Automatic head changing method and system for double-gantry shared head library of numerical control gantry machining center

Abstract

The invention discloses an automatic head changing method and system for a double-gantry shared head library of a numerical control gantry machining center, and the method comprises the steps: firstly, obtaining the position of a main shaft and the type information of an accessory head, matching the serial number and coordinates of the head library, generating an initial positioning instruction sequence, and driving a head library base to move to a changing station; then, on the basis of coordinate deviation vector analysis of a state confirmation signal and a theoretical docking reference coordinate, a positioning adjustment algorithm is called to correct control parameters, and accurate docking is ensured; and finally, head changing operation is completed through a hydraulic clamping device and a cooperative control algorithm, and cooperative scheduling and head library resetting of the multiple gantry spindles are achieved in combination with action interlocking logic. According to the method, the automation degree and the positioning precision of accessory head replacement are remarkably improved, the multi-spindle cooperation efficiency is optimized, and stable and reliable technical support is provided for a complex numerical control machining scene.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of numerical control machining equipment, and particularly discloses an automatic tool changing method and system for a double-gantry shared tool magazine of a numerical control gantry machining center. BACKGROUND

[0002] As an important pillar of modern manufacturing industry, numerical control machining equipment plays an irreplaceable role in improving production efficiency and machining precision. Especially in the machining of large and complex parts, numerical control gantry machining centers become indispensable key equipment in the industry due to their large working space and high load capacity. However, with the diversification and complexity of machining demands, how to balance flexibility and efficiency in equipment design has become a pressing issue.

[0003] Currently, the accessory head changing method of many numerical control gantry machining centers still has great limitations. Traditional equipment often configures independent tool magazines for each gantry. Although this method can meet basic needs, it leads to complex equipment structure, large space occupation, and high cost.

[0004] More importantly, this design makes it difficult to achieve efficient sharing of resources when multiple gantries work together, limiting the flexibility and adaptability of the equipment in multi-task scenarios, especially when different types of accessory heads need to be frequently changed. In this context, the technical difficulty gradually focuses on how to optimize the equipment structure and control method to achieve efficient cooperation between multiple gantries. Among them, the sharing of accessory head resources is a key factor. Accessory heads are key components of machining centers for different processes, such as right-angle heads for side machining and universal heads for multi-angle operation. If each gantry needs a separate tool magazine to store and manage these components, not only does it increase the equipment size and maintenance difficulty, but it also leads to the idle of some accessory heads while another gantry is stopped due to the lack of suitable components. Further, due to the lack of a unified scheduling mechanism, multiple gantries may experience motion conflicts when changing accessory heads, which can even affect machining quality due to inaccurate positioning. This uneven resource allocation and low cooperation efficiency directly restricts the performance of the equipment in complex machining tasks.

[0005] Therefore, how to design a shared mechanism in a double-gantry structure that can uniformly manage accessory heads and ensure accurate positioning and safe cooperation during frequent changes has become a key issue to improve the overall performance of the equipment. SUMMARY

[0006] The present application provides an automatic tool changing method and system for a double-gantry shared tool magazine of a numerical control gantry machining center, aiming to solve at least one of the deficiencies in the prior art.

[0007] One aspect of the present application relates to an automatic tool changing method for a double-gantry machining center double-gantry shared tool magazine, comprising the following steps: S100, acquiring current position data of the double-gantry spindle and accessory head type information planned to be replaced, and matching the corresponding tool magazine number and its positioning coordinates in the tool magazine from the support of the shared tool magazine according to the accessory head type; S200, using a numerical control coordination module to calculate the movement trajectory of the tool magazine base according to the positioning coordinates, and generating an initial positioning instruction sequence of the tool magazine; S300, controlling the driving motor and synchronous belt transmission assembly to operate according to the initial positioning instruction sequence, driving the ball screw assembly to move the tool magazine base to the replacement station, and receiving a state confirmation signal indicating that the tool magazine base has been stably positioned; S400, obtaining the theoretical docking reference coordinates of the spindle and the accessory head based on the state confirmation signal, and if the coordinate deviation vector of the theoretical docking reference coordinates obtained and the preset reference coordinates exceeds the allowed range, calling a positioning adjustment algorithm to correct the control parameters of the U-axis to obtain a set of accurate docking coordinates; S500, starting the hydraulic clamping device according to the accurate docking coordinates, executing the loosening and placing operation of the old accessory head through a cooperative control algorithm, then picking up and fastening the new accessory head, and generating a tool changing operation completion flag when the fastening of the new accessory head is completed; S600, according to the tool changing operation completion flag, receiving a calling request of another gantry spindle in combination with the action interlocking logic of the double-gantry system, controlling the tool magazine base to move along the calculated reset path and retracting the protective cover.

[0008] Further, step S100 comprises: S110, acquiring current position data of the double-gantry spindle and target accessory head type information planned to be replaced; S120, traversing the digital mapping model of the shared tool magazine according to the target accessory head type information, and screening out candidate supports compatible with the mechanical interface; S130, calculating the spatial distance between the current position data and the preset grabbing coordinates of the candidate support, and determining the only optimal support object with the closest spatial distance from the candidate supports; S140, extracting the logical index number and high-precision three-dimensional spatial point data associated with the only optimal support object, and obtaining the tool magazine number corresponding to the only optimal support object and its positioning coordinates in the tool magazine.

[0009] Further, step S200 comprises: S210, acquiring the positioning coordinates and calculating the motion axis relative displacement vector in combination with the mechanical origin, discretizing the motion axis relative displacement vector to obtain a set of theoretical movement trajectory points; S220, assign a velocity to the set of theoretical moving track points and superimpose a compensation value, generate a motion control data stream with timing attributes; S230, verify the motion control data stream with timing attributes to obtain the headstock base running path data, encode and package the headstock base running path data, and generate an initial positioning instruction sequence of the headstock.

[0010] Further, the step S300 includes: S310, parse the initial positioning instruction sequence to obtain a digital pulse stream, and modulate the stator voltage vector of the motor according to the digital pulse stream; S320, obtain the mechanical torque excited by the stator voltage vector, and the mechanical torque is transmitted through the synchronous belt transmission assembly to generate a real-time linear displacement of the headstock base; S330, calculate the current position following error according to the real-time linear displacement, and if the current position following error converges to a preset range and the acceleration amplitude of the headstock base satisfies a zero speed determination threshold, output a state confirmation signal indicating that the headstock base has been stably positioned.

[0011] Further, the step S400 includes: S410, parse the state confirmation signal to obtain a theoretical docking reference coordinate, and the theoretical docking reference coordinate is constructed by extracting spatial vector data from the signal analysis protocol; S420, calculate the coordinate deviation vector of the theoretical docking reference coordinate and the preset reference coordinate, and if the coordinate deviation vector exceeds the allowed range, call a positioning adjustment algorithm to solve a kinematic error compensation value; S430, superimpose the kinematic error compensation value to the original instruction to generate a modified U-axis control parameter; S440, perform a virtual interpolation operation according to the modified U-axis control parameter to obtain an accurate docking coordinate after eliminating spatial misplacement.

[0012] Further, the step S500 includes: S510, generate a hydraulic drive instruction set according to the accurate docking coordinate, and the hydraulic drive instruction set is used to activate a cooperative control algorithm model to complete the unlocking action of the old accessory head; S520, place the old accessory head and pick up the new accessory head according to the state feedback after the unlocking action is completed, until a new accessory head in place signal is triggered; S530, start a fastening program in response to the new accessory head in place signal, and the fastening program regulates the output pressure of the hydraulic system until the monitored fastening pressure value is stable in a preset safe locking interval; S540, if the fastening pressure value is maintained in the safe locking interval, output a head replacement operation completion flag.

[0013] Further, the step S600 includes: S610: Obtain the head-changing operation completion flag and the real-time interlock status data of the dual gantry system. If the real-time interlock status data is verified, receive the call request signal sent by the other gantry spindle. S620: Respond to the call request signal, collect the current coordinate values ​​of the head storage base, and generate a collision-free reset path sequence for the head storage base based on the current coordinate values ​​of the head storage base. S630: Parse the collision-free reset path sequence into control commands to drive the headrest base to move, and trigger the protective cover to retract after detecting that the headrest base has reached the end point, controlling the headrest base to move along the calculated reset path and retract the protective cover.

[0014] Another aspect of the present invention relates to an automatic head-changing system for a CNC gantry machining center with a shared headstock for dual gantry machining centers, for executing the aforementioned automatic head-changing method for a CNC gantry machining center with a shared headstock for dual gantry machining centers, comprising: The headstock number and positioning coordinate matching module is used to obtain the current position data of the double gantry spindle and the type information of the attachment head to be replaced. Based on the attachment head type, it matches the corresponding headstock number and its positioning coordinates in the headstock from the bracket of the shared headstock. The initial positioning command sequence generation module is used to calculate the movement trajectory of the headstock base based on the positioning coordinates using the CNC collaborative module, and generate the initial positioning command sequence of the headstock. The status confirmation signal receiving module is used to control the drive motor and synchronous belt drive assembly to operate according to the initial positioning command sequence, drive the ball screw assembly to move the head magazine base to the replacement station, and receive a status confirmation signal indicating that the head magazine base has been stably positioned. The precise docking coordinate acquisition module is used to obtain the theoretical docking reference coordinates between the main spindle and the accessory head based on the status confirmation signal. If the coordinate deviation vector between the obtained theoretical docking reference coordinates and the preset reference coordinates exceeds the allowable range, the positioning adjustment algorithm is called to correct the control parameters of the U-axis and obtain a set of precise docking coordinates. The head replacement operation completion marker generation module is used to start the hydraulic clamping device based on the precise docking coordinates, execute the loosening and placement operation of the old accessory head through the collaborative control algorithm, then pick up and tighten the new accessory head, and generate a head replacement operation completion marker when the new accessory head is tightened. The dual-gantry motion interlock control module is used to receive a call request from the other gantry spindle based on the head-changing operation completion flag and the motion interlock logic of the dual-gantry system, and control the head magazine base to move along the calculated reset path and retract the protective cover.

[0015] The beneficial effects achieved by this invention are as follows: This invention provides an automatic head-changing method and system for a shared head magazine in a dual-gantry CNC machining center. Addressing the issues of low efficiency in accessory head replacement, insufficient positioning accuracy, and the complexity of multi-spindle collaborative operations in dual-gantry systems, this invention achieves efficient and precise head-changing operations through integrated control logic and algorithm design. First, by acquiring spindle position and accessory head type information, matching the head magazine number and coordinates, an initial positioning command sequence is generated to drive the head magazine base to the replacement station. Then, based on the coordinate deviation vector analysis between the status confirmation signal and the theoretical docking reference coordinates, a positioning adjustment algorithm is invoked to correct the control parameters, ensuring precise docking. Finally, the head-changing operation is completed through a hydraulic clamping device and a collaborative control algorithm, and the collaborative scheduling of multiple gantry spindles and head magazine reset are achieved by combining action interlock logic. This invention significantly improves the automation level and positioning accuracy of accessory head replacement, optimizes multi-spindle collaborative efficiency, and provides stable and reliable technical support for complex CNC machining scenarios. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating an embodiment of the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machines according to the present invention. Figure 2 This is a functional block diagram of an embodiment of the automatic head changing system of the CNC gantry machining center with a shared head magazine for dual gantry machining centers according to the present invention.

[0017] Explanation of icon numbers: 10. Head unit number and positioning coordinate matching module; 20. Initial positioning command sequence generation module; 30. Status confirmation signal receiving module; 40. Precise docking coordinate acquisition module; 50. Head replacement operation completion mark generation module; 60. Double gantry action interlock control module. Detailed Implementation

[0018] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0019] like Figure 1 As shown, the first embodiment of the present invention proposes an automatic head-changing method for a CNC gantry machining center with a shared head magazine for dual gantry machines, comprising the following steps: Step S100: Obtain the current position data of the double gantry spindle and the type information of the attachment head to be replaced. Based on the attachment head type, match the corresponding head library number and its positioning coordinates in the head library from the bracket of the shared head library.

[0020] The position detection module of the dual-gantry system acquires real-time position data of the two gantry spindles and simultaneously receives information on the planned replacement accessory head type from the process planning terminal. Based on the preset accessory head-head library mapping table, the unique head library number of the corresponding accessory head is accurately matched from the bracket of the shared head library of the dual-gantry system, as well as the fixed positioning coordinates of the accessory head in the head library coordinate system. This provides core target parameters for the subsequent calculation of the movement trajectory of the head library base and serves as the preliminary positioning basis for realizing automatic head replacement.

[0021] Step S200: Calculate the movement trajectory of the headstock base based on the positioning coordinates using the CNC collaborative module, and generate the initial positioning command sequence of the headstock.

[0022] Using the attachment head positioning coordinates output in step S100 as the target value, and relying on the trajectory planning algorithm built into the CNC collaborative module, combined with the kinematic constraints of the headstock base (such as maximum moving speed and acceleration limits), the optimal moving trajectory of the headstock base from its current position to the change station is calculated. The trajectory parameters are discretized into motion commands that the CNC system can recognize, generating the initial positioning command sequence of the headstock, clarifying the start and stop sequence of the drive motor, the speed adjustment range, and the feed amount of the ball screw, realizing the accurate conversion of "target coordinates → motion commands", and providing an executable control basis for the precise movement of the headstock base.

[0023] Step S300: Control the drive motor and synchronous belt transmission assembly to run according to the initial positioning command sequence, drive the ball screw assembly to move the head magazine base to the replacement station, and receive a status confirmation signal indicating that the head magazine base has been stably positioned.

[0024] Using the initial positioning command sequence generated in step S200 as the control basis, the servo motor drives the synchronous belt transmission assembly to rotate, which in turn drives the ball screw assembly to achieve linear displacement of the headstock base. After the headstock base moves to the preset replacement station, the position accuracy and stability data of the headstock base are collected by the position sensor and pressure sensor. After the data is verified to be correct, a status confirmation signal that the headstock base has been stably positioned is sent to the CNC collaborative module, providing a stable mechanical reference for the subsequent docking and calibration of the spindle and accessory head.

[0025] Step S400: Based on the status confirmation signal, the theoretical docking reference coordinates of the spindle and the accessory head are obtained. If the coordinate deviation vector between the theoretical docking reference coordinates obtained by the analysis and the preset reference coordinates exceeds the allowable range, the positioning adjustment algorithm is called to correct the control parameters of the U-axis and obtain a set of accurate docking coordinates.

[0026] Based on the status confirmation signal in step S300, the positioning coordinates of the attachment head are converted into theoretical docking reference coordinates in the spindle coordinate system using a coordinate analysis algorithm. The coordinate deviation vector of this theoretical docking reference coordinates is calculated with the preset standard docking reference. If the coordinate deviation vector value exceeds the docking accuracy range allowed by the system, the positioning adjustment algorithm is immediately invoked to optimize and correct the U-axis control parameters (such as feed compensation amount and position correction coefficient) responsible for fine-tuning the attachment head's attitude. The coordinate deviation vector is eliminated through iterative calculation, and finally a set of accurate docking coordinates that meet the high-precision docking requirements is obtained, ensuring the precise meshing of the spindle and the attachment head.

[0027] Step S500: Start the hydraulic clamping device according to the precise docking coordinates, and perform the loosening and placement operation of the old accessory head through the collaborative control algorithm. Then pick up and tighten the new accessory head. When the new accessory head is tightened, generate a head replacement operation completion mark.

[0028] Using the precise docking coordinates output in step S400 as the alignment basis, the hydraulic clamping device is activated. Through the collaborative control algorithm, the clamping mechanism at the spindle end is first controlled to release the old accessory head, and the old accessory head is precisely placed into the slot of the corresponding bracket in the head magazine. Then, the pushing mechanism at the head magazine end is controlled to send the new accessory head to the docking position, and the spindle clamping mechanism is driven to complete the fastening and locking of the new accessory head. After the clamping force sensor feedback that the fastening force has reached the preset threshold, a head replacement operation completion mark is generated to confirm that the accessory head replacement task of the current gantry spindle has been successfully completed.

[0029] Step S600: Based on the head change operation completion flag and combined with the action interlock logic of the dual gantry system, receive the call request from the other gantry spindle, control the head magazine base to move along the calculated reset path and retract the protective cover.

[0030] Based on the head-changing operation completion flag in step S500, and combined with the action interlock logic of the dual gantry system, it is determined whether the other gantry spindle has a head-changing call request. If a call request exists, the reset path of the head storage base from the current changing station to the next target station is calculated, and the head storage base is driven to move to the corresponding position. If there is no call request, the head storage base is controlled to return to the initial standby position, and the protective cover retraction mechanism is activated to close the head storage protective cover. The entire process uses interlock logic to prevent both gantry spindles from calling the head storage simultaneously, ensuring the orderly scheduling and safe operation of the shared head storage of the dual gantry spindles.

[0031] Furthermore, the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machining provided in this embodiment includes step S100: Step S110: Obtain the current position data of the double gantry spindle and the target accessory head type information to be replaced.

[0032] The following formula is used to accurately calculate the current position data of the double gantry spindle: (1) In formula (1), This represents the data vector indicating the current position of the dual-gantry main shaft. This represents the real-time velocity vector of the principal axis. Indicates the time of data collection. The reference initial position is indicated. The control logic of formula (1) is "time integral cumulative displacement of velocity + initial position reference anchoring = real-time absolute position". This is the basic principle of deriving position through velocity in kinematics. The displacement relative to the initial position is obtained by the real-time velocity vector of the integral principal axis, and then the reference initial position is superimposed to finally accurately calculate the current absolute position of the double gantry principal axis.

[0033] The following formula is used to select the optimal target type for the target attachment header: (2) In formula (2), Indicates the type of the target attachment header to be replaced. This represents the maximum similarity localization operator. Represents the set of alternative attachment headers The elements in This indicates the description of the attachment header. With task requirements The similarity measurement. The control logic of formula (2) is "similarity measurement matching + optimal target positioning". By calculating the similarity between each candidate attachment head and the current task requirements, the attachment head with the highest matching degree is automatically selected as the target type, so as to realize the accurate and automated selection of the head replacement task.

[0034] First, it's necessary to obtain the current position data of the twin-gantry spindle and the type of the target attachment head to be replaced. This twin-gantry spindle typically refers to a precision CNC machine tool structure with a twin-gantry frame to support high-precision machining operations. The current position data is acquired in real-time through the machine tool's built-in sensors or encoders. For example, in a factory environment processing automotive parts, the spindle might currently be positioned at X=1500mm, Y=800mm, Z=500mm in the coordinate system, while the target attachment head to be replaced is a high-speed milling head for subsequent fine surface treatment. This data is directly read through the machine tool control system's API (Application Programming Interface) or PLC (Programmable Logic Controller) module, ensuring real-time accuracy and providing fundamental support for the subsequent attachment replacement process. This method not only avoids manual input errors but also improves the overall automation level and reduces downtime in actual production.

[0035] Step S120: Based on the target accessory header type information, traverse the shared header library digital mapping model and select candidate brackets that are compatible with mechanical interfaces.

[0036] The following formula is used to select a set of candidate stents with compatible mechanical interfaces: (3) In formula (3), Represents the set of candidate stents. Indicates bracket A collection of all supports from the shared head library , Indicates the filtering criteria. Indicates the number of dimensions in the digital mapping. Indicates the target attachment header Digital mapping dimension, Indicates bracket Digital mapping dimension, This represents the matching function. The threshold is represented by the formula, which is used to select a set of candidate stents whose mapping model matching degree is not lower than the threshold. The control logic of formula (3) is "multi-dimensional feature matching + minimum threshold verification + accurate screening of compatible stents". By performing multi-dimensional and multi-feature matching verification on the digital mapping of the target accessory head and the stent, all candidate stents with mechanical interface compatibility are selected to ensure mechanical compatibility when changing the head.

[0037] The shared head library digital mapping model is traversed based on the target attachment head type information to filter out candidate supports with compatible mechanical interfaces. Here, the shared head library digital mapping model is a virtualized database system that maps various attachment heads and supports from the physical head library to digital twins, including the mechanical interface specifications, dimensions, and compatibility parameters of each support. For example, in a smart manufacturing workshop, this shared head library digital mapping model is built based on CAD software and contains 3D models and metadata for hundreds of supports. The traversal process involves query algorithms, such as using an SQL-like query language to scan the model. When the target attachment head type is a high-speed milling head, the system filters out all supports with an ISO40 interface standard as candidates. These supports ensure seamless connection of the attachment head, avoiding mechanical conflicts. The core of this filtering mechanism lies in the compatibility matching logic, which determines the candidate list by comparing interface parameters such as taper, keyway, and fixing bolt positions, thereby achieving resource sharing in a multi-machine collaborative environment.

[0038] Step S130: Calculate the spatial distance between the current location data and the preset grasping coordinates of the candidate supports, and determine the unique optimal support object with the closest spatial distance from the candidate supports.

[0039] The spatial distance between the current location data and the preset grasping coordinates of the candidate support is calculated using the following formula: (4) In formula (4), Indicates the first Spatial distance between candidate stents Represents the coordinate components of the current location data. Indicates the first The coordinate components of the preset grasping coordinates of each candidate support. The control logic of formula (4) is "three-dimensional spatial distance quantization + nearest neighbor positioning and filtering". By calculating the three-dimensional Euclidean distance between the current position of the double gantry spindle and the preset grasping coordinates of each candidate support, the nearest support is found as the optimal object, so as to minimize the spindle movement distance and improve the head-changing efficiency.

[0040] The index of the spatially closest unique optimal support object is obtained using the following formula: (5) In formula (5), The index representing the unique optimal support object. This represents the set of candidate stents. Indicates the first The spatial distance of each candidate stent. The control logic of formula (5) is "minimum distance positioning operator + unique optimal stent determination". By positioning the stent with the smallest spatial distance among all candidate stents, the unique optimal stent object is determined, providing a clear target for subsequent head-changing actions.

[0041] The spatial distance between the current position data and the preset grasping coordinates of the candidate supports is calculated, and the single optimal support object with the closest spatial distance is determined from the candidate supports. This calculation typically uses the Euclidean distance formula to evaluate the distance between points in three-dimensional space. For example, assuming the current position of the main axis is (1500, 800, 500), the grasping coordinates of candidate support A are (1600, 850, 480), and support B is (1400, 700, 520), then the distance calculation is sqrt((1600-1500)). 2 +(850-800) 2 +(480-500) 2 The distance of bracket B is approximately 102.4 mm, while the distance of bracket B is approximately sqrt((1400-1500)). 2 +(700-800) 2 +(520-500)2 Since the distance is approximately 141.4 mm, A is selected as the optimal object. This method emphasizes minimizing the travel path, which can significantly reduce the non-productive travel time of the spindle and improve efficiency in actual machine tool operation, especially avoiding unnecessary energy consumption on high-load production lines.

[0042] Step S140: Extract the logical index number and high-precision three-dimensional spatial point data associated with the unique optimal support object to obtain the head library number corresponding to the unique optimal support object and its positioning coordinates in the head library.

[0043] The head library number corresponding to the unique optimal stent object is obtained using the following formula: (6) In formula (6), This represents the header database number corresponding to the unique optimal support object. The logical index number representing the unique optimal support object. This indicates the number of stents in each head library. The control logic of formula (6) is "block mapping of global logical index + floor positioning". By dividing the global continuous stent logical index into blocks according to the capacity of each head library, the head library number where the optimal stent is located is quickly calculated, thus achieving accurate positioning from the global index to the head library.

[0044] The location coordinates of the unique optimal stent object within the head library are obtained using the following formula: (7) In formula (7), Indicates the location coordinates. This represents high-precision three-dimensional spatial point data. The reference point of the head storage is indicated. The control logic of formula (7) is "offset conversion from absolute coordinates to local coordinates". By subtracting the reference point of the head storage from the high-precision absolute three-dimensional coordinates of the support, the positioning coordinates of the support in the local coordinate system of the head storage are obtained, thereby achieving accurate positioning within the head storage.

[0045] The logical index number and high-precision 3D spatial point data associated with the unique optimal support object are extracted to obtain the head library number corresponding to the unique optimal support object and its positioning coordinates within the head library. The logical index number is a unique identifier, such as "BRK-045", associated with a data record in the model, while the high-precision 3D spatial point data includes coordinates accurate to 0.01mm, such as (1200, 600, 300). The extraction process is implemented through key-value pair queries, for example, pulling this information from the model database, and finally outputting the head library number "HL-02" and positioning coordinates (1200, 600, 300) to facilitate the robotic arm's grasping operation. This extraction ensures the accuracy of the operation and can bring seamless integration effects in business, such as reducing the scrap rate caused by replacement errors in aerospace parts processing.

[0046] Preferably, the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machining provided in this embodiment includes step S200: Step S210: Obtain the positioning coordinates and calculate the relative displacement vector of the motion axis in combination with the mechanical origin. Discretize the relative displacement vector of the motion axis to obtain the theoretical movement trajectory point set.

[0047] The relative displacement vector of the axis of motion is obtained by the following formula: (8) In formula (8), Represents the relative displacement vector of the axis of motion. Indicates the location coordinates. The mechanical origin is represented. The control logic of formula (8) is "relative offset quantization from positioning coordinates to mechanical origin". By calculating the vector difference between the positioning coordinates in the head library and the mechanical origin of the motion axis, the relative displacement vector that the motion axis needs to move is obtained, which provides an accurate displacement reference for the subsequent generation of theoretical motion trajectory.

[0048] The theoretical trajectory point set is derived using the following formula: (9) In formula (9), Represents the theoretical trajectory point set, Indicates the first A theoretical trajectory point, The number of points in the point set is indicated. The control logic of formula (9) is "discretization sampling of continuous displacement + smooth trajectory point sequence generation". By decomposing the continuous relative displacement of the motion axis into uniformly distributed discrete trajectory points, a theoretical motion trajectory point set that can be directly executed by the motion controller is constructed to ensure that the motion axis reaches the target position along a smooth path.

[0049] No. Theoretical movement trajectory points This can be derived from the following formula: (10) In formula (10), Represents a discrete index. The total number of discrete points is represented. The control logic of formula (10) is "linear uniform interpolation + smooth transition from the reference origin to the target position". By decomposing the continuous displacement from the mechanical origin to the positioning coordinate into uniformly distributed discrete trajectory points, the theoretical movement path of the motion axis is generated, ensuring that the motion axis reaches the target position along a smooth, impact-free trajectory.

[0050] First, the positioning coordinates are obtained and combined with the machine origin to calculate the relative displacement vector of the motion axis. Here, the positioning coordinates typically refer to the specific spatial position data of the support within the head magazine, while the machine origin is the reference point of the machine tool coordinate system, used to unify all motion calculations. For example, in a precision machine tool machining environment, assuming the positioning coordinates of the support within the head magazine are X=1200mm, Y=600mm, Z=300mm, and the machine origin is set to (0, 0, 0), the system will calculate the relative displacement through vector difference, such as the difference between the current spindle position and the target coordinates after subtracting the origin, forming a three-dimensional vector. This process ensures the accurate basis of motion planning and avoids errors caused by coordinate system offset. In subsequent operations, this relative displacement vector directly affects trajectory generation, thus providing reliable path support for accessory head replacement. For example, the relative displacement vector of the motion axis is discretized to obtain the theoretical movement trajectory point set. This involves decomposing a continuous vector into a series of discrete points to adapt to the stepping control of the CNC system. For example, in an automotive parts manufacturing plant, if the relative displacement vector is (200, 150, 100), the system divides it into multiple points using a uniform sampling method, such as one sampling point every 10 mm, forming a point set sequence. These point sets represent the ideal path of the spindle from the starting point to the ending point. Considering the limitations of the machine tool's axis motion, this discretization helps to simulate actual movement and avoid collisions.

[0051] Step S220: Assign velocities to the theoretical trajectory point set and superimpose compensation values ​​to generate a motion control data stream with temporal attributes.

[0052] The following formula is used to generate motion control data streams with timing attributes: (11) In formula (11), Indicates the first A motion control data stream, This represents the trajectory points after superimposed compensation. Indicates the first The control logic of formula (11) is "three-dimensional data stream encapsulation of precise position + velocity allocation + timing identifier". By integrating the superimposed compensated trajectory points, allocated motion speed and timing identifier into a complete data packet, a motion control data stream with timing attributes is generated to ensure that the motion controller can execute each trajectory point in sequence and according to speed, so as to achieve smooth and high-precision motion control.

[0053] No. The allocation speed of each trajectory point This can be derived from the following formula: (12) In formula (12), Indicates the first A theoretical trajectory point, Indicates the first A timestamp, Indicates the first The formula is used to assign velocities to the theoretical trajectory point set using the timestamp. The control logic of formula (12) is "to calculate the average velocity based on the displacement difference constrained by the timestamp". By calculating the ratio of the position difference between two adjacent theoretical trajectory points to the timestamp difference, the average velocity of the motion segment is obtained and used as the first time stamp. The speed of each trajectory point is allocated to ensure that the speed of the motion axis is strictly matched with the preset time rhythm, so as to achieve smooth and precise motion control.

[0054] Trajectory points after superposition and compensation This can be derived from the following formula: (13) In formula (13), Represents the original theoretical trajectory point, The formula represents the compensation value, which is used to superimpose the compensation value to correct the trajectory. The control logic of formula (13) is "vector superposition of the original theoretical trajectory point and the compensation value". By superimposing the compensation value of the equipment system error on the original theoretical trajectory point, the coordinate deviation vector of the trajectory point is corrected, thereby obtaining a precise trajectory point that eliminates system errors such as mechanical backlash and thermal deformation, providing a higher precision position reference for motion control.

[0055] A motion control data stream with temporal attributes is generated by assigning velocities to the theoretical motion trajectory point set and superimposing compensation values. Here, the velocity assignment is based on the distance between points and the machine tool's maximum speed, while the compensation values ​​correct for factors such as thermal expansion or mechanical backlash. For example, in aerospace component manufacturing, each point in the point set is assigned a velocity, such as 2 m / s, and a compensation of 0.05 mm Z-axis offset is added, ultimately forming a data stream that includes a sequence of timestamps, such as t=0s to t=5s. This data stream integrates temporal information, ensures smooth motion transitions, improves changeover efficiency in operations, and reduces the impact of vibration on precision machining.

[0056] Step S230: Verify the motion control data stream with timing attributes to obtain the head library base running path data, encode and encapsulate the head library base running path data, and generate the initial positioning instruction sequence of the head library.

[0057] The initial positioning instruction sequence of the head library is derived using the following formula: (14) In formula (14), This represents the initial positioning instruction sequence. Represents a generating function. This represents the encoded and encapsulated running path data of the head storage base. The control logic of formula (14) is "mapping generation of encoded path data to executable instructions". The encoded and encapsulated running path data of the head storage base is converted into an initial positioning instruction sequence that can be directly executed by the head storage base motion controller through the generation function, so as to ensure that the head storage base accurately completes the initial positioning action according to the planned path.

[0058] Encoded and encapsulated header base running path data This can be derived from the following formula: (15) In formula (15), This indicates an encoding encapsulation function. This represents the data of the head library base running path. The control logic of formula (15) is "structured encoding and secure encapsulation of the head library base running path data". The original path data after verification is converted into a secure, transmissible and parseable structured data packet through the encoding and encapsulation function, so as to ensure the integrity, security and compatibility of the data in the transmission and storage process, and provide a reliable data source for the subsequent generation of instruction sequences.

[0059] Headstock base running path data This can be derived from the following formula: (16) In formula (16), Represents the verification function. The timing attribute is represented. The control logic of formula (16) is "multi-dimensional verification of motion control data flow with timing attribute". The verification function performs collision, timing, speed and other verifications on the motion control data flow and the timing / model constraints of the head library, and generates safe and feasible head library base running path data, providing reliable input for subsequent coding and encapsulation.

[0060] Verifying the motion control data stream with timing attributes yields the headstock base's running path data. This step verifies the data stream's integrity and security, such as checking if the speed exceeds limits or if the path avoids obstacles. For example, in a smart factory scenario, the system simulates the running data stream and, after confirming no anomalies, outputs the headstock base path, i.e., the specific movement route data of the machine tool's headstock base. In one implementation, the headstock base's running path data is encoded and encapsulated to generate an initial positioning instruction sequence for the headstock. This includes converting the path data into a machine tool-executable format, such as G-code encapsulation. For example, on a high-load production line, the path data is encoded into a sequence of instructions and sent to the headstock system to achieve initial positioning, thereby seamlessly connecting subsequent gripping operations and bringing higher integration and reliability to the overall automation process.

[0061] Furthermore, the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machining centers provided in this embodiment includes step S300: Step S310: Analyze the initial positioning command sequence to obtain the digital pulse stream, and modulate the stator voltage vector of the drive motor according to the digital pulse stream.

[0062] The digital pulse current is derived using the following formula: (17) In formula (17), Indicates the digital pulse stream at time... The value, Represents the first position in the initial positioning command sequence. One element, This represents the filter response during the analysis process. The sequence length is indicated. The control logic of formula (17) is the time-domain convolution operation of the initial positioning command sequence and the analytical filter. By convolving the discrete command sequence with the system's impulse response, a smooth and noise-resistant digital pulse stream is generated, providing a stable input for the stator voltage vector modulation of the drive motor and avoiding jitter or shock in the motor drive.

[0063] The stator voltage vector is derived using the following formula: (18) In formula (18), Represents the stator voltage vector. Indicates the DC bus voltage. This indicates that the first modulation duty cycle is determined by the digital pulse stream. This indicates that the second modulation duty cycle is determined by the digital pulse stream. Indicates the zero vector duty cycle. Represents the first fundamental voltage vector. Represents adjacent fundamental voltage vectors. The zero vector is represented. The control logic of formula (18) is the precise voltage synthesis of space vector pulse width modulation (SVPWM). By decomposing the target stator voltage vector into a weighted combination of two adjacent basic voltage vectors and a zero vector, the duty cycle of each vector is calculated using digital pulse stream, and finally the stator voltage vector that meets the motor control requirements is synthesized, so as to realize the precise speed and torque control of the drive motor.

[0064] The modulation duty cycle is obtained using the following formula: (19) In formula (19), Indicates the modulation duty cycle. Indicates the on-time of the digital pulse stream. The switching cycle is represented by the control logic of formula (19). The ratio of the on-time to the switching cycle in PWM modulation is quantized. The modulation duty cycle is obtained by calculating the proportion of the on-time of the digital pulse current in one switching cycle. This proportion directly determines the amplitude of the inverter output voltage and is the core parameter of SVPWM voltage synthesis.

[0065] The process of parsing the initial positioning command sequence to obtain a digital pulse stream involves decomposing the command sequence into controllable pulse signals, which are directly used for motor control. For example, in a headstock positioning system of a precision machine tool, the initial command sequence may contain a series of G-codes, such as commands to move to specific coordinates. The system converts these codes into a digital pulse stream using a decoder, with each pulse corresponding to a micro-stepping motion of the motor, thus ensuring precise signal transmission. This pulse stream then modulates the stator voltage vector of the drive motor according to its frequency and amplitude. The stator voltage vector here refers to the rotating magnetic field vector formed in the stator coils of the motor. Space vector modulation technology is used to adjust the phase and magnitude of the voltage to achieve efficient motor drive. In an automotive parts processing workshop, if the command sequence requires the headstock base to move to a position of X=500mm, the system will generate a pulse stream, such as 1000 pulses per second, and adjust the stator voltage vector accordingly to form a balanced voltage distribution in the three-phase system, preventing motor overheating and improving response speed. This modulation method not only optimizes energy consumption but also provides a stable foundation for subsequent torque generation.

[0066] Step S320: Obtain the mechanical torque excited by the stator voltage vector. The mechanical torque is transmitted through the synchronous belt drive assembly to generate the real-time linear displacement of the headstock base. Mechanical torque is obtained through the following formula: (20) In formula (20), Indicates mechanical torque. Represents the extreme logarithm. Indicates permanent magnet flux linkage. Represents the stator voltage vector Axial components, The formula represents the electric angular velocity; it describes the calculation of mechanical torque excited by the stator voltage vector. The control logic of formula (20) is the direct calculation of torque of the permanent magnet synchronous motor (PMSM) through the stator voltage vector. The mechanical torque output of the motor is calculated in real time using shaft components, inherent motor parameters (number of pole pairs, permanent magnet flux linkage), and electrical angular velocity, providing precise power feedback and control for the movement of the headstock base.

[0067] The real-time linear displacement of the headstock base is obtained by the following formula: (twenty one) In formula (21), This represents the linear displacement of the headstock base. This represents the linear force generated by a synchronous belt drive. Indicates equivalent mass. The formula represents time and describes the real-time linear displacement generated under the action of force. The control logic of formula (21) is the calculation of uniformly accelerated linear motion displacement with an initial velocity of 0. It combines Newton's second law and kinematic formulas to calculate the linear displacement of the headstock base in real time under the constant thrust of synchronous belt drive, providing accurate position feedback for motion control.

[0068] Linear force generated by synchronous belt drive This can be derived from the following formula: (twenty two) In formula (22), Indicates the input mechanical torque. The radius of the synchronous belt pulley is represented by the formula, which describes the linear force generated by the mechanical torque transmitted through the synchronous belt drive assembly. The control logic of formula (22) is the torque balance conversion of rigid body rotation. Based on the basic mechanical relationship between torque and lever arm, the rotational mechanical torque output by the motor is converted into the linear thrust of the synchronous belt, realizing the precise transmission of rotational power to linear power and providing a driving source for the linear motion of the headstock base.

[0069] When obtaining the mechanical torque excited by the stator voltage vector, it's necessary to understand that mechanical torque is the rotational torque generated by the motor through electromagnetic action. This torque is transmitted via a synchronous belt drive assembly to produce the real-time linear displacement of the headstock base. The synchronous belt drive assembly is a mechanical structure utilizing toothed belts and pulleys, efficiently converting rotational motion into linear motion. The real-time linear displacement refers to the actual positional change of the headstock base over time. In aerospace component manufacturing environments, the torque excited by the stator voltage vector can reach 10 Nm. After transmission through the synchronous belt assembly, it drives the headstock base to move along the guide rail at a speed of, for example, 50 mm per second. This ensures a smooth transition when changing accessory heads. This transmission mechanism reduces transmission losses and, combined with the aforementioned pulse modulation, forms a complete chain from signal to physical motion.

[0070] Step S330: Calculate the current position following error based on the real-time linear displacement. If the current position following error converges to the preset range and the acceleration amplitude of the headstock base meets the zero speed determination threshold, then output a status confirmation signal indicating that the headstock base has been stably positioned.

[0071] The convergence criterion for position following error is defined by the following formula: (twenty three) In formula (23), This indicates the current position following error. This indicates the preset allowable error range; if the current position follows the absolute value of the error... Less than or equal to the preset error allowable range When the position following error is within an acceptable range, it is considered that the current position following error has entered an acceptable range. The control logic of formula (23) is to determine whether the absolute value of the position following error has converged to the preset threshold. By comparing the real-time position deviation with the allowable error range, it is determined whether the headstock base has met the positioning accuracy requirements. This is the core judgment basis for "stable positioning" in the motion control closed loop.

[0072] Current position following error This can be derived from the following formula: (twenty four) In formula (24), This represents the real-time linear displacement of the target. The formula represents the current actual displacement of the headstock base. This formula is used to calculate the magnitude of the current position following error. The control logic of formula (24) is to calculate the dynamic deviation between the target trajectory and the actual motion. The position following error is obtained by subtracting the current actual displacement of the headstock base from the real-time linear displacement of the target. This error is the core feedback signal of the closed-loop motion control and directly reflects the degree of deviation between the motion of the headstock base and the target trajectory.

[0073] The following formula is used for zero velocity determination: (25) In formula (25), Indicates the headstock base at time acceleration, This indicates the threshold for determining zero velocity. Indicates the length of the most recent sampling time window. This indicates the moment when a steady-state determination is being made, specifically the maximum absolute value of the acceleration within the time window. Threshold for determining speed less than or equal to zero When the headstock base has reached a stable and stationary state, it is determined that the control logic of formula (25) is based on the statistical determination of acceleration fluctuations within a time window. By observing the maximum fluctuation amplitude of the acceleration of the headstock base in a recent period, it is determined whether it has entered a stable and stationary state, thus avoiding misjudgment caused by instantaneous noise or vibration. This is one of the key conditions for determining "stable positioning".

[0074] The process of calculating the position following error based on real-time linear displacement includes comparing the deviation between the actual displacement and the expected path. If the position following error converges to a preset range (e.g., less than 0.1 mm) and the acceleration amplitude of the headstock base meets the zero-velocity threshold (e.g., less than 0.01 m / s²), a status confirmation signal indicating that the headstock base has been stably positioned is output. Here, the position following error is an indicator used in the control system to evaluate tracking accuracy. It is calculated in real time through a feedback loop, while the zero-velocity threshold helps confirm that the movement has stopped, avoiding false stability. In CNC applications in smart factories, the system monitors the displacement data of the headstock base. If the error converges from the initial 1 mm to 0.05 mm, and the acceleration approaches zero, a signal is output to the host computer, triggering the next operation, such as attachment head gripping. This judgment logic continues the aforementioned displacement generation process, ensuring the reliability of overall positioning and improving the automation level of machine tools in business operations, reducing errors caused by human intervention.

[0075] Preferably, the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machining provided in this embodiment includes step S400: Step S410: Analyze the status confirmation signal to obtain the theoretical docking reference coordinates. The theoretical docking reference coordinates are constructed by extracting spatial vector data from the signal analysis protocol.

[0076] The theoretical docking reference coordinates are derived using the following formula: (26) In formula (26), Indicates the theoretical docking reference coordinates. Indicates the signal parsing protocol. The formula (26) represents the status confirmation signal. It indicates that the theoretical docking reference coordinates are obtained by directly processing the status confirmation signal through the signal analysis protocol. The control logic of formula (26) is the standardized analysis and transformation of the status confirmation signal into the docking reference coordinates. The precise three-dimensional docking reference coordinates are extracted and transformed from the stable position status confirmation signal through the signal analysis protocol, providing a globally unified position reference for the physical docking of the double gantry and the head warehouse support.

[0077] Spatial vector data is derived using the following formula: (27) In formula (27), Represents spatial vector data, The formula (27) represents the extraction function, which extracts spatial vector data from the state confirmation signal using a signal analysis protocol. The control logic of formula (27) is based on the precise data extraction of the analysis protocol. The extraction function locates, decodes, and extracts three-dimensional spatial vector data from the structured state confirmation signal according to the rules defined by the signal analysis protocol, providing an original and reliable data source for the subsequent construction of theoretical docking reference coordinates.

[0078] When analyzing status confirmation signals, it's essential to first understand that these signals are feedback data collected by sensors. For example, in a CNC machine tool's attachment head changing system, the spindle emits electrical signals indicating its current posture, containing position and angle information. Specifically, a signal analysis protocol is a standardized set of rules used to extract spatial vector data from these signals. For instance, through a frame structure defined by the protocol, the signal is decomposed into X, Y, and Z-axis components to construct a theoretical alignment reference coordinate system. This coordinate system represents the ideal alignment position of the spindle and attachment head. For example, if the spindle signal indicates a Z-axis offset of 0.5 mm, the protocol will extract the vector (0, 0, 0.5) to form the reference coordinates, providing a basis for subsequent deviation calculations.

[0079] Step S420: Calculate the coordinate deviation vector between the theoretical docking reference coordinates and the preset reference coordinates. If the coordinate deviation vector exceeds the allowable range, call the positioning adjustment algorithm to calculate the kinematic error compensation value.

[0080] The coordinate deviation vector is obtained by the following formula: (28) In formula (28), Represents the coordinate deviation vector. Indicates the theoretical docking reference coordinates. The preset reference coordinates are represented. The control logic of formula (28) is to calculate the three-dimensional vector deviation between the theoretical docking reference and the preset reference coordinates. The vector deviation vectors of the two in the three directions of x / y / z are quantified by vector subtraction, which provides a clear quantitative basis for determining whether positioning adjustment needs to be triggered. It is a key verification link before docking.

[0081] The following formula is used to define the criteria for determining the numerical solution of kinematic error compensation: (29) In formula (29), The magnitude of the coordinate deviation vector is represented. This indicates the allowable range threshold, if the magnitude of the coordinate deviation vector... Greater than the allowable range threshold If it exceeds the allowable range, then it exceeds the allowable range. The control logic of formula (29) is to determine whether the overall size of the coordinate deviation vector exceeds the limit. By comparing the magnitude of the coordinate deviation vector with the preset allowable range threshold, it is determined whether the overall deviation exceeds the acceptable range, thereby deciding whether to trigger kinematic error compensation. This is the core verification condition before docking.

[0082] The kinematic error compensation value is obtained through the following formula: (30) In formula (30), This represents the kinematic error compensation value. The inverse Jacobian matrix is ​​represented in the positioning adjustment algorithm. The control logic of formula (30) is the inverse kinematic mapping from Cartesian space deviation to joint space compensation. The coordinate deviation vector in the global coordinate system is converted into the compensation displacement of each motion axis (such as the x / y / z axis of the double gantry) through the inverse Jacobian matrix, so as to realize the accurate kinematic error compensation of the multi-axis linkage system.

[0083] On a precision assembly line, when the accessory head approaches the spindle, calculating the coordinate deviation vector between the theoretical docking reference coordinates and the preset reference coordinates becomes particularly crucial. Here, the preset reference coordinates are the ideal zero-position coordinates predefined by the system. If the coordinate deviation vector, such as (0.2, 0.3, 0.1), exceeds the allowable range, such as a threshold of 0.1 mm, the positioning adjustment algorithm is invoked. This positioning adjustment algorithm is essentially an iterative solution process based on a kinematic model. It analyzes error sources such as thermal expansion or mechanical wear and calculates compensation values. For example, it estimates the micro-displacement value of 0.15 mm that needs to be adjusted through the inverse kinematic equation, thereby ensuring docking accuracy.

[0084] Step S430: Superimpose the kinematic error compensation values ​​onto the original command to generate the modified U-axis control parameters.

[0085] The modified U-axis control parameters are obtained using the following formula: (31) In formula (31), This indicates the modified U-axis control parameters. Indicates the original instruction. Indicates the superposition coefficient. The formula represents the kinematic error compensation value. The modified U-axis control parameters are generated by weighted superposition. The control logic of formula (31) is the weighted superposition correction of the original command and the kinematic compensation amount. The compensation weight is adjusted by the superposition coefficient to generate accurate U-axis control parameters, so that the U-axis motion can dynamically offset the kinematic error and ultimately improve the docking accuracy of the double gantry and the headstock.

[0086] The process of superimposing kinematic error compensation values ​​onto the original command is similar to a command correction mechanism. For example, if the original command is to move the U-axis to a position of 50 mm, and the compensation value is -0.2 mm, then the modified U-axis control parameters will be 49.8 mm. In the scenario of the robot arm docking with the attachment head, this can effectively eliminate accumulated errors and achieve more stable parameter output.

[0087] Step S440: Perform virtual interpolation calculations based on the modified U-axis control parameters to obtain the precise docking coordinates after eliminating spatial misalignment.

[0088] The precise docking coordinates after eliminating spatial misalignment are obtained using the following formula: (32) In formula (32), Indicates precise docking coordinates. This represents a virtual interpolation function based on the modified U-axis control parameters. The parameter interval integral is represented. The control logic of formula (32) is based on the virtual interpolation time integral of the modified U-axis control parameters. By accumulating the instantaneous motion of the U-axis over time, it generates continuous, smooth, and precise docking coordinates that eliminate spatial misalignment, providing a precise position reference for the final physical docking of the double gantry and the head warehouse.

[0089] When performing virtual interpolation calculations based on the modified U-axis control parameters, this virtual interpolation calculation is a simulated path planning method. It obtains precise docking coordinates by simulating interpolation points in software. For example, in a virtual environment, after inputting the modified U-axis control parameters, the calculation generates a series of intermediate point paths. After eliminating spatial misalignment, the final coordinates are obtained, such as (100, 200, 300). In aerospace component manufacturing, this can lead to a higher docking success rate and technical benefits, such as reducing scrap rates and improving overall production efficiency. In one embodiment, the connection of the above process lies in the fact that signal analysis directly affects the accuracy of deviation calculation. For example, if the initial vector data extraction is inaccurate, subsequent compensation will fail. Therefore, in actual business, such as on electronic equipment assembly machines, protocol compatibility should be ensured first, and then algorithm parameters should be adjusted step by step to form a complete error correction chain.

[0090] Furthermore, the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machining provided in this embodiment includes step S500: Step S510: Generate a hydraulic drive instruction set based on the precise docking coordinates. The hydraulic drive instruction set is used to activate the cooperative control algorithm model to complete the unlocking action of the old accessory head.

[0091] The hydraulic drive instruction set is derived from the following formula: (33) In formula (33), Indicates the hydraulic drive instruction set. Represents a generating function. This indicates a precise docking coordinate mapping. The hydraulic parameters are represented. The control logic of formula (33) is to map the precise docking coordinates to the hydraulic drive commands and adapt the parameters. The precise docking coordinates after eliminating spatial misalignment are converted into basic hydraulic command templates through the generation function. Then, the inherent parameters of the hydraulic system are combined for adaptation and correction to generate a set of hydraulic drive commands that can be directly executed, providing a precise hydraulic control basis for the unlocking action of the old accessory head.

[0092] The unlocking action is derived using the following formula: (34) In formula (34), Indicates the unlocking action. Indicates the completion function. Indicates the active state. This represents the parameters of the old attachment header. The control logic of formula (34) is the adaptation and linkage between the activation state and the attachment header parameters. The activation state output by the collaborative control algorithm is converted into the trigger logic of the unlocking action through the completion function. Then, the inherent parameters of the old attachment header are combined to generate a precise unlocking action sequence, ensuring that the unlocking action is only executed in a safe state and adapting to the unlocking requirements of different attachment headers.

[0093] Activated state This can be derived from the following formula: (35) In formula (35), This represents the activation function. This represents the collaborative control algorithm model. The control logic of formula (35) is the adaptation and linkage between the activation state and the attachment head parameters. The activation state output by the collaborative control algorithm is converted into the trigger logic of the unlocking action through the completion function. Then, the inherent parameters of the old attachment head are combined to generate a precise unlocking action sequence, ensuring that the unlocking action is only executed in a safe state and adapting to the unlocking requirements of different attachment heads.

[0094] The process of generating a hydraulic drive command set based on precise docking coordinate mapping first requires understanding that precise docking coordinates are accurate spatial position data obtained through prior calculations. For example, in the attachment head replacement system of a CNC machine tool, these precise docking coordinates, such as (100, 200, 300), represent the ideal alignment point between the spindle and the attachment head. Specifically, generating the hydraulic drive command set involves converting these coordinates into executable control signals. The hydraulic drive command set is essentially a set of parameterized instructions used to control the extension and retraction of the hydraulic cylinder. For example, a hydraulic drive command set might include a sequence with a pressure setting of 50 MPa and a displacement of 20 mm. These hydraulic drive commands are derived from the coordinate data through a mapping algorithm. The mapping algorithm analyzes the vector components of the coordinates and estimates the required hydraulic thrust direction and amplitude, thus ensuring that the command set accurately corresponds to the docking requirements. Activating the collaborative control algorithm model is a crucial step in this process. The collaborative control algorithm model is a software framework integrating multi-axis linkage. It combines a PID controller and a feedback loop to coordinate actions. For example, after receiving the command set, the collaborative control algorithm model simulates the path planning for unlocking the old attachment head, gradually releasing the locking mechanism to avoid sudden vibrations. The specific analysis process includes first analyzing the error threshold of the coordinate mapping. If the coordinate deviation vector is less than 0.1mm, a basic command is generated. Then, through iterative optimization, the command parameters are adjusted to match the response characteristics of the hydraulic system. For example, on an automotive parts processing line, this can ensure that the unlocking action is performed smoothly and reduce mechanical stress.

[0095] Step S520: Based on the status feedback after the unlocking action is completed, place the old accessory head and pick up the new accessory head until the new accessory head is triggered to the position signal.

[0096] The following formula is used to define the action of placing the old attachment head and picking up the new attachment head: (36) In formula (36), Indicates the execution of an action. Indicates the old attachment header, Indicates the new attachment header, Indicates a placement operation. Indicates a pick operation. This indicates that the old attachment header is placed and the new attachment header is picked up in parallel. The control logic of formula (36) is that the old attachment header placement and the new attachment header picking are executed in parallel and synchronously. By using parallel operators, the two actions are bound into a composite action sequence that is executed synchronously, which greatly shortens the head-swapping time and improves the efficiency and continuity of the head-swapping process.

[0097] The following formula is used to define the termination time of the process that triggers the signal for the new attachment head to be in place: (37) In formula (37), Indicates the end time of the process. This represents the minimum time operator. Represents a time variable. This indicates that the new attachment header is in place. Indicates the termination condition, when When the value is 1, termination is triggered until the condition is met. The control logic of formula (37) is based on the earliest termination time determination of the state feedback. The moment when the new attachment head arrival signal first takes effect is captured by the minimum time operator as the process termination time of the head replacement action, ensuring that the action terminates immediately once it is completed, avoiding unnecessary waiting, and improving the efficiency and accuracy of the head replacement process.

[0098] The process of placing the old accessory head and picking up the new accessory head based on the status feedback after the unlocking action is completed typically comes from real-time data collected by a sensor array, such as a confirmation signal issued by a position sensor when it detects that unlocking is complete. In one embodiment, this process triggers an automated sequence of the robotic arm. For example, in a precision instrument assembly workshop, after receiving feedback, the system first controls the arm to move the old accessory head to a designated storage rack, with path planning based on feedback data to avoid collisions. Then, the new accessory head is picked up, and its type and orientation are confirmed by a visual recognition module until a sensor at the arm end triggers a new accessory head positioning signal. This new accessory head positioning signal is a digital pulse indicating that the new accessory head has entered the docking range. Specifically, the analysis of the picking action involves path interpolation calculations. The system extracts speed and torque information from the feedback and dynamically adjusts the arm's trajectory. For example, if the feedback indicates a slight offset when the old accessory head was placed, the system compensates for the picking path to ensure precise alignment of the new accessory head, thus forming a continuous operation chain from unlocking to picking.

[0099] Step S530: In response to the new accessory head positioning signal, the fastening procedure is initiated. The fastening procedure regulates the output pressure of the hydraulic system until the monitored fastening pressure value stabilizes within the preset safety locking range.

[0100] The following formula is used to define the start condition for the fastening procedure: (38) In formula (38), This indicates that the fastening process has started. This represents a step function, which occurs when the new attachment head reaches its position signal. hour Start the fastening procedure. The control logic of formula (38) is based on the step trigger of the new accessory head's position signal. The discrete position state is directly converted into the start command of the fastening procedure through the step function, ensuring that the fastening procedure starts without delay once the new accessory head is stably in position, thus ensuring the safety of the connection between the new accessory head and the double gantry and the continuity of the process.

[0101] When the fastening procedure is initiated in response to the new accessory head's arrival signal, it utilizes a pressure regulation mechanism. This mechanism achieves locking by adjusting the hydraulic system's output pressure. For example, after the procedure starts, the pressure is gradually increased from an initial 10 MPa to a target 40 MPa, until the monitored fastening pressure stabilizes within a preset safe locking range, such as 35-45 MPa. Specifically, this regulation process involves real-time monitoring of pressure sensor data and adjusting valve openings through closed-loop control. If pressure fluctuates, the procedure fine-tunes the output to maintain stability. In electronic equipment manufacturing, this provides a reliable locking effect.

[0102] Step S540: If the tightening pressure value remains within the safe locking range, output a head change operation completion flag.

[0103] The following formula is used to define the criteria for determining whether a head-swapping operation is complete: (39) In formula (39), This indicates that the head replacement operation is complete. Indicates an indicator function, This indicates the tightening pressure value. This indicates the lower limit of the safety locking range. The formula indicates that the completion flag is 1 when the tightening pressure value is maintained within the safe tightening range, and 0 otherwise. The control logic of formula (39) is based on the binary judgment of the stability of the tightening pressure range. The indicator function directly maps the state of whether the real-time monitored tightening pressure is continuously stable within the safe tightening range to the completion flag of the head replacement operation. It is the final closed-loop verification of the head replacement process, ensuring that the connection between the new accessory head and the double gantry is firm and safe.

[0104] If the tightening pressure remains within the safe locking range, a head-changing operation completion flag is output. This flag is a system-level signal used to notify the upper-level control module that the operation is complete. In one embodiment, the connection between the above steps lies in the hydraulic command set directly supporting the accuracy of unlocking and subsequent actions. For example, in medical device manufacturing, from generating the command to outputting the completion flag, a complete replacement process is formed.

[0105] Preferably, the automatic head changing method for a CNC gantry machining center with a shared head magazine for dual gantry machining provided in this embodiment includes step S600: Step S610: Obtain the head-changing operation completion flag and the real-time interlock status data of the dual gantry system. If the real-time interlock status data is verified, receive the call request signal sent by the other gantry spindle.

[0106] The following formula is used to define the real-time state data vector: (40) In formula (40), It represents a real-time status data vector, a two-dimensional structured vector that integrates the head-swapping operation completion flag and the dual-gantry interlock status, serving as a unified basis for determining subsequent request reception. This indicates the completion of the head replacement operation. It is a Boolean value (1 indicates that the head replacement is complete and the connection is secure; 0 indicates that the operation is incomplete or the connection is abnormal). The real-time interlock status data of the dual-gantry system is represented by a Boolean value (1 indicates that the interlock is effective and there is no risk of interference between the two gantry systems; 0 indicates that the interlock is ineffective and there is a risk of collision or operation). The control logic of formula (40) is a structured integration of the head-swapping completion state and the interlock safety state. Two key verification points are encapsulated by a two-dimensional vector to provide a unified state judgment basis for subsequent dual-gantry collaborative scheduling, ensuring that the call request from the other gantry is only allowed when the head-swapping is completed and the system is interlocked safely.

[0107] The following formula is used to define the judgment condition for interlock state verification: (41) In formula (41), This indicates the interlock state verification result, with a Boolean output (1 for verification passed, 0 for verification failed), which is the final determination of whether the interlock state is safe. This represents the verification threshold, a preset minimum score for safety compliance (e.g., 8 points). A score that reaches or exceeds this value indicates that the interlocking state is sufficiently safe and collaborative operation is permitted. The judgment condition is as follows: when the quantitative score of the real-time interlock status is not lower than the threshold, the verification is passed; otherwise, the interlock status is judged to be at risk. The control logic of formula (41) is based on the binary verification of the interlock status according to the quantitative threshold. By comparing the real-time interlock status data with the preset safety threshold, a clear verification result is output to ensure that the dual-gantry system is allowed to receive the call request only when the safety level of the interlock status reaches or exceeds the requirements. This is a key judgment link to ensure the collaborative safety of dual-gantry systems.

[0108] The following formula is used to define the received call request signal: (42) In formula (42), This indicates a call request signal, which is the actual request that the system responds to. If the verification is successful, the original request is passed; otherwise, an invalid signal (0) is output. This indicates a call request signal issued by another gantry spindle, containing complete instruction information such as the request attachment header type, priority, and timing. The verification passed, and the head-swapping process is complete. Interlock state verification results Joint decision (usually) Only when both are 1, The control logic of formula (42) is a request access control based on the comprehensive verification results. It only receives and transmits the original call request of the other gantry when the head change is completed and the comprehensive verification of the interlock state is passed; otherwise, it directly rejects the request and outputs an invalid signal. It is a safety access gate for dual-gantry collaborative scheduling.

[0109] When the system needs to confirm that the head-changing process is complete, it first obtains a completion indicator through an integrated sensor network. For example, in an automated machine tool system, after a sensor detects that the new attachment head has been tightened in place, it generates a digital signal. This digital signal is transmitted to the control unit via an internal communication bus. Simultaneously, the system collects real-time interlock status data of the dual-gantry system. This data includes the locking status of each axis and safety door opening / closing information to ensure there is no abnormal interference. For example, if the interlock status data verification passes, it means that all safety conditions are met, such as no conflict signals between the two spindles of the dual-gantry system. At this point, the system receives a call request signal from the other spindle. This signal may be a request packet sent via Ethernet protocol, containing the current task identifier of the spindle, thus allowing the coordinated operation to continue.

[0110] Step S620: Respond to the call request signal, collect the current coordinate values ​​of the head storage base, and generate a collision-free reset path sequence for the head storage base based on the current coordinate values ​​of the head storage base.

[0111] The current coordinates of the headstock base are obtained using the following formula: (43) In formula (43), This represents the current coordinates of the head unit base. The final coordinates, after mean filtering, have an accuracy of up to 0.001mm and are the core input for generating a collision-free reset path. This indicates the number of sampling times. The preset number of sampling times (e.g., 5–10 times) is used. The more sampling times, the better the filtering effect, but the real-time performance will be slightly reduced. A balance needs to be struck between accuracy and efficiency. Indicates the first This response call request signal The coordinates are collected. Each request triggers a coordinate collection. For the first The original coordinates collected in the first sampling include sensor noise and mechanical vibration interference. The control logic of formula (43) is to use the coordinate mean filtering of multiple sampling points. By averaging the coordinate values ​​of the head base collected when responding to multiple call requests, the noise and mechanical vibration interference of a single sampling are eliminated, and accurate and stable current coordinate values ​​are obtained, providing a reliable position reference for the subsequent generation of a collision-free reset path.

[0112] The collision-free reset path sequence for the headrest base is derived using the following formula: (44) In formula (44), Indicates the first The collision-free reset path point, the middle coordinate in the path sequence, is the target position point for the movement of the headstock base. This indicates the total number of points in the path sequence. The preset number of path points (e.g., 10–30) will result in a smoother path with more points, but the real-time performance will be slightly reduced. This represents the point index, with values ​​1, 2, ... Each point corresponds to a path point number, controlling the interpolation ratio for each point. This represents the target reset coordinate position vector of the headstock base, the endpoint coordinate of the reset action, which is usually the reference standby position of the headstock. This formula is used to generate a collision-free reset path sequence based on the current coordinates of the headstock base. The control logic of formula (44) is to generate a smooth reset path by linear uniform interpolation. By decomposing the displacement from the current coordinate to the target reset coordinate into uniformly distributed intermediate path points, a continuous, stable and collision-free reset path sequence is generated, ensuring that the headstock base will not interfere with the double gantry or accessory head during the movement.

[0113] Upon responding to this call request signal, the system immediately activates the coordinate acquisition module to obtain the current coordinate values ​​of the headstock base. Specifically, this coordinate acquisition module uses a laser rangefinder or encoder to measure the position of the headstock base in three-dimensional space. For example, on a precision assembly line, the headstock base might be located at coordinates (x=1500, y=2000, z=500) millimeters. These values ​​are recorded in real time and used for subsequent calculations. For instance, based on these current coordinate values, the system calculates and generates a collision-free reset path sequence for the headstock base. This calculation process involves a path planning algorithm. First, the work area is modeled as a grid map. Then, the A* algorithm is used to search for a path from the current point to the reset point, avoiding collisions with machine tool components. For example, in a robotic arm collaborative environment, the collision-free reset path sequence includes a series of intermediate points, such as moving from (1500, 2000, 500) to (1200, 1800, 500), and then to (800, 1500, 300), ensuring a smooth and unobstructed path.

[0114] Step S630: Parse the collision-free reset path sequence into control commands to drive the head unit base to move, and trigger the protective cover to retract after detecting that the head unit base has reached the end point, control the head unit base to move along the calculated reset path and retract the protective cover.

[0115] Control commands are derived using the following formula: (45) In formula (45), The control commands are the final output of an executable command sequence, which includes parameters such as the axial displacement, speed, and acceleration of the headstock base movement, as well as the trigger timing for the protective cover to retract. This is the direct basis for driving the hardware actions. The parsing function, the core conversion module, is responsible for mapping the path sequence to underlying instructions, including kinematic coordinate transformation, timing planning, velocity curve generation, safety verification, and other functions. This formula describes the parsing of the collision-free reset path sequence into a control instruction sequence. The control logic of formula (45) is a precise mapping from the collision-free reset path to the underlying executable instructions. The parsing function converts the abstract path sequence into control instructions that the headrest base drive system can recognize, while planning the trigger timing of the protective cover retraction, thus achieving seamless coordination between the headrest base reset and the protective cover action.

[0116] The following formula is used to define the condition for determining whether the headstock base has reached its destination: (46) In formula (46), This indicates the endpoint indicator, with a Boolean output (1 indicates the endpoint has been reached, 0 indicates the endpoint has not been reached). It is a switch signal that triggers subsequent actions (such as the retraction of the protective shield). This indicates the current position of the head unit base. The filtered real-time coordinates reflect the actual position of the head unit base. Indicates the endpoint position, the target coordinates of the reset path (headstock baseline standby position). The position threshold represents the preset allowable deviation range (e.g., 0.01 mm), reflecting the system's accuracy requirement for "arrival." The smaller the threshold, the higher the accuracy. This formula describes the judgment process for whether the headstock base has reached the endpoint. The control logic of formula (46) is based on the binary judgment of the position deviation modulus. By calculating the Euclidean distance (modulus) between the current position of the headstock base and the endpoint position, and comparing it with the preset position threshold, it accurately judges whether the headstock base has reached the endpoint, which is the direct basis for triggering subsequent actions such as the retraction of the protective cover.

[0117] The following formula is used to define the overall control framework for the motion interlock of the dual-gantry system: (47) In formula (47), This represents the overall control command set of the dual-gantry system, which integrates the linkage commands for the movement of the headstock base and the retraction of the protective cover. It is the top-level control logic executed by the system. Indicates the movement control of the headstock base. Indicates the headstock base. This command indicates the reset path and drives the head unit (HB) to move smoothly along the collision-free reset path (CFPR), including parameters such as speed, acceleration, and path points. The arrival indicator is a Boolean status signal (1 indicates that the headstock base has reached the destination, 0 indicates that it has not reached the destination), which is a conditional switch that triggers the retraction of the protective cover. This indicates that the protective shield is retracting. The instruction for retracting the protective cover (PC) is indicated by the protective cover body and includes parameters such as retraction speed and positioning detection. This formula describes the process of controlling the headstock base to move along the reset path and triggering the retraction of the protective cover after reaching the end point. The control logic of formula (47) is a conditionally triggered action timing interlocking framework. By using conditional parallel operators, the two actions of "headstock base movement" and "protective cover retraction" are bound into a linked control flow, ensuring that the protective cover is only retracted after the headstock base reaches the end point. This avoids the risk of motion interference and improves the efficiency of action connection. It is the core control rule for the safe coordination of the dual gantry system.

[0118] When this collision-free reset path sequence is parsed into control instructions, the system decomposes it into specific commands for stepper motors or servo drives. For example, each path point is converted into speed and direction commands, such as "move 300 mm along the negative x-axis at a speed of 5 m / s". These commands are sent to the drive system via the PLC controller, thereby driving the headstock base to move. For example, after detecting that the headstock base has reached its endpoint, the system triggers the protective cover to retract. This monitoring is achieved through limit switches or vision sensors. Specifically, when the headstock base coordinates match the endpoint value, such as (0, 0, 0), a signal is sent to the pneumatic actuator, causing the protective cover to retract back to its initial position, thus completing the entire reset process. In one implementation, controlling the headstock base to move along the calculated reset path and retract the protective cover in the above manner not only ensures operational safety but also achieves efficient equipment reset in business operations. For example, in a multi-spindle machining center, this control can reduce downtime and improve production continuity.

[0119] Please see Figure 2This embodiment provides an automatic head-changing system for a CNC gantry machining center with a shared headstock for dual gantry machining centers. This system executes the aforementioned automatic head-changing method for a CNC gantry machining center with a shared headstock for dual gantry machining centers. It includes a headstock number and positioning coordinate matching module 10, an initial positioning command sequence generation module 20, a status confirmation signal receiving module 30, a precise docking coordinate acquisition module 40, a head-changing operation completion flag generation module 50, and a dual-gantry action interlock control module 60. The headstock number and positioning coordinate matching module 10 acquires the current position data of the dual-gantry spindle and the type information of the attachment head to be replaced. Based on the attachment head type, it matches the corresponding headstock number and its positioning coordinates within the headstock from the shared headstock's support. The initial positioning command sequence generation module 20 uses a CNC collaborative module to calculate the movement trajectory of the headstock base based on the positioning coordinates, generating the initial positioning command sequence for the headstock. The status confirmation signal receiving module 30 controls the drive motor and synchronization based on the initial positioning command sequence. The belt drive assembly operates, driving the ball screw assembly to move the head magazine base to the replacement station, and receives a status confirmation signal indicating that the head magazine base has been stably positioned. The precise docking coordinate acquisition module 40 is used to analyze the status confirmation signal to obtain the theoretical docking reference coordinates between the spindle and the attachment head. If the coordinate deviation vector between the analyzed theoretical docking reference coordinates and the preset reference coordinates exceeds the allowable range, the positioning adjustment algorithm is called to correct the control parameters of the U-axis to obtain a set of precise docking coordinates. The head replacement operation completion mark generation module 50 is used to start the hydraulic clamping device according to the precise docking coordinates, and execute the loosening and placement operation of the old attachment head through the collaborative control algorithm. Then, the new attachment head is picked up and tightened. When the new attachment head is tightened, a head replacement operation completion mark is generated. The double gantry action interlock control module 60 is used to receive the call request of the other gantry spindle according to the head replacement operation completion mark and the action interlock logic of the double gantry system, and control the head magazine base to move along the calculated reset path and retract the protective cover.

[0120] This embodiment provides an automatic head-changing method and system for a dual-gantry shared head magazine in a CNC gantry machining center. Compared with existing technologies, it first acquires spindle position and attachment head type information, matches the head magazine number and coordinates, generates an initial positioning command sequence, and drives the head magazine base to move to the changing station. Then, based on the coordinate deviation vector analysis between the status confirmation signal and the theoretical docking reference coordinates, it calls a positioning adjustment algorithm to correct control parameters, ensuring precise docking. Finally, it completes the head-changing operation through a hydraulic clamping device and a collaborative control algorithm, and combines action interlock logic to achieve collaborative scheduling of multiple gantry spindles and head magazine reset. This embodiment significantly improves the automation level and positioning accuracy of attachment head replacement, optimizes multi-spindle collaborative efficiency, and provides stable and reliable technical support for complex CNC machining scenarios.

[0121] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. An automatic tool changing method for a double gantry shared head magazine of a CNC gantry machining center, characterized in that, The method comprises the following steps: S100, acquiring the current position data of the double-gantry spindle and the type information of the accessory head to be replaced, and matching the corresponding head library number and its positioning coordinates in the head library from the support of the shared head library according to the type of the accessory head; S200, using the numerical control coordination module to calculate the movement trajectory of the head library base according to the positioning coordinates, and generating the initial positioning instruction sequence of the head library; S300, controlling the driving motor and the synchronous belt transmission assembly to operate according to the initial positioning instruction sequence, driving the ball screw assembly to move the head library base to the replacement station, and receiving a state confirmation signal indicating that the head library base has been stably positioned; S400, obtaining the theoretical docking reference coordinates of the spindle and the accessory head based on the state confirmation signal, and if the coordinate deviation vector of the theoretical docking reference coordinates obtained and the preset reference coordinates exceeds the allowed range, calling the positioning adjustment algorithm to correct the control parameters of the U-axis to obtain a set of accurate docking coordinates; S500, starting the hydraulic clamping device according to the accurate docking coordinates, executing the loosening and placing operations of the old accessory head through the cooperative control algorithm, then picking up and fastening the new accessory head, and generating a head replacement operation completion flag when the fastening of the new accessory head is completed; S600, according to the head replacement operation completion flag, receiving a calling request of another gantry spindle in combination with the action interlocking logic of the double-gantry system, controlling the head library base to move along the calculated reset path and retracting the protective cover.

2. The automatic tool changing method of the double gantry shared head magazine of the CNC gantry machining center according to claim 1, characterized in that, Step S100 comprises: S110, acquiring the current position data of the double-gantry spindle and the type information of the target accessory head to be replaced; S120, traversing the digital mapping model of the shared head library according to the target accessory head type information, and screening out candidate supports compatible with the mechanical interface; S130, calculating the spatial distance between the current position data and the preset grabbing coordinates of the candidate support, and determining the only optimal support object with the closest spatial distance from the candidate supports; S140, extracting the logical index number and high-precision three-dimensional space point data associated with the only optimal support object, and obtaining the head library number corresponding to the only optimal support object and its positioning coordinates in the head library.

3. The automatic tool changing method of double gantry shared head magazine of CNC gantry machining center according to claim 1, characterized in that, Step S200 comprises: S210, acquiring the positioning coordinates and calculating the motion axis relative displacement vector in combination with the mechanical origin, discretizing the motion axis relative displacement vector to obtain a set of theoretical movement trajectory points; S220, assigning a velocity to the set of theoretical movement trajectory points and superimposing a compensation value to generate a motion control data stream with timing attributes; S230, verifying the motion control data stream with timing attributes to obtain head library base running path data, encoding and packaging the head library base running path data to generate the initial positioning instruction sequence of the head library.

4. The method of claim 1, wherein, Step S300 comprises: S310, parsing the initial positioning instruction sequence to obtain a digital pulse stream, and modulating the stator voltage vector of the driving motor according to the digital pulse stream; S320, acquiring the mechanical torque excited by the stator voltage vector, and transmitting the mechanical torque through the synchronous belt transmission assembly to generate the real-time linear displacement of the head library base; S330, calculating a current position following error according to the real-time straight-line displacement, and outputting a state confirmation signal indicating that the head library base has been stably positioned if the current position following error converges to a preset range and an acceleration amplitude of the head library base meets a zero-speed judgment threshold.

5. The method of claim 1, wherein, Step S400 includes: S410, obtaining a theoretical docking reference coordinate by analyzing the state confirmation signal, the theoretical docking reference coordinate being constructed by extracting spatial vector data according to a signal analysis protocol; S420, calculating a coordinate deviation vector of the theoretical docking reference coordinate and a preset reference coordinate, and calling a positioning adjustment algorithm to solve a kinematic error compensation value if the coordinate deviation vector exceeds an allowed range; S430, superimposing the kinematic error compensation value to original instructions to generate a modified U-axis control parameter; S440, performing a virtual interpolation operation according to the modified U-axis control parameter to obtain an accurate docking coordinate after eliminating spatial misplacement.

6. The method of claim 1, wherein, Step S500 includes: S510, generating a hydraulic drive instruction set according to the accurate docking coordinate, the hydraulic drive instruction set being used to activate a cooperative control algorithm model to complete an unlocking action of the old accessory head; S520, placing the old accessory head and picking up a new accessory head according to a state feedback after completion of the unlocking action until a new accessory head in-place signal is triggered; S530, starting a fastening program in response to the new accessory head in-place signal, the fastening program regulating a hydraulic system output pressure until a monitored fastening pressure value is stabilized in a preset safe locking interval; S540, outputting a head replacement operation completion flag if the fastening pressure value is maintained in the safe locking interval.

7. The method of claim 1, wherein, Step S600 includes: S610, obtaining a head replacement operation completion flag and real-time interlocking state data of the double-gantry system, and receiving a calling request signal issued by another gantry spindle if the real-time interlocking state data is verified; The real-time state data vector is defined by the following formula: ； wherein, represents a real-time status data vector, represents a head operation completion flag, represents a real-time interlock status data of the double-door system; The judgment condition for interlocking state verification is defined by the following formula: ； wherein, represents the interlock status verification result, represents the verification threshold; The received calling request signal is defined by the following formula: ； wherein, represents a call request signal, represents a call request signal emitted by another gantry spindle, represents a verification pass flag; S620, collecting a current coordinate value of the head library base in response to the calling request signal, and generating a collision-free reset path sequence of the head library base according to the current coordinate value of the head library base; S630, analyzing the collision-free reset path sequence into control instructions to drive the head library base to move, and triggering a protective cover to perform a retracting action after monitoring that the head library base reaches an end point, controlling the head library base to move along the calculated reset path and retract the protective cover.

8. The automatic tool changing method of the double gantry shared head magazine of the CNC gantry machining center according to claim 7, characterized in that, In step S620, the current coordinate value of the head library base is obtained by the following formula: ； wherein, represents the current coordinate value of the head library base, represents the number of times of collecting samples, represents the coordinate collection value of the first response call request signal . The collision-free reset path sequence of the head library base is obtained by the following formula: ； wherein, represents the first collision-free reset path point, represents the total number of path points, represents the point index, represents the head library base target reset coordinate position vector.

9. The automatic tool changing method of a double gantry shared head magazine of a CNC gantry machining center according to claim 8, characterized in that, In step S630, the control instructions are obtained by the following formula: ； wherein, represents a control instruction, represents a resolution function, which formula describes resolving the collision-free reset path sequence into a control instruction sequence; The judgment condition for the head library base to reach the end point is defined by the following formula: ； wherein, represents the end point indicator, represents the current position of the head tank base, represents the end point position, represents the position threshold, the formula is used to describe the judgment process of monitoring whether the head tank base reaches the end point. The action interlocking overall control framework of the double-gantry system is defined by the following formula: ； wherein, represents the total control command set of the double-gantry system, represents the headstock base movement control, represents the headstock base, represents the reset path represents the protective cover retraction action, represents the protective cover, the formula describes the process of controlling the headstock base to move along the reset path and trigger the protective cover retraction after reaching the end point.

10. An automatic tool changing system of a double gantry shared headstock of a CNC gantry machining center for performing the automatic tool changing method of the double gantry shared headstock of the CNC gantry machining center according to any one of claims 1 to 9, characterized in that, It includes: A head library number and positioning coordinate matching module (10) is configured to acquire current position data of a double-gantry main shaft and planned replacement accessory head type information, and match a corresponding head library number and its positioning coordinate in the head library from a support of a shared head library according to the accessory head type; An initial positioning instruction sequence generation module (20) is configured to calculate a movement track of a head library base according to the positioning coordinate by using a numerical control coordination module, and generate an initial positioning instruction sequence of the head library; A state confirmation signal receiving module (30) is configured to control a driving motor and a synchronous belt transmission assembly to operate according to the initial positioning instruction sequence, drive a ball screw assembly to move the head library base to a replacement station, and receive a state confirmation signal indicating that the head library base has been stably positioned; An accurate docking coordinate acquisition module (40) is configured to obtain theoretical docking reference coordinates of the main shaft and the accessory head based on the state confirmation signal, and if a coordinate deviation vector of the obtained theoretical docking reference coordinates and preset reference coordinates exceeds a permitted range, a positioning adjustment algorithm is called to correct a control parameter of a U-axis to obtain a set of accurate docking coordinates; A head replacement operation completion flag generation module (50) is configured to start a hydraulic clamping device according to the accurate docking coordinates, execute loosening and placing operations of an old accessory head by using a coordination control algorithm, subsequently pick up and fasten a new accessory head, and generate a head replacement operation completion flag when the fastening of the new accessory head is completed; A double-gantry action interlocking control module (60) is configured to receive a calling request of another gantry main shaft according to the head replacement operation completion flag, control the head library base to move along a calculated reset path and retract a protective cover in combination with an action interlocking logic of a double-gantry system.

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