A dynamic compensation control method and system for the deflection of the slide of a numerical control floor-type milling and boring machine

Abstract

The embodiment of the application provides a dynamic compensation control method and system for the deflection of a ram of a numerical control floor-type milling and boring machine, and belongs to the field of numerical control machining. The method comprises the following steps: in the process of machining and operation of the numerical control floor-type milling and boring machine, collecting a displacement deviation signal of a front-end reference surface of the ram relative to an axis of a main shaft of the machine tool, a real-time rotating speed of the main shaft, a real-time overhanging length of the ram determined based on real-time coordinate position information, and a real-time position of a main shaft box, so as to construct a multi-dimensional machining state parameter set; based on the multi-dimensional machining state parameter set, using a pre-constructed dynamic compensation model for the deflection of the ram, calculating real-time compensation amounts required by each shaft of the numerical control floor-type milling and boring machine in the current machining state; and superimposing the real-time compensation amounts to given values of position closed-loop control of corresponding servo driving shafts respectively, so as to form full-closed-loop position control instructions with deflection feedforward compensation. The method can adapt to dynamic fluctuations of deflection deformation caused by real-time changes of the overhanging length of the ram, the rotating speed of the main shaft and the cutting load.

Description

Technical Field

[0001] This invention relates to the field of CNC machining technology, and specifically to a dynamic compensation control method and system for the ram sag deflection of a CNC floor-type milling and boring machine. Background Technology

[0002] As the high-end equipment manufacturing industry develops towards larger scale, integration, and precision, various fields are placing increasingly stringent demands on the machining accuracy, efficiency, and machining range of large and complex parts. CNC floor-type milling and boring machines, as the core basic equipment for machining such parts, directly determine the machining quality and production efficiency of the workpiece. Among them, four-axis linkage CNC floor-type milling and boring machines, with their advantage of multi-axis synchronous motion, can achieve integrated machining of multiple surfaces and multiple processes of the workpiece, reducing the number of clamping operations and lowering positioning errors, and have become key equipment for machining large parts.

[0003] As a key actuator in CNC floor-type milling and boring machines, the ram's front end typically extends over the machine tool's worktable area. Under the combined action of its own weight and cutting forces, it is prone to sagging and bending deformation. When the ram is extended over a large stroke, the vertical displacement of its front end and the angular deviation around the X and Y directions increase significantly, severely restricting the machining accuracy and surface quality of the machine tool.

[0004] In existing technologies, auxiliary support devices are typically installed at the front end of the ram or a balance compensation mechanism is added inside the ram to partially offset gravitational deformation through mechanical means. However, such mechanical compensation methods have drawbacks such as complex structure, slow response, and limited compensation range, making it difficult to adapt to the dynamic fluctuations in flexural deformation caused by real-time changes in ram overhang length, spindle speed, and cutting load during machining. Summary of the Invention

[0005] The purpose of this invention is to provide a dynamic compensation control method and system for the sag deflection of the slide of a CNC floor-type milling and boring machine, which is used to solve the problem of dynamic deflection control of the slide under large overhang conditions.

[0006] To achieve the above objectives, embodiments of the present invention provide a dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine, comprising: During the machining operation of a CNC floor-type milling and boring machine, the displacement deviation signal of the front reference surface of the slide relative to the axis of the machine tool spindle, the real-time spindle speed, and the real-time overhang length of the slide and the real-time position of the spindle box determined based on the real-time coordinate position information are collected in real time to construct a multi-dimensional machining state parameter set. Based on the multidimensional machining state parameter set, the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state is calculated using a pre-constructed dynamic compensation model for ram sag deflection. The dynamic compensation model includes a mathematical expression for ram flexure deformation based on a combination of finite element analysis and experimental calibration. The real-time compensation values ​​are superimposed on the corresponding servo drive shaft's position closed-loop control setpoint to form a full closed-loop position control command with deflection feedforward compensation.

[0007] Optionally, the process of constructing the dynamic compensation model for the ram sagging deflection includes: Based on finite element analysis software, a three-dimensional parametric finite element model of the slide and spindle box assembly was established. Different slide overhang lengths, different spindle box Y-axis positions, different spindle speeds, bearing temperature rise thermal loads, and different cutting force conditions were applied as combined boundary conditions. The flexural deformation data of the slide front end under various working conditions were obtained through finite element calculation, forming an initial deflection feature database. On the experimental calibration platform, the same working condition combination as the finite element calculation was used to carry out actual loading tests, and the actual deformation of the front end of the slide was measured simultaneously using a laser interferometer and a capacitive displacement sensor. The flexural deformation data is compared with the actual deformation, and the initial deflection feature database is corrected based on the comparison results to obtain the corrected deflection feature database. A multiple regression analysis was performed on the modified deflection feature database to construct a mathematical expression for the ram deflection deformation, with the ram overhang length, spindle box Y-axis coordinate, spindle speed and cutting torque as independent variables, and the vertical deflection of the ram front end and the angular deviation of the front end around the X-axis and Y-axis as dependent variables, thus obtaining a dynamic compensation model for ram sag deflection.

[0008] Optionally, the mathematical expression for the ram flexure deformation is as follows:

[0009] In the formula, The vertical deflection of the front end of the ram. This refers to the ram extension length. The Y-axis coordinate of the spindle box Main spindle speed For cutting torque, , These are the angular deflections of the front end of the ram around the X-axis and around the Y-axis, respectively. - , - , - These are the fitting coefficients.

[0010] Optionally, the real-time compensation amounts required for each axis of the CNC floor-type milling and boring machine under the current machining state include: additional movement compensation components for the Z-axis, additional movement compensation components for the W-axis, and additional oscillation compensation components for the X-axis and Y-axis.

[0011] Optionally, based on the multi-dimensional machining state parameter set, using a pre-built dynamic compensation model for ram sag deflection, the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state is calculated, including: The real-time overhang length of the ram, the real-time position of the spindle box, the real-time speed of the spindle, the displacement deviation signal and the cutting torque are substituted as input variables into the mathematical expression of the ram deflection to obtain the vertical deflection of the ram front end, the angular deviation around the X-axis and the angular deviation around the Y-axis in the current state. The vertical deflection of the front end of the slide block is allocated into Z-axis movement compensation component and W-axis movement compensation component according to a preset ratio. The angular deviation around the X-axis is mapped into Y-axis swing compensation component, and the angular deviation around the Y-axis is mapped into X-axis swing compensation component, thereby obtaining the real-time compensation amount required for the Z-axis, W-axis, X-axis and Y-axis.

[0012] Optionally, a non-contact displacement detector located below the front end of the slide can be used to collect real-time displacement deviation signals of the front end reference surface of the slide relative to the axis of the machine tool spindle. The non-contact displacement detector includes at least three eddy current displacement sensors or laser triangular displacement sensors arranged in a triangle and fixedly installed on the reference surface of the bottom surface of the front end of the slide. The detection end face of each sensor is set opposite to the machine tool worktable and is used to detect the vertical displacement change at different positions of the front end of the slide.

[0013] Secondly, the present invention also provides a dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine, comprising: The data acquisition unit is used to collect in real time the displacement deviation signal of the front reference surface of the slide relative to the axis of the machine tool spindle, the real-time spindle speed, and the real-time overhang length of the slide and the real-time position of the spindle box determined based on the real-time coordinate position information during the machining operation of the CNC floor milling and boring machine, so as to construct a multi-dimensional machining state parameter set. The compensation unit is used to calculate the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state based on the multi-dimensional machining state parameter set and using a pre-constructed dynamic compensation model for ram sag deflection; wherein, the dynamic compensation model includes a mathematical expression for ram flexure deformation based on finite element analysis and experimental calibration. The control unit is used to superimpose the real-time compensation amount onto the position closed-loop control setpoint of the corresponding servo drive axis to form a full closed-loop position control command with deflection feedforward compensation.

[0014] Optionally, the compensation unit is used for: Based on finite element analysis software, a three-dimensional parametric finite element model of the slide and spindle box assembly was established. Different slide overhang lengths, different spindle box Y-axis positions, different spindle speeds, bearing temperature rise thermal loads, and different cutting force conditions were applied as combined boundary conditions. The flexural deformation data of the slide front end under various working conditions were obtained through finite element calculation, forming an initial deflection feature database. On the experimental calibration platform, the same working condition combination as the finite element calculation was used to carry out actual loading tests, and the actual deformation of the front end of the slide was measured simultaneously using a laser interferometer and a capacitive displacement sensor. The flexural deformation data is compared with the actual deformation, and the initial deflection feature database is corrected based on the comparison results to obtain the corrected deflection feature database. A multiple regression analysis was performed on the modified deflection feature database to construct a mathematical expression for the ram deflection deformation, with the ram overhang length, spindle box Y-axis coordinate, spindle speed and cutting torque as independent variables, and the vertical deflection of the ram front end and the angular deviation of the front end around the X-axis and Y-axis as dependent variables, thus obtaining a dynamic compensation model for ram sag deflection.

[0015] Optionally, the real-time compensation amounts required for each axis of the CNC floor-type milling and boring machine under the current machining state include: additional movement compensation components for the Z-axis, additional movement compensation components for the W-axis, and additional oscillation compensation components for the X-axis and Y-axis.

[0016] Optionally, the compensation unit is used for: The real-time overhang length of the ram, the real-time position of the spindle box, the real-time speed of the spindle, the displacement deviation signal and the cutting torque are substituted as input variables into the mathematical expression of the ram deflection to obtain the vertical deflection of the ram front end, the angular deviation around the X-axis and the angular deviation around the Y-axis in the current state. The vertical deflection of the front end of the slide block is allocated into Z-axis movement compensation component and W-axis movement compensation component according to a preset ratio. The angular deviation around the X-axis is mapped into Y-axis swing compensation component, and the angular deviation around the Y-axis is mapped into X-axis swing compensation component, thereby obtaining the real-time compensation amount required for the Z-axis, W-axis, X-axis and Y-axis.

[0017] The above technical solution replaces the mechanical auxiliary support and balance compensation mechanism, eliminates the response lag and compensation stroke limitation of the mechanical structure, and allows the compensation amount to be updated synchronously with the real-time changes of the slide overhang length, spindle speed and cutting load, so as to adapt to the dynamic fluctuations of flexural deformation throughout the machining process.

[0018] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a dynamic compensation control method for the sag deflection of the slide of a CNC floor-type milling and boring machine, provided in an embodiment of the present invention. Figure 2 This is a flowchart illustrating the construction process of a dynamic compensation model for ram sagging deflection provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0020] Various embodiments of this disclosure will be described more fully in the following detailed description. This disclosure may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of this disclosure to the specific embodiments disclosed herein, but rather this disclosure should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of this disclosure.

[0021] In the following, the terms “comprising” or “may include”, which may be used in various embodiments of this disclosure, indicate the presence of the disclosed functions or operations and do not limit the addition of one or more functions or operations. Furthermore, as used in various embodiments of this disclosure, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, or combination of the foregoing and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, or combinations of the foregoing, or the possibility of adding one or more features, numbers, steps, operations, or combinations of the foregoing.

[0022] In various embodiments of this disclosure, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0024] See Figure 1 The diagram shows a flowchart of a dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine in a specific embodiment, including the following execution steps: Step 100: During the machining operation of the CNC floor-type milling and boring machine, the displacement deviation signal of the front reference surface of the slide relative to the axis of the machine tool spindle, the real-time spindle speed, and the real-time overhang length of the slide and the real-time position of the spindle box determined based on the real-time coordinate position information are collected in real time to construct a multi-dimensional machining state parameter set.

[0025] Specifically, a non-contact displacement detector located below the front end of the slide is used to collect real-time displacement deviation signals between the front end reference surface of the slide and the axis of the machine tool spindle.

[0026] The non-contact displacement detector includes at least three eddy current displacement sensors or laser triangular displacement sensors arranged in a triangle and fixedly installed on the reference surface of the bottom surface of the front end of the slide. The detection end face of each sensor is set opposite to the machine tool worktable and is used to detect the vertical displacement change at different positions of the front end of the slide.

[0027] Step 101: Based on the multi-dimensional machining state parameter set, use the pre-built dynamic compensation model for slide ram sag deflection to calculate the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state.

[0028] The dynamic compensation model includes a mathematical expression for the ram deflection deformation based on a combination of finite element analysis and experimental calibration.

[0029] For details, see Figure 2 As shown, the construction process of the dynamic compensation model for the ram sagging deflection includes: S1: Based on finite element analysis software, a three-dimensional parametric finite element model of the slide and spindle box assembly is established. Different slide overhang lengths, different spindle box Y-axis positions, different spindle speeds, bearing temperature rise thermal loads, and different cutting force conditions are applied as combined boundary conditions. The flexural deformation data of the slide front end under various working condition combinations are obtained through finite element calculation to form an initial deflection feature database.

[0030] Specifically, a three-dimensional parametric finite element model of the slide block and spindle box assembly is constructed according to the following steps: S10: Use 3D parametric modeling software to establish a parametric 3D solid geometric model of the slide and spindle box assembly, and set the slide overhang length, slide cross-sectional dimensions, stiffener thickness and spindle box Y-axis installation position as adjustable parameters.

[0031] S11: Import the established parametric three-dimensional solid geometric model into the preprocessing environment of the finite element analysis software, perform geometric cleaning on the imported geometric model, remove threaded holes, oil holes, chamfers and fillets whose influence on stiffness analysis results is less than a preset threshold, and identify and mark the assembly surfaces between each component.

[0032] Specifically, the geometric diagnostic tools of the preprocessing software are used to detect geometric defects in the model, such as free edges, overlapping surfaces, non-manifold boundaries, and small cracks. Geometric repair is then performed on the detected defects. Each type of subtle geometric feature in the model is identified sequentially. For each identified feature, its contribution to the overall stiffness analysis result of the model in the finite element calculation is evaluated. If the contribution is less than a preset threshold, the feature is geometrically suppressed or deleted. For threaded holes and oil holes, they are removed by closing the end face of the hole and subtracting or filling the hole from the solid model. For chamfers and fillets, they are removed by extending adjacent curved surfaces and intersecting to form sharp corner boundaries.

[0033] The fine geometric features include at least threaded holes, oil holes, chamfers, and fillets.

[0034] After feature simplification, the surface topology analysis function of the preprocessing software is used to automatically identify the contact interfaces between the components. Each automatically identified mating surface is then manually checked and corrected. Incorrectly identified mating surfaces are deleted, and missing mating surfaces are manually added. Each mating surface is assigned a unique number and name label in the preprocessing environment. At the same time, the normal vector, area, and geometric center coordinates of each mating surface are recorded for later use when setting up contact pairs.

[0035] S12: In the finite element analysis software, define the material properties of the slide and the spindle box respectively, and set the contact pairs for the assembly mating surfaces between the slide and the spindle box. According to the actual connection method of the mating surfaces, set the contact type of the mating surface between the spindle box and the slide guide rail to non-penetrating friction contact, and set the contact type of the connection surface between the spindle box and the slide drive screw to binding contact.

[0036] The material properties include at least the elastic modulus, Poisson's ratio, and material density.

[0037] S13: After completing the contact settings, use high-order three-dimensional solid elements to mesh the slide block body and the spindle box body, and refine the mesh locally in the slide block overhang section, the area around the spindle mounting hole, the intersection of the stiffener plates and the guide rail mounting surface, so that the mesh size in the above areas is smaller than the main body mesh size.

[0038] For example, the grid size of the aforementioned region is less than half the size of the main grid.

[0039] S14: After the mesh is generated, apply a fixed constraint to the mounting base where the spindle box and the column slide connect, constraining all translational and rotational degrees of freedom; apply a normal displacement constraint to the mating surface between the slide and the spindle box guide rail; and apply the spindle gravity load and cutting force equivalent load to the spindle front bearing mounting position, while applying the bearing temperature rise thermal load caused by the spindle speed to the spindle bearing mounting position.

[0040] S15: By assigning different numerical combinations to the adjustable parameters to change the slide ram overhang length, spindle box Y-axis position and cutting force loading conditions, multiple combination boundary conditions are generated and submitted to the finite element solver one by one for solving, obtaining the vertical displacement of the slide ram front end and the angular displacement data around the X and Y axes of each working condition combination, forming an initial deflection feature database covering the full overhang stroke range of the slide ram and the full Y-axis stroke range of the spindle box.

[0041] S2: On the experimental calibration platform, the same working condition combination as the finite element calculation was used to carry out actual loading tests, and the actual deformation of the front end of the slide was measured simultaneously using a laser interferometer and a capacitive displacement sensor.

[0042] S3: Compare the flexural deformation data with the actual deformation amount, and correct the initial deflection feature database based on the comparison results to obtain the corrected deflection feature database.

[0043] S4: Perform multiple regression analysis on the modified deflection feature database to construct a mathematical expression for the ram deflection deformation with the ram overhang length, spindle box Y-axis coordinate, spindle speed and cutting torque as independent variables, and the ram front vertical deflection and the angular deviation of the front end around the X-axis and Y-axis as dependent variables, and obtain the dynamic compensation model for ram sag deflection.

[0044] Specifically, the mathematical expression for the ram flexure deformation is as follows:

[0045] In the formula, The vertical deflection of the front end of the ram. This refers to the ram extension length. The Y-axis coordinate of the spindle box Main spindle speed For cutting torque, , These are the angular deflections of the front end of the ram around the X-axis and around the Y-axis, respectively. - , - , - These are the fitting coefficients.

[0046] It should be understood that the real-time compensation required for each axis of the CNC floor-type milling and boring machine under the current machining state includes: additional movement compensation component for the Z-axis, additional movement compensation component for the W-axis, and additional oscillation compensation components for the X-axis and Y-axis.

[0047] Furthermore, when performing step 101, the following steps can be specifically performed: S1010: Substitute the real-time overhang length of the ram, the real-time position of the spindle box, the real-time speed of the spindle, the displacement deviation signal, and the cutting torque as input variables into the mathematical expression of the ram deflection deformation to obtain the vertical deflection of the ram front end, the angular deviation around the X-axis, and the angular deviation around the Y-axis in the current state.

[0048] S1011: The vertical deflection of the front end of the slide block is allocated into Z-axis movement compensation component and W-axis movement compensation component according to a preset ratio. The angular deviation around the X-axis is mapped into Y-axis swing compensation component, and the angular deviation around the Y-axis is mapped into X-axis swing compensation component, thereby obtaining the real-time compensation amount required for the Z-axis, W-axis, X-axis and Y-axis.

[0049] Specifically, the calculated total sag deflection compensation value is distributed to the W-axis and Z-axis additional movement compensation components according to a preset proportional coefficient K. This proportional coefficient K ranges from 0.3 to 0.7 and is dynamically adjusted based on the real-time overhang length of the ram and the current Z-axis lead screw preload. Any remaining compensation amount in the total sag deflection compensation value exceeding the upper limit of the W-axis single-axis compensation stroke is automatically allocated to the Z-axis for collaborative compensation. Finally, the angular deviation at the front end of the ram is converted into additional oscillation compensation components for the machine tool's X and Y axes, respectively.

[0050] The Z-axis additional motion compensation component, W-axis additional motion compensation component, X-axis additional oscillation compensation component, and Y-axis additional oscillation compensation component are each subjected to amplitude limiting processing to ensure that the compensation amount of each axis does not exceed the corresponding safety limit threshold.

[0051] The conversion formula is as follows:

[0052]

[0053] in, , These are the additional oscillation compensation amounts for the X and Y axes, respectively. This is the effective overhang length of the ram. , These are the kinematic transformation coefficients in the X and Y axes, respectively.

[0054] Step 102: The real-time compensation values ​​are superimposed on the position closed-loop control setpoints of the corresponding servo drive axes to form a full closed-loop position control command with deflection feedforward compensation.

[0055] In this embodiment, a multi-dimensional machining state parameter set is constructed based on real-time acquired displacement deviation signals, spindle speed, ram overhang length, and spindle box position. A mathematical model of ram deflection deformation is used to calculate the real-time compensation amount for each axis, and this compensation amount is directly superimposed onto the position closed-loop control setpoint of each servo drive axis. This achieves real-time dynamic adjustment of the compensation amount according to changes in machining state, eliminates the response lag and stroke limitation of the mechanical compensation structure, and ensures that the compensation response cycle is consistent with the servo control cycle. This allows it to adapt to dynamic fluctuations in deflection deformation caused by real-time changes in ram overhang length, spindle speed, and cutting load.

[0056] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0057] like Figure 3 As shown, the following is an embodiment of the dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine provided in this disclosure. It belongs to the same inventive concept as the dynamic compensation control method for the ram sag deflection of the CNC floor-type milling and boring machine in the above embodiments. For details not described in detail in the embodiments of the dynamic compensation control system for the ram sag deflection of the CNC floor-type milling and boring machine, please refer to the embodiments of the dynamic compensation control method for the ram sag deflection of the CNC floor-type milling and boring machine described above.

[0058] A dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine includes: The data acquisition unit is used to collect in real time the displacement deviation signal of the front reference surface of the slide relative to the axis of the machine tool spindle, the real-time spindle speed, and the real-time overhang length of the slide and the real-time position of the spindle box determined based on the real-time coordinate position information during the machining operation of the CNC floor milling and boring machine, so as to construct a multi-dimensional machining state parameter set. The compensation unit is used to calculate the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state based on the multi-dimensional machining state parameter set and using a pre-constructed dynamic compensation model for ram sag deflection; wherein, the dynamic compensation model includes a mathematical expression for ram flexure deformation based on finite element analysis and experimental calibration. The control unit is used to superimpose the real-time compensation amount onto the position closed-loop control setpoint of the corresponding servo drive axis to form a full closed-loop position control command with deflection feedforward compensation.

[0059] Specifically, the compensation unit is used for: Based on finite element analysis software, a three-dimensional parametric finite element model of the slide and spindle box assembly was established. Different slide overhang lengths, different spindle box Y-axis positions, different spindle speeds, bearing temperature rise thermal loads, and different cutting force conditions were applied as combined boundary conditions. The flexural deformation data of the slide front end under various working conditions were obtained through finite element calculation, forming an initial deflection feature database. On the experimental calibration platform, the same working condition combination as the finite element calculation was used to carry out actual loading tests, and the actual deformation of the front end of the slide was measured simultaneously using a laser interferometer and a capacitive displacement sensor. The flexural deformation data is compared with the actual deformation, and the initial deflection feature database is corrected based on the comparison results to obtain the corrected deflection feature database. A multiple regression analysis was performed on the modified deflection feature database to construct a mathematical expression for the ram deflection deformation, with the ram overhang length, spindle box Y-axis coordinate, spindle speed and cutting torque as independent variables, and the vertical deflection of the ram front end and the angular deviation of the front end around the X-axis and Y-axis as dependent variables, thus obtaining a dynamic compensation model for ram sag deflection.

[0060] Specifically, the real-time compensation required for each axis of the CNC floor-type milling and boring machine under the current machining state includes: additional movement compensation component for the Z-axis, additional movement compensation component for the W-axis, and additional oscillation compensation components for the X-axis and Y-axis.

[0061] Specifically, the compensation unit is used for: The real-time overhang length of the ram, the real-time position of the spindle box, the real-time speed of the spindle, the displacement deviation signal and the cutting torque are substituted as input variables into the mathematical expression of the ram deflection to obtain the vertical deflection of the ram front end, the angular deviation around the X-axis and the angular deviation around the Y-axis in the current state. The vertical deflection of the front end of the slide block is allocated into Z-axis movement compensation component and W-axis movement compensation component according to a preset ratio. The angular deviation around the X-axis is mapped into Y-axis swing compensation component, and the angular deviation around the Y-axis is mapped into X-axis swing compensation component, thereby obtaining the real-time compensation amount required for the Z-axis, W-axis, X-axis and Y-axis.

[0062] Figure 4 This is a schematic diagram of the hardware structure of an electronic device that implements various embodiments of the present invention.

[0063] The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine provided in this application embodiment can be applied to electronic devices. Those skilled in the art will understand that the electronic device structure involved in the embodiments of this invention does not constitute a limitation on the electronic device. An electronic device may include more or fewer components than illustrated, or combine certain components, or have different component arrangements. In the embodiments of this invention, the electronic device includes, but is not limited to, laptop computers, desktop computers, workbenches, 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. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the embodiments of this application described and / or claimed herein.

[0064] Electronic devices may include processors, external memory interfaces, internal memory, universal serial bus (USB) interfaces, charging management modules, power management modules, batteries, wireless communication modules, audio modules, speakers, microphones, sensor modules, buttons, cameras, displays, and SIM card interfaces, etc.

[0065] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device. In other embodiments of this application, the electronic device may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0066] A processor may include one or more processing units, such as: a central processing unit (CPU), an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.

[0067] The processor can serve as the nerve center and command center of an electronic device. The controller can generate operation control signals based on the instruction opcode and timing signals to control the fetching and execution of instructions.

[0068] The processor may also include memory for storing instructions and data. In some embodiments, the memory in the processor is a cache memory. This memory can store instructions or data that the processor has just used or that are used repeatedly. If the processor needs to use the instruction or data again, it can retrieve it directly from this memory. This avoids repeated accesses, reduces processor latency, and thus improves system efficiency.

[0069] An external storage interface (ESI) can be used to connect external memory cards, such as microSD cards, to expand the storage capacity of electronic devices. The external memory card communicates with the processor through the ESI to perform data storage functions, such as saving music and video files on the external memory card.

[0070] Internal memory can be used to store computer executable program code, which includes instructions. The processor executes various functional applications and data processing of electronic devices by running the instructions stored in internal memory. Internal memory can include a program storage area and a data storage area. Internal memory can include high-speed random access memory, and can also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.

[0071] Wireless communication functionality in electronic devices can be achieved through antennas, wireless communication modules, modem processors, and baseband processors.

[0072] Wireless communication modules can provide solutions for wireless communication applications in electronic devices, including wireless local area networks (WLANs) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies.

[0073] Electronic devices can implement audio functions through audio modules, speakers, receivers, microphones, headphone jacks, and application processors.

[0074] Electronic devices can achieve shooting functions through ISPs, cameras, video codecs, GPUs, displays, and application processors.

[0075] Electronic devices can achieve display functions through GPUs, displays, and application processors.

[0076] A GPU is a microprocessor for image processing, connected to the display screen and application processor. GPUs are used to perform mathematical and geometric calculations for graphics rendering. A processor may include one or more GPUs, which execute program instructions to generate or modify display information.

[0077] A display screen is used to display images, videos, etc. A display screen includes a display panel.

[0078] The storage medium provided in this application stores a program product capable of implementing a dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine.

[0079] The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine includes: during the machining operation of the CNC floor-type milling and boring machine, real-time acquisition of the displacement deviation signal of the ram front reference surface relative to the machine tool spindle axis, the real-time spindle speed, and the real-time overhang length of the ram and the real-time position of the spindle box determined based on the real-time coordinate position information, to construct a multi-dimensional machining state parameter set; based on the multi-dimensional machining state parameter set, using a pre-constructed dynamic compensation model for ram sag deflection, calculating the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state; wherein, the dynamic compensation model includes a mathematical expression for ram flexure deformation constructed based on finite element analysis and experimental calibration; the real-time compensation amount is superimposed on the position closed-loop control setpoint of the corresponding servo drive axis to form a full closed-loop position control command with deflection feedforward compensation.

[0080] In some possible implementations, the subject matter of this disclosure, namely, the method and system for dynamic compensation control of ram sag deflection of a CNC floor-type milling and boring machine, can be implemented as a program product comprising program code. When the program product is run on a terminal device, the program code is used to cause the terminal device to perform the steps described in the "Exemplary Methods" section above, according to various exemplary embodiments of this disclosure.

[0081] The storage medium disclosed herein can take the form of any combination of one or more readable media. A readable medium can be a readable signal medium or a readable storage medium. A readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine, characterized in that, include: During the machining operation of a CNC floor-type milling and boring machine, the displacement deviation signal of the front reference surface of the slide relative to the axis of the machine tool spindle, the real-time spindle speed, and the real-time overhang length of the slide and the real-time position of the spindle box determined based on the real-time coordinate position information are collected in real time to construct a multi-dimensional machining state parameter set. Based on the multidimensional machining state parameter set, the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state is calculated using a pre-constructed dynamic compensation model for ram sag deflection. The dynamic compensation model includes a mathematical expression for ram flexure deformation based on a combination of finite element analysis and experimental calibration. The real-time compensation values ​​are superimposed on the corresponding servo drive shaft's position closed-loop control setpoint to form a full closed-loop position control command with deflection feedforward compensation.

2. The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 1, characterized in that, The construction process of the dynamic compensation model for the ram sagging deflection includes: Based on finite element analysis software, a three-dimensional parametric finite element model of the slide and spindle box assembly was established. Different slide overhang lengths, different spindle box Y-axis positions, different spindle speeds, bearing temperature rise thermal loads, and different cutting force conditions were applied as combined boundary conditions. The flexural deformation data of the slide front end under various working conditions were obtained through finite element calculation, forming an initial deflection feature database. On the experimental calibration platform, the same working condition combination as the finite element calculation was used to carry out actual loading tests, and the actual deformation of the front end of the slide was measured simultaneously using a laser interferometer and a capacitive displacement sensor. The flexural deformation data is compared with the actual deformation, and the initial deflection feature database is corrected based on the comparison results to obtain the corrected deflection feature database. A multiple regression analysis was performed on the modified deflection feature database to construct a mathematical expression for the ram deflection deformation, with the ram overhang length, spindle box Y-axis coordinate, spindle speed and cutting torque as independent variables, and the vertical deflection of the ram front end and the angular deviation of the front end around the X-axis and Y-axis as dependent variables, thus obtaining a dynamic compensation model for ram sag deflection.

3. The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 2, characterized in that, The mathematical expression for the ram flexure deformation is as follows: In the formula, The vertical deflection of the front end of the ram. This refers to the ram extension length. The Y-axis coordinate of the spindle box Main spindle speed For cutting torque, , These are the angular deflections of the front end of the ram around the X-axis and around the Y-axis, respectively. - , - , - These are the fitting coefficients.

4. The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 1, characterized in that, The real-time compensation quantities required for each axis of the CNC floor-type milling and boring machine under the current machining state include: additional movement compensation components for the Z-axis, additional movement compensation components for the W-axis, and additional oscillation compensation components for the X-axis and Y-axis.

5. The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 4, characterized in that, Based on the multi-dimensional machining state parameter set, and using a pre-built dynamic compensation model for ram sag deflection, the real-time compensation required for each axis of the CNC floor-type milling and boring machine under the current machining state is calculated, including: The real-time overhang length of the ram, the real-time position of the spindle box, the real-time speed of the spindle, the displacement deviation signal and the cutting torque are substituted as input variables into the mathematical expression of the ram deflection to obtain the vertical deflection of the ram front end, the angular deviation around the X-axis and the angular deviation around the Y-axis in the current state. The vertical deflection of the front end of the slide block is allocated into Z-axis movement compensation component and W-axis movement compensation component according to a preset ratio. The angular deviation around the X-axis is mapped into Y-axis swing compensation component, and the angular deviation around the Y-axis is mapped into X-axis swing compensation component, thereby obtaining the real-time compensation amount required for the Z-axis, W-axis, X-axis and Y-axis.

6. The dynamic compensation control method for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 1, characterized in that, The real-time displacement deviation signal between the front reference surface of the slide and the axis of the machine tool spindle is collected in real time by a non-contact displacement detector set below the front end of the slide. The non-contact displacement detector includes at least three eddy current displacement sensors or laser triangular displacement sensors arranged in a triangle and fixedly installed on the reference surface of the bottom surface of the front end of the slide. The detection end face of each sensor is set opposite to the machine tool worktable and is used to detect the vertical displacement change at different positions of the front end of the slide.

7. A dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine, characterized in that, include: The data acquisition unit is used to collect in real time the displacement deviation signal of the front reference surface of the slide relative to the axis of the machine tool spindle, the real-time spindle speed, and the real-time overhang length of the slide and the real-time position of the spindle box determined based on the real-time coordinate position information during the machining operation of the CNC floor milling and boring machine, so as to construct a multi-dimensional machining state parameter set. The compensation unit is used to calculate the real-time compensation amount required for each axis of the CNC floor-type milling and boring machine under the current machining state based on the multi-dimensional machining state parameter set and using a pre-constructed dynamic compensation model for ram sag deflection; wherein, the dynamic compensation model includes a mathematical expression for ram flexure deformation based on finite element analysis and experimental calibration. The control unit is used to superimpose the real-time compensation amount onto the position closed-loop control setpoint of the corresponding servo drive axis to form a full closed-loop position control command with deflection feedforward compensation.

8. The dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 7, characterized in that, The compensation unit is used for: Based on finite element analysis software, a three-dimensional parametric finite element model of the slide and spindle box assembly was established. Different slide overhang lengths, different spindle box Y-axis positions, different spindle speeds, bearing temperature rise thermal loads, and different cutting force conditions were applied as combined boundary conditions. The flexural deformation data of the slide front end under various working conditions were obtained through finite element calculation, forming an initial deflection feature database. On the experimental calibration platform, the same working condition combination as the finite element calculation was used to carry out actual loading tests, and the actual deformation of the front end of the slide was measured simultaneously using a laser interferometer and a capacitive displacement sensor. The flexural deformation data is compared with the actual deformation, and the initial deflection feature database is corrected based on the comparison results to obtain the corrected deflection feature database. A multiple regression analysis was performed on the modified deflection feature database to construct a mathematical expression for the ram deflection deformation, with the ram overhang length, spindle box Y-axis coordinate, spindle speed and cutting torque as independent variables, and the vertical deflection of the ram front end and the angular deviation of the front end around the X-axis and Y-axis as dependent variables, thus obtaining a dynamic compensation model for ram sag deflection.

9. The dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 7, characterized in that, The real-time compensation quantities required for each axis of the CNC floor-type milling and boring machine under the current machining state include: additional movement compensation components for the Z-axis, additional movement compensation components for the W-axis, and additional oscillation compensation components for the X-axis and Y-axis.

10. The dynamic compensation control system for the ram sag deflection of a CNC floor-type milling and boring machine according to claim 9, characterized in that, The compensation unit is used for: The real-time overhang length of the ram, the real-time position of the spindle box, the real-time speed of the spindle, the displacement deviation signal and the cutting torque are substituted as input variables into the mathematical expression of the ram deflection to obtain the vertical deflection of the ram front end, the angular deviation around the X-axis and the angular deviation around the Y-axis in the current state. The vertical deflection of the front end of the slide block is allocated into Z-axis movement compensation component and W-axis movement compensation component according to a preset ratio. The angular deviation around the X-axis is mapped into Y-axis swing compensation component, and the angular deviation around the Y-axis is mapped into X-axis swing compensation component, thereby obtaining the real-time compensation amount required for the Z-axis, W-axis, X-axis and Y-axis.

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