following is a schematic diagram showing the cooperation principle of the motion controller and the FPGA for an exemplary embodiment of the present application;

[0022] Figure 4 A diagram showing the coordination relationship between an accelerator and a linear array detector according to an exemplary embodiment of the present application;

[0023] Figure 5 This is a schematic diagram showing the implementation principle of the micro-motion of a linear array detector according to an exemplary embodiment of the present application;

[0024] Figure 6 This is a timing diagram of air correction scanning shown in another exemplary embodiment of the present application;

[0025] Figure 7 A flowchart of a first embodiment of the synchronous scanning method provided by the present application;

[0026] Figure 8 The overall timing diagram of the synchronous scanning method shown in an exemplary embodiment of the present application;

[0027] Fig. 9 This is a diagram showing the implementation principle of image interpolation according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0028] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0029] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0030] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0031] It should be noted that in conventional scanning systems, the number of channels of linear array detectors can generally reach hundreds to thousands. Due to the difficulty and cost of crystal processing, the channel spacing cannot be further reduced, resulting in the inability to further improve the resolution of the scanned image. The use of the encrypted sampling method, that is, by slightly moving the detector position, can equivalently reduce the detector spacing, thereby improving the image resolution.

[0032] Specifically, in the encrypted sampling method, the X-ray corresponding to the linear array detector is a fan-shaped beam, which scans the workpiece to be measured, and then the scanned images obtained by each scan are interpolated to form a higher pixel and clearer scanned image, thereby improving the resolution of the image and improving the image quality. The specific implementation principle and implementation method of the encrypted sampling method will be described in detail in the scanning method below, and will not be repeated here.

[0033] It is understandable that in order to ensure that the interpolated scanned image is not misaligned due to different positions, it is necessary to ensure that the starting and ending positions and the sampling positions in between are completely consistent each time the encrypted sampling is performed. The present application provides a synchronous scanning system, which can ensure that the starting and ending positions during scanning are completely consistent, and then multiple encrypted sampling can be performed based on this scanning system, and the final scanned image can be interpolated based on the multiple scanned images obtained by the multiple encrypted sampling, so as to improve the resolution of the scanned image and improve the image quality.

[0034] Specific embodiments are given below to introduce the technical solution of the present application in detail.

[0035] Figure 1 This is a schematic diagram of a scanning system shown in an exemplary embodiment of the present application. Figure 1 The scanning system provided in this embodiment includes an accelerator, a lifting platform, a linear array detector, a motion controller, a field-editable gate array FPGA and a data processing unit; wherein,

[0036] The synchronous scanning system includes an accelerator, a lifting platform, a linear array detector, a motion controller, a field programmable gate array FPGA and a data processing unit; wherein,

[0037] The motion controller is used to control the lifting platform to accelerate from rest to a preset speed, and to set the sampling enable signal to 0 before reaching the preset speed; the motion controller is also used to record the sampling starting position after reaching the preset speed, and to set the sampling enable signal to 1 to indicate the entry into the sampling phase; the motion controller is also used to control the lifting platform to move at a constant speed at the preset speed for a first preset distance and then reach the end position during the sampling phase; the motion controller is also used to set the sampling enable signal to 0 after reaching the end position to indicate the end of sampling, and to control the lifting platform to decelerate to stop after the end of sampling, thereby completing a load scanning process;

[0038] The motion controller is further used to generate an initial pulse signal for synchronously triggering the accelerator to emit beams and the linear array detector to collect data each time the lifting platform moves a second preset distance during a scanning sampling process;

[0039] The FPGA is used to generate a first synchronization pulse signal for driving the accelerator and a second synchronization pulse signal for driving the linear array detector according to a sampling enable signal and an initial pulse signal from the motion controller; wherein, when the sampling enable signal is at a low level, the FPGA generates a target pulse signal by itself, and uses the target pulse signal as the first synchronization pulse signal of the accelerator, so as to control the accelerator to generate rays in advance and achieve stability, and control the linear array detector not to perform sampling at this stage; when the sampling enable signal is at a high level, the FPGA switches to use the initial pulse signal as both the first synchronization pulse signal and the second synchronization pulse signal, so as to control the accelerator to generate rays continuously and the linear array detector starts synchronous acquisition; wherein, the target pulse signal and the initial pulse signal generated by the FPGA by itself have the same frequency, so as to ensure that the rays of the accelerator remain stable;

[0040] The linear array detector is used to perform photoelectric conversion and analog-to-digital conversion on the collected signals, and transmit the converted data to the data processing unit; the data processing unit is used to generate a frame of scanned image according to the converted data.

[0041] Figure 2 This is a working timing diagram of the scanning system shown in an exemplary embodiment of the present application. Please also refer to Figure 1 and Figure 2 In this application, the scanning system divides a load scanning process into three stages, which are the acceleration stage, the sampling stage (uniform speed stage) and the deceleration stage.

[0042] It should be noted that the lifting platform can move up and down in the vertical direction; further, the object scanning refers to the scanning process of an object placed on the lifting platform. Optionally, in a possible implementation, during a scanning process, the object carried by the lifting platform is a workpiece, and the motion controller controls the lifting platform, and the lifting platform drives the workpiece to move up and down to perform corresponding scanning.

[0043] Please also refer to Figure 1 and Figure 2 During the object scanning process, the motion controller controls the lifting platform to move in the vertical direction. It can be understood that the scanning system also includes a motor, and the motion controller directly controls the motor, which drives the lifting platform to move; further, the movement of the lifting platform is divided into three stages, which are the acceleration stage, the uniform speed stage and the deceleration stage; wherein, in the acceleration stage, the lifting platform accelerates from rest to a preset speed and reaches the sampling start position; in the uniform speed stage, the lifting platform moves at a preset speed for a first preset distance and then reaches the end position; in the deceleration stage, the lifting platform decelerates from the end position to stop.

[0044] It should be noted that the preset speed is set according to actual needs, and is not limited in this embodiment. Further, the first preset distance is also set according to actual needs, and is not limited in this embodiment.

[0045] Furthermore, in a possible implementation, a speed sensor and a displacement sensor are provided at the lifting platform. The speed sensor is used to monitor the speed of the lifting platform and feed back the monitored speed to the motion controller; the displacement sensor is used to detect the displacement of the lifting platform and feed back the monitored displacement to the motion controller. For example, in one embodiment, a position sensor can be installed in the vertical direction beside the lifting platform. It should be noted that a suitable position sensor can be selected according to actual needs; for example, in one embodiment, an optical encoder can be selected to monitor the displacement; for another example, please refer to Figure 1 In another embodiment, a grating ruler can be selected to monitor the displacement.

[0046] In addition, it should be noted that, in the acceleration phase, the acceleration of the lifting platform is a fixed preset value. In a possible implementation, the motion controller can determine whether the speed of the lifting platform reaches the preset speed by monitoring the duration of the acceleration phase.

[0047] Furthermore, during a load scanning process, the motion controller generates a sampling enable signal and sends the sampling enable signal to the FPGA (Field-Programmable Gate Array, referred to as FPGA). Figure 1 and Figure 2 In the acceleration phase, the sampling enable signal is set to 0, in the sampling phase, the sampling enable signal is set to 1, and in the deceleration phase, the sampling enable signal is set to 0 again. By feeding back the sampling enable signal to the FPGA, the FPGA can know the current phase.

[0048] Referring to the previous description, the motion controller is used to control the lifting platform to accelerate from rest to a preset speed, and set the sampling enable signal to 0 before reaching the preset speed; after reaching the preset speed, the sampling enable signal is set to 1, and the sampling starting position is recorded at the same time, the system enters the sampling stage, and controls the lifting platform to move at a constant speed at the preset speed for the first preset distance and then reach the end position, the sampling enable signal is set to 0, the sampling ends, and the lifting platform decelerates to stop, thereby completing a scanning motion process.

[0049] Furthermore, the motion controller is also used to generate an initial pulse signal every time the lifting platform moves a second preset distance during a load scanning process.

[0050] It should be noted that the specific value of the second preset distance is set according to actual needs and is not limited here.

[0051] Please refer to Figure 2 It can be understood that after the lifting platform starts to move, the motion controller starts to generate an initial pulse signal; further, in the acceleration stage, since the speed of the lifting platform is changing, the time corresponding to each movement of the second preset distance is changing, and at this time, the initial pulse signal generated is an uneven pulse signal; further, in the uniform speed stage, the time corresponding to each movement of the second preset distance is fixed, and at this time, the initial pulse signal generated is a uniform pulse signal; further, in the deceleration stage, similarly, since the speed of the lifting platform is changing, the time corresponding to each movement of the second preset distance is changing, and at this time, the initial pulse signal generated is an uneven pulse signal.

[0052] Specifically, referring to the above description, a grating ruler can be used to monitor the distance moved by the lifting platform, and then an initial pulse signal is generated every time the lifting platform moves a second preset distance.

[0053] It should be noted that in the present application, during a load scanning process, it is desired to perform sampling evenly from the starting position (the position when the speed of the lifting platform reaches the preset speed is the starting position) to the ending position, that is, from the starting position to the ending position, the positions of the workpiece scanning samples are evenly distributed. Therefore, a grating ruler can be used to monitor the distance moved by the lifting platform. Every time the lifting platform drives the workpiece to rise the same second preset distance, an initial pulse signal is generated by the motion controller. This signal is used to synchronously trigger the accelerator beam output and the linear array detector for collection.

[0054] Referring to the previous description, since the initial pulse signal is uneven during the acceleration stage and the deceleration stage, the initial pulse signal cannot be directly used as the trigger pulse signal of the accelerator and the linear array detector. In this application, FPGA is introduced to generate the trigger pulse signal of the accelerator and the linear array detector.

[0055] Figure 3 This is an exemplary embodiment of the present application showing the coordination principle diagram of the motion controller and the FPGA. Figure 3 It can be understood that the FPGA is connected to the motion controller, the accelerator and the linear array detector respectively, and receives the sampling enable signal and the initial pulse signal from the motion controller, and based on this, generates a first synchronization pulse signal for driving the accelerator and a second synchronization pulse signal for driving the linear array detector.

[0056] The following is a brief introduction to the working principle of FPGA:

[0057] For details, please continue to refer to Figure 2 ,First, FPGA learns the current stage by sampling the enable signal. ,Further, according to the current stage, it determines whether to trigger the accelerator beam ,out alone, or to trigger the accelerator beam out and the linear array detector ,collection at the same time.

[0058] It should be noted that in this application, it is hoped that the accelerator will emit a beam and remain stable before the linear array detector starts sampling. Furthermore, it is hoped that sampling will be performed from the start position to the end position, that is, sampling will be performed only during the sampling phase. Figure 2 When the sampling enable signal is at a low level, the FPGA generates a first synchronization pulse signal which is only used to drive the accelerator to control the accelerator to generate rays, and the linear array detector does not perform sampling.

[0059] Furthermore, when the sampling enable signal is at a high level, the FPGA switches to the initial pulse signal generated by the motion controller, which is used to drive the first synchronization pulse signal of the accelerator and the second synchronization pulse signal of the linear array detector, so as to control the accelerator to generate rays and the linear array detector to perform synchronous sampling.

[0060] In other words, during the acceleration of the lifting platform and the previous stage, the FPGA works in the first mode. In the first mode, the FPGA generates a target pulse signal by itself, and uses the target pulse signal generated by itself as the first synchronization pulse signal for driving the accelerator. The accelerator starts to emit beams driven by the first synchronization pulse signal, so that when the linear array detector starts to collect, the dose of the accelerator can be stabilized; further, in the sampling stage, the FPGA switches to the second mode. In the second mode, the FPGA divides the initial pulse signal generated by the motion controller into two paths, one as the first synchronization pulse signal, and the other as the second synchronization pulse signal. At this time, the accelerator and the linear array detector work synchronously; further, in the deceleration stage after the sampling is completed, the FPGA switches back to the first mode, the FPGA generates a target pulse signal by itself, and uses the target pulse signal as the first synchronization pulse signal for driving the accelerator, that is, in the deceleration stage, only the accelerator is emitting beams, and the linear array detector does not perform sampling, and finally the accelerator stops emitting beams.

[0061] It should be noted that since the X-rays generated by the accelerator are pulsed and very short, only 4.5us, the sampling time of the linear array detector must cover the beam emission time of the accelerator, so strict synchronization of the two is required.

[0062] In the present application, during the sampling phase, it is necessary to ensure that the trigger pulse of the accelerator and the acquisition pulse of the linear array detector are strictly synchronized, that is, it is necessary to ensure that the first synchronization pulse signal and the second synchronization pulse signal are strictly synchronized. Referring to the previous description, it can be seen that during the sampling phase, the initial pulse signal generated by the motion controller is uniform. Therefore, during the sampling phase, the FPGA can use the initial pulse signal generated by the motion controller as the first synchronization pulse signal and the second synchronization pulse signal at the same time, that is, the initial pulse signal is divided into two paths, one of which triggers the accelerator to emit a beam, and the other triggers the linear array detector to collect.

[0063] For further information, please refer to Figure 2 In the acceleration and deceleration stages, the FPGA generates a first synchronization pulse signal for triggering the accelerator to emit a beam. In specific implementation, the FPGA can be informed in advance of the period of the initial pulse signal generated by the motion controller and the duration of the high level, and then the FPGA generates the first synchronization pulse signal based on this, that is, the period and duration of the high level of the generated first synchronization pulse signal are consistent with the period and duration of the high level of the initial pulse signal.

[0064] For details, please continue to refer to Figure 1 The linear array detector is also used to process the collected sampling signals and transmit them to the data processing unit, and the data processing unit generates a frame of scanned images according to the collected signals. The specific implementation process and implementation principle of the data processing unit generating a frame of scanned images according to the collected signals refer to the description in the related art, which will not be repeated here.

[0065] With reference to the above description, it can be understood that the scanning system provided by the present application can ensure:

[0066] (1) The accelerator can emit a beam and remain stable before the linear array detector starts collecting data;

[0067] (2) Each time the object is scanned, the collected workpiece positions (starting position, ending position, and each sampling position between the starting position and the ending position) are completely consistent;

[0068] (3) The trigger pulse of the accelerator and the acquisition pulse of the linear array detector are strictly synchronized.

[0069] Furthermore, Figure 4 This is a diagram showing the coordination relationship between the accelerator and the linear array detector according to an exemplary embodiment of the present application. Figure 4 In a possible implementation, the linear array detector is an arc-shaped linear array detector; the detection surface of the linear array detector device has N detector channels; and the N detector channels are arranged at equal intervals.

[0070] It should be noted that the specific number of detector channels is set according to actual needs and is not limited in this embodiment.

[0071] Figure 5 This is a schematic diagram showing the implementation principle of the micro-motion of the linear array detector according to an exemplary embodiment of the present application. Figure 5 In the present application, the linear array detector can slightly move along one side of the detection surface, that is, the linear array detector can move as a whole along one side of the detection surface. Specifically, Figure 5 In the figure, for the convenience of distinction, a group of red detector channels are used to represent the linear array detectors before the micro-motion, and a group of yellow detector channels are used to represent the linear array detectors after the micro-motion. By interpolating the data collected by the detection channels before and after the micro-motion of the linear array detector, the density of the detection channels can be equivalently improved to obtain a scanning image with higher resolution. The specific implementation principle and implementation process of the interpolation will be described in detail in the following embodiments and will not be repeated here.

[0072] The scanning system provided in this embodiment, on the one hand, accurately controls the movement of the lifting platform through a motion controller, and adjusts the sampling enable signal output to the FPGA during the acceleration, uniform speed and deceleration stages of the lifting platform, so that the FPGA can accurately control when to sample based on the sampling enable signal, thereby ensuring that the starting position and ending position of each sampling are consistent; on the other hand, during the sampling stage, the FPGA uses the initial pulse signal as the driving signal of the accelerator and the linear array detector at the same time, thereby ensuring that the accelerator and the detector operate synchronously, thereby ensuring that during each sampling period, the ray generation and detection are accurately corresponded, and further, by generating an initial pulse signal every time the lifting platform moves a second preset distance, the consistency of each sampling position during the scanning process can be ensured; in summary, the scanning system can accurately control the starting position, sampling position and ending position of the sampling during each scanning process, thereby avoiding the sampling inconsistency problem caused by speed changes or pulse triggering errors, thereby ensuring the accuracy and consistency of multiple scans.

[0073] Furthermore, in order to improve the quality of the scanned image, it is necessary to use the air correction image to perform air correction on the scanned image. The specific implementation process and implementation principle of the scanning system to obtain the air correction image are introduced below:

[0074] Optionally, in a possible implementation, the motion controller is further used to send an air correction enable signal to the FPGA when acquiring air correction data; wherein, when the synchronous scanning system acquires air correction data, the lifting platform is in a stationary state and is outside the field of view of the linear array detector; the air correction enable signal is composed of a low level that lasts for a first preset time length, a high level that lasts for a second preset time length, and a low level that lasts for a third preset time length;

[0075] The FPGA is further used to generate an air correction synchronization pulse signal by itself, and send the air correction synchronization pulse signal to the accelerator within a first time range when the air correction enable signal persists, and send the air correction synchronization pulse signal to the linear array detector to start acquisition within a second time range when the air correction enable signal is at a high level, so that the accelerator continues to generate rays and remains stable within the first time range, and the linear array detector only performs sampling within the second time range;

[0076] The linear array detector is further used to send the collected air correction data to the data processing unit;

[0077] The data processing unit is further used to store the air correction data so as to perform air correction of the image using the air correction data.

[0078] It should be noted that when acquiring air correction data, there is no workpiece between the accelerator and the linear array detector, the lifting platform is stationary and outside the field of view of the linear array detector, the accelerator generates X-rays, and the linear array detector collects data synchronously. Since the turntable is stationary, the motion controller does not generate an initial pulse signal. Therefore, at this time, the synchronous pulse signals of the accelerator and the linear array detector are generated by the FPGA itself.

[0079] Specifically, Figure 6 For another exemplary embodiment of the present application, please refer to the air correction scan timing diagram. Figure 6 In the initial stage, the air correction enable signal is a low level signal that lasts for a first preset time period; in the middle stage, the air correction enable signal is a high level signal that lasts for a second preset time period; in the end stage, the air correction enable signal is a low level signal that lasts for a third preset time period.

[0080] It should be noted that the first preset time length, the second preset time length and the third preset time length are set according to actual needs. In this embodiment, the air correction enable signal is not limited thereto.

[0081] Furthermore, in the process of acquiring the air correction image, the air correction pulse signal is generated by the FPGA; further, the FPGA determines whether to trigger the accelerator alone or the accelerator and the linear array detector at the same time according to whether it is a high level or a low level. Specifically, within the first time range when the air correction enable signal lasts, the air correction pulse signal is sent to the accelerator; further, when the air correction enable signal is at a high level, the air correction pulse signal is sent to the linear array detector, so that the accelerator can continuously generate rays within the first time range when the air correction enable signal lasts, and the linear array detector only performs sampling within the second time range when the air correction enable signal is at a high level.

[0082] Furthermore, the linear array detector sends the collected data as air correction data to the data processing unit, which processes the air correction data and then performs air correction on the image. When acquiring the air correction data, the motion controller accurately controls the operation of the FPGA through the air correction enable signal, so that the accelerator continues to generate rays within the first time range when the air correction enable signal continues, and the linear array detector only samples within the second time range when the air correction enable signal is at a high level, which can avoid collecting data when the rays are unstable, and can ensure that the linear array detector only samples under stable ray conditions, thereby improving the quality of the sampled data.

[0083] Furthermore, corresponding to the above-mentioned embodiment of a scanning system, the present application also provides an imaging method, and the imaging method provided by the present application is introduced below:

[0084] Figure 7 This is a flowchart of Embodiment 1 of the synchronous scanning method provided by this application. Please refer to Figure 7 , the method provided in this embodiment may include:

[0085] S701 , performing an object scan using a scanning system for a workpiece to be scanned.

[0086] Specifically, the specific implementation principle and implementation process of the object scanning can be found in the previous description, which will not be repeated here.

[0087] S702, fine-tune the linear array detector once according to a preset fine-tune distance; wherein the preset fine-tune distance is equal to L / (n+1); L is the spacing of the linear array detectors, n is the number of encrypted sampling times, and n is a positive integer.

[0088] Specifically, the preset micro-motion distance only needs to be equal to L / (n+1). Furthermore, the specific value of the preset micro-motion distance is set according to actual needs, and is not limited in this embodiment. For example, in one possible implementation, n is equal to 1, and the preset micro-motion distance is equal to L / 2; for another example, in another possible implementation, n is equal to 2, and the preset micro-motion distance is equal to L / 3.

[0089] S703, performing another object scan based on the linear array detector after micro-movement.

[0090] Specifically, after the linear array detector is slightly moved, the linear array detector after the slight movement performs another object scanning. The specific implementation principle and implementation process of the object scanning refer to the description in the previous embodiment, which will not be repeated here.

[0091] S704, when the total number of object scanning times does not reach n+1 times, the step of fine-moving the linear array detector once according to the preset fine-movement distance is executed again until the total number of object scanning times reaches n+1 times.

[0092] It should be noted that when the preset micro-motion distance is equal to L / (n+1), the total number of load scans is n+1 times. For example, when the preset micro-motion distance is L / 2, the total number of load scans is 2 times, that is, a load scan is first performed, and then the linear array detector is micro-moved once, and further, based on the linear array detector after micro-movement, another load scan is performed, and a total of 2 load scans are performed. For another example, when the preset micro-motion distance is L / 3, the total number of load scans is 3 times, that is, a load scan is first performed, and then the linear array detector is micro-moved once, and based on the linear array detector after micro-movement, another load scan is performed, and further, the linear array detector is micro-moved again, and then based on the linear array detector after micro-movement, another load scan is performed, and a total of 3 load scans are performed.

[0093] Referring to the previous description, it can be seen that the total number of load scans is equal to n+1 times, one of which is the load scan before the micro-motion. Furthermore, the linear array detector micro-motions n times, and the distance of each micro-motion is L / (n+1). After each micro-motion, a load scan is performed, that is, the remaining n load scans are the load scans after the micro-motion. Figure 5 , through the micro-motion linear array detector, the equivalent detector spacing is L / (n+1).

[0094] S705 , interpolating the n+1 frames of scanned images obtained by the n+1 object scans to obtain a final scanned image.

[0095] It should be noted that, for the sake of distinction, the initial sampling is recorded as sampling (the sampling before the linear array detector is slightly moved is recorded as sampling), and the object scanning after the linear array detector is slightly moved is recorded as encrypted sampling.

[0096] Figure 8 This is a general timing diagram of a synchronous scanning method according to an exemplary embodiment of the present application. Figure 8 ,During the synchronous scanning process, the entire scanning process includes 1 standard sampling and n encrypted sampling, generating a total of n+1 frames of images.

[0097] Referring to the above description of the object scanning, it can be understood that in each sampling process, the accelerator dose is kept stable, and the accelerator needs to start beaming before the sampling starts, stop beaming after all sampling is completed, and keep the beaming continuously and stably during this period. The linear array detector needs to collect data when it is moving at a uniform speed (i.e., it reaches the sampling start position) during each object scanning process, that is, it collects data when the sampling enable signal is set to 1. Therefore, the first synchronization pulse signal of the accelerator needs to be kept continuous and stable during the whole process, and the second synchronization pulse signal of the linear array detector only needs to be generated when the sampling enable signal is set to 1, and it is synchronized with the first synchronization pulse signal of the accelerator.

[0098] Specifically, when the sampling enable signal is set to 0, the pulse signal generated by the FPGA itself is used as the first synchronization pulse signal of the accelerator; when the sampling enable signal is set to 1, the FPGA receives the initial pulse signal of the motion controller and divides it into two identical pulse signals, one of which is used as the first synchronization pulse signal of the accelerator and the other is used as the second synchronization pulse signal of the linear array detector, thereby achieving synchronization. It should be noted that the pulse signal generated by the FPGA itself has the same frequency as the initial pulse signal of the motion controller.

[0099] Referring to the previous description, it can be understood that after each object scan, a frame of scanning image can be generated based on the signal collected by the linear array detector. After n+1 object scans, n+1 frames of scanning images can be obtained. In this step, after obtaining the n+1 frames of scanning images, these n+1 frames of scanning images are interpolated to obtain the final scanning image.

[0100] Specifically, Fig. 9 This is a schematic diagram showing the implementation principle of image interpolation according to an exemplary embodiment of the present application. Fig. 9 The implementation principle of using three frames of scanned images to interpolate and obtain the final scanned image is shown in FIG. Fig. 9 The specific implementation process of this step may include:

[0101] Step 1. For each detection channel, in accordance with the order of acquisition, the n+1 groups of acquisition data corresponding to the detection channel in the n+1 frame scanning image are used as virtual acquisition data of each group of virtual detection channels; wherein each group of virtual detection channels includes n+1 virtual detection channels corresponding to the n+1 frame scanning image, the detection interval of the n+1 virtual detection channels is L / n+1, and the virtual acquisition data of a virtual detection channel corresponding to a frame scanning image is a group of acquisition data corresponding to the detection channel in the scanning image.

[0102] Step 2: Generate the final scan image based on the virtual acquisition data of the N groups of virtual detection channels.

[0103] See also Fig. 9 For the convenience of explanation, the i-th detection channel in the linear array detector is recorded as Gi, where i ranges from 1 to N. Furthermore, during the j-th object scanning process, the data collected by the i-th detection channel is recorded as A ji , where j ranges from 1 to n+1 and i ranges from 1 to N.

[0104] See also Fig. 9 , Fig. 9 In the example, n is equal to 2. When n is equal to 2, refer to the previous description, a total of 3 load scans are performed. After the first load scan, the data collected by the i-th detection channel is recorded as A 1i , i ranges from 1 to N, and based on the data collected by the N detection channels, a scanned image 1 can be obtained. Further, the linear array detector is slightly moved once (the micro-movement distance of the linear array detector is L / 3), and the linear array detector is slightly moved, and the object is scanned again to obtain a scanned image 2 (in the process of the second object scanning, the data collected by the i-th detection channel is recorded as A 2i , i ranges from 1 to N, and based on the data collected by the N detection channels, a scanned image 2 can be obtained). Further, based on the above, the linear array detector is slightly moved again (the micro-movement distance of the linear array detector is still L / 3, that is, relative to the initial position of the linear array detector, the linear array detector has been micro-moved by 2L / 3 at this time), and after the linear array detector is micro-moved, the object is scanned again to obtain a scanned image 3 (in the process of the third object scan, the data collected by the i-th detection channel is recorded as A 3i , i ranges from 1 to N, and based on the data collected by N detection channels, a scanned image 3 can be obtained.

[0105] For further information, please refer to Figure 8 In step 1, for each detection channel, according to the order of acquisition, the n+1 groups of acquisition data corresponding to the detection channel in the n+1 frame scanning image are used as the acquisition data of each group of virtual detection channels, that is, the acquisition data of N groups of virtual detection channels can be obtained.

[0106] It should be noted that each group of virtual detection channels consists of n+1 virtual detection channels. Fig. 9 In , each group of virtual detection channels consists of 3 virtual detection channels. For further information, see Figure 5 It can be understood that the detection spacing of these n+1 virtual detection channels is L / n+1.

[0107] Furthermore, for each group of virtual detection channels, according to the order of acquisition, it includes n+1 virtual detection channels corresponding to n+1 frames of scanned images. Figure 8In the order from front to back, it includes a first virtual detection channel corresponding to scan image 1, a second virtual detection channel corresponding to scan image 2, and a third virtual detection channel corresponding to scan image 3, which includes a total of 3 virtual detection channels. For further information, see Figure 8 , the acquisition data of a virtual detection channel corresponding to a frame of scanned image is a group of acquisition data corresponding to the detection channel in the scanned image.

[0108] Furthermore, after obtaining the acquisition data of N groups of virtual detection channels, the (n+1)*N virtual detection channels contained in these N groups of virtual detection channels can be regarded as actual detection channels, and then the final scanning image can be generated based on the acquisition data of these (n+1)*N virtual detection channels.

[0109] See also Fig. 9 The final scanned image obtained by the above method is equivalent to a linear array detector having (n+1)*N detection channels and a detection spacing of L / n+1, which can improve the resolution of the final scanned image and improve the quality of the final scanned image.

[0110] The method provided in this embodiment is to scan the workpiece to be scanned by using the above scanning system, and to micro-move the linear array detector once according to the preset micro-motion distance, and then to scan the workpiece again based on the linear array detector after micro-motion, and when the total number of scans of the workpiece does not reach n+1 times, the step of micro-moving the linear array detector once according to the preset micro-motion distance is performed again until the total number of scans of the workpiece is equal to n+1 times, and finally the n+1 frames of scanned images obtained by the n+1 scans of the workpiece are interpolated to obtain the final scanned image. Among them, the preset micro-motion distance is equal to L / (n+1); the L is the spacing of the linear array detector, so that by micro-moving the linear array detector and multiple scans, the originally limited detector resolution can be improved to a higher level, and a final scanned image with a higher resolution can be generated. In addition, the method has relatively low requirements for the linear array detector, and the resolution of the final scanned image can be improved by software interpolation method without significantly increasing the hardware cost.

[0111] Optionally, based on the above embodiment, before performing interpolation processing on the n+1 frame scanned image obtained by the n+1 object scans, the method further includes:

[0112] Step 1: Perform a scan using the scanning system without any object loaded to obtain an air correction image.

[0113] Specifically, the specific implementation process and implementation principle of this step can be found in the description of the previous embodiment, and will not be repeated here.

[0114] Step 2: preprocessing the air correction image and the scanned image; wherein the preprocessing includes denoising and smoothing.

[0115] Specifically, after the air correction image is acquired, the air correction image is preprocessed first, and the preprocessing includes denoising processing for reducing noise in the image and smoothing processing for reducing high-frequency noise in the image.

[0116] It can be understood that, through preprocessing, the quality and accuracy of the image can be significantly improved, providing more reliable data for the subsequent correction of the scanned image based on the air correction image.

[0117] Step 3: For each scanned image obtained by scanning the object, the air correction image is used to perform air correction on the scanned image.

[0118] Specifically, after the air correction image is preprocessed, the air correction is performed on the scanned image obtained by each object scanning using the air correction image.

[0119] It should be noted that by using the air correction image to perform air correction on the scanned image, it can be used to correct and compensate for the errors and non-uniformities introduced by the system hardware (such as detectors and accelerators) during the actual scanning process, which can significantly improve the quality of the corrected scanned image, making the image clearer and more accurate, and reducing artifacts and noise, thereby improving the reliability and stability of the entire scanning system.

[0120] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A synchronous scanning system, characterized in that: The synchronous scanning system includes an accelerator, a lifting platform, a linear array detector, a motion controller, a field programmable gate array FPGA and a data processing unit; wherein, The motion controller is used to control the lifting platform to accelerate from rest to a preset speed, and to set the sampling enable signal to 0 before reaching the preset speed; the motion controller is also used to record the sampling starting position after reaching the preset speed, and to set the sampling enable signal to 1 to indicate the entry into the sampling phase; the motion controller is also used to control the lifting platform to move at a constant speed at the preset speed for a first preset distance and then reach the end position during the sampling phase; the motion controller is also used to set the sampling enable signal to 0 after reaching the end position to indicate the end of sampling, and to control the lifting platform to decelerate to stop after the end of sampling, thereby completing a load scanning process; The motion controller is further used to generate an initial pulse signal for synchronously triggering the accelerator to emit beams and the linear array detector to collect data each time the lifting platform moves a second preset distance during a scanning sampling process; The FPGA is used to generate a first synchronization pulse signal for driving the accelerator and a second synchronization pulse signal for driving the linear array detector according to a sampling enable signal and an initial pulse signal from the motion controller; wherein, when the sampling enable signal is at a low level, the FPGA generates a target pulse signal by itself, and uses the target pulse signal as the first synchronization pulse signal of the accelerator, so as to control the accelerator to generate rays in advance and achieve stability, and control the linear array detector not to perform sampling at this stage; when the sampling enable signal is at a high level, the FPGA switches to use the initial pulse signal as both the first synchronization pulse signal and the second synchronization pulse signal, so as to control the accelerator to generate rays continuously and the linear array detector starts synchronous acquisition; wherein, the target pulse signal and the initial pulse signal generated by the FPGA by itself have the same frequency, so as to ensure that the rays of the accelerator remain stable; The linear array detector is used to perform photoelectric conversion and analog-to-digital conversion on the collected signals, and transmit the converted data to the data processing unit; the data processing unit is used to generate a frame of scanned image according to the converted data.

2. The synchronous scanning system according to claim 1, characterized in that: The motion controller is further used to send an air correction enable signal to the FPGA when acquiring air correction data; wherein, when the synchronous scanning system acquires air correction data, the lifting platform is in a stationary state and is outside the field of view of the linear array detector; the air correction enable signal is composed of a low level that lasts for a first preset time length, a high level that lasts for a second preset time length, and a low level that lasts for a third preset time length; The FPGA is further used to generate an air correction synchronization pulse signal by itself, and send the air correction synchronization pulse signal to the accelerator within a first time range when the air correction enable signal persists, and send the air correction synchronization pulse signal to the linear array detector to start acquisition within a second time range when the air correction enable signal is at a high level, so that the accelerator continues to generate rays and remains stable within the first time range, and the linear array detector only performs sampling within the second time range; The linear array detector is further used to send the collected air correction data to the data processing unit; The data processing unit is further used to store the air correction data so as to perform air correction of the image using the air correction data.

3. The synchronous scanning system according to claim 1, characterized in that: The linear array detector is an arc-shaped linear array detector; the detection surface of the linear array detector device is provided with N detector channels; the N detector channels are arranged at equal intervals.

4. The synchronous scanning system according to claim 3, characterized in that: The linear array detector can slightly move along one side of the detection surface.

5. The synchronous scanning system according to claim 4, characterized in that: The distance of each micro-movement of the linear array detector is equal to L / (n+1); L is the spacing between the channels of the linear array detector, and n is a positive integer.

6. The synchronous scanning system according to claim 1, characterized in that: During a scanning process, the object carried on the lifting platform is a workpiece to be measured.

7. A synchronous scanning method, characterized in that: The synchronous scanning method comprises: For a workpiece to be scanned, use the synchronous scanning system described in any one of claims 1 to 6 to perform a load scanning; The linear array detector is fine-moved once according to a preset fine-movement distance; wherein the preset fine-movement distance is equal to L / (n+1); L is the spacing of the linear array detector channels, n is the number of encrypted sampling times, and n is a positive integer; The linear array detector performs another object scan based on the micro-motion; When the total number of object scanning times does not reach n+1 times, the step of fine-moving the linear array detector once according to the preset fine-movement distance is performed again until the total number of object scanning times reaches n+1 times; The n+1 frames of scanned images obtained by the n+1 object scans are interpolated to obtain a final scanned image.

8. The synchronous scanning method according to claim 7, characterized in that: The synchronous scanning method also includes: In the case of no object being loaded, performing a scan using the synchronous scanning system to obtain air correction data; Before interpolation processing is performed on the n+1 frames of scanned images obtained by the n+1 object scans, air correction is performed on the scanned images obtained by each object scan using the air correction data.

9. The synchronous scanning method according to claim 8, characterized in that: Before performing air correction on the scanned image using the air correction data, the method further includes: The air correction data and the scanned image are preprocessed.

10. The synchronous scanning method according to claim 7, characterized in that: The n is 2.

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