Numerical control system, control method, numerical control apparatus, storage medium, and program product

Abstract

The invention relates to a numerical control system, a control method, numerical control equipment, a storage medium and a program product. The numerical control system comprises a user operation module which is used for outputting an operation instruction; the control module is used for outputting a shaft position instruction according to the operation instruction; the servo driving module is used for executing a motor action corresponding to the shaft position instruction; a data acquisition end of the encoder module is used for acquiring motor position information of the servo driving module so as to input the motor position information into the field bus; the user operation module, the control module, the servo driving module and the encoder module are sequentially connected through a field bus to form a loop. The dynamic performance consistency of all shafts of the numerical control system can be improved.

Description

Technical Field

[0001] This application relates to the field of CNC machine tool technology, and in particular to a CNC system, control method, CNC equipment, storage medium and program product. Background Technology

[0002] After years of development, CNC systems have evolved from early point-to-point analog signal or pulse signal connections to fieldbus connections. Fieldbus CNC systems are a new generation of industrial control systems that deeply integrate fieldbus technology with CNC systems, achieving efficient data transmission and collaborative control between various components of the CNC system through standard communication protocols.

[0003] In traditional bus-based CNC systems, the NC controller sends the planned position of each interpolated axis to each servo drive via fieldbus in each interpolation cycle. Each servo drive then independently performs closed-loop position control after receiving the position command.

[0004] However, because each actuator has different loads and mechanical characteristics, its dynamic response also varies. This leads to some axes responding slower than others in traditional bus-based CNC systems during machining, and the movement of some axes can introduce disturbances to others. This results in the synthesized motion deviating from the intended plan, leading to position errors. Furthermore, each driver samples its position independently, and the asynchronous sampling clocks cause the position data of each axis to be out of sync in time, further introducing position errors. Summary of the Invention

[0005] Therefore, it is necessary to provide a CNC system, control method, CNC equipment, storage medium, and program product that improves the consistency of dynamic performance across all axes.

[0006] In a first aspect, this application provides a numerical control system, the system comprising:

[0007] The user operation module is used to output operation commands.

[0008] The control module is used to output axis position commands according to the operation instructions;

[0009] The servo drive module is used to execute the motor actions corresponding to axis position commands.

[0010] The encoder module's data acquisition end is used to obtain the motor position information from the servo drive module, so as to input the motor position information into the fieldbus;

[0011] The user operation module, control module, servo drive module, and encoder module are connected sequentially via a fieldbus to form a loop.

[0012] In one embodiment, the servo drive module includes a multi-stage servo drive subsystem connected in series; the servo drive subsystem includes a servo driver, a motor connected to the servo driver, and a displacement sensor for acquiring motor position information.

[0013] In the multi-level cascaded servo drive subsystem, one end of the servo driver of the first-level servo drive subsystem is connected to the first end of the loop via a fieldbus, and one end of the servo driver of the last-level servo drive subsystem is connected to the second end of the loop via a fieldbus.

[0014] The encoder module's data acquisition end connects to the displacement sensors of each servo drive subsystem to obtain the motor position information fed back by the displacement sensors.

[0015] In one embodiment, the displacement sensor includes a grating ruler.

[0016] In one embodiment, the system further includes an I / O module; the I / O module is connected between the other end of the encoder module and the other end of the user operation module;

[0017] The IO module is used to acquire sensor information from external sensors and to output IO control commands from the control module to external actuators.

[0018] In one embodiment, the control module includes an NC controller.

[0019] Secondly, this application provides a control method applied to the control module of a CNC system as described in any embodiment of the first aspect; the method includes:

[0020] Based on the operation instructions from the user operation module, send axis position instructions to the servo drive module;

[0021] Among them, the axis position command is used to instruct the servo drive module to execute the motor action corresponding to the operation command.

[0022] In one embodiment, the method further includes:

[0023] Obtain motor position information fed back from the encoder module;

[0024] Based on the motor position information, a position adjustment command is sent to the servo drive module; the position adjustment command is used to instruct the servo drive module to drive the motor to move towards the target position.

[0025] Thirdly, this application provides a numerical control device, including the numerical control system as described in any embodiment of the first aspect.

[0026] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in any embodiment of the second aspect.

[0027] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in any embodiment of the second aspect.

[0028] The aforementioned CNC system, control method, CNC equipment, storage medium, and program products involve the CNC system outputting operation commands through a user operation module, the control module outputting axis position commands based on the operation commands, the servo drive module executing the motor actions corresponding to the axis position commands, and the encoder module acquiring the motor position information from the servo drive module to input the motor position information into the fieldbus. This application introduces motor position feedback into the bus network through the above method, thereby placing the position loop control in the servo drive into the control module. This method enables centralized multi-axis cross-coupling control and error compensation for each axis in the control module, thereby achieving higher control accuracy. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a block diagram of a traditional three-loop servo control scheme in one embodiment;

[0031] Figure 2 This is a first structural block diagram of a numerical control system in one embodiment;

[0032] Figure 3 This is a second structural block diagram of a numerical control system in one embodiment;

[0033] Figure 4 This is a block diagram of the control logic of the CNC system of this application in one embodiment;

[0034] Figure 5 This is a third structural block diagram of a numerical control system in one embodiment;

[0035] Figure 6 This is a fourth structural block diagram of a numerical control system in one embodiment;

[0036] Figure 7 This is a flowchart illustrating the control method in one embodiment;

[0037] Figure 8 This is a flowchart illustrating the implementation of shaft position compensation in one embodiment;

[0038] Figure 9 This is a structural block diagram of the control device in one embodiment;

[0039] Figure 10 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0040] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be more thorough and complete.

[0041] 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 particular embodiments only and is not intended to be limiting of the application.

[0042] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0043] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0044] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0045] After years of development, CNC systems have evolved from early point-to-point analog or pulse signal connections to fieldbus connections. Fieldbus CNC systems are a new generation of industrial control systems that deeply integrate fieldbus technology with CNC systems, achieving efficient data transmission and collaborative control between various components of the CNC system through standard communication protocols. As an industrial computer network protocol, fieldbus employs digital, bidirectional communication, connecting various field devices of the CNC system (such as servo drives, sensors, and actuators) as network nodes to a unified communication network. This architecture completely changes the traditional point-to-point cable connection mode of CNC systems, realizing distributed control and information sharing between devices.

[0046] The common system architecture of bus-based CNC systems currently on the market is as follows: The NC controller acts as the master station, connecting servo drives, I / O modules, and the operator panel in series via a fieldbus. Each servo drive is responsible for the position control of a single actuator. The current control signal output by the servo drive is sent to the motor through the power line, and then the encoder on the actuator transmits the position feedback information to the drive through the encoder line. The NC (Numerical Control Controller) connects all servo drives, I / O modules, and the operator panel in series via a fieldbus, such as Glink-II.

[0047] In this system, the NC controller acts as the master station, while the servo drives, I / O modules, and operator panels are slave stations. The NC controller core is responsible for code interpretation, interpolation calculations, and PLC control. It then sends the interpolated axis position commands and I / O control commands to each servo drive and I / O module via the bus. The servo drives receive the position commands from the NC controller and perform closed-loop position control based on the position information fed back from the motor encoders. Figure 1 The three-loop servo control shown transmits the final current control signal to the motor through the power line, completing the closed-loop position control of the motor.

[0048] In traditional bus-based CNC systems, the NC controller sends the planned position of each axis obtained from interpolation to each servo drive via the fieldbus during each interpolation cycle. Each servo drive then receives the position command and executes it accordingly. Figure 1The control block diagram shown performs independent closed-loop position control. However, each actuator has different loads and mechanical characteristics, resulting in different dynamic responses. This leads to some axes responding slower than others during machining, and the movement of some axes can introduce disturbances to others, causing the final composite motion to deviate from the expected plan, thus resulting in position errors. Furthermore, on some large CNC machine tools, the electrical cabinet and encoder are far apart, requiring long encoder cables. However, encoders transmit weak electrical signals and are susceptible to electromagnetic interference from the servo system. To address these issues, this application provides a CNC system that effectively improves the consistency of dynamic performance across axes.

[0049] In one exemplary embodiment, such as Figure 2 As shown, this application provides a CNC system 200, the system including:

[0050] User operation module 202, which is used to output operation commands;

[0051] Control module 204 is used to output axis position commands according to operation commands;

[0052] Servo drive module 206 is used to execute motor actions corresponding to axis position commands;

[0053] The encoder module 208 has a data acquisition terminal used to acquire the motor position information of the servo drive module 206, so as to input the motor position information into the fieldbus.

[0054] The user operation module 202, control module 204, servo drive module 206 and encoder module 208 are connected in sequence via fieldbus to form a loop.

[0055] It should be noted that the connection order of the user operation module 202, control module 204, servo drive module 206, and encoder module 208 in the loop can be arbitrary. Figure 2 The connection method corresponding to the CNC system 200 shown is one exemplary implementation method, and other possible implementation methods will not be described here.

[0056] The user operation module 202 may include components such as an operation panel. The control module 204 may include an NC controller.

[0057] For example, the motor position information of the servo drive module 206 can be obtained by encoders (such as displacement sensors 306 such as grating rulers) installed on each motor in the servo drive module 206. Further, the motor position information acquired by the encoders installed on the motors can be transmitted to the encoder module 208 through the encoder signal line, and then the encoder module 208 inputs the motor position information corresponding to each encoder into the fieldbus of the input CNC system 200.

[0058] Understandably, compared to traditional solutions, this application introduces a bus-type encoder module 208 into the CNC system 200. The motor position information from the servo drive module 206 is connected to the encoder module 208 nearby and then transmitted via a fieldbus. This approach effectively shortens the encoder signal line length in traditional solutions, reducing the likelihood of encoder signal interference. Furthermore, digitizing the encoder signal before network transmission makes it more reliable. On the other hand, by introducing encoder feedback into the bus network, the position loop control in the driver can be moved to the NC controller. This allows for centralized multi-axis cross-coupling control and error compensation, achieving higher control accuracy. Moreover, since the encoder module uses a single clock for position sampling, this method results in higher axis position synchronization accuracy, leading to better axis position control.

[0059] In one embodiment, such as Figure 3 As shown, the servo drive module 206 includes a multi-stage servo drive subsystem 300 connected in series; the servo drive subsystem 300 includes a servo driver 302, a motor 304 connected to the servo driver 302, and a displacement sensor 306 for acquiring motor position information.

[0060] In the multi-level cascaded servo drive subsystem 300, one end of the servo driver 302 of the first-level servo drive subsystem is connected to the first end of the loop via a fieldbus, and one end of the servo driver 302 of the last-level servo drive subsystem in the multi-level cascaded servo drive subsystem 300 is connected to the second end of the loop via a fieldbus.

[0061] The data acquisition terminal of the encoder module 208 is connected to the displacement sensor 306 of each servo drive subsystem 300 to obtain the motor position information fed back by the displacement sensor 306.

[0062] For example, with Figure 3Taking the loop shown as an example, one end of the servo driver 302 of the first-level servo drive subsystem in the multi-level servo drive subsystem 300 is connected to the control module 204 via a fieldbus, and one end of the servo driver 302 of the last-level servo drive subsystem in the multi-level servo drive subsystem 300 is connected to one end of the encoder module 208 via a fieldbus.

[0063] For example, the displacement sensor 306 (i.e., the encoder mounted on the motor) may include a sensor such as a grating ruler for feedback on the current shaft position of the motor 304.

[0064] In some examples, encoder module 208 is also used to ensure compatibility with the communication protocols of different displacement sensors 306 (encoders). In practical applications, since different manufacturers may use different protocols, encoder module 208 can be pre-configured with the communication protocol and communication rate used by each connected encoder during actual use.

[0065] Furthermore, since digital signal transmission is not limited by distance and has better anti-interference capabilities, in practical applications, the encoder module 208 can be installed close to the displacement sensor 306. This can significantly shorten the length of the encoder signal cable, thereby effectively reducing the possibility of interference with the encoder feedback signal, and also saving cable costs compared to traditional solutions.

[0066] Specifically, the CNC system 200 of this application can connect the measurement signals of all displacement sensors 306 in the servo drive module 206 to the encoder module 208 to convert them into digital signals, and then connect them to the CNC system 200 via a fieldbus. For example... Figure 4 As shown, this application introduces encoder data into the fieldbus network through encoder module 208. Under this system architecture, the position loop controller can be placed in control module 204. Control module 204 can synchronously acquire the position information of the actuator in the actuator in real time. This makes it convenient to implement more complex multi-axis coupling control and error compensation in the controller of control module 204, thereby realizing synchronous control of multi-axis errors: control module 204 calculates the following error of each axis according to the actual position and command position of each axis, and then performs error synchronization control through multi-axis error synchronization control module 204 to ensure consistent following performance of each axis.

[0067] In one embodiment, the displacement sensor 306 includes a grating ruler.

[0068] For example, taking a CNC system 200 that includes five servo drive subsystems 300 as an example, the connection relationships of the components of the CNC system 200 are as follows: Figure 5 As shown. Among them, as Figure 5As shown, the grating ruler, as an encoder, can obtain the current position information of the motor 304 and transmit the current position information of the motor to the encoder module 208, so that the position information of each motor 304 can be introduced into the fieldbus through the encoder module 208.

[0069] In one embodiment, such as Figure 6 As shown, the system also includes an IO module 210; the IO module 210 is connected between the other end of the encoder module 208 and the other end of the user operation module 202;

[0070] The IO module 210 can be used to acquire sensor information from external sensors and to output IO control commands from the control module 204 to external actuators.

[0071] The IO module 210 can be used as a digital input / output module in a control system. Specifically, the IO module 210 can be used to connect to external sensors such as limit switches to obtain sensor information from the external sensors; on the other hand, the IO module 210 can also output digital information to external actuators (such as solenoid valves) according to the instructions of the user operation module 202, so as to realize the control function of the external actuators.

[0072] In one embodiment, the control module 204 includes an NC controller.

[0073] For example, the NC controller can output axis position commands and I / O control commands according to user instructions.

[0074] In some examples, axis position commands can be used to indicate the target position that the servo drive 302 needs to reach, and I / O control commands can be used to control external electrical actuators such as solenoid valves.

[0075] In one exemplary embodiment, this application provides a CNC device, including a CNC system as described in any of the foregoing embodiments.

[0076] It is understood that the solution to the problem provided in this application is similar to the solution from the perspective of CNC system described above. Therefore, the specific limitations of this application can be found in the limitations of the various CNC system embodiments above, and will not be repeated here.

[0077] In one exemplary embodiment, such as Figure 7 As shown, this application provides a control method applied to the control module of a CNC system as described in any embodiment of the first aspect; the method includes the following step S702. Wherein:

[0078] Step S702: Send axis position commands to the servo drive module according to the operation commands from the user operation module.

[0079] Among them, axis position commands can be used to instruct the servo drive module to execute the motor action corresponding to the operation command.

[0080] Specifically, the control module of the CNC system can send axis position commands to the servo drive module based on the operation commands from the user operation module, so as to instruct the servo drive module to execute the motor action corresponding to the user operation command (such as moving a certain axis to the target position).

[0081] It is understood that the solution to the problem provided in this application is similar to the solution from the perspective of CNC system described above. Therefore, the specific limitations of this application and one or more control method embodiments provided below can be found in the limitations of the CNC system embodiments above, and will not be repeated here.

[0082] In one embodiment, such as Figure 8 As shown, the method further includes steps S802 to S804. Wherein:

[0083] Step S802: Obtain motor position information fed back from the encoder module.

[0084] Step S804: Based on the motor position information, send a position adjustment command to the servo drive module; the position adjustment command is used to instruct the servo drive module to drive the motor to move towards the target position.

[0085] Specifically, please refer to Figure 4 The system control logic diagram shown illustrates that after the encoder module introduces the motor position information into the fieldbus network, the position loop controller of the CNC system will be located in the control module. At this time, the control module can centrally perform multi-axis cross-coupling control and error compensation on each axis of the servo drive module based on the motor position information fed back by the encoder module, thereby achieving higher control accuracy of the CNC system.

[0086] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0087] Based on the same inventive concept, this application also provides a control device for implementing the control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, specific limitations in one or more control device embodiments provided below can be found in the limitations of the control method described above, and will not be repeated here.

[0088] In one exemplary embodiment, such as Figure 9 As shown, a control device 900 is provided, the device 900 including:

[0089] The axis position control unit 902 is used to send axis position commands to the servo drive module according to the operation commands from the user operation module; wherein, the axis position commands are used to instruct the servo drive module to execute the motor action corresponding to the user operation commands.

[0090] In one embodiment, the device 900 further includes:

[0091] The position compensation unit is used to acquire motor position information fed back from the encoder module; based on the motor position information, it sends a position adjustment command to the servo drive module; the position adjustment command is used to instruct the servo drive module to drive the motor to move towards the target position.

[0092] Each module in the aforementioned control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0093] In one exemplary embodiment, an electronic device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 10 As shown, this electronic device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores motor position information. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements a control method.

[0094] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the electronic device to which the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0095] In one embodiment, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0096] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0097] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0098] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A numerical control system, characterized in that, The system includes: User operation module, which is used to output operation instructions; The control module is used to output axis position commands according to the operation commands; A servo drive module, which is used to execute the motor action corresponding to the axis position command; The encoder module has a data acquisition terminal for acquiring the motor position information of the servo drive module, and inputting the motor position information into the fieldbus. The user operation module, the control module, the servo drive module, and the encoder module are connected sequentially via the fieldbus to form a loop.

2. The system according to claim 1, characterized in that, The servo drive module includes a multi-stage servo drive subsystem connected in series; the servo drive subsystem includes a servo driver, a motor connected to the servo driver, and a displacement sensor for acquiring the position information of the motor. In the multi-level cascaded servo drive subsystem, one end of the servo driver of the first-level servo drive subsystem is connected to the first end of the loop through the fieldbus, and one end of the servo driver of the last-level servo drive subsystem is connected to the second end of the loop through the fieldbus. The data acquisition terminal of the encoder module is connected to the displacement sensors of each of the servo drive subsystems to obtain the motor position information fed back by the displacement sensors.

3. The system according to claim 2, characterized in that, The displacement sensor includes a grating ruler.

4. The system according to claim 1, characterized in that, The system also includes an I / O module; the I / O module is connected between the other end of the encoder module and the other end of the user operation module; The IO module is used to acquire sensor information from external sensors and to output IO control commands from the control module to external actuators.

5. The system according to claim 1, characterized in that, The control module includes an NC controller.

6. A control method, characterized in that, The method is applied to the control module of the CNC system as described in any one of claims 1 to 5; the method includes: Based on the operation instructions from the user operation module, the axis position command is sent to the servo drive module; The axis position command is used to instruct the servo drive module to execute the motor action corresponding to the operation command.

7. The control method according to claim 6, characterized in that, The method further includes: Obtain motor position information fed back from the encoder module; Based on the motor position information, a position adjustment command is sent to the servo drive module; the position adjustment command is used to instruct the servo drive module to drive the motor to move towards the target position.

8. A numerical control device, characterized in that, Including the numerical control system as described in any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 6 or 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 6 or 7.

Images