CT scanning bed control method and system based on EtherCAT motion control

Abstract

The invention discloses a CT scanning bed control method and system based on EtherCAT motion control, and the method comprises the steps: selecting a scanning mode according to a scanning demand, and calculating a motion parameter corresponding to the scanning mode; receiving the scanning mode and the motion parameter information, and converting the scanning mode and the motion parameter information into a motion mode instruction of the scanning bed through TCP protocol processing; receiving the motion mode instruction, and converting the motion mode instruction into an EtherCAT protocol format; and receiving the motion mode instruction in the EtherCAT protocol format, and controlling the scanning bed to act through the servo driver based on the motion mode instruction in the EtherCAT protocol format so as to complete a scanning task. EtherCAT full duplex communication is adopted, so that data transmission is more timely and accurate, and high-speed and stable information interaction is realized; a sine line planning model is introduced, the motion trail of the scanning bed can be accurately planned according to different scanning modes, motion errors and jitter are reduced, and the CT scanning precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motion control, and particularly to a CT scan bed control method and system based on EtherCAT motion control. Background Art

[0002] In the field of CT medical equipment, precise motion control of the scan bed is crucial for obtaining high-quality scan images, improving diagnostic accuracy, and enhancing the patient experience. With the continuous development of medical technology, higher requirements have been put forward for the accuracy, speed, and stability of CT scans. However, traditional CT scan bed motion control technologies have exposed many problems in practical applications. For example, there are defects in the communication method and control architecture. In the past, CAN or RS485 communication methods were mostly used to control servo drivers for CT scan bed motion control. This communication method is a half-duplex mode, with a communication rate of only 1M, obvious delay in data transmission, communication time in the ms level, and poor synchronization. When the scan bed performs complex motion control, information cannot be transmitted between components in a timely and accurate manner, resulting in poor motion coordination and affecting scan accuracy. Moreover, its control method is mostly parallel wiring, with complex circuits, which not only increases the wiring cost and fault risk of the equipment, but also limits the number of extended nodes. The maximum number of extended nodes for CAN or RS485 is 127 or 255 respectively, making it difficult to meet the requirements of the increasingly complex CT system for more functional nodes. At the same time, the communication distance between the master station and the slave station is short, restricting the layout flexibility of the equipment. On this basis, when the traditional 7-segment line constant Jerk control method is used for scan bed motion planning, since Jerk is discontinuous during the acceleration and deceleration periods, the construction of the motion curve depends on piecewise integral operations and complex logical judgments. This not only increases the computational burden of the control system, prolongs the motion planning time, but also easily introduces errors in the calculation process, resulting in a deviation between the actual motion trajectory of the scan bed and the ideal trajectory, affecting the quality of the scan image. For example, when scanning a small lesion, insufficient motion accuracy of the scan bed may cause the lesion to be blurred in the image, affecting the doctor's judgment of the condition. The above deficiencies in communication and motion control directly lead to an extended scan preparation time, an increase in the patient's waiting time on the scan bed, a decrease in the patient turnover rate, and an impact on the hospital's examination efficiency. In addition, the complex wiring method and unstable motion control challenge the reliability and stability of the entire CT system, increase the equipment failure probability, raise the maintenance cost, and are difficult to meet the requirements of long-term stable clinical use. Summary of the Invention

[0003] In view of this, the present invention proposes a CT scan bed control method and system based on EtherCAT motion control, which can achieve high-speed communication, simple wiring, precise motion control, efficient scanning, and stable and reliable system operation. The present invention provides the following technical solutions:

[0004] A CT scan bed control method based on EtherCAT motion control, the method comprising: selecting a scanning mode according to scanning requirements, and calculating motion parameters corresponding to the scanning mode; receiving the scanning mode and motion parameter information, and processing and converting same into a motion mode instruction for the scan bed via the TCP protocol; receiving the motion mode instruction, and converting same into EtherCAT protocol format; receiving the motion mode instruction in EtherCAT protocol format, and controlling the scan bed to act based on the motion mode instruction in EtherCAT protocol format via a servo drive, so as to complete a scanning task.

[0005] Optionally, the method further comprises: receiving an IO input signal; if the input signal is an emergency stop signal and a brake signal, then outputting a brake feedback signal.

[0006] Optionally, the step of controlling the scan bed to act based on the motion mode instruction in EtherCAT protocol format via a servo drive comprises:

[0007] Controlling the scan bed to act based on the motion mode instruction in EtherCAT protocol format via an EtherCAT_X servo drive, and feeding back its status;

[0008] Controlling the scan bed to act based on the motion mode instruction in EtherCAT protocol format via an EtherCAT_Y servo drive, and feeding back its status;

[0009] Controlling the scan bed to act based on the motion mode instruction in EtherCAT protocol format via an EtherCAT_Z servo drive, and feeding back its status.

[0010] Optionally, the scanning mode includes stationary scanning, positioning scanning, helical scanning, and axial scanning;

[0011] If helical scanning is selected, the scanning mode information includes: target speed V m , maximum Jerk value J m , maximum acceleration limit value A l , and scanning length L;

[0012] If axial scanning is selected, the scanning mode information includes: step distance D, maximum Jerk value J m , maximum acceleration limit value A l , and limit speed V l .

[0013] Optionally, the method for calculating motion parameters corresponding to the scanning mode includes:

[0014] If it is recognized that the current scanning mode is helical scanning, then calculating the maximum acceleration using a sine curve planning model:

[0015] When A m ≤ A l , determine the acceleration time Constant velocity time

[0016] Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: The velocity function of the acceleration section: where t0 < t < t0 + T, and t0 is the starting time of the motion; The velocity function of the deceleration section: where t0 < t < t0 + T; The acceleration function of the acceleration section: The acceleration function of the deceleration section: The position function of the acceleration section: where t0 < t < t0 + T, and p(t0) = 0; The position function of the deceleration section: where t0 < t < t0 + T, and p(t0) = 0; The Jerk function of the acceleration section: The Jerk function of the deceleration section:

[0017] Optionally, if the current scanning mode is identified as axial scanning, first determine the maximum velocity

[0018] Compare Vm with Vl. If V m ≤ V l , then A m = A l , otherwise and V m = V l ;

[0019] Calculate the total displacement P of the acceleration section m , Compare P m with . When , When , t2 = 0;

[0020] Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: The velocity function of the acceleration section: where t0 < t < t0 + T, and t0 is the starting time of the motion; The velocity function of the deceleration section: where t0 < t < t0 + T; The acceleration function of the acceleration section: The acceleration function of the deceleration section: The position function of the acceleration section: where \(t_0 \lt t \lt t_0 + T\), and \(p(t_0)=0\); the position function in the deceleration phase: where \(t_0 \lt t \lt t_0 + T\), and \(p(t_0)=0\); the Jerk function in the acceleration phase: The Jerk function in the deceleration phase:

[0021] The present invention further discloses a CT scan bed control system based on EtherCAT motion control, including:

[0022] A parameter calculation module, configured to select a scanning mode according to scanning requirements and calculate motion parameters corresponding to the scanning mode;

[0023] A protocol conversion module, configured to receive the scanning mode and motion parameter information, and process and convert it into a motion mode instruction for the scan bed through the TCP protocol; and also for,

[0024] receiving the motion mode instruction and converting it into the EtherCAT protocol format;

[0025] A motion control module, configured to receive the motion mode instruction in the EtherCAT protocol format and control the scan bed to act based on the motion mode instruction in the EtherCAT protocol format through a servo driver to complete the scanning task.

[0026] Optionally, it further includes: an IO control module, configured to receive IO input signals; if the input signals are emergency stop signals and brake signals, then output brake feedback signals.

[0027] The present invention further discloses a computer-readable storage medium, where the storage medium stores a computer program, and when the computer program is executed by a processor, the above method is implemented.

[0028] The present invention further discloses an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the program, the above method is implemented.

[0029] According to the technical solution of the present invention, first, the scanning method is determined according to the patient's examination requirements. When performing spiral scanning, parameters such as the target speed and the maximum Jerk value are obtained, and when performing AxialStep scanning, parameters such as the stepping distance are obtained. Then, the sine curve planning model is used to calculate the motion trajectory parameters according to the parameters of different scanning methods, such as speed, acceleration, position, and Jerk function. Then, the CT scanning control system transmits the scanning method information to the ARM+FPGA control unit, and generates a scanning bed motion instruction through the TCP protocol in combination with the model parameters. During this period, the IO interface board processes relevant signals to ensure the safety and stability of the system. Subsequently, the ARM+EtherCAT control unit converts the instruction into the EtherCAT protocol format, sends it to each servo driver through the network, and monitors its status. Finally, each servo driver drives the servo motor to drive the scanning bed to move precisely according to the planned motion curve, completing the scanning task. By adopting EtherCAT full-duplex communication, compared with the traditional CAN or RS485 half-duplex communication, the communication time is improved from the ms level to the us level, the rate is increased from 1M to 100M, the synchronization is better, the data transmission is more timely and accurate, and high-speed and stable information interaction is achieved. The control method is changed from parallel to daisy-chain serial, the wiring is greatly reduced, which is convenient for system expansion and flexible layout, and distributed real-time control is realized. The sine curve planning model is introduced to simplify the complex 7-segment planning into 3 segments. The motion curve is n-order differentiable and the Jerk is continuous in the variable speed control section, which can accurately plan the motion trajectory of the scanning bed according to different scanning modes, reduce motion errors and jitters, and improve the scanning accuracy. Description of the Drawings

[0030] For purposes of illustration and not limitation, the present invention will now be described in connection with the embodiments and drawings of the present invention, wherein:

[0031] Figure 1 is a schematic flow chart of a CT scanning bed control method based on EtherCAT motion control in an embodiment of the present invention;

[0032] Figure 2 is a schematic structural diagram of a CT scanning bed control system based on EtherCAT motion control in an embodiment of the present invention;

[0033] Figure 3 is a schematic structural diagram of an electronic device in an embodiment of the present invention;

[0034] Figure 4 is a schematic structural diagram of a control device of an exemplary CT scanning bed in an embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of the principle of a control device of an exemplary CT scanning bed in an embodiment of the present invention. Detailed Embodiments

[0036] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solution in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0037] It should be noted that, without conflict, the embodiments of this application and the features in the embodiments may be combined with each other. The following will detail the embodiments of this application in conjunction with the drawings.

[0038] Reference Figure 1 , this embodiment discloses a CT scan bed control method based on EtherCAT motion control. This method is applied to the control device of the CT scan bed. Exemplarily, the control device includes a control layer, a network layer, a drive layer, and an execution layer. Among them, the control layer includes a CT scan control system for executing the scan mode, and also includes an ARM+FPGA control unit for receiving the selected scan mode in TCP mode. The network layer includes an ARM+EtherCAT control unit, which includes an EtherCAT master station for forming the information received by the ARM+FPGA control unit into an EtherCAT protocol and sending it to the corresponding EtherCAT servo drive to achieve motion and monitor its status. The drive layer includes multiple servo drives for performing the actions of the servo drives according to the control information of the EtherCAT protocol.

[0039] Specifically, the method includes:

[0040] S100: Select a scan mode according to the scan requirements and calculate the motion parameters corresponding to the scan mode.

[0041] Before scanning, the operator selects a suitable scan mode according to the specific condition of the patient, the examination site, and the clinical diagnosis purpose. The optional scan modes include static scan, positioning scan, spiral scan, and axial scan. For spiral scan and axial scan, precise control of the motion route of the CT scan is required.

[0042] Traditionally, for spiral scan and axial scan, a constant Jerk control method with 7 segments of lines is usually adopted. The Jerk is discontinuous during the acceleration and deceleration time periods, and the construction of the motion curve depends on piecewise integral operation and complex logical judgment.

[0043] Based on this, in this embodiment, a sine curve planning model is adopted to construct a motion curve, so as to accurately plan the motion trajectory of the scanning bed according to different scanning modes, reduce motion errors and jitters, and improve the scanning accuracy. By introducing an nth-order differentiable motion equation in the sine curve planning model to describe the trajectory of the speed change section, based on specific parameter inputs, the relationships among Jerk, acceleration, speed, and position can be directly calculated without integration, making the mutual dependencies and restrictions more intuitive. The motion curve planning is reduced from 7 segments to 3 segments, significantly reducing the complexity of the theoretical model, decreasing the computational amount, and improving the motion planning efficiency.

[0044] In this embodiment, taking helical scanning and axial scanning as examples, when the scanning mode is selected as helical scanning, the scanning mode information includes: the target speed V m , the maximum Jerk value J m , the maximum acceleration limit value A l and the scanning length L. Further, the method for calculating the motion parameters corresponding to the scanning mode includes: calculating the maximum acceleration using the sine curve planning model: When A m ≤A l , determine the acceleration time The constant speed time Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: the speed function of the acceleration section: where t0 < t < t0 + T, and t0 is the starting time of the motion; the speed function of the deceleration section: where t0 < t < t0 + T; the acceleration function of the acceleration section: The acceleration function of the deceleration section: The position function of the acceleration section: where t0 < t < t0 + T, and p(t0) = 0; the position function of the deceleration section: where t0 < t < t0 + T, and p(t0) = 0; the Jerk function of the acceleration section: The Jerk function of the deceleration section:

[0045] When the scanning mode is axial scanning, the scanning mode information includes: the step distance D, the maximum Jerk value J m , the maximum acceleration limit value A l and the limit speed V l . Then first determine the maximum speed Compare Vm and Vl. If V m ≤V l , then A m =A l , otherwise and V m =V l ; Calculate the total displacement P of the acceleration sectionm , Compare P m with When , When , t2 = 0; Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: The velocity function of the acceleration section: where t0 < t < t0 + T, and t0 is the starting time of the motion; The velocity function of the deceleration section: where t0 < t < t0 + T; The acceleration function of the acceleration section: The acceleration function of the deceleration section: The position function of the acceleration section: where t0 < t < t0 + T, and p(t0) = 0; The position function of the deceleration section: where t0 < t < t0 + T, and p(t0) = 0; The Jerk function of the acceleration section: The Jerk function of the deceleration section:

[0046] S200: Receive the scanning method and motion parameter information, and process and convert it into a motion mode instruction for the scanning bed through the TCP protocol.

[0047] Exemplarily, after the above ARM+FPGA control unit receives the scanning method and motion parameter information, it performs in-depth processing using the TCP protocol. The TCP protocol, with its reliable data transmission characteristics, plays a key role in this process. It first verifies the received data through a specific verification algorithm, such as cyclic redundancy check (CRC), etc., to check whether errors occur during data transmission. If an error is found, the retransmission mechanism is immediately started to ensure the accuracy of the data. After confirming that the data is correct, the TCP protocol encapsulates the data and adds necessary transmission control information, such as source address, destination address, port number, etc., so that the data can be accurately transmitted in the network and correctly parsed at the receiving end.

[0048] Furthermore, the ARM+FPGA control unit converts the scanning mode and motion parameter information into specific motion mode instructions for the scanning bed based on the data processed according to the TCP protocol, combined with the mechanical structure characteristics, dynamic parameters of the scanning bed, and the actual working requirements of CT scanning. During the conversion process, various motion stages such as the start, acceleration, constant speed, deceleration, and stop of the scanning bed are fully considered. Exemplarily, according to the calculated acceleration and speed parameters, the time nodes and changes in motion states at each stage are determined; based on the displacement parameters, the motion path of the scanning bed is accurately planned. At the same time, the instructions are optimized, considering factors such as the inertia and friction of the scanning bed, and the instruction parameters are adjusted in advance to compensate for the errors during the motion process, ensuring the smoothness and accuracy of the scanning bed motion. After completing the instruction conversion, the ARM+FPGA control unit verifies the generated motion mode instructions for the scanning bed. By simulating the motion process of the scanning bed, the actual motion trajectory is compared with the theoretically planned trajectory to check the rationality and accuracy of the instructions. If problems are found in the instructions, such as motion conflicts and sudden speed changes, they are adjusted and corrected in a timely manner. In addition, this unit also establishes a feedback mechanism to feedback the results of the instruction conversion and the verification situation to the CT scanning control system, enabling the system to grasp the status of instruction generation in real time, providing comprehensive information support for subsequent scanning operations, and ensuring the efficient and stable operation of the entire CT scanning process.

[0049] S300: Receive the motion mode instruction and convert it into the EtherCAT protocol format.

[0050] Taking an exemplary ARM+EtherCAT control unit as the receiver of the motion mode instruction, it obtains the already generated scanning bed motion mode instruction from the ARM+FPGA control unit. During the receiving process, a specific communication handshake protocol is used to ensure the accuracy and integrity of data transmission. Once the instruction is received, the ARM+EtherCAT control unit immediately starts a preliminary verification program to check the integrity of the instruction by calculating the checksum of the instruction or using the cyclic redundancy check (CRC) algorithm. If an error is found in the instruction during verification, the ARM+EtherCAT control unit will promptly send an error feedback message to the ARM+FPGA control unit, requesting retransmission of the correct instruction to ensure the accuracy of the instruction data for subsequent processing. After confirming that the motion mode instruction is accurate, the ARM+EtherCAT control unit first parses the parameters in the motion mode instruction to clarify key information such as the target position, speed, acceleration, and motion time series of the scanning bed movement. Then, according to the specifications and requirements of the EtherCAT protocol, these information are classified, sorted, and formatted. Exemplarily, the speed parameter in the motion instruction is re-encoded according to the data type and encoding method specified by the EtherCAT protocol so that it can be smoothly embedded into the EtherCAT protocol frame later. At the same time, the ARM+EtherCAT control unit also queries the system configuration information to obtain parameters related to the EtherCAT network, such as the slave node address, communication rate, etc., to provide the necessary network configuration support for protocol conversion.

[0051] Furthermore, the ARM+EtherCAT control unit encapsulates the sorted motion mode instruction information into an EtherCAT protocol frame according to the standards of the EtherCAT protocol. During the encapsulation process, the necessary header information for the EtherCAT protocol is added to the instruction, including the frame start flag, frame length, command type, source address, and destination address, etc. These header information can not only ensure the correct transmission and identification of the protocol frame in the EtherCAT network but also provide a key basis for subsequent slave node instruction parsing. At the same time, according to the data content in the motion mode instruction, the data field of the protocol frame is filled. Exemplarily, if the motion mode instruction contains the speed and position information of the scanning bed at different times, this information will be accurately filled into the data field and arranged in the format specified by the EtherCAT protocol. In addition, to ensure the reliability of the data, the ARM+EtherCAT control unit also adds a check field to the protocol frame, calculates the checksum of the entire protocol frame through a specific check algorithm, generates a check value, and fills it into the check field.

[0052] After the protocol conversion is completed, the ARM+EtherCAT control unit optimizes the generated EtherCAT protocol format instructions. Specifically, according to the real-time load condition of the EtherCAT network and the priority requirements of the scanning bed movement, the sending order and time interval of the protocol frames are adjusted. For example, when the network load is high, the sending interval of the instruction frames is appropriately adjusted to avoid network congestion and ensure stable transmission of the instructions; for the instructions related to the emergency braking or critical movement stage of the scanning bed, their sending priority is increased to ensure that the scanning bed can respond in a timely manner. The optimized EtherCAT protocol format instructions are temporarily stored in the buffer of the AR+EtherCAT control unit, waiting to be sent to the servo drives in the EtherCAT network.

[0053] S400: Receive the movement mode instructions in EtherCAT protocol format, and control the movement of the scanning bed through the servo drive based on the movement mode instructions in EtherCAT protocol format to complete the scanning task.

[0054] In this embodiment, the servo drives include EtherCAT_X servo drive, EtherCAT_Y servo drive and EtherCAT_Z servo drive to achieve multi-directional control of the CT scanning bed. After receiving the movement mode instructions in EtherCAT protocol format, the EtherCAT_X servo drive, EtherCAT_Y servo drive and EtherCAT_Z servo drive control the movement of the scanning bed based on the movement mode instructions in EtherCAT protocol format and feedback their states.

[0055] Specifically, the EtherCAT_X, Y, and Z-axis servo drives, as the receiving terminals of the movement mode instructions, continuously monitor the EtherCAT network and wait to receive the protocol format movement mode instructions sent by the ARM+EtherCAT control unit. Once an instruction is received, the servo drive immediately starts the instruction reception verification mechanism and performs an integrity check on the instruction through a verification algorithm consistent with the sending end, such as cyclic redundancy check (CRC). If the verification passes, the servo drive deeply analyzes the instruction according to the EtherCAT protocol specification. During the analysis process, key information related to the movement of the scanning bed in the X, Y, and Z directions is extracted, including target position, speed, acceleration, movement time series, and various control flag bits, etc. These information will directly determine the movement state of the scanning bed in each direction.

[0056] The servo driver generates corresponding drive signals based on the motion instruction information obtained by parsing and in combination with its own drive control algorithm. When generating drive signals, by combining the motion curve corresponding to the motion instruction information constructed by the sine curve planning model, the dynamic characteristics of the scanning bed movement, such as inertia, friction and other factors, can be fully considered, and the changes in speed and acceleration in the instruction can be smoothed to avoid excessive impact on the scanning bed movement caused by instruction mutations. For example, during the start-up acceleration phase of the scanning bed, according to the acceleration required by the instruction and in accordance with the preset acceleration change curve, the output torque of the drive motor is gradually increased to smoothly accelerate the scanning bed. The generated drive signals are usually in the form of electrical signals, and the servo motors of the scanning bed may require drive currents or voltages of specific types and amplitudes to operate normally. Therefore, the servo driver also needs to convert the generated electrical signals. Through circuit modules such as power amplification and signal modulation, they are converted into current or voltage signals suitable for driving the servo motors. The converted drive signals are transmitted to the corresponding servo motors in the X, Y, and Z directions to drive the motors to operate. During the operation of the motors, the servo driver real-time monitors feedback information such as the position and speed of the motors through the encoders built into the motors or external sensors. By comparing this feedback information with the target motion parameters in the instruction, if it is found that there is a deviation between the actual motion state and the target state, the servo driver activates the closed-loop control adjustment mechanism. According to the magnitude and direction of the deviation, the amplitude, frequency or phase of the drive signal is adjusted to make the motion of the motor gradually approach the target state and ensure the motion accuracy of the scanning bed. For example, when the actual motion speed of the scanning bed in the X direction is lower than the speed required by the instruction, the servo driver will increase the current of the drive motor to increase the motor speed and accelerate the scanning bed to the target speed.

[0057] Further, this CT scanning bed control method further includes an emergency stop control method, including: receiving an IO input signal; if the input signal is an emergency stop signal and a brake signal, then output a brake feedback signal. Refer to Figure 4 and Figure 5 , the said brake signal is used to control the emergency stop control of the EtherCAT_X servo driver, EtherCAT_Y servo driver and EtherCAT_Z servo driver. After detecting the emergency stop control signal, a fault alarm message is sent to the ARM+EtherCAT control unit.

[0058] In summary, the CT scan bed control method of this embodiment realizes efficient and accurate scanning operations through a series of coordinated technical means. First, after determining the scanning method according to the scanning requirements, a sine curve planning model is introduced, and the motion trajectory parameters are accurately calculated in combination with various key parameters, simplifying the complex 7-segment motion planning to 3 segments. This avoids the complex integral operations and logical judgments caused by the discontinuous Jerk in the acceleration and deceleration time periods in the traditional 7-segment line constant Jerk control method, reducing the complexity of motion planning. At the same time, it ensures the continuity of Jerk in the variable speed control section, reduces the jitter and impact during the movement of the scan bed, and improves the scanning accuracy. Further, the relevant information is sent to the ARM+FPGA control unit, which is reliably transmitted and accurately processed through the TCP protocol, and converted into a fine motion mode instruction to avoid instruction deviation and improve the scanning accuracy and stability. Then, the ARM+EtherCAT control unit converts the instruction into the EtherCAT protocol format with the advantages of high speed, real-time, and synchronization, solves the disadvantages of traditional communication, realizes the fast and accurate transmission of instructions, and ensures the coordinated linkage of each component of the scan bed. Finally, the EtherCAT servo driver receives the instruction, generates a drive signal considering the dynamic characteristics, precisely adjusts according to the feedback using closed-loop control, monitors the state of the scan bed in real time, responds promptly in case of abnormalities, and comprehensively ensures that the scan bed moves accurately according to the requirements, completes the scanning task, and effectively improves the scanning accuracy, reliability, safety, and the stability of the entire system.

[0059] Reference Figure 2 , this embodiment further discloses a CT scan bed control system based on EtherCAT motion control, including:

[0060] A parameter calculation module 21, configured to select a scanning method according to the scanning requirements and calculate motion parameters corresponding to the scanning method; wherein, the scanning methods include static scanning, positioning scanning, helical scanning, and axial scanning; if helical scanning is selected, the scanning method information includes: target speed V m , maximum Jerk value J m , maximum acceleration limit value A l , and scanning length L; the method for calculating the motion parameters corresponding to the scanning method includes: calculating the maximum acceleration using the sine curve planning model: When A m ≤A l , determine the acceleration time Constant speed time Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: the speed function of the acceleration section: Where t0 < t < t0 + T, t0 is the starting moment of the motion; the speed function of the deceleration section: Where t0 < t < t0 + T; the acceleration function of the acceleration section: Acceleration function of the deceleration section: Position function of the acceleration section: where t0 < t < t0 + T, and p(t0) = 0; Position function of the deceleration section: where t0 < t < t0 + T, and p(t0) = 0; Jerk function of the acceleration section: Jerk function of the deceleration section: If axis scanning is selected, the scanning mode information includes: step distance D, maximum Jerk value J m , maximum acceleration limit value A l and limit speed V l ; First, determine the maximum speed Compare Vm with Vl. If V m ≤ V l , then A m = A l , otherwise and V m = V l ; Calculate the total displacement P of the acceleration section m , Compare P m with . When , When , t2 = 0; Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: Speed function of the acceleration section: where t0 < t < t0 + T, and t0 is the starting time of the motion; Speed function of the deceleration section: where t0 < t < t0 + T; Acceleration function of the acceleration section: Acceleration function of the deceleration section: Position function of the acceleration section: where t0 < t < t0 + T, and p(t0) = 0; Position function of the deceleration section: where t0 < t < t0 + T, and p(t0) = 0; Jerk function of the acceleration section: Jerk function of the deceleration section:

[0061] Protocol conversion module 22 is used to receive the scanning mode and motion parameter information, and process and convert it into the motion mode instruction of the scanning bed through the TCP protocol; It is also used to receive the motion mode instruction and convert it into the EtherCAT protocol format.

[0062] The motion control module 23 is configured to receive motion mode instructions in the EtherCAT protocol format and control the movement of the scanning bed through a servo driver based on the motion mode instructions in the EtherCAT protocol format to complete the scanning task; it is also configured to control the movement of the scanning bed through the EtherCAT_X servo driver based on the motion mode instructions in the EtherCAT protocol format and feedback its status; control the movement of the scanning bed through the EtherCAT_Y servo driver based on the motion mode instructions in the EtherCAT protocol format and feedback its status; control the movement of the scanning bed through the EtherCAT_Z servo driver based on the motion mode instructions in the EtherCAT protocol format and feedback its status.

[0063] The IO control module 24 is configured to receive IO input signals; if the input signals are emergency stop signals and brake signals, then output brake feedback signals.

[0064] Figure 3 Schematic diagram of the physical structure of the electronic device provided by the embodiment of the present invention, as Figure 3 shown, the electronic device 50 includes: a processor 501 (processor), a memory 502 (memory), and a bus 503;

[0065] Among them, the processor 501 and the memory 502 communicate with each other through the bus 503; the processor 501 is configured to call program instructions in the memory 502 to execute the methods provided by the above method embodiments.

[0066] This embodiment provides a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium stores computer instructions, and the computer instructions cause the computer to execute the methods provided by the above method embodiments.

[0067] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by hardware related to program instructions. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments; and the foregoing storage medium includes: various storage media such as ROM, RAM, magnetic disk, or optical disk that can store program codes.

[0068] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0069] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiments.

[0070] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A CT scan bed control method based on EtherCAT motion control, characterized in that, The method includes: Select a scanning mode according to the scanning requirements and calculate the motion parameters corresponding to the scanning mode; Receive the scanning mode and motion parameter information, and process and convert it into a motion mode instruction for the scanning bed through the TCP protocol; Receive the motion mode instruction and convert it into the EtherCAT protocol format; Receive the motion mode instruction in the EtherCAT protocol format, and control the action of the scanning bed through the servo driver based on the motion mode instruction in the EtherCAT protocol format to complete the scanning task.

2. The CT scan bed control method based on EtherCAT motion control according to claim 1, wherein The method further includes: Receive the IO input signal; If the input signal is an emergency stop signal and a brake signal, output a brake feedback signal.

3. The CT scan bed control method based on EtherCAT motion control according to claim 1, wherein, The step of controlling the action of the scanning bed through the servo driver based on the motion mode instruction in the EtherCAT protocol format includes: Control the action of the scanning bed through the EtherCAT_X servo driver based on the motion mode instruction in the EtherCAT protocol format and feedback its status; Control the action of the scanning bed through the EtherCAT_Y servo driver based on the motion mode instruction in the EtherCAT protocol format and feedback its status; Control the action of the scanning bed through the EtherCAT_Z servo driver based on the motion mode instruction in the EtherCAT protocol format and feedback its status.

4. The CT scan bed control method based on EtherCAT motion control according to claim 1, characterized in that The scanning modes include stationary scanning, positioning scanning, spiral scanning, and axis scanning; If spiral scanning is selected, the scanning mode information includes: target speed V m , maximum Jerk value J m , maximum acceleration limit value A l and scanning length L; If the axis scanning is selected, the scanning mode information includes: the step distance D, the maximum Jerk value J m , the maximum acceleration limit value A l and the limit speed V l .

5. The CT scan bed control method based on EtherCAT motion control according to claim 4, wherein The method for calculating the motion parameters corresponding to the scanning mode includes: If it is recognized that the current scanning mode is spiral scanning, the maximum acceleration is calculated using the sine curve planning model: When A m ≤ A l Determine the acceleration time Constant velocity time Calculate the motion parameters of the acceleration and deceleration sections according to the model formula. Specifically: the velocity function of the acceleration section: Where t0 < t < t0 + T, and t0 is the starting time of the motion; the velocity function of the deceleration section: Where t0 < t < t0 + T; the acceleration function of the acceleration section: The acceleration function of the deceleration section: The position function of the acceleration section: Where t0 < t < t0 + T, and p(t0) = 0; the position function of the deceleration section: Where t0 < t < t0 + T, and p(t0) = 0; the Jerk function of the acceleration section: The Jerk function of the deceleration section:

6. The CT scan bed control method based on EtherCAT motion control according to claim 5, characterized in that, If it is recognized that the current scanning method is axial scanning, first determine the maximum speed Compare Vm with Vl. If V m ≤V l , then A m = A l , otherwise and V m = V l ; Total displacement P of the acceleration section of the calculation m , Compare P m with . When , When , t2 = 0; Calculate the motion parameters of the acceleration section and the deceleration section according to the model formula. Specifically: the velocity function of the acceleration section: where t0 < t < t0 + T, and t0 is the starting time of the motion; Velocity function in the deceleration phase: where \(t_0 < t < t_0 + T\); Acceleration function in the acceleration phase: Acceleration function in the deceleration phase: Position function in the acceleration phase: where \(t_0 < t < t_0 + T\), and \(p(t_0)=0\); Position function in the deceleration phase: where \(t_0 < t < t_0 + T\), and \(p(t_0)=0\); Jerk function in the acceleration phase: Jerk function in the deceleration phase:

7. A CT scan bed control system based on EtherCAT motion control, characterized in that, including: A parameter calculation module for selecting a scanning mode according to the scanning requirements and calculating the motion parameters corresponding to the scanning mode; A protocol conversion module for receiving the scanning mode and motion parameter information, and processing and converting it into a motion mode instruction for the scanning bed through the TCP protocol; and also for, Receiving the motion mode instruction and converting it into the EtherCAT protocol format; A motion control module for receiving the motion mode instruction in the EtherCAT protocol format and controlling the action of the scanning bed through the servo driver based on the motion mode instruction in the EtherCAT protocol format to complete the scanning task.

8. The CT scan bed control method based on EtherCAT motion control according to claim 7, wherein It further includes: An IO control module for receiving the IO input signal; If the input signal is an emergency stop signal and a brake signal, output a brake feedback signal.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any one of claims 1-6 above is implemented.

10. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, the method described in any one of claims 1-6 above is implemented.

Images