X-ray imaging equipment control methods, X-ray imaging equipment and storage media

Abstract

This application provides a control method for an X-ray imaging device, an X-ray imaging device, and a storage medium, belonging to the field of X-ray imaging device control technology. The method includes: determining a first PWM duty cycle based on a tube current feedback signal; determining a second PWM duty cycle based on a tube voltage feedback signal; determining a third PWM duty cycle based on the first and second PWM duty cycles; determining a target weight based on the primary current and attenuation coefficient; and obtaining a target PWM duty cycle based on the third PWM duty cycle and the target weight. The control of the target PWM duty cycle simultaneously considers the adjustment of the X-ray tube's voltage and current. Compared to adjustments based on a single control parameter or simple switching, this method offers higher adjustment accuracy. By adjusting the accuracy and response speed of the target voltage in a single cycle, the stability of the tube voltage and current is improved, ensuring that the imaging quality and radiation dose of the X-ray image formed by the X-ray tube meet medical requirements.

Description

Technical Field

[0001] This application relates to the field of X-ray imaging equipment control technology, and in particular to an X-ray imaging equipment control method, an X-ray imaging equipment, and a storage medium. Background Technology

[0002] In X-ray imaging equipment, a high-voltage generator typically provides a DC voltage to the X-ray tube, creating a high-voltage electric field inside the tube. This field accelerates thermionic electrons from the cathode, bombarding the anode target and generating X-rays. Medical applications often demand extremely high image quality and radiation dose from X-rays. Both image quality and radiation dose are directly related to the DC voltage provided by the high-voltage generator. Therefore, to obtain X-ray images that meet medical requirements for image quality and radiation dose control, the output waveform must have extremely low overshoot and a very fast response speed. However, in actual operating environments, the high-frequency switching noise generated by the inverter circuit of the high-voltage generator severely interferes with the detection accuracy of the feedback sampling signal. Consequently, when DC voltage control is performed based on the feedback sampling signal, the tube voltage and current of the X-ray tube still exhibit poor stability, ultimately resulting in X-ray image quality and radiation dose that fail to meet medical requirements. Summary of the Invention

[0003] The main objective of this application is to provide an X-ray imaging equipment control method, an X-ray imaging equipment, and a storage medium, which aims to improve the stability of the tube voltage and tube current of the X-ray tube, thereby enabling the imaging quality and radiation dose of the X-ray image formed by the X-ray tube to meet medical needs.

[0004] To achieve the above objectives, a first aspect of this application provides a method for controlling an X-ray imaging device, the X-ray imaging device including a high-voltage generator and an X-ray tube, the method comprising: Acquire electrical signal sampling feedback data, wherein the electrical signal sampling feedback data includes the primary current of the high voltage generator, the tube current feedback signal of the X-ray tube, and the tube voltage feedback signal; Based on the tube current feedback signal, a first PWM duty cycle is determined, wherein the first PWM duty cycle is used to make the actual tube current of the X-ray tube match a preset tube current setting value. Based on the tube voltage feedback signal, a second PWM duty cycle is determined, wherein the second PWM duty cycle is used to make the actual tube voltage of the X-ray tube match the preset tube voltage setting value; The third PWM duty cycle is determined based on the first PWM duty cycle and the second PWM duty cycle; The target weight is determined based on the primary-side current and attenuation coefficient. The target PWM duty cycle is obtained by weighting the third PWM duty cycle and the target weight. Based on the target PWM duty cycle, a control signal is output to the high-voltage generator to control the high-voltage generator to output the target voltage to the X-ray tube.

[0005] To achieve the above objectives, a second aspect of this application provides an X-ray imaging device, which includes an X-ray tube; a high-voltage generator; a DSP control unit, wherein the PWM control terminal of the DSP control unit is connected to the high-voltage generator; the sampling terminal of the DSP control unit is connected to the X-ray tube; and a memory storing a computer program, which, when executed by the DSP control unit, implements the method described in the first aspect.

[0006] To achieve the above objectives, a third aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0007] The X-ray imaging equipment control method, X-ray imaging equipment, and storage medium proposed in this application acquire electrical signal sampling feedback data, including the primary current of the high-voltage generator, the tube current feedback signal of the X-ray tube, and the tube voltage feedback signal. Based on the tube current feedback signal and the tube voltage feedback signal, a first PWM duty cycle and a second PWM duty cycle are determined respectively. Based on the first PWM duty cycle and the second PWM duty cycle, a third PWM duty cycle is determined. Based on the primary current and the attenuation coefficient, a target weight is determined, and the third PWM duty cycle is used to obtain the target PWM duty cycle. Since the determination of the target PWM duty cycle is based on the tube current feedback signal and the tube voltage feedback signal, the control of the target PWM duty cycle can simultaneously take into account the adjustment of the voltage and current of the X-ray tube. Compared with the adjustment method based on a single control parameter for independent adjustment or simple switching, the adjustment accuracy of the embodiments of this application is higher. Furthermore, the target PWM duty cycle in this embodiment is actually determined by the first PWM duty cycle, the second PWM duty cycle, and the attenuation coefficient. In other words, this embodiment is essentially based on a fusion of multiple PI controls. Therefore, this embodiment has a lower risk of over-adjustment while the adjustment process is smoother and the response speed is faster. Thus, this embodiment can improve the stability of the X-ray tube voltage and current by adjusting the accuracy and response speed of the target voltage in a single cycle, thereby ensuring that the imaging quality and radiation dose of the X-ray image formed by the X-ray tube meet medical requirements. Attached Figure Description

[0008] Figure 1This is a flowchart of an X-ray imaging device control method in one embodiment; Figure 2 This is a flowchart illustrating the determination of target weights in an X-ray imaging device control method according to one embodiment; Figure 3 This is a flowchart of the target second-order filter acquisition method of the X-ray imaging device control method in one embodiment; Figure 4 This is a flowchart of the initialization of a second-order filter in an X-ray imaging device control method according to one embodiment; Figure 5 This is a flowchart of a combined control scenario for an X-ray imaging device control method in one embodiment; Figure 6 This is a comparison diagram of the output waveforms of the X-ray imaging equipment control method in one embodiment; Figure 7 This is a schematic diagram of the hardware structure of the X-ray imaging device provided in the embodiments of this application; Figure 8 This is a schematic diagram of the DSP control unit in the X-ray imaging device provided in this application embodiment. Detailed Implementation

[0009] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0010] It should be noted that while the flowchart illustrates a logical order, in some cases, the steps shown or described may be performed in a different order than that shown in the flowchart. The terms "first," "second," etc., used in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0011] Unless otherwise defined, all 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 belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0012] In X-ray imaging equipment, a high-voltage generator typically provides a DC voltage to the X-ray tube, creating a high-voltage electric field inside the tube. This field accelerates thermionic electrons from the cathode, bombarding the anode target and generating X-rays. Medical applications often demand extremely high image quality and radiation dose from X-rays. Both image quality and radiation dose are directly related to the DC voltage provided by the high-voltage generator. Therefore, to obtain X-ray images that meet medical requirements for image quality and radiation dose control, the output waveform must have extremely low overshoot and a very fast response speed. However, in actual operating environments, the high-frequency switching noise generated by the inverter circuit of the high-voltage generator severely interferes with the detection accuracy of the feedback sampling signal. Consequently, when DC voltage control is performed based on the feedback sampling signal, the tube voltage and current of the X-ray tube still exhibit poor stability, ultimately resulting in X-ray image quality and radiation dose that fail to meet medical requirements.

[0013] In X-ray imaging equipment, a high-voltage generator typically provides a DC voltage to the X-ray tube, creating a high-voltage electric field inside the tube. This accelerates thermionic electrons from the cathode, bombarding the anode target and generating X-rays. In the medical field, there are often extremely high requirements for the image quality and radiation dose of X-ray images. Both image quality and radiation dose are related to the DC voltage provided by the high-voltage generator. Therefore, to obtain X-ray images that meet medical requirements for image quality and radiation dose control, the output waveform is often required to have extremely low overshoot and extremely fast response speed. However, in actual working environments, the high-frequency switching noise generated by the inverter circuit of the high-voltage generator severely interferes with the detection accuracy of the feedback sampling signal. Consequently, when DC voltage control is performed based on the feedback sampling signal, the tube voltage and tube current of the X-ray tube still exhibit poor stability, ultimately resulting in X-ray image quality and radiation dose that fail to meet medical requirements. Therefore, this application provides an X-ray imaging equipment control method, an X-ray imaging device, and a storage medium, aiming to ensure the stability of the tube voltage and tube current of the X-ray tube to improve image quality.

[0014] The X-ray imaging device control method, X-ray imaging device and storage medium provided in this application are specifically described through the following embodiments. First, the X-ray imaging device control method in this application embodiment is described.

[0015] The X-ray imaging equipment control method provided in this application relates to the field of X-ray imaging equipment control technology. The X-ray imaging equipment control method provided in this application can be applied to a DSP centralized control unit, which can be applied to a terminal, a server, or software running on either the terminal or the server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, etc.; the server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms; the software can be an application implementing the X-ray imaging equipment control method, but is not limited to the above forms.

[0016] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer X-ray imaging devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0017] Figure 1 This is a schematic flowchart of an optional embodiment of the X-ray imaging equipment control method provided in this application. The X-ray imaging equipment includes a high-voltage generator and an X-ray tube. Figure 1 The method may include, but is not limited to, steps S101 to S106.

[0018] Step S101: Obtain electrical signal sampling feedback data, wherein the electrical signal sampling feedback data includes the primary current of the high voltage generator, the tube current feedback signal of the X-ray tube, and the tube voltage feedback signal. Step S102: Based on the tube current feedback signal, determine the first PWM duty cycle, wherein the first PWM duty cycle is used to make the actual tube current of the X-ray tube match the preset tube current setting value. Step S103: Based on the tube voltage feedback signal, determine the second PWM duty cycle, wherein the second PWM duty cycle is used to make the actual tube voltage of the X-ray tube match the preset tube voltage setting value. Step S104: Take the minimum value between the first PWM duty cycle and the second PWM duty cycle as the third PWM duty cycle; Step S105: If the value of the primary current is greater than the preset upper limit threshold, the preset third weight is used as the target weight. Step S106: If the value of the primary current is less than a preset lower threshold, the preset first weight is used as the target weight. Step S107: When the value of the primary current is greater than the lower threshold and less than the upper threshold, a second weight is determined according to the attenuation coefficient, and the second weight is used as the target weight. The third weight is greater than the second weight, the second weight is greater than the first weight, the third weight is 1, the first weight is 0, the attenuation coefficient is the reciprocal of the threshold range, and the threshold range is determined based on the upper threshold and the lower threshold. Step S108: Calculate the target PWM duty cycle by weighting the third PWM duty cycle and the target weight. Step S109: Based on the target PWM duty cycle, output a control signal to the high voltage generator to control the high voltage generator to output the target voltage to the X-ray tube.

[0019] Since the target PWM duty cycle is determined based on both the tube current feedback signal and the tube voltage feedback signal, the control of the target PWM duty cycle can simultaneously regulate the voltage and current of the X-ray tube. Compared to adjustment methods that rely on independent adjustment of a single control parameter or simple switching, the adjustment accuracy of this embodiment is higher. Furthermore, the target PWM duty cycle of this embodiment is actually determined by the first PWM duty cycle, the second PWM duty cycle, and the attenuation coefficient. In other words, this embodiment is essentially based on a fusion of multiple PI controls. Therefore, the risk of over-adjustment is lower, while the adjustment process is smoother and the response speed is faster. Thus, this embodiment can improve the stability of the tube voltage and current of the X-ray tube by adjusting the accuracy and response speed of the target voltage in a single cycle, thereby ensuring that the imaging quality and radiation dose of the X-ray image formed by the X-ray tube meet medical requirements.

[0020] Here, primary current refers to the current input to the primary winding of the high-voltage generator. Tube voltage feedback signal refers to the signal fed back from the actual high-voltage value applied between the anode and cathode of the X-ray tube. Tube current feedback signal refers to the signal fed back from the actual current value flowing between the cathode and anode of the X-ray tube.

[0021] In this embodiment, there are no restrictions on the sampling method of the electrical signal sampling feedback data. For example, the hardware synchronous triggering function of the PWM module can be used to synchronously sample the primary current of the high voltage generator, the tube current feedback signal of the X-ray tube, and the tube voltage feedback signal at a frequency of 100KHz.

[0022] This application does not limit how the first PWM duty cycle is determined. For example, in some embodiments, the first PWM duty cycle can be determined based on the current closed-loop error between the tube current feedback signal and the tube current setpoint. In other embodiments, the tube current feedback signal can be input into a preset model to obtain the first PWM duty cycle. For example, taking the determination of the first PWM duty cycle based on the current closed-loop error between the tube current feedback signal and the tube current setpoint as an example, the specific steps are as follows: The tube current feedback signal can be filtered to obtain a filtered tube current feedback value; then, based on the preset tube current setpoint and the filtered tube current feedback value, the current closed-loop error of the current cycle is determined; based on the current closed-loop error of the current cycle and the first incremental PI regulator, the duty cycle change output by the first incremental PI regulator is obtained as the first duty cycle change; by accumulating the first duty cycle change of the current cycle with the first PWM duty cycle of the previous cycle, the accumulated result is used as the first PWM duty cycle of the current cycle. This application will not elaborate on these details.

[0023] This application does not limit how the second PWM duty cycle is determined. For example, in some embodiments, the second PWM duty cycle can be determined based on the voltage closed-loop error between the transistor voltage feedback signal and the transistor voltage setpoint. In other embodiments, the transistor voltage feedback signal can be input into a preset model to obtain the second PWM duty cycle. For example, taking the determination of the second PWM duty cycle based on the voltage closed-loop error between the transistor voltage feedback signal and the transistor voltage setpoint as an example, the specific steps are as follows: The transistor voltage feedback signal can be filtered to obtain a filtered transistor voltage feedback value; then, based on the preset transistor voltage setpoint and the filtered transistor voltage feedback value, the voltage closed-loop error of the current cycle is determined; based on the voltage closed-loop error of the current cycle and the second incremental PI regulator, the duty cycle change output by the second incremental PI regulator is obtained as the second duty cycle change; by accumulating the second duty cycle change of the current cycle with the second PWM duty cycle of the previous cycle, the accumulated result is used as the second PWM duty cycle of the current cycle. This application will not elaborate on these details in the embodiments.

[0024] The third PWM duty cycle is determined by comparing the values ​​of the first and second PWM duty cycles. Specifically, the minimum value between the first and second PWM duty cycles is selected as the third PWM duty cycle. It's important to note that the PWM duty cycle directly determines the output energy of the high-voltage generator; a smaller duty cycle results in lower output energy and higher safety. When the duty cycle calculated by the tube current loop is smaller, priority is given to ensuring the control accuracy of the tube current and radiation dose safety. When the duty cycle calculated by the tube voltage loop is smaller, priority is given to ensuring the control accuracy of the tube voltage and high-voltage output safety. This ensures that the output energy is always controlled within a safer loop, fundamentally avoiding output overshoot problems caused by a single loop malfunction.

[0025] Understandably, the lower threshold is a preset safe normal current upper limit, which can be the rated current of the X-ray tube. The upper threshold is a preset maximum allowable operating current, which can be the maximum operating current of the X-ray tube. The third weight is the weight value when the primary current is greater than the upper threshold, which can usually be set to 0, meaning that the duty cycle is completely turned off at this time. The first weight is the weight value when the primary current is less than the lower threshold, which can usually be set to 1, meaning that the duty cycle is fully output at this time. The attenuation coefficient can be calculated based on the difference between the upper and lower thresholds, and can be used to attenuate the weight to 0 when the primary current reaches the upper threshold. Under normal operating conditions where the primary current is lower than the lower threshold, using the first weight as the target weight can reduce the interference with the PWM duty cycle, fully ensuring the control accuracy and fast response characteristics of the tube current and voltage; under warning conditions where the primary current is between the upper and lower thresholds, the target weight is linearly calculated through the attenuation coefficient to achieve smooth and flexible current limiting; under fault conditions where the primary current exceeds the upper threshold, the third weight is directly used as the target weight, which can turn off or reduce the power output and reduce the probability of X-ray tube overcurrent damage.

[0026] Understandably, the attenuation coefficient is determined through the following steps: determining the threshold range based on the upper and lower thresholds; and determining the attenuation coefficient based on the reciprocal of the threshold range. In this embodiment, the upper threshold can be subtracted from the lower threshold to obtain the difference, which is used as the threshold range, and the reciprocal of the threshold range is used as the attenuation coefficient.

[0027] This application does not impose any restrictions on how the target weight is determined. In some embodiments, the target weight can be obtained by multiplying the primary current and the attenuation coefficient.

[0028] Weighted calculation means adjusting the third PWM duty cycle by using the weight coefficient of the target weight as the third PWM duty cycle. In this embodiment of the application, there is no restriction on whether to add redundancy value during the weighted calculation process. Taking the weighted calculation process without adding redundancy value as an example, the target PWM duty cycle is equal to the product of the third PWM duty cycle and the target weight.

[0029] The tube current setting value and tube voltage setting value are preset control targets. The target voltage is the voltage output by the high voltage generator to the X-ray tube. By using the target voltage, the actual tube current of the X-ray tube is matched with the tube current setting value or the actual tube voltage is matched with the tube voltage setting value.

[0030] Understandably, the target PWM duty cycle generates a corresponding inverter drive control signal, which is then output to the drive circuit of the high voltage generator, thereby controlling the drive circuit to output a stable target DC high voltage to the X-ray tube.

[0031] Understandably, the first PWM duty cycle is periodically acquired. Based on the tube current feedback signal, the first PWM duty cycle is determined. The step of using the first PWM duty cycle to match the actual tube current of the X-ray tube with a preset tube current setting includes: Step S1021: Based on the target second-order IIR filter, the tube current feedback signal is filtered to obtain the filtered tube current feedback value. Step S1022: Based on the tube current set value and the filtered tube current feedback value, obtain the current closed-loop error for the current cycle. Step S1023: Input the current closed-loop error of the current cycle and the current closed-loop error of the previous cycle into the first incremental PI regulator to obtain the first duty cycle change. Step S1024: The change in the first duty cycle is accumulated with the first PWM duty cycle of the previous cycle to obtain the first PWM duty cycle of the current cycle.

[0032] The first incremental PI controller is an incremental PI controller used to output the increment of the control quantity. The parameters of the first incremental PI controller can be pre-adjusted.

[0033] This application does not limit how the tube current feedback value is obtained. For example, in some embodiments, the tube current feedback signal can be input into a target second-order IIR filter and filtered by the target second-order IIR filter to obtain the filtered tube current feedback value output by the target second-order IIR filter.

[0034] This application does not impose any restrictions on how the current closed-loop error of the current cycle is obtained. For example, in some embodiments, the current closed-loop error of the current cycle can be obtained by subtracting the filtered tube current feedback value from the tube current set value.

[0035] The embodiments of this application do not limit how the first PWM duty cycle is obtained. For example, in some embodiments, the current closed-loop error of the current cycle and the current closed-loop error of the previous cycle are input into the first incremental PI regulator to obtain the duty cycle change output by the first incremental PI regulator, which is used as the first duty cycle change. Then, the first duty cycle change is accumulated with the first PWM duty cycle of the previous cycle to obtain the first PWM duty cycle of the current cycle.

[0036] Understandably, the second PWM duty cycle is obtained periodically. Step S103 includes: Step S1031: Based on the target second-order IIR filter, the tube voltage feedback signal is filtered to obtain the filtered tube voltage feedback value. Step S1032: Based on the tube voltage setpoint and the filtered tube voltage feedback value, the voltage closed-loop error for the current cycle is obtained. In this embodiment, the difference between the tube voltage setpoint and the filtered tube current feedback value can be used as the voltage closed-loop error for the current cycle. Step S1033: Input the voltage closed-loop error of the current cycle and the voltage closed-loop error of the previous cycle into the second incremental PI regulator to obtain the second duty cycle change. In this embodiment, the second incremental PI regulator calculates the input voltage closed-loop error of the current cycle and the voltage closed-loop error of the previous cycle, and outputs the duty cycle change as the second duty cycle change.

[0037] Step S1034: The change in the second duty cycle is accumulated with the second PWM duty cycle of the previous cycle to obtain the second PWM duty cycle of the current cycle.

[0038] Among them, the second incremental PI controller is an incremental PI controller used to output the increment of the control quantity.

[0039] The embodiments of this application do not limit how the filtered tube voltage feedback value is obtained. For example, in some embodiments, the tube voltage feedback signal can be input into the target second-order IIR filter and filtered by the target second-order IIR filter to obtain the filtered tube voltage feedback value output by the target second-order IIR filter.

[0040] The embodiments of this application do not restrict how the voltage closed-loop error of the current cycle is obtained. For example, in some embodiments, the voltage closed-loop error of the current cycle can be obtained by subtracting the filtered tube voltage feedback value from the tube voltage set value.

[0041] The embodiments of this application do not limit how the second PWM duty cycle is obtained. For example, in some embodiments, the voltage closed-loop error of the current cycle and the voltage closed-loop error of the previous cycle are input into the second incremental PI regulator to obtain the duty cycle change output by the second incremental PI regulator, which is used as the second duty cycle change. Then, the second duty cycle change is accumulated with the second PWM duty cycle of the previous cycle to obtain the second PWM duty cycle of the current cycle.

[0042] Understandably, the second weight is determined through the following steps: subtracting the lower threshold from the magnitude of the primary current yields the target difference; multiplying the target difference by the attenuation coefficient yields the multiplication result; subtracting the multiplication result from 1 yields the second weight, which is expressed as follows:

[0043]

[0044] in, As the second weight, This refers to the attenuation coefficient. This refers to the primary current. This refers to the lower threshold. This refers to the upper limit threshold.

[0045] Understandably, reference Figure 3 , Figure 3 This is an optional flowchart of the X-ray imaging device control method provided in the embodiments of this application. Before acquiring electrical signal sampling feedback data, the method further includes at least one of the following: Step 301: In response to determining that the high voltage generator is in the exposure preparation stage, acquire the target second-order IIR filter corresponding to the X-ray tube. Step 302: In response to determining that the high voltage generator is in the pulse gap period, acquire the target second-order IIR filter corresponding to the X-ray tube.

[0046] When it is determined that the high-voltage generator is in the exposure preparation stage or the pulse gap period, a target second-order IIR filter corresponding one-to-one with the X-ray tube is first obtained. This allows for real-time matching with the X-ray tube without affecting pulse control. The filter parameters of the target second-order IIR filter are precisely matched with the current operating impedance of the X-ray tube, which can effectively suppress the interference of high-frequency switching noise of the inverter circuit on the sampling feedback signal, improve the sampling accuracy of tube current and tube voltage, and thus ensure that the imaging quality and radiation dose of the X-ray image formed by the X-ray tube meet medical requirements.

[0047] The exposure preparation stage refers to the time interval before the high-voltage generator controls the X-ray tube to output X-rays. In some embodiments, the X-ray tube output is controlled by a command; therefore, the exposure preparation stage is determined upon receiving the exposure command and the configured tube current setting. In other embodiments, the exposure preparation stage can also be determined by the output of the high-voltage generator's PWM duty cycle. For example, if the high-voltage generator's PWM duty cycle is 0, it is determined that the high-voltage generator is in the exposure preparation stage.

[0048] The pulse gap period refers to the time interval between two adjacent X-ray exposure pulses during continuous pulsed exposure in an X-ray imaging device. During this interval, the high-voltage generator pauses its high-voltage output, or there is no X-ray emission, or there is no active filtering output. In some embodiments, the pulse gap period can be determined by the output of the high-voltage generator's PWM duty cycle. For example, if the PWM duty cycle of the high-voltage generator is 0, it is determined that the high-voltage generator is in the pulse gap period.

[0049] Understandably, reference Figure 4 , Figure 4 This is an optional flowchart of the X-ray imaging device control method provided in the embodiments of this application. Before the step of obtaining sampling feedback data, it includes: Step S401: Match the tube current setting value of the X-ray tube with each preset tube current segment interval to determine the target interval. Different tube current segment intervals correspond to different impedance characteristics. Step S402: Based on the target coefficients corresponding to the target interval, initialize the second-order IIR filter to obtain the target second-order IIR filter that corresponds one-to-one with the X-ray tube.

[0050] The equivalent impedance characteristics of an X-ray tube are related to the tube current setting. The smaller the tube current, the larger the equivalent impedance of the tube, and the more significant the change in the noise characteristics of the sampling circuit. This means that a fixed-parameter IIR filter cannot achieve optimal filtering across the entire tube current range. This application's embodiment uses a segmented filter coefficient design to pre-match the optimal IIR filter coefficients for the impedance and noise characteristics of different tube current ranges. Under full-range tube current conditions, it can simultaneously achieve optimal noise removal and minimal control phase lag. Furthermore, for X-ray tubes with different power ratings, since different power ratings correspond to different tube currents, i.e., different power ratings also have different impedance characteristics, this application's embodiment can also be adapted to X-ray tubes of different power ratings.

[0051] Therefore, by adopting the strategy of matching corresponding IIR filter coefficients with different tube current segmentation intervals, after initializing to obtain the target second-order IIR filter according to the set tube current value, combined with the tube current feedback signal and the tube voltage feedback signal, the calculation accuracy of the first and second PWM duty cycles can be greatly improved. This improvement enables the generation of the third PWM duty cycle, the target weight and the final target PWM duty cycle to better adapt to the actual working state, thereby achieving stable output of the target voltage, and improving the adjustment accuracy and response speed at the same time. Furthermore, the imaging quality and radiation dose of the X-ray image formed by the X-ray tube can meet medical requirements.

[0052] Wherein, the target interval is the tube current segmentation interval to which the set tube current value in the current exposure instruction belongs. The target coefficient is the second-order IIR filter coefficient corresponding to the target interval, which is used to adjust filter parameters.

[0053] The embodiments of the present application do not limit how to divide the tube current segmentation intervals. For example, mA≤5mA is tube current segmentation interval 1, 5mA<mA≤10mA is tube current segmentation interval 2, 10mA<mA≤20mA is tube current segmentation interval 3, 20mA<mA≤40mA is tube current segmentation interval 4, and mA≥40mA is tube current segmentation interval 5, where mA refers to the set tube current value, and the impedance characteristics of tube current segmentation interval 1, tube current segmentation interval 2, tube current segmentation interval 3 and tube current segmentation interval 4 are all different.

[0054] In some embodiments, for each tube current segmentation interval, the optimal second-order IIR coefficients under the corresponding impedance characteristic can be pre-calculated and stored by the bilinear transformation method. The embodiments of the present application do not limit the storage mode of the optimal second-order IIR coefficients. They can be stored in a matrix mode or other modes, which will not be repeated one by one in the embodiments of the present application.

[0055] It can be understood that the X-ray imaging apparatus further includes a hardware detection control circuit, and the X-ray imaging apparatus control method further includes: Step S501, in response to detecting, through the hardware detection control circuit at the end moment of the current cycle, that the target PWM duty cycle satisfies the PWM over-regulation condition, initialize the first incremental PI regulator and the second incremental PI regulator, and stop outputting the target voltage to the X-ray tube.

[0056] At the end of each control cycle, the hardware detection and control circuit monitors the target PWM duty cycle for overshoot. When overshoot is detected, the incremental PI regulator is immediately initialized and the target voltage output to the X-ray tube is stopped. This can quickly block the continuous output of abnormal PWM duty cycle, effectively prevent large voltage and current overshoot caused by integral saturation of the PI regulator, and avoid damage to the X-ray tube due to overvoltage and overcurrent.

[0057] In this embodiment, at the end of each PWM control cycle, the hardware detection control circuit can verify whether the target PWM duty cycle exceeds the safety threshold. If the target PWM duty cycle exceeds the safety threshold, it is determined that the target PWM duty cycle meets the PWM overshoot condition, and two actions are executed simultaneously: first, the incremental PI regulators corresponding to the tube current and tube voltage are initialized; second, the high voltage output to the X-ray tube is immediately stopped to avoid irreversible damage caused by overvoltage and overcurrent, thus realizing single-cycle ultra-fast fault protection.

[0058] For example, see below. Figure 5 In the context of controlling a high-voltage generator in an X-ray imaging device, the technical solution of this invention will be further explained. Taking a tube current setpoint mA_set of 20mA as an example, the specific steps are as follows: Step 1: Receive the exposure command sent by the host computer and obtain the tube current setting value mA_set and the tube voltage setting value KV_se; Step 2, determine the coefficients of the second-order IIR filter: For example, the corresponding second-order IIR filter coefficients are retrieved based on the tube current setting value mA_set. Specifically, the tube current setting value mA_set is determined to belong to the tube current segment interval of 10 to 20mA; the corresponding second-order IIR filter coefficients are retrieved based on this tube current segment interval. Step 3, Second-order IIR filter initialization: For example, the second-order IIR filter is initialized based on the retrieved second-order IIR filter coefficients to obtain the target second-order IIR filter, and then a smooth transition process is performed. The control cycle of the X-ray imaging equipment is adjusted according to a preset cycle duration. Specifically, a 100kHz timer interrupt is executed every 10 microseconds, and the following steps are performed in each cycle: Step 4, Obtaining sampling feedback data: For example, during each PWM switching cycle, the primary current IP of the high voltage generator, the tube current feedback signal mA of the X-ray tube, and the tube voltage feedback signal KV are synchronously acquired. Step 5, Filtering of sampled feedback data: For example, the tube current feedback signal mA and tube voltage feedback signal KV of the X-ray tube are filtered according to the target second-order IIR filter; Step 6, Dual-channel PI controller calculation: For example, based on the filtered tube voltage feedback signal KV and the KV-channel incremental PI regulator, the second PWM duty cycle Duty_KV is output; based on the filtered tube current feedback signal mA and the mA-channel incremental PI regulator, the first PWM duty cycle Duty_mA is output. Step 7, Security Competition Decision: For example, the minimum value between the first PWM duty cycle Duty_mA and the second PWM duty cycle Duty_KV is taken as the third PWM duty cycle Duty_target.

[0059] Step 8, Primary-side current weighting protection: For example, the target weight W is calculated based on the magnitude of the primary current, combined with the preset protection threshold (lower protection threshold 20A, upper protection threshold 25A) and the attenuation coefficient; Step 9, PWM duty cycle correction: The target PWM duty cycle (Duty_out) is obtained by correcting the third PWM duty cycle using the target weight. Step 10: Check if the target PWM duty cycle (Duty_out) is abnormal. If not, proceed to step 11; if yes, proceed to step 12. For example, is the target PWM duty cycle greater than 95%? If it is, then it is abnormal. Step 11, output target PWM duty cycle: If the target PWM duty cycle verification passes and there is no abnormality in the target PWM duty cycle, a drive signal is generated based on the target PWM duty cycle Duty_out to control the inverter circuit to output high voltage to the X-ray tube. At the same time, anti-integral saturation processing and fault protection procedures are executed to ensure stable system operation. Step 12: Block the PWM output and clear the integral of the PI regulator to zero.

[0060] refer to Figure 6 The figure shows a comparison of the output waveforms of the X-ray imaging equipment control method of the present invention and the conventional scheme at the instant of high-pressure loading. Curve A represents the output under conventional filtering and single PI control, while curve B represents the output under the control of the X-ray imaging equipment control method of the present application. Comparing curves A and B reveals that the present invention has at least the following advantages.

[0061] 1. Suppressing overshoot. The traditional method (curve A) produces a significant overshoot (overshoot of about 25%) when the set value is reached, which can easily lead to tube breakdown in the high-pressure environment of medical settings; while the X-ray imaging equipment control method of the present invention (curve B) achieves a smooth rise with almost no overshoot (<5%).

[0062] 2. Shortened stabilization time: Compared to existing technologies that require approximately 40ms to reach a steady state due to oscillations, the present invention can quickly lock the set value within 10ms, meeting the real-time requirements of instantaneous medical X-ray exposure.

[0063] 3. Control precision: Due to the existence of the dual-path PI competition mechanism, the waveform of curve B is extremely stable after entering steady state, and the steady state error is kept within 1%, which effectively ensures the stability of medical imaging.

[0064] Please see Figure 7 , Figure 7 The hardware structure of another embodiment of an X-ray imaging device is illustrated. The X-ray imaging device includes: The DSP control unit 701 has its PWM control terminal connected to the high-voltage generator; the sampling terminal of the DSP control unit is connected to the X-ray tube. The high voltage generator 702 is an electrical device capable of generating high voltage. The high voltage output port of the high voltage generator 702 is connected to the high voltage input port of the X-ray tube 703. The X-ray tube 703 is a core component of X-ray equipment. As a controllable X-ray beam generator, it provides a key X-ray source for fields such as medical imaging and industrial inspection through the energy conversion of electrical energy into radiation energy and thermal energy. The memory 704 stores a computer program, and the DSP control unit executes the computer program to implement the X-ray imaging device control method of this application.

[0065] The X-ray imaging equipment control method, X-ray imaging equipment, and storage medium proposed in this application acquire electrical signal sampling feedback data, including the primary current of the high-voltage generator, the tube current feedback signal of the X-ray tube, and the tube voltage feedback signal. Based on the tube current feedback signal and the tube voltage feedback signal, a first PWM duty cycle and a second PWM duty cycle are determined respectively. Based on the first PWM duty cycle and the second PWM duty cycle, a third PWM duty cycle is determined. Based on the primary current and the attenuation coefficient, a target weight is determined, and the third PWM duty cycle is used to obtain the target PWM duty cycle. Since the determination of the target PWM duty cycle is based on the tube current feedback signal and the tube voltage feedback signal, the control of the target PWM duty cycle can simultaneously take into account the adjustment of the voltage and current of the X-ray tube. Compared with the adjustment method based on a single control parameter for independent adjustment or simple switching, the adjustment accuracy of the embodiments of this application is higher. Furthermore, the target PWM duty cycle in this embodiment is actually determined by the first PWM duty cycle, the second PWM duty cycle, and the attenuation coefficient. In other words, this embodiment is essentially based on a fusion of multiple PI controls. Therefore, this embodiment has a lower risk of over-adjustment while the adjustment process is smoother and the response speed is faster. Thus, this embodiment can improve the stability of the X-ray tube voltage and current by adjusting the accuracy and response speed of the target voltage in a single cycle, thereby ensuring that the imaging quality and radiation dose of the X-ray image formed by the X-ray tube meet medical requirements.

[0066] Understandably, refer to Figure 8 As an example, the DSP control unit includes an internally integrated SCI communication module, an overvoltage and overcurrent detection and protection module, a fault detection and protection module, a power regulation module, and an electrical signal sampling and feedback module. The SCI communication module is connected to an external host computer communication module and an HMI human-machine interface module. The power regulation module is connected to a high-voltage generator. The overvoltage and overcurrent detection and protection module is connected to an external battery. The electrical signal sampling and feedback module is connected to an X-ray tube.

[0067] The SCI communication module is the external communication interface of the DSP, used for bidirectional communication with external host computer communication modules and HMI human-machine interface modules. The overvoltage and overcurrent detection and protection module is used to acquire battery voltage and current signals in real time, monitor battery power supply status, trigger hardware protection when overvoltage or overcurrent occurs, and report the fault signal to the fault detection and protection module. The electrical signal sampling feedback module is used to acquire tube voltage, tube current, and primary current Ip feedback signals. The power regulation module is used to convert PWM signals into power drive signals to regulate the output power of the high-voltage generator. The fault detection and protection module is used to monitor the operating status of each module in the system in real time, execute the PI regulator's anti-integral saturation logic, and immediately block the PWM output or execute non-impact derating protection when abnormal data, excessive primary current, or hardware fault is detected.

[0068] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0069] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0070] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0071] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0072] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0073] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0075] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A control method for an X-ray imaging device, characterized in that, The X-ray imaging equipment includes a high-voltage generator and an X-ray tube, and the method includes: Acquire electrical signal sampling feedback data, wherein the electrical signal sampling feedback data includes the primary current of the high voltage generator, the tube current feedback signal of the X-ray tube, and the tube voltage feedback signal; Based on the tube current feedback signal, a first PWM duty cycle is determined, wherein the first PWM duty cycle is used to make the actual tube current of the X-ray tube match a preset tube current setting value. Based on the tube voltage feedback signal, a second PWM duty cycle is determined, wherein the second PWM duty cycle is used to make the actual tube voltage of the X-ray tube match the preset tube voltage setting value; The minimum value between the first PWM duty cycle and the second PWM duty cycle is taken as the third PWM duty cycle; If the value of the primary current is greater than a preset upper limit threshold, the preset third weight is used as the target weight. If the value of the primary current is less than a preset lower threshold, the preset first weight is used as the target weight. When the value of the primary current is greater than the lower threshold and less than the upper threshold, a second weight is determined according to the attenuation coefficient, and the second weight is used as the target weight. The third weight is greater than the second weight, the second weight is greater than the first weight, the third weight is 1, the first weight is 0, the attenuation coefficient is the reciprocal of the threshold range, and the threshold range is determined based on the upper threshold and the lower threshold. The target PWM duty cycle is obtained by weighting the third PWM duty cycle and the target weight. Based on the target PWM duty cycle, the high-voltage generator is controlled to output the target voltage to the X-ray tube.

2. The method according to claim 1, characterized in that, The second weight is shown in the following formula: in, As the second weight, This refers to the attenuation coefficient. This refers to the primary current. This refers to the lower threshold. This refers to the upper limit threshold.

3. The X-ray imaging equipment control method according to claim 1, characterized in that, The first PWM duty cycle is obtained periodically. Determining the first PWM duty cycle based on the transistor current feedback signal includes: Based on the target second-order IIR filter, the tube current feedback signal is filtered to obtain the filtered tube current feedback value. Based on the tube current setpoint and the filtered tube current feedback value, the current closed-loop error for the current cycle is obtained. The current closed-loop error of the current cycle and the current closed-loop error of the previous cycle are input into the first incremental PI regulator to obtain the first duty cycle change. The change in the first duty cycle is summed with the first PWM duty cycle of the previous cycle to obtain the first PWM duty cycle of the current cycle.

4. The X-ray imaging equipment control method according to claim 1, characterized in that, The second PWM duty cycle is obtained periodically. The step of determining the second PWM duty cycle based on the tube voltage feedback signal includes: Based on the target second-order IIR filter, the tube voltage feedback signal is filtered to obtain the filtered tube voltage feedback value. The voltage closed-loop error for the current cycle is obtained based on the tube voltage setpoint and the filtered tube voltage feedback value. The voltage closed-loop error of the current cycle and the voltage closed-loop error of the previous cycle are input into the second incremental PI regulator to obtain the second duty cycle change. The second duty cycle change is summed with the second PWM duty cycle of the previous cycle to obtain the second PWM duty cycle of the current cycle.

5. The X-ray imaging equipment control method according to claim 4, characterized in that, Before acquiring electrical signal sampling feedback data, the method further includes at least one of the following: In response to determining that the high voltage generator is in the exposure preparation stage, the target second-order IIR filter corresponding to the X-ray tube is acquired; In response to determining that the high voltage generator is in the pulse gap period, the target second-order IIR filter corresponding to the X-ray tube is acquired.

6. The X-ray imaging equipment control method according to claim 5, characterized in that, The step of acquiring the target second-order IIR filter corresponding one-to-one with the X-ray tube includes: The tube current setting value of the X-ray tube is matched with each preset tube current segment interval to determine the target interval, wherein different tube current segment intervals correspond to different impedance characteristics. Based on the target coefficients corresponding to the target interval, a second-order IIR filter is initialized to obtain a target second-order IIR filter that corresponds one-to-one with the X-ray tube.

7. The X-ray imaging equipment control method according to claim 1, characterized in that, The X-ray imaging device further includes a hardware detection and control circuit; the method further includes: In response to the hardware detection control circuit detecting that the target PWM duty cycle meets the PWM overshoot condition at the end of the current cycle, the first incremental PI regulator and the second incremental PI regulator are initialized, and the output of the target voltage to the X-ray tube is stopped.

8. An X-ray imaging device, characterized in that, The X-ray imaging device includes: X-ray tube; High voltage generator; A DSP control unit, the PWM control terminal of which is connected to the high-voltage generator; and a sampling terminal of which is connected to the X-ray tube. The memory stores a computer program, and the DSP control unit executes the computer program to implement the X-ray imaging device control method according to any one of claims 1 to 8.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the DSP control unit, it implements the X-ray imaging equipment control method according to any one of claims 1 to 8.

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