Control method and device for rapid positioning of ct scan bed

Abstract

The application discloses a control method and system for rapid positioning of a CT scanning bed, and through unified time planning and space interference checking on movement of the scanning bed in X / Y / Z three directions, three-way synchronous starting, synchronous running and synchronous positioning under aperture limitation in a gantry are realized. The method effectively solves problems of time superposition, low efficiency and extensive interference control caused by three-way positioning in sequence in the traditional technology, and has remarkable practical value and popularization significance.

Description

Technical Field

[0001] This invention relates to the field of information processing technology, and specifically to a control method and device for rapid positioning of a CT scanning bed. Background Technology

[0002] With the rapid development of medical imaging technology, spiral CT (Computed Tomography) has become an important piece of equipment for clinical diagnosis. A spiral CT scanner typically includes a gantry, X-ray tube and detector assembly, a scanning bed (also known as a patient bed or bed board), and a corresponding control system. The scanning bed supports the user and allows for precise positional adjustment within the gantry during the examination to meet the scanning needs of different body parts.

[0003] The existing scanning bed positioning control methods have significant shortcomings in terms of efficiency, collaborative optimization, and utilization of spatial interference constraints. There is an urgent need for a new control method that can achieve simultaneous movement of the scanning bed's three degrees of freedom and simultaneous arrival at the target position while fully ensuring safety, thereby shortening the positioning time and improving clinical efficiency. Summary of the Invention

[0004] The main objective of this invention is to provide a control method and device for rapid positioning of a CT scanning bed, so as to overcome the shortcomings of related technologies.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a control method for rapid positioning of a CT scanning bed is provided, applied to a spiral CT system comprising a gantry and a three-degree-of-freedom scanning bed, wherein the scanning bed is configured with a Y-axis lifting motion mechanism, a Z-axis longitudinal motion mechanism, and an X-axis lateral motion mechanism. The method includes the following steps: acquiring positioning target data; calculating target displacement components in the X, Y, and Z axes based on the current position of a bed surface reference point and the positioning target data; determining the total duration of unified synchronous motion of the three axes based on a preset three-axis coordinated time planning rule and in combination with the target displacement components in the three axes; adjusting the motion parameters of each axis according to the total duration of synchronous motion; performing interference verification of the three-axis synchronous motion trajectory based on a preset gantry aperture safety constraint model and in combination with the target displacement components in the three axes; correcting the trajectory according to the verification result to obtain a compliant and safe execution trajectory; driving each motion mechanism to perform real-time closed-loop control based on the compliant and safe execution trajectory to complete the three-axis linkage positioning; and performing a three-axis joint positioning determination when the positioning operation is nearing completion, and performing error compensation based on the determination result.

[0006] According to a second aspect of the present invention, a control system for rapid positioning of a CT scanning bed is provided, comprising: a calculation unit for acquiring positioning target data and calculating target displacement components in the X, Y, and Z axes based on the current position of a reference point on the bed surface and the positioning target data; a planning unit for determining the total duration of unified synchronous motion of the three axes based on a preset three-axis coordinated time planning rule and in combination with the target displacement components in the three axes, and adjusting the motion parameters of each axis according to the total duration of synchronous motion; a correction unit for performing interference verification of the three-axis synchronous motion trajectory based on a preset gantry aperture safety constraint model and in combination with the target displacement components in the three axes, correcting the trajectory according to the verification result to obtain a compliant and safe execution trajectory; driving each motion mechanism to perform real-time closed-loop control based on the compliant and safe execution trajectory to complete the three-axis linkage positioning; and performing a three-axis joint positioning determination when the positioning operation is nearing its end, and performing error compensation based on the determination result.

[0007] According to a third aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing the computer to perform the method described in any one of the first aspects.

[0008] According to a fourth aspect of the present invention, a computer program product is provided, which, when executed by a processor, implements the method described in the first aspect implementation.

[0009] This embodiment presents a control method and system for rapid CT scanning bed positioning. By performing unified time planning and spatial interference checks on the movement of the scanning bed in the X, Y, and Z directions, it achieves synchronous start-up, synchronous operation, and synchronous positioning in three directions under the constraint of the gantry's internal aperture. This effectively solves the problems of time superposition, low efficiency, and coarse interference control caused by sequential positioning in the three directions in traditional technologies, demonstrating significant practical value and potential for widespread application. Attached Figure Description

[0010] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a flowchart of a method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0013] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention 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 for the embodiments of the invention 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.

[0014] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0015] Current spiral CT scanning tables generally have multiple degrees of freedom of movement, including: vertical (Y-axis or Elev): used to raise or lower the bed to achieve height matching between the patient and the central axis of the gantry; front-back (Z-axis or Cradle): used to move the patient into or out of the gantry aperture to achieve longitudinal adjustment of the examination position; and left-right (X-axis or Crab): used to fine-tune the patient's left and right position so that the lesion area is accurately located on the scanning field of view and the rotation center line.

[0016] In relevant technical solutions, to ensure safety and simplify control logic, scanning beds often employ a sequential, axis-by-axis movement method when adjusting their positioning. This means that movement in one direction is completed before initiating movement in the next direction. For example, when positioning a user from their current position to the target inspection position, the following sequence is typically followed: 1. First, complete the lifting or lowering in the Y direction (up or down); 2. Then move in the Z direction (forward or backward); 3. Finally, make fine adjustments in the X direction (left and right).

[0017] Or, the movements in each direction can be completed sequentially according to a pre-set order.

[0018] The above method has the following significant drawbacks: Long total time: When executing in the three directions sequentially, the overall positioning time is equal to the simple sum of the movement times in each direction. This is inefficient when the user needs to make large-scale displacements or frequent position adjustments, severely impacting examination throughput and user experience. Inflexible response: In clinical practice, different users have different body shapes and lesion locations, requiring varying three-dimensional position adjustments. If a fixed sequence of movements is used, the control system struggles to optimize globally based on actual conditions. Lack of collaborative optimization: Traditional control often only ensures smoothness and limit safety in single-axis movements, failing to plan collaborative trajectories in the three directions and not utilizing the capability balance and time matching of the actuators in each direction, thus failing to achieve the optimization goal of "simultaneous arrival." Crude safety and interference risk control: When the scanning bed moves in the Y, Z, and X directions, it must always meet the geometric constraints of the gantry's internal aperture to avoid collisions or interference between the bed plate or bed body and the gantry. Traditional methods often ensure safety by setting conservative limits or safety zones in each direction, which reduces the available adjustment range and, when displacements are superimposed in multiple directions, cannot achieve true real-time spatial interference verification and dynamic planning.

[0019] According to an embodiment of the present invention, a control method for rapid positioning of a CT scanning bed is provided, applicable to a spiral CT system with a gantry and a scanning bed. The spiral CT system mainly includes: a gantry, an X-ray tube assembly, a detector assembly, a scanning bed, a control host, and a human-machine interface terminal. The scanning bed includes a Y-axis lifting mechanism: composed of a servo motor, a lead screw or lifting column, guide rails, and an encoder, etc., to realize the vertical lifting of the bed plate; a Z-axis longitudinal motion mechanism: composed of a servo motor and a bed propulsion mechanism, used to realize the forward and backward movement of the bed plate in the axial (front-back) direction of the gantry; and an X-axis lateral movement mechanism: composed of a lateral servo motor and a slide mechanism, used to realize the fine adjustment of the bed plate in the left and right directions. Each movement direction is equipped with a high-precision position encoder or linear displacement sensor for real-time position feedback. The control host communicates with each servo driver via a bus to achieve three-axis coordinated control. Figure 1 As shown, steps 101 to 103 are included below: Step 101: Obtain the target positioning data. Based on the current position of the bed surface reference point and the target positioning data, calculate the target displacement components of the X, Y, and Z axes.

[0020] In this step, based on the user-inputted desired positioning parameters, preset examination protocols, or image guidance information, the displacement components in the X, Y, and Z directions between the current bed reference point and the target position are calculated. For example, the operator selects the examination site and inputs or selects a predefined scan protocol on the CT control interface. The system calculates the target position based on the relative position parameters stored in the scan protocol and the current bed zero point. By reading the current position of the bed surface reference point. The target displacements in three directions are obtained: The aforementioned displacement values ​​are used as inputs for synchronous trajectory planning.

[0021] Step 102: Based on the preset three-axis coordinated time planning rules, and combined with the target displacement components of the three axes, determine the total duration of the unified synchronous motion of the three axes, adjust the motion parameters of each axis according to the total duration of the synchronous motion, and initially plan the three-axis synchronous motion trajectory.

[0022] As an optional implementation of this embodiment, the three-axis coordinated time planning rule is preset through the following steps: determining the shortest independent motion time of each single axis under the constraints of rated maximum speed and maximum acceleration; taking the maximum value of the shortest independent motion time of each single axis as the total synchronous motion time; for axes where the shortest independent motion time of a single axis is less than the total synchronous motion time, matching the total synchronous motion time by adjusting the peak speed, adjusting the acceleration range, and adding a uniform speed running segment.

[0023] In this optional implementation, in this embodiment, the maximum speed of the three-axis servo drive device in actual control is... and maximum acceleration They are usually different. To ensure that the target location is reached simultaneously from three directions, the following steps are used for time planning: For each direction, based on the given displacements ΔX, ΔY, ΔZ and their respective maximum velocities and accelerations, first calculate the shortest time Tx, Ty, Tz required under single-axis conditions using the standard "S-shaped acceleration / deceleration" or "trapezoidal acceleration / deceleration" trajectory.

[0024] Take the maximum value among the three: Among them, As a unified synchronous motion time across three axes. For those requiring less than In the direction of motion, the velocity-time curve is redesigned by reducing the peak velocity, adjusting the acceleration, or adding a uniform velocity segment, so that the total motion time is exactly equal to... .

[0025] Obtain the X / Y / Z directions in the time interval Parametric displacement function on: ,in And each of them satisfies its own speed and acceleration constraints.

[0026] The above plan ensures that the system starts simultaneously in all three directions at t = 0. They arrive at the target location simultaneously.

[0027] Step 103: Based on the preset frame aperture safety constraint model, and combined with the three-axis target displacement components, perform interference verification of the three-axis synchronous motion trajectory, correct the trajectory according to the verification results, and obtain a compliant and safe execution trajectory.

[0028] In this step, the inner diameter of the frame is typically circular or nearly circular, and its effective radius is assumed to be... The central axis of the gantry is denoted as the Z-axis. When the scanning bed is in any position, the coordinates of a reference point on its bed plate within the cross-section are (X, Y), and the bed plate thickness and edge dimensions are known. Based on the CT structural design data, the following constraint model is constructed: For any time t, calculate the distance D(t) from the edge of the bed closest to the center of the frame to the center, requiring D(t) + safety margin ≤ If the bed frame or accessories are considered, these parts are incorporated into the geometric model to form a more complete "virtual outline," and spatial interference with the inner diameter of the frame is determined. The above constraint model is stored in the control system in the form of tables, parametric equations, or three-dimensional geometric approximation models for subsequent trajectory verification.

[0029] In one optional implementation of this embodiment, the frame aperture safety constraint model is adapted to the user's body shape data for dynamic safety boundary expansion, including: the frame inner aperture is a circular or approximately circular structure, and its effective base radius is set to Rg; the scanning bed base structure dimension data is collected, wherein the base structure dimension data includes the bed board thickness, bed board edge dimensions, and / or, bed frame support, and accessory shape dimensions; for the bed board posture at any time, a base distance determination rule is established, wherein the base distance determination rule includes calculating the distance D(t) from the bed board edge point closest to the frame center to the center, and setting the base constraint condition as D(t) + safety margin ≤ Rg; the safety margin is dynamically adjusted based on the user's actual body shape data.

[0030] In this optional implementation, the dynamic safety boundary expansion of the patient's body shape is considered. Based on the above implementation, the system needs to acquire the patient's body shape information, incorporate the patient's body contour into the interference model, and construct a combined shape of "scanning bed + patient" to further improve safety.

[0031] Patient contour modeling: In the patient information entry module of the CT control interface, the operator inputs or selects: - Patient height (unit: cm) - Patient weight (unit: kg) - Patient gender (male / female) - Body type (standard / underweight / overweight / obese, or BMI index) - Based on this basic information, the system calls the built-in human body model database to generate a preliminary estimate of the patient's body contour.

[0032] During the trajectory interference check phase, the patient's external shape model is superimposed on the scanning bed's geometric model, and geometric calculations are performed on the combined model and the gantry's inner aperture. The trajectory is considered safe only when the overall outline of the "scanning bed + patient" does not intersect with the gantry's inner wall at any given time point. Otherwise, trajectory correction is performed according to the method in Example 1.

[0033] In this way, the present invention not only avoids collisions between the scanning bed and the gantry, but also reduces the risk of patient contact with the gantry, further improving the safety of clinical use. It innovatively incorporates patient body shape information to achieve dynamic safety boundary expansion, automatically adjusting the safety margin according to the patient's actual body shape, ensuring both safety and improving space utilization.

[0034] As an optional implementation method in this embodiment, the interference verification of the three-axis synchronous motion trajectory is performed, and the trajectory is corrected according to the verification result. This includes: dividing the total synchronous motion time into multiple discrete verification nodes, calculating the real-time spatial coordinates of key structural points of the scanning bed for each node; substituting the coordinates of each point into the frame aperture safety constraint model, comparing them with the interference judgment threshold to determine the interference risk; if the interference risk is determined to exist, correcting the original preliminary trajectory until the interference risk is eliminated, and obtaining the safe execution trajectory.

[0035] In this optional implementation, to ensure that the scanning bed does not interfere with the gantry during the entire synchronous motion process, the trajectory is discretely checked within the time interval [0, Tsync]: the time axis is equally divided into several check nodes. (e.g., every 10ms or finer time granularity); for each Calculate the spatial coordinates of key structural points of the scanning bed (such as the four corners of the bed board, the center point of the bed surface, and the supporting structure); substitute these coordinates into the aperture constraint model inside the frame to calculate the minimum safe distance from the inner surface of the frame; if the safe distance is less than the predetermined threshold or there is geometric overlap at one or more time points, it is judged as a potential interference risk and the trajectory needs to be corrected.

[0036] As an optional implementation method in this embodiment, correcting the original preliminary trajectory until the risk of interference is eliminated includes correcting the original trajectory by adjusting the total duration of synchronous motion, optimizing the timing of three-axis displacement, or splitting synchronous motion segments.

[0037] In this optional implementation, the trajectory correction method may include, but is not limited to: Extend total exercise time To reduce speed, the maximum displacement during the transition process is decreased, increasing the safety margin; the temporal shape of the three-axis displacement distribution is altered, for example, by delaying or advancing the main displacement in a certain direction, maintaining a smaller displacement in the intermediate period, and avoiding sensitive areas of the frame; the overall three-axis synchronous motion is decomposed into two or more sub-trajectories, achieving local "synchronous positioning" at a certain intermediate position, and then continuing the next segment of synchronous motion within the safe area. After interference checks and necessary corrections, the final executable safe synchronous trajectory is generated.

[0038] Step 104: Drive each motion mechanism to perform real-time closed-loop control based on the compliant and safe execution trajectory to complete the three-axis linkage positioning; when the positioning operation is nearing its end, perform a three-axis joint positioning determination, and perform error compensation based on the determination result.

[0039] In this step, the planned three-axis synchronous trajectory is sent to each servo drive in the form of discrete position commands or continuous trajectory functions. The control host acquires the encoder feedback position, compares it with the reference trajectory, and adjusts the output of each axis through the position loop and speed loop to achieve coordinated operation of the three axes.

[0040] As an optional implementation method in this embodiment, the compliant and safe execution trajectory is sent to the servo drive unit corresponding to each motion mechanism; the position data and speed data fed back by the encoder of each axis are collected in real time, so that the servo drive unit can adjust the servo drive output power through position closed loop and speed closed loop dual-layer regulation. During the motion, the limit signal, emergency stop signal and drive operation status are monitored to ensure that the three-axis linkage positioning is stable and compliant.

[0041] In this step, during the movement, the current position deviation in three directions is monitored in real time to see if it is within the allowable range; whether the current and speed of the servo drive are abnormal; and whether the emergency stop and limit switch status are normal.

[0042] As an optional implementation of this embodiment, when the positioning operation is nearing its end, a three-axis joint positioning determination is performed. Error compensation is carried out for cases where the determination exceeds the tolerance, including: when the positioning operation time reaches a preset proportion threshold of the total synchronous motion time, the actual displacement data of the three axes are collected synchronously, and the position deviation is calculated by comparing the target displacement components of the three axes; if the position deviation is within the preset tolerance range, the positioning is determined to be in place; if the position deviation exceeds the tolerance range, under the premise of conforming to the frame aperture safety constraint model, a small-range fine-tuning compensation is performed until the position deviations of the three axes all fall within the tolerance range.

[0043] In this optional implementation, when the time approaches At that time, a joint determination is made on the positioning status in the three directions: If the positional errors of each axis are within the preset tolerance, the synchronization is considered successful. If the error in a certain direction exceeds the threshold, a small local compensation movement is performed without violating spatial constraints. If an abnormality occurs (e.g., a certain axis cannot continue to run or the positional error exceeds a large range), a safety stop is triggered, and a prompt is displayed on the interface. Through the above steps, the scanning bed is moved from the initial position to the target position quickly and safely.

[0044] The control method for rapid CT scanning bed positioning achieves synchronous start-up, synchronous operation, and synchronous positioning in three directions under the constraint of the gantry aperture by uniformly planning the movement of the scanning bed in the X, Y, and Z directions and checking spatial interference. In particular, this embodiment effectively solves the problems of time superposition, low efficiency, coarse interference control, and failure to consider patient body size differences caused by sequential positioning in three directions in traditional technologies, and has significant practical value and promotional significance.

[0045] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0046] According to an embodiment of the present invention, a control system for rapid positioning of a CT scanning bed is also provided. The system is applied to a spiral CT system including a gantry and a three-degree-of-freedom scanning bed. The scanning bed is equipped with a Y-axis lifting motion mechanism, a Z-axis longitudinal motion mechanism, and an X-axis lateral motion mechanism. The system includes a calculation unit for acquiring positioning target data and calculating the target displacement components in the X, Y, and Z axes based on the current position of the bed surface reference point and the positioning target data; a planning unit for determining the total duration of unified synchronous motion of the three axes based on a preset three-axis coordinated time planning rule and in combination with the target displacement components in the three axes, and adjusting the motion parameters of each axis according to the total duration of synchronous motion; and a correction unit for performing interference verification of the three-axis synchronous motion trajectory based on a preset gantry aperture safety constraint model and in combination with the target displacement components in the three axes, correcting the trajectory according to the verification result to obtain a compliant and safe execution trajectory; driving each motion mechanism to perform real-time closed-loop control based on the compliant and safe execution trajectory to complete the three-axis linkage positioning; and performing a three-axis joint positioning determination when the positioning operation is nearing its end, and performing error compensation based on the determination result.

[0047] According to embodiments of the present invention, the present invention also provides an electronic device, the electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to implement the methods described in any of the above embodiments.

[0048] According to embodiments of the present invention, the present invention also provides a readable storage medium storing computer instructions that enable a computer to perform the methods described in any of the above embodiments when executed.

[0049] According to embodiments of the present invention, the present invention also provides a computer program product that, when executed by a processor, can implement the methods described in any of the above embodiments.

[0050] Figure 2 A schematic block diagram of an example electronic device 300 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices.

[0051] like Figure 2 As shown, the electronic device 300 includes a computing unit 301, which can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) 302 or a computer program loaded from a storage unit 308 into a random access memory (RAM) 303. The RAM 303 may also store various programs and data required for the operation of the electronic device 300. The computing unit 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0052] Multiple components in electronic device 300 are connected to I / O interface 305, including: input unit 306, such as keyboard, mouse, etc.; output unit 307, such as various types of displays, speakers, etc.; storage unit 308, such as disk, optical disk, etc.; and communication unit 309, such as network card, modem, wireless transceiver, etc. Communication unit 309 allows electronic device 300 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0053] The computing unit 301 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 301 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 301 performs the various methods and processes described above, such as the object matching method. For example, in some embodiments, the object matching method may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 308. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 300 via ROM 302 and / or communication unit 309. When the computer program is loaded into RAM 303 and executed by the computing unit 301, one or more steps of the methods described above may be performed.

[0054] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0055] The program code used to implement the methods of the present invention can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code can be executed entirely on the machine, partially on the machine, as a standalone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0056] In the context of this invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

Claims

1. A control method for rapid positioning of a CT scanning bed, characterized in that, An application to a spiral CT system comprising a gantry and a three-degree-of-freedom scanning bed, wherein the scanning bed is equipped with a Y-axis lifting mechanism, a Z-axis longitudinal motion mechanism, and an X-axis lateral movement mechanism, the method comprising the following steps: Acquire the target positioning data, and calculate the target displacement components along the X, Y, and Z axes based on the current position of the bed surface reference point and the target positioning data. Based on the preset three-axis coordinated time planning rules, combined with the target displacement components of the three axes, the total duration of the unified synchronous motion of the three axes is determined, and the motion parameters of each axis are adjusted according to the total duration of the synchronous motion. Based on the preset frame aperture safety constraint model, combined with the three-axis target displacement components, the interference verification of the three-axis synchronous motion trajectory is performed, and the trajectory is corrected according to the verification results to obtain a compliant and safe execution trajectory. Based on the compliant and safe execution trajectory, each motion mechanism is driven to perform real-time closed-loop control to complete the three-axis linkage positioning; when the positioning operation is nearing its end, the three-axis joint positioning judgment is performed, and error compensation is performed based on the judgment result.

2. The control method for rapid positioning of a CT scanning bed according to claim 1, characterized in that, Perform interference verification of the three-axis synchronous motion trajectory, and correct the trajectory based on the verification results, including: The total duration of synchronous motion is divided into multiple discrete verification nodes, and the real-time spatial coordinates of key structural points of the scanning bed are calculated for each node. Substitute the coordinates of each point into the frame aperture safety constraint model, compare them with the interference judgment threshold to determine the interference risk; if the interference risk is determined, correct the original preliminary trajectory until the interference risk is eliminated, and obtain the safe execution trajectory.

3. The control method for rapid positioning of a CT scanning bed according to claim 2, characterized in that, Revising the original preliminary trajectory until the risk of interference is eliminated includes: The original trajectory can be corrected by adjusting the total duration of synchronous motion, optimizing the timing of three-axis displacement, or splitting synchronous motion segments.

4. The control method for rapid positioning of a CT scanning bed according to claim 1, characterized in that, The three-axis collaborative time planning rules are preset through the following steps: Determine the shortest independent motion time for each single axis of X, Y, and Z under the constraints of rated maximum speed and maximum acceleration; The maximum value of the shortest independent motion duration of each single axis is taken as the total duration of the synchronous motion. For axes where the shortest independent motion time is less than the total synchronous motion time, the total synchronous motion time is matched by adjusting the peak speed, adjusting the acceleration range, and adding a uniform speed running segment.

5. The control method for rapid positioning of a CT scanning bed according to claim 1, characterized in that, The real-time closed-loop control driven by the compliant and safe execution trajectory for each motion mechanism includes: The compliant and safe execution trajectory is sent to the servo drive unit corresponding to each motion mechanism; The position and speed data fed back by the encoders of each axis are collected in real time, so that the servo drive unit can adjust the output power of the servo drive through a two-layer control of position closed loop and speed closed loop.

6. The control method for rapid positioning of a CT scanning bed according to claim 1, characterized in that, When the positioning operation is nearing completion, a three-axis joint positioning determination is performed, and error compensation is carried out for cases where the determination exceeds the tolerance, including: When the running time of the positioning reaches the preset proportion threshold of the total synchronous motion time, the actual displacement data of the three axes is collected synchronously, and the position deviation is calculated by comparing the target displacement components of the three axes. If the positional deviation is within the preset tolerance range, the placement is determined to be in place. If the positional deviation exceeds the tolerance range, a small-range fine-tuning compensation will be performed, provided that the frame aperture safety constraint model is met, until the positional deviations of all three axes fall within the tolerance range.

7. The control method for rapid positioning of a CT scanning bed according to claim 1, characterized in that, The rack aperture safety constraint model is adapted to user body size data for dynamic safety boundary expansion, including: The inner diameter of the frame is circular or approximately circular, and its effective radius is set as Rg. Collect basic structural dimension data of the scanning bed, wherein the basic structural dimension data includes bed board thickness, bed board edge dimensions, and / or, bed frame and accessory dimensions; For the bed board posture at any time, a basic distance determination rule is established, wherein the basic distance determination rule includes calculating the distance D(t) from the edge point of the bed board closest to the center of the frame to the center, and setting the basic constraint condition as D(t) + safety margin ≤ Rg; The safety margin is dynamically adjusted based on the user's actual body size data.

8. A control system for rapid positioning of a CT scanning bed, characterized in that, The system is applied in a spiral CT system that includes a gantry and a three-degree-of-freedom scanning bed. The scanning bed is equipped with a Y-axis lifting mechanism, a Z-axis longitudinal motion mechanism, and an X-axis lateral motion mechanism, including: The calculation unit is used to acquire the target positioning data and calculate the target displacement components in the X, Y, and Z axes based on the current position of the bed surface reference point and the target positioning data. The planning unit is used to determine the total duration of the unified synchronous motion of the three axes based on the preset three-axis coordinated time planning rules and the target displacement components of the three axes, and to adjust the motion parameters of each axis according to the total duration of the synchronous motion. The correction unit is used to perform interference verification of the three-axis synchronous motion trajectory based on the preset frame aperture safety constraint model and the three-axis target displacement components, and correct the trajectory according to the verification result to obtain a compliant and safe execution trajectory; drive each motion mechanism to perform real-time closed-loop control based on the compliant and safe execution trajectory to complete the three-axis linkage positioning; when the positioning operation is close to the end, perform three-axis joint positioning determination, and perform error compensation based on the determination result.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method according to any one of claims 1-7.

10. A computer program product, characterized in that, When executed by a processor, the computer program implements the method described in any one of claims 1-7.

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