Die wear online compensation method and device for precise plastic part production

Abstract

The invention provides a mold wear online compensation method and device for precise plastic part production, and the method comprises the steps: obtaining an actual indexing termination position of a mold indexing mechanism based on a position sensor signal of a precise plastic part after each time of demolding, and obtaining a mold wear online compensation result based on the actual indexing termination position and a preset standard indexing termination position; determining the drift distance of the mold indexing track; based on the geometric mapping relation between the drift distance and the mold cavity structure, determining a local space displacement field caused by the drift of the indexing track; based on the space coupling relation between the local space displacement field and the filling path of the plastic melt in the cavity, determining the flow resistance change distribution borne by the plastic melt; and determining a compensation driving force vector based on the flow resistance change distribution and the driving response characteristic of the injection molding execution mechanism, and controlling the injection molding execution mechanism to implement driving force output in the next molding period based on the compensation driving force vector. According to the invention, the product consistency and the production continuity of the precise plastic parts are improved.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a method and apparatus for online compensation of mold wear in the production of precision plastic parts. Background Technology

[0002] In the production of precision plastic parts, long-term use of molds can lead to wear on the cavity surface due to factors such as friction, thermal fatigue, and material creep, resulting in dimensional deviations in the molded parts. In existing technologies, a common compensation method involves periodically stopping the machine to measure the geometric deviations of key mold feature points and then offline correcting injection molding process parameters (such as holding time and injection speed) based on historical deviation data.

[0003] However, existing methods rely on manual intervention and periodic inspections, which cannot detect changes in the actual wear state of the mold during the interval between two inspections. This results in a lag in compensation and makes it difficult to cope with the indexing trajectory drift caused by nonlinear and non-uniform wear of the mold during continuous production. Consequently, it is impossible to detect the drift of the mold indexing trajectory in real time and achieve dynamic online compensation for molding errors without stopping the machine, making it difficult to guarantee the product consistency and production continuity of precision plastic parts. Summary of the Invention

[0004] This invention provides a method and apparatus for online compensation of mold wear in the production of precision plastic parts, in order to improve the product consistency and production continuity of precision plastic parts.

[0005] In a first aspect, the present invention provides an online compensation method for mold wear in the production of precision plastic parts, comprising: Based on the position sensor signal after each demolding during the continuous production of precision plastic parts, the actual indexing termination position of the mold indexing mechanism in the current molding cycle is obtained, and based on the actual indexing termination position and the preset standard indexing termination position, the drift amount of the mold indexing trajectory in the current molding cycle is determined. Based on the geometric mapping relationship between the drift amount and the mold cavity structure, the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle is determined. Based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity, the distribution of flow resistance changes experienced by the plastic melt in the current molding cycle is determined. Based on the flow resistance variation distribution and the driving response characteristics of the injection molding actuator, the compensation driving force vector applied by the injection molding actuator in the current molding cycle is determined, and the injection molding actuator is controlled to implement driving force output in the next molding cycle based on the compensation driving force vector.

[0006] Secondly, the present invention also provides an online mold wear compensation device for precision plastic parts production, applied to the online mold wear compensation method for precision plastic parts production as described in the first aspect; the online mold wear compensation device for precision plastic parts production includes: The trajectory drift analysis module is used to obtain the actual indexing termination position of the mold indexing mechanism in the current molding cycle based on the position sensor signal after each demolding during the continuous production of precision plastic parts, and to determine the drift amount of the mold indexing trajectory in the current molding cycle based on the actual indexing termination position and the preset standard indexing termination position. The spatial displacement analysis module is used to determine the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle based on the geometric mapping relationship between the drift amount and the mold cavity structure. The flow resistance analysis module is used to determine the distribution of flow resistance changes experienced by the plastic melt in the current molding cycle based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity. The error compensation module is used to determine the compensation driving force vector applied by the injection molding actuator in the current molding cycle based on the flow resistance change distribution and the driving response characteristics of the injection molding actuator, and to control the injection molding actuator to implement driving force output in the next molding cycle based on the compensation driving force vector.

[0007] Thirdly, the present invention also provides an electronic device, comprising: a memory for storing computer software programs; and a processor for reading and executing the computer software programs, thereby realizing the online compensation method for mold wear in precision plastic parts production as described above.

[0008] Fourthly, the present invention also provides a non-transitory computer-readable storage medium storing a computer software program, which, when executed by a processor, implements the online compensation method for mold wear in precision plastic parts production as described above.

[0009] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the above-mentioned online compensation method for mold wear in the production of precision plastic parts.

[0010] The online wear compensation method for precision plastic parts production provided by this invention obtains the actual indexing termination position of the mold indexing mechanism in the current molding cycle through the position sensor signal after each demolding of the precision plastic part. It then determines the drift amount of the mold indexing trajectory in the current molding cycle by combining the position sensor signal with a preset standard indexing termination position. Based on the geometric mapping relationship between the drift amount and the mold cavity structure, it obtains the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle. Based on the spatial coupling relationship between this local spatial displacement field and the filling path of the plastic melt in the cavity, it determines the distribution of flow resistance changes experienced by the plastic melt in the current molding cycle. Finally, it determines the distribution of flow resistance changes based on the relationship between this flow resistance change distribution and the injection molding actuator. The driving response characteristics determine the compensation driving force vector that the injection actuator needs to apply in the current molding cycle, and based on this compensation driving force vector, the injection actuator is controlled to implement driving force output in the next molding cycle. This enables real-time sensing of mold indexing trajectory drift during continuous production without stopping the machine, breaking the limitations of compensation lag caused by manual intervention and periodic detection. It effectively addresses the indexing trajectory drift problem caused by nonlinear and non-uniform wear in continuous mold production, and realizes dynamic online compensation for molding errors. It solves the problem of not being able to sense mold indexing trajectory drift in real time and dynamically compensate for molding errors online without stopping the machine, thus improving the product consistency and production continuity of precision plastic parts. Attached Figure Description

[0011] Figure 1 This is a schematic flowchart of an online mold wear compensation method for precision plastic parts production provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the online mold wear compensation device for precision plastic parts production provided in an embodiment of the present invention; Figure 3 An embodiment diagram of the electronic device provided in this invention; Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with the present invention. Detailed Implementation

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

[0013] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0014] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0015] Optionally, see Figure 1 , Figure 1 This is a schematic flowchart of the online mold wear compensation method for precision plastic parts production provided by the present invention. In this embodiment of the invention, the executing entity of the online mold wear compensation method for precision plastic parts production is a mold compensation device. Therefore, the online mold wear compensation method for precision plastic parts production includes: Step 10: Based on the position sensor signal after each demolding during the continuous production of the precision plastic part, obtain the actual indexing termination position of the mold indexing mechanism in the current molding cycle, and determine the drift amount of the mold indexing trajectory in the current molding cycle based on the actual indexing termination position and the preset standard indexing termination position.

[0016] Optionally, the mold compensation device acquires position sensor signals after each demolding of the precision plastic part during continuous production. The position sensor is a device capable of detecting the movement position of the mold indexing mechanism in real time and converting the position information into an electrical signal recognizable by the mold compensation device. The position sensor is pre-installed at key detection points along the movement trajectory of the mold indexing mechanism to ensure accurate capture of position changes throughout the entire process from the initial indexing position to the final indexing position.

[0017] Optionally, after the precision plastic part is molded and demolded, the mold indexing mechanism will complete the indexing movement of the current molding cycle and stop at a specific position. At this time, the position sensor will transmit the electrical signal corresponding to the stop position to the mold compensation device.

[0018] Furthermore, the mold compensation device performs signal preprocessing on the received position sensor signals, which includes two steps: signal filtering and signal calibration.

[0019] Signal filtering removes environmental interference noise from the signal. Environmental interference noise refers to stray signals that affect the accuracy of position detection, generated by factors such as electromagnetic radiation and mechanical vibration in the production environment. This is achieved by retaining the effective signal frequency band related to the movement position of the mold indexing mechanism and filtering out stray signals outside the frequency band. Signal calibration corrects the systematic error of the position sensor itself. Systematic error refers to the fixed deviation generated by the position sensor during manufacturing or installation. This is done by comparing the sensor's detected signal with the reference signal corresponding to the standard position, calculating the deviation value, and correcting the detected signal.

[0020] Furthermore, the pre-processed position sensor signal is converted by the mold compensation device into the actual indexing termination position of the mold indexing mechanism in the current molding cycle. The logic of the position conversion is as follows: based on the preset calibration relationship of the position sensor, that is, the correspondence between the sensor output signal and the actual position, the pre-processed electrical signal is quantized into specific spatial position coordinates. Further, the mold compensation device calls the pre-stored preset standard indexing termination position. This preset standard indexing termination position refers to the ideal termination position of the indexing mechanism determined during the mold design phase to ensure that the molding quality of the precision plastic parts meets the requirements. This position is calibrated through the mold design drawings and pre-entered into the storage module of the mold compensation device.

[0021] Furthermore, the mold compensation device calculates the difference between the actual indexing termination position and the preset standard indexing termination position. This difference is the drift amount of the mold indexing trajectory in the current molding cycle. The calculation logic of the drift amount is as follows: taking the preset standard indexing termination position as a reference, the coordinate difference between the actual indexing termination position and the reference position in three-dimensional space is taken. The differences in each direction are integrated to obtain the drift amount, which represents the degree to which the indexing trajectory deviates from the ideal trajectory. The positive or negative sign of the drift amount represents the drift direction, and the absolute value of the drift amount represents the magnitude of the drift.

[0022] In one embodiment, the precision plastic injection mold adopts a rotary indexing mechanism to realize continuous molding of multiple cavities. A high-precision photoelectric position sensor is installed at the end of the rotating shaft of the indexing mechanism. The detection accuracy of the sensor is 0.001 mm. The preset standard indexing termination position is the spatial position corresponding to a rotation angle of 30 degrees, and its three-dimensional coordinates are pre-calibrated as (X0=100 mm, Y0=50 mm, Z0=20 mm).

[0023] In the 50th molding cycle, after the precision plastic part is demolded, the indexing mechanism stops moving. The photoelectric position sensor detects the electrical signal at the current termination position, and this signal is transmitted to the mold compensation device. The mold compensation device first filters the electrical signal to remove electromagnetic interference signals generated by the injection molding machine motor in the production workshop. Then, it compares the signal with a pre-stored standard position-signal calibration curve to complete signal calibration and correct the 0.002 mm system deviation caused by the sensor installation.

[0024] After preprocessing, the mold compensation device converts the electrical signal into three-dimensional coordinates of the actual indexing termination position (X1=100.003 mm, Y1=50.001 mm, Z1=19.998 mm). The mold compensation device calls the preset standard indexing termination position coordinates and calculates the difference in the X direction as 100.003 mm - 100 mm = 0.003 mm, the difference in the Y direction as 50.001 mm - 50 mm = 0.001 mm, and the difference in the Z direction as 19.998 mm - 20 mm = -0.002 mm.

[0025] Furthermore, the mold compensation device integrates the differences in the above three directions to obtain the drift amount of the mold indexing trajectory in the current molding cycle. This drift amount represents the indexing mechanism termination position drifting 0.003 mm in the positive X direction, 0.001 mm in the positive Y direction, and 0.002 mm in the negative Z direction.

[0026] Step 20: Based on the geometric mapping relationship between the drift amount and the mold cavity structure, determine the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle.

[0027] Optionally, the mold compensation device invokes a pre-established geometric mapping relationship between the drift amount and the mold cavity structure. This geometric mapping relationship refers to the corresponding correlation between the indexing trajectory drift amount and the spatial position changes of each region of the cavity, established based on the three-dimensional structural features of the mold cavity. The mold compensation device uses the drift amount of the current molding cycle obtained in step 10 as input, and derives the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle through this geometric mapping relationship, as specifically in steps 201 to 204. Here, the local spatial displacement field refers to the set of spatial position offsets caused by the indexing drift at each point on the surface and inside of the cavity.

[0028] Step 30: Based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity, determine the distribution of the flow resistance change of the plastic melt in the current molding cycle.

[0029] Optionally, the mold compensation device invokes a pre-established spatial coupling relationship between the local spatial displacement field and the filling path of the molten plastic in the cavity. This spatial coupling relationship refers to the influence of the offset of the cavity spatial position on the flow channel morphology during molten plastic filling, and thus relates to the corresponding relationship of the melt flow state. The mold compensation device uses the local spatial displacement field as input and, through this spatial coupling relationship, derives and determines the flow resistance variation distribution experienced by the molten plastic in the current molding cycle, specifically as in steps 301 to 304. The flow resistance variation distribution refers to the spatial distribution of the change in resistance caused by cavity displacement when the molten plastic fills various areas of the cavity compared to the normal state (without indexing drift).

[0030] Step 40: Based on the distribution of flow resistance changes and the driving response characteristics of the injection actuator, determine the compensation driving force vector applied by the injection actuator in the current molding cycle, and control the injection actuator to implement driving force output in the next molding cycle based on the compensation driving force vector.

[0031] Optionally, the mold compensation device invokes a pre-established correlation between the distribution of flow resistance changes and the driving response characteristics of the injection molding actuator. The driving response characteristics of the injection molding actuator refer to the correspondence between the magnitude, direction, and response speed of the output driving force after receiving the driving signal and the input signal and external load (here, the flow resistance of the plastic melt).

[0032] Optionally, the mold compensation device uses the flow resistance change distribution obtained in step 30 as input, and combines it with the driving response characteristics of the injection molding actuator to derive and determine the compensation driving force vector that the injection molding actuator needs to apply in the current molding cycle, as in steps 401 to 404. The compensation driving force vector refers to the magnitude and direction parameters of the additional driving force that the injection molding actuator needs to apply in order to offset the influence of the flow resistance change on the molding quality.

[0033] Furthermore, the mold compensation device converts the compensation driving force vector into a corresponding control signal, and controls the injection molding actuator to output driving force according to the set compensation driving force vector in the next molding cycle based on the control signal, so as to offset the molding error of plastic parts caused by the drift of the mold indexing trajectory.

[0034] This invention enables real-time sensing of mold indexing trajectory drift during continuous production without stopping the machine. It overcomes the limitations of compensation lag caused by reliance on manual intervention and periodic inspection, effectively addressing the indexing trajectory drift problem caused by nonlinear and non-uniform wear in continuous mold production. It achieves dynamic online compensation for molding errors, solving the problem of not being able to sense mold indexing trajectory drift in real time and dynamically compensate for molding errors online without stopping the machine, thus improving the product consistency and production continuity of precision plastic parts.

[0035] Optionally, the processes of steps 201 to 204 include: Step 201: Based on the spatial orientation relationship between the direction vector of the drift amount and the rotation axis of the mold indexing mechanism, determine the spatial direction of the drift of the mold indexing trajectory in the mold body coordinate system.

[0036] Optionally, the mold compensation device extracts the direction vector of the drift amount. The direction vector refers to the vector parameter that characterizes the distribution trend of the drift amount in three-dimensional spatial directions. It is determined by the sign and relative magnitude of the difference in the drift amount in the X, Y, and Z directions, and can accurately reflect the spatial orientation of the indexing trajectory drift.

[0037] Optionally, the mold compensation device calls the pre-stored rotation axis parameters of the mold indexing mechanism. The rotation axis parameters refer to the spatial position parameters of the core rotation axis that enables the indexing motion of the mold indexing mechanism, including the coordinates of the starting end point, the coordinates of the ending end point, and the direction of axis extension. These parameters are calibrated by the mold design drawings and pre-entered into the storage module of the mold compensation device. At the same time, the mold compensation device calls the pre-established mold body coordinate system. The mold body coordinate system is a three-dimensional rectangular coordinate system established with the geometric center of the fixed end of the mold as the origin, the mold opening and closing direction as the X-axis, the mold indexing rotation radial direction as the Y-axis, and the direction perpendicular to the mold opening and closing plane as the Z-axis. This system is used to uniformly characterize the spatial position of each component of the mold.

[0038] Furthermore, the mold compensation device analyzes the spatial orientation relationship between the direction vector of the drift and the rotation axis of the mold indexing mechanism. The spatial orientation relationship includes three types: parallel, perpendicular, and inclined. Specifically, it is determined by judging the angle between the direction vector and the rotation axis. When the included angle is 0 degrees, the two are parallel; when the included angle is 90 degrees, the two are perpendicular; when the included angle is between 0 and 90 degrees, the two are inclined.

[0039] Based on the above spatial orientation relationship, the mold compensation device projects the direction vector of the drift amount onto the three coordinate axes of the mold body coordinate system. By calculating the proportion and sign of each projection component, the spatial action direction of the drift of the mold indexing trajectory in the mold body coordinate system is determined. The spatial action direction refers to the specific spatial direction in which the drift acts on the mold cavity, which can clearly identify the direction in which the drift affects the cavity.

[0040] Step 202: Based on the spatial action direction and the geometric layout relationship between each cavity unit in the mold cavity structure and the mold indexing center, determine the disturbed area of ​​each cavity unit under the drift of the mold indexing trajectory.

[0041] Optionally, the mold compensation device calls pre-stored mold cavity structure parameters, which refer to parameters such as the overall layout of the cavities in the mold, the number of each cavity unit, the spatial position of each cavity unit, and the contour dimensions. At the same time, the mold compensation device extracts the mold indexing center parameters, which refer to the center position of the circle where the mold indexing mechanism realizes the rotational indexing movement. Its coordinates are marked by the mold design drawings and pre-stored in the mold compensation device.

[0042] The mold compensation device analyzes the geometric layout relationship of each cavity unit in the mold cavity structure relative to the mold indexing center. The geometric layout relationship refers to the distance between each cavity unit and the indexing center, the distribution angle of each cavity unit around the indexing center, and the relative positional relationship between each cavity unit. This is achieved by calculating the straight-line distance between the geometric center of each cavity unit and the indexing center, and the angle between the connecting line and the X-axis of the mold body coordinate system.

[0043] Furthermore, the mold compensation device, considering the spatial action direction, determines whether each cavity unit will be directly affected by the indexing trajectory drift in that spatial action direction: cavity units that overlap with the projection of the spatial action direction and whose distance from the indexing center is within the drift influence range are determined to be affected cavity units; cavity units that do not overlap with the projection of the spatial action direction or whose distance from the indexing center exceeds the drift influence range are determined to be unaffected cavity units. The drift influence range refers to the spatial range within which the drift can have a detectable impact on the cavity, determined based on the absolute value of the drift and the transmission accuracy of the mold indexing mechanism. This range is pre-calibrated and stored through mold debugging experiments.

[0044] Furthermore, for each cavity unit determined to be affected, the mold compensation device further determines its disturbed area. The disturbed area refers to the local area in the cavity unit where the spatial position is offset due to the drift of the indexing trajectory. Specifically, it is determined by analyzing the intersection range of the spatial action direction and the contour of the cavity unit: taking the spatial action direction as the reference, extending into the cavity unit, the intersection area of ​​the extension trajectory and the inner wall of the cavity unit is determined as the disturbed area.

[0045] Step 203: Based on the surface continuity characteristics of the disturbed region and the cavity wall of each cavity in the mold cavity structure, determine the normal projection path of each cavity wall in the disturbed region along the drift direction of the mold indexing trajectory.

[0046] Optionally, the mold compensation device extracts the cavity wall parameters corresponding to each disturbed area. The cavity wall parameters refer to parameters such as the surface type, surface equation parameters, and wall thickness of the cavity wall.

[0047] Optionally, the mold compensation device analyzes the surface continuity characteristics of each cavity wall. The surface continuity characteristics refer to the smoothness and connection method of the cavity wall in different areas, including three types: G0 continuity (positional continuity, no gaps but sharp corners), G1 continuity (tangential continuity, no sharp corners but curvature abrupt changes), and G2 continuity (curvature continuity, no curvature abrupt changes). Specifically, it is determined by detecting the tangential direction and curvature changes at different positions of the wall.

[0048] Furthermore, the mold compensation device extracts the drift direction of the mold indexing trajectory. Using this drift direction as a reference, it calculates the normal direction of the cavity wall in each disturbed area. The normal direction refers to the spatial direction perpendicular to the tangent direction of the cavity wall. For planar walls, the normal direction is a fixed direction; for curved walls, the normal direction changes with the position of the wall and is specifically determined by derivation from the tangent direction of the wall.

[0049] Furthermore, based on the aforementioned normal direction, the mold compensation device determines the normal projection path of each cavity wall surface in the disturbed area along the drift direction. The normal projection path refers to the trajectory formed by projecting the cavity wall surface in the disturbed area along the normal direction of the drift direction to the drift action direction. Specifically, it is achieved by projecting the key points of the wall surface in the disturbed area along the normal direction and connecting the projection points to form a continuous path. This path can reflect the potential displacement trend of the cavity wall surface under the drift action.

[0050] Step 204: Determine the local spatial displacement field based on the normal projection path and the actual curvature distribution of each cavity wall surface in the three-dimensional space.

[0051] Optionally, the mold compensation device calls upon the pre-stored actual curvature distribution of each cavity wall surface in the three-dimensional space within the mold cavity structure. The actual curvature distribution refers to the magnitude and variation law of curvature in different regions of the cavity wall surface. Based on the normal projection path of each cavity wall surface in the disturbed area, the mold compensation device establishes a correlation between the projection path offset and the spatial displacement of the wall surface, combined with the actual curvature distribution. Through the correlation, the spatial displacement parameters of the cavity wall surface and internal points in each disturbed area are derived, and all displacement parameters are integrated to form a local spatial displacement field, as described in steps 2041 to 2044. The local spatial displacement field refers to the collection of spatial positional offsets caused by indexing drift of each point on the cavity surface and internal points.

[0052] The embodiments of the present invention can accurately determine the local spatial displacement field of the cavity caused by the indexing trajectory drift, providing accurate basic data support for determining the distribution of flow resistance changes and compensating for injection driving force in subsequent steps, ensuring the effective control of the mold compensation device on the molding quality of precision plastic parts, thereby improving the product consistency and production continuity of precision plastic parts.

[0053] Optionally, the process of steps 2041 to 2044 includes: Step 2041: Based on the normal projection path and the actual curvature distribution of each cavity wall in the mold cavity structure in three-dimensional space, determine the local rigid body displacement trend of each cavity wall in the disturbed area caused by the indexing trajectory drift.

[0054] Optionally, the mold compensation device analyzes the extension direction of the projection path, the path curvature and the matching relationship between the actual curvature distribution of the corresponding cavity wall. The matching relationship refers to the degree of fit between the curvature change of the projection path and the actual curvature change of the wall, including three types: complete matching, partial matching and no matching.

[0055] Furthermore, based on this matching relationship, the mold compensation device determines the motion pattern of the cavity wall under the drift action: when the curvature of the projected path matches or partially matches the actual curvature of the wall, it is determined that the wall has undergone displacement in the form of rigid body motion; when they do not match, the motion pattern determination result is corrected by combining the wall thickness parameter. Subsequently, the mold compensation device determines the local rigid body displacement trend of each cavity wall in the disturbed area caused by the indexing trajectory drift. The local rigid body displacement trend refers to the direction and degree of spatial position shift of the wall while maintaining its shape under the drift action, specifically determined by deriving the offset direction and amount of the projected path in combination with the wall curvature.

[0056] Step 2042: Based on the local rigid body displacement trend and the structural connection constraint information between adjacent cavity units in the mold cavity structure, determine the boundary displacement transmission effect of each cavity unit in the disturbed area.

[0057] Optionally, the mold compensation device calls the pre-stored structural connection constraint information between adjacent cavity units in the mold cavity structure. The structural connection constraint information refers to the parameters of the connection structure between adjacent cavity units used to achieve fixation and positioning, including the connection method (such as bolt connection, pin connection, one-piece molding), the stiffness parameters of the connection part, the size of the connection gap, etc.

[0058] Furthermore, the mold compensation device analyzes the interaction between the local rigid body displacement trend and the structural connection constraint information: when the local rigid body displacement trend matches the allowable stiffness range of the connecting structure, the displacement can be transmitted to adjacent cavity units through the connection; when it exceeds the allowable stiffness range, the connecting structure restricts the displacement transmission. Based on this interaction, the mold compensation device determines the boundary displacement transmission effect of each cavity unit in the disturbed area. The boundary displacement transmission effect refers to the degree and range of displacement in the disturbed area transmitted through the boundary of the cavity unit to the undisturbed area and adjacent cavity units. Specifically, it is achieved by calculating the displacement transmission efficiency of the connecting structure. The displacement transmission efficiency is the ratio of the transmitted displacement to the original displacement; the larger the ratio, the stronger the transmission effect.

[0059] Step 2043: Based on the boundary displacement transfer effect and the geometric continuity characteristics of the mold cavity structure, determine the spatial displacement vector of each local area of ​​the mold cavity caused by the indexing trajectory drift in the current molding cycle.

[0060] Optionally, the mold compensation device calls up the pre-stored geometric continuity features of the mold cavity structure. The geometric continuity features refer to the smoothness of the connection between the overall mold cavity and each cavity unit in terms of geometric shape, including the surface continuity of the inner wall of the cavity unit and the connection surface continuity between adjacent cavity units.

[0061] Furthermore, the mold compensation device analyzes the relationship between boundary displacement transmission effect and geometric continuity characteristics: for regions with high geometric continuity, displacement transmission is smoother and displacement distribution is more uniform; for regions with low geometric continuity, displacement transmission may abruptly change or attenuate.

[0062] Furthermore, based on this correlation, the mold compensation device corrects the original displacement of the disturbed area. The correction logic is as follows: combining the displacement attenuation coefficient corresponding to the geometric continuity characteristics, the displacement transmitted from the boundary is converted. The displacement attenuation coefficient is a coefficient determined according to the geometric continuity level; the higher the continuity level, the closer the coefficient is to 1. After correction, the mold compensation device determines the spatial displacement vector of each local area of ​​the mold cavity caused by the indexing trajectory drift in the current molding cycle. The spatial displacement vector is a parameter characterizing the magnitude and direction of the spatial displacement of each local area, composed of displacement components in three dimensions.

[0063] Step 2044: Determine the local spatial displacement field based on the spatial displacement vector of each local region and the topological coverage relationship of the mold cavity structure in three-dimensional space.

[0064] Optionally, the mold compensation device calls the pre-stored topological coverage relationship of the mold cavity structure in three-dimensional space. The topological coverage relationship refers to the spatial position and mutual coverage and inclusion relationship of each local area in the three-dimensional topological structure of the mold cavity.

[0065] Optionally, the mold compensation device integrates the spatial displacement vectors of each local region according to their corresponding spatial positions based on topological coverage relationships. The integration logic is as follows: a compatibility check is performed on the displacement vectors of adjacent local regions. When the difference between the displacement vectors of adjacent regions is within the allowable range, a smooth transition is used for integration; when the difference exceeds the allowable range, the displacement vectors are corrected based on geometric continuity characteristics before integration. After integration, the mold compensation device obtains a set that can comprehensively characterize the spatial positional offset of each point in the mold cavity caused by the indexing trajectory drift; this set is the local spatial displacement field.

[0066] The embodiments of the present invention can accurately determine the local spatial displacement field, providing basic data for the subsequent calculation of the flow resistance distribution and injection driving force compensation, ensuring the effective control of molding quality by the mold compensation device, thereby improving the product consistency and production continuity of precision plastic parts.

[0067] Optionally, the processes of steps 301 to 304 include: Step 301: Determine the actual position offset vector of each cavity wall in the mold cavity in three-dimensional space based on the local spatial displacement field. Based on the spatial relative relationship between the actual position offset vector and the standard filling path in the cavity, determine the actual contact area between the plastic melt and each offset cavity wall during the filling process.

[0068] Optionally, the mold compensation device extracts the displacement parameters of the corresponding positions of each cavity wall surface in the mold cavity from the local spatial displacement field, and determines the actual position offset vector of each cavity wall surface in three-dimensional space based on the displacement parameters. The actual position offset vector refers to the spatial vector parameter that characterizes the deviation of each cavity wall surface from its standard position. It is composed of offset components in three-dimensional direction and can accurately reflect the magnitude and direction of the actual position offset of the wall surface relative to the standard position.

[0069] Furthermore, the mold compensation device calls the pre-stored standard filling path in the cavity. The standard filling path refers to the preset flow path of the plastic melt from the gate to the cavity until it is filled, under ideal conditions where there is no positional offset in the mold cavity and the plastic melt molding parameters are stable.

[0070] Furthermore, the mold compensation device analyzes the spatial relative relationship between the actual position offset vector of each cavity wall and the standard filling path. The spatial relative relationship refers to the positional association between the offset cavity wall and the standard filling path in three-dimensional space, including three types: no intersection between the path and the wall, partial overlap between the path and the wall, and complete fit between the path and the wall. Specifically, this is achieved by comparing the spatial coordinates of the wall after the actual position offset with the coordinate range of the standard filling path.

[0071] Furthermore, for cases where the spatial relationship involves partial overlap or complete contact between the path and the wall, the mold compensation device determines the actual contact area between the molten plastic and the offset cavity walls during the filling process. The actual contact area refers to the spatial area where the molten plastic makes physical contact with the offset cavity wall as it flows along the standard filling path. The determination logic is as follows: extract the path segment in the standard filling path that overlaps with the offset wall, and extend it to both sides from the center of this path segment to the range that coincides with the edge of the offset wall. This range is the actual contact area, and the cavity wall position and offset information corresponding to this area are recorded.

[0072] Step 302: Based on the actual contact area and the mainstream direction of the plastic melt during the filling process, determine the local flow cross-sectional state of the plastic melt at each contact area.

[0073] Optionally, the mold compensation device extracts the spatial range parameters of each actual contact area, including the three-dimensional coordinate boundary of the contact area, the shape of the area outline, and the size of the area.

[0074] Furthermore, the mold compensation device calls upon the pre-stored mainstream direction of the plastic melt during the filling process. The mainstream direction refers to the main direction in which the plastic melt flows along the standard filling path under ideal filling conditions. The mainstream direction is determined through flow simulation analysis during the mold design stage, and different mainstream direction parameters correspond to different cavity regions.

[0075] Furthermore, the mold compensation device performs spatial attitude matching between the spatial range of each actual contact area and the mainstream direction of the corresponding area. Spatial attitude matching refers to determining the angular relationship between the mainstream direction and the contour plane of the contact area. The angular relationship includes three types: perpendicular, parallel, and inclined. Specifically, it is determined by calculating the angle between the mainstream direction vector and the normal vector of the contour plane of the contact area.

[0076] Based on the aforementioned angular relationship, the mold compensation device determines the local flow cross-sectional state of the molten plastic at each contact area. The local flow cross-sectional state refers to the shape and dimensional parameters of the flow cross-section perpendicular to the main flow direction when the molten plastic flows through the contact area, including cross-sectional shape, cross-sectional area, maximum cross-sectional width, and minimum cross-sectional width. The determination logic is as follows: A plane perpendicular to the main flow direction is drawn; the intersection of this plane and the actual contact area is the local flow cross-section. The morphological and dimensional parameters of this cross-section are measured and integrated to obtain the local flow cross-sectional state. If the main flow direction is inclined to the contour plane of the contact area, the cross-sectional dimensions need to be projected and corrected to ensure that the parameters accurately reflect the effective cross-sectional situation of the melt flow.

[0077] Step 303: Based on the local flow cross-sectional state and the flow channel geometric continuity information that the plastic melt depends on when flowing in the cavity, determine the streamline disturbance characteristics of the plastic melt at each contact area.

[0078] Optionally, the mold compensation device extracts local flow cross-sectional state parameters at each contact area, including cross-sectional shape, cross-sectional area, and cross-sectional dimensions.

[0079] Furthermore, the mold compensation device calls upon the pre-stored geometric continuity information of the runners that the molten plastic relies on when flowing within the mold cavity. This geometric continuity information refers to the geometric connection characteristics of the mold cavity runners (including the main runner, branch runners, and internal runners) in three-dimensional space, including the gradual / abrupt characteristics of the runner cross-section, the transition radius of the runner corners, and the angle between the axes of adjacent runners.

[0080] Furthermore, the mold compensation device analyzes the degree of fit between the local flow cross-section state and the flow channel geometric continuity information. The degree of fit refers to the matching between the local flow cross-section state of the current contact area and the flow channel geometric continuity requirements. Specifically, it is achieved by comparing the dimensional change rate of the local flow cross-section with the allowable dimensional change rate of the flow channel geometric continuity, and the difference between the shape of the local flow cross-section and the shape of the standard flow channel cross-section. When the dimensional change rate of the local flow cross-section is within the allowable range and the shape difference is less than a preset threshold, the degree of fit is determined to be high; otherwise, the degree of fit is determined to be low.

[0081] Furthermore, based on the aforementioned degree of fit, the mold compensation device determines the streamline disturbance characteristics of the plastic melt at each contact area. Streamline disturbance characteristics refer to the degree and morphological characteristics of the plastic melt's streamlines deviating from the ideal streamlines when flowing through the contact area, including parameters such as disturbance amplitude, disturbance frequency, and disturbance range. Optionally, the determination logic in this embodiment of the invention is as follows: if the degree of fit is high, the streamline disturbance is determined to be small, with the disturbance amplitude within 5% of the local flow cross-sectional size deviation, and the disturbance range limited to the interior of the contact area; if the degree of fit is low, the disturbance amplitude and disturbance range of the streamlines are calculated based on the value of the dimensional change rate exceeding the allowable range and the magnitude of the shape difference. The greater the dimensional change rate and the greater the shape difference, the greater the disturbance amplitude and the wider the disturbance range. Simultaneously, the morphology of the streamline disturbance (e.g., vortex-like, wave-like) is recorded.

[0082] Step 304: Based on the streamline disturbance characteristics and the viscous shear stress characteristics between the plastic melt and the cavity wall during flow in the cavity, determine the distribution of flow resistance variation.

[0083] Optionally, the mold compensation device calls upon the pre-stored viscous shear stress characteristics between the molten plastic and the cavity wall during its flow in the cavity. The viscous shear stress characteristics refer to the correlation between the magnitude of the shear stress and the melt flow velocity, wall roughness, and melt temperature when the molten plastic moves relative to the cavity wall due to its own viscosity during the flow process.

[0084] Furthermore, the mold compensation device establishes a correlation between the streamline disturbance characteristics and the viscous shear stress action characteristics. Through this correlation, the change in viscous shear stress caused by streamline disturbance at each contact area is derived. The stress change and corresponding spatial position of each area are integrated to obtain the distribution of flow resistance change of the plastic melt in the current molding cycle, as shown in steps 3041 to 3044.

[0085] The embodiments of the present invention can accurately determine the changes in melt flow resistance, providing data support for the calculation of the compensation driving force of the subsequent injection molding actuator, ensuring the pertinence and effectiveness of the compensation strategy, guaranteeing the molding quality stability of precision plastic parts, thereby improving product consistency and production continuity.

[0086] Optionally, the processes of steps 3041 to 3044 include: Step 3041: Based on the streamline disturbance characteristics and the viscous shear stress characteristics between the plastic melt and the cavity wall when it flows in the cavity, determine the trend of wall friction effect of the plastic melt at each contact area.

[0087] Optionally, the mold compensation device analyzes the correlation between streamline disturbance characteristics and viscous shear stress characteristics: the larger the streamline disturbance amplitude, the more violent the relative motion velocity fluctuation between the melt and the wall, and the greater the change amplitude of viscous shear stress; the higher the disturbance frequency, the more frequent the instantaneous change of shear stress; the wider the disturbance range, the larger the melt area affected by the change of shear stress.

[0088] Based on the above correlation, the mold compensation device determines the trend of wall friction effect of the plastic melt at each contact area. The trend of wall friction effect refers to the development direction and intensity change law of the friction between the melt and the cavity wall as the flow line disturbance changes.

[0089] Optionally, the determination logic of this embodiment of the invention is as follows: the friction effect intensity level is divided according to the magnitude of the streamline disturbance amplitude. A disturbance amplitude within 5% indicates a weak friction effect trend, a disturbance amplitude between 5% and 15% indicates a moderate friction effect trend, and a disturbance amplitude above 15% indicates a strong friction effect trend; the change rhythm of the friction effect is determined by combining the disturbance frequency, with high-frequency disturbances corresponding to a rapid fluctuation trend of the friction effect and low-frequency disturbances corresponding to a stable change trend of the friction effect; the range of the friction effect is determined according to the disturbance range to ensure that the trend determination can fully cover the affected contact area.

[0090] Step 3042: Based on the wall friction effect trend and the flow connectivity constraints between adjacent regions of the plastic melt on the filling path, determine the pressure gradient perturbation distribution of the plastic melt in each segment of the filling path.

[0091] Optionally, the mold compensation device invokes pre-stored flow connectivity constraints between adjacent areas of the plastic melt on the filling path. The flow connectivity constraints refer to the channel characteristics restrictions that allow melt flow between two adjacent areas on the filling path, including the minimum cross-sectional size of the connecting channel, the channel length, and the channel corner transition characteristics.

[0092] Furthermore, the mold compensation device analyzes the interaction between the wall friction effect trend and the flow connectivity constraint: a strong friction effect trend leads to increased energy loss of the melt in the contact area. If the cross-section of the flow connectivity channel in adjacent areas is small, it will further aggravate the energy loss, resulting in an increase in the pressure difference between adjacent areas. Under moderate and weak friction effect trends, the melt energy loss is relatively small, and the pressure difference between adjacent areas changes relatively smoothly. The rapid fluctuation trend of the friction effect will cause the pressure difference to exhibit periodic fluctuations, while the stable change trend corresponds to the stable change of the pressure difference.

[0093] Based on the above-mentioned interaction, the mold compensation device determines the pressure gradient disturbance distribution of the plastic melt in each segment of the filling path. The pressure gradient disturbance distribution refers to the spatial distribution of the deviation of the pressure change rate between adjacent regions on the filling path from the ideal filling state (without streamline disturbance). Optionally, the determination logic of this embodiment is as follows: First, calculate the standard pressure gradient between adjacent regions under the ideal state; then, determine the disturbance coefficient of the pressure gradient according to the intensity level of the wall friction effect. Strong friction effect corresponds to a larger disturbance coefficient, while medium and weak friction effects correspond to successively decreasing disturbance coefficients; combine the rhythm of friction effect change to determine the temporal characteristics of the pressure gradient disturbance. A rapid fluctuation trend corresponds to high-frequency disturbance of the pressure gradient, while a stable change trend corresponds to a slow change of the pressure gradient; integrate the pressure gradient disturbance parameters of each adjacent region according to their spatial position on the filling path to obtain the pressure gradient disturbance distribution.

[0094] Step 3043: Based on the pressure gradient disturbance distribution and the local flow channel cross-sectional geometry of the plastic melt in each contact area, determine the change in cross-sectional flow area of ​​the plastic melt caused by wall offset in each contact area.

[0095] Optionally, the mold compensation device analyzes the correlation between the pressure gradient disturbance distribution and the local flow channel cross-sectional geometry: the larger the pressure gradient disturbance amplitude, the more significant the change in the degree of flow obstruction of the melt in this region, and the greater the change in the flow area of ​​the corresponding flow channel cross-section; when the pressure gradient disturbance direction is positive (pressure gradient increases), the corresponding cross-sectional flow area usually decreases, and when the disturbance direction is negative (pressure gradient decreases), the corresponding cross-sectional flow area usually increases; different cross-sectional geometries have different sensitivities to pressure gradient disturbances. For example, a narrow slit cross-section is more sensitive to changes in flow area than a circular cross-section, and the flow area of ​​a narrow slit cross-section changes more under the same pressure gradient disturbance.

[0096] Furthermore, based on the aforementioned correlation, the mold compensation device determines the change in cross-sectional flow area of ​​the molten plastic at each contact area due to wall offset. The determination logic is as follows: First, the cross-sectional sensitivity coefficient is determined based on the local flow channel cross-sectional geometry. Different cross-sectional shapes correspond to preset sensitivity coefficient values, with narrow slit cross-sections having the highest sensitivity coefficient, followed by circular cross-sections. Irregular cross-sections are determined based on the ratio of their equivalent width to equivalent height. Then, the change in cross-sectional flow area is calculated based on the pressure gradient disturbance amplitude and the sensitivity coefficient. The calculation logic is as follows: using the original cross-sectional area under ideal conditions as a benchmark, the pressure gradient disturbance amplitude is multiplied by the sensitivity coefficient to obtain the area change ratio, and then the original cross-sectional area is multiplied by this ratio to obtain the specific area change amount. The trend of area change (increasing or decreasing) is determined by combining the pressure gradient disturbance direction, ultimately obtaining the cross-sectional flow area change parameters at each contact area, including the amount of change and the trend of change.

[0097] Step 3044: Determine the distribution of flow resistance variation based on the change in cross-sectional flow area and the continuous flow requirement of the plastic melt in the filling path.

[0098] Optionally, the mold compensation device calls upon pre-stored continuous flow requirements of the plastic melt on the filling path. The continuous flow requirements refer to the minimum flow velocity, maximum pressure loss, and flow continuity stability that the melt must meet when flowing on the filling path to ensure that the plastic melt can completely and uniformly fill the entire cavity.

[0099] Furthermore, the mold compensation device analyzes the adaptation relationship between changes in cross-sectional flow area and continuous flow requirements: when the reduction in cross-sectional flow area exceeds the allowable range for continuous flow requirements, the melt flow velocity will decrease, the pressure loss will increase, and the flow resistance will increase significantly; when the increase in cross-sectional flow area is within the allowable range, the melt flow velocity will increase slightly, the pressure loss will decrease, and the flow resistance will decrease slightly; when changes in cross-sectional flow area cause the melt flow velocity to be lower than the minimum flow velocity or the pressure loss to exceed the maximum allowable value, the flow continuity will be disrupted, resulting in a sharp change in flow resistance.

[0100] Furthermore, based on the aforementioned adaptation relationship, the mold compensation device determines the flow resistance variation distribution. The flow resistance variation distribution refers to the spatial distribution of the resistance caused by cavity displacement when the molten plastic fills various areas of the mold cavity, compared to the normal state (without indexing drift). The determination logic is as follows: using the flow resistance of each area under normal conditions as a benchmark, the resistance change of each contact area is calculated based on the change in cross-sectional flow area. A decrease in cross-sectional flow area corresponds to an increase in resistance, and an increase in cross-sectional flow area corresponds to a decrease in resistance; the larger the change, the more significant the resistance change. The resistance change is corrected in conjunction with the adaptation to continuous flow requirements. For areas that disrupt flow continuity, the assigned value of the resistance change is increased. The resistance change parameters of each contact area are mapped and integrated according to their spatial coordinates within the mold cavity, while supplementing the resistance benchmark value (without change) for non-contact areas, thus obtaining the flow resistance variation distribution.

[0101] The flow resistance variation distribution obtained in this embodiment of the invention can comprehensively reflect the influence of cavity displacement on melt flow resistance, solve the problem of accurate characterization of flow resistance variation, provide data support for the calculation of compensation driving force of subsequent injection molding actuator, ensure that the compensation strategy can specifically offset the adverse effects of resistance variation on molding quality, ensure product consistency of precision plastic parts, and maintain the continuity of the production process.

[0102] Optionally, the processes of steps 401 to 404 include: Step 401: Based on the distribution of flow resistance changes, determine the local resistance enhancement areas at various positions along the filling path of the injection molding actuator during the filling process, and based on the spatial correspondence between the local resistance enhancement areas and the screw propulsion direction of the injection molding actuator, determine the axial travel range compensated by the injection molding actuator during the propulsion process.

[0103] Optionally, the mold compensation device divides and identifies the distribution of changes in flow resistance, and selects the areas where the flow resistance is increased compared to the normal state, namely the local resistance enhancement area. The local resistance enhancement area refers to the spatial area along the filling path where the melt flow resistance is significantly increased.

[0104] Optionally, the judgment criterion is: when the change in flow resistance in a certain area is greater than the preset resistance enhancement threshold, the area is designated as a local resistance enhancement area. The resistance enhancement threshold refers to the minimum resistance increment value that will have an adverse effect on the melt filling quality, which is determined by the mold forming process debugging.

[0105] Furthermore, the mold compensation device invokes pre-stored screw advance direction parameters of the injection molding actuator. These parameters refer to the spatial direction parameters by which the screw in the injection molding actuator pushes the molten plastic into the cavity along its axial direction, which is consistent with the axis of the main runner in the mold cavity. Simultaneously, the mold compensation device invokes a pre-established spatial mapping relationship between the screw advance stroke and the filling path position. This mapping relationship refers to the correlation between the axial advance stroke of the screw and the corresponding position of the molten plastic on the cavity filling path. This mapping relationship is pre-determined through stroke-position calibration experiments during the injection molding process, enabling the mutual conversion between the screw advance stroke and the filling path position.

[0106] Furthermore, the mold compensation device analyzes the spatial correspondence between each local resistance enhancement area and the screw propulsion direction of the injection molding actuator. The spatial correspondence refers to the spatial orientation and distance of the local resistance enhancement area on the filling path relative to the screw propulsion direction. Specifically, it is determined by projecting the three-dimensional coordinates of the local resistance enhancement area onto the axis of the screw propulsion direction, thus obtaining the projection position of each enhancement area on the screw propulsion axis.

[0107] Furthermore, based on the aforementioned spatial correspondence and the spatial mapping relationship between the screw propulsion stroke and the filling path position, the mold compensation device determines the axial stroke range to be compensated by the injection molding actuator during the propulsion process. The axial stroke range refers to the range of axial propulsion stroke in which the screw needs to apply additional compensating driving force to offset the resistance effect of the local resistance enhancement area. Optionally, the determination logic of this embodiment is as follows: based on the projection position of the local resistance enhancement area on the screw propulsion axis, it is converted into the corresponding screw propulsion stroke value through spatial mapping relationship; the minimum value of the stroke value corresponding to each enhancement area is taken as the starting point of the stroke range, and the maximum value is taken as the ending point of the stroke range, forming a continuous axial stroke range; if there are multiple discontinuous local resistance enhancement areas, multiple discontinuous axial stroke ranges are correspondingly divided, and the resistance increment of the local resistance enhancement area corresponding to each stroke range is recorded.

[0108] Step 402: Based on the time series of the axial stroke range and the angular displacement feedback signal of the servo motor rotor of the injection actuator, determine the driving phase range of the injection actuator corresponding to the local resistance enhancement region in the current molding cycle.

[0109] Optionally, the compensation device acquires the time sequence of the angular displacement feedback signal of the servo motor rotor of the injection molding actuator. The servo motor rotor angular displacement feedback signal refers to the rotor rotation angle signal collected in real time by the angular displacement sensor during the driving of the screw by the servo motor. The time sequence refers to the signal sequence formed by arranging the angular displacement feedback signals collected at different times in chronological order. This signal sequence is transmitted in real time from the control system of the injection molding actuator to the mold compensation device. Further, the mold compensation device calls the pre-stored conversion relationship between the servo motor rotor angular displacement and the screw axial stroke of the injection molding actuator. This conversion relationship refers to the correlation between the rotation angle of the servo motor rotor and the amount of axial stroke of the screw, which is determined by parameters such as the transmission ratio of the servo motor and the lead of the screw. The specific conversion logic is: the amount of axial stroke of the screw is equal to the servo motor rotor angular displacement (converted to radians) multiplied by the screw lead and then divided by (2 multiplied by pi). Through this relationship, the mutual conversion between angular displacement and axial stroke can be realized.

[0110] Furthermore, based on the aforementioned conversion relationship, the mold compensation device converts the starting and ending stroke values ​​of the axial travel interval into corresponding servo motor rotor angular displacement values, namely, the starting angular displacement value and the ending angular displacement value. Subsequently, in the time series of the servo motor rotor angular displacement feedback signal, the time points corresponding to the starting and ending angular displacement values ​​are found. The time point corresponding to the starting angular displacement value is taken as the start time of the drive phase interval, and the time point corresponding to the ending angular displacement value is taken as the end time of the drive phase interval. The time period between the start and end times is the drive phase interval of the injection molding actuator corresponding to the region of increased local resistance. If there are multiple discontinuous axial travel intervals, multiple discontinuous drive phase intervals are determined accordingly, with each drive phase interval corresponding one-to-one with the corresponding axial travel interval.

[0111] Step 403: Based on the transmission characteristic curves of displacement and pressure corresponding to the hydraulic cylinder piston rod of the injection molding actuator in the drive phase interval, determine the output pressure increment trend of the injection molding actuator in maintaining the standard filling rate increase within the drive phase interval.

[0112] Optionally, the mold compensation device calls a pre-stored standard filling rate parameter. This standard filling rate parameter refers to the preset flow rate that the molten plastic must maintain during cavity filling to ensure the molding quality of precision plastic parts. Simultaneously, the mold compensation device calls a pre-stored displacement and pressure transmission characteristic curve corresponding to the hydraulic cylinder piston rod of the injection molding actuator. This curve describes the relationship between the axial displacement of the hydraulic cylinder piston rod and the output pressure of the hydraulic cylinder. This curve is obtained through hydraulic cylinder performance testing experiments and reflects the pressure output capability of the hydraulic cylinder at different displacement positions.

[0113] Furthermore, the correlation between the drive phase interval and the displacement-pressure transmission characteristic curve is analyzed: based on the axial stroke interval corresponding to the drive phase interval, the displacement range corresponding to the hydraulic cylinder piston rod within the drive phase interval is determined by the linkage relationship between the screw stroke and the hydraulic cylinder piston rod displacement (this linkage relationship is determined by the mechanical transmission structure of the injection molding actuator); subsequently, the standard output pressure value (i.e., the basic pressure value required to maintain the standard filling rate) corresponding to this displacement range is found on the displacement-pressure transmission characteristic curve.

[0114] Furthermore, based on the above correlation and the magnitude of the resistance increment in the local resistance enhancement area, the mold compensation device determines the output pressure increment trend of the injection molding actuator in maintaining the standard filling rate within the drive phase interval. The output pressure increment trend refers to the development law of the additional pressure required by the hydraulic cylinder to maintain the standard filling rate over time in order to offset the local resistance enhancement.

[0115] Optionally, the determination logic of this embodiment of the invention is as follows: calculate the required pressure increment base value based on the magnitude of the resistance increment; the larger the resistance increment, the larger the pressure increment base value; combine the displacement change law within the driving phase interval, and superimpose the pressure increment base value on the displacement-pressure transmission characteristic curve to obtain the pressure increment value corresponding to different times; arrange the pressure increment values ​​at each time in chronological order to form the output pressure increment trend. This trend must ensure that the superimposed total output pressure can offset the effect of increased resistance within the entire driving phase interval, ensuring that the melt filling rate is maintained within the standard range.

[0116] Step 404: Determine the compensation driving force vector based on the output pressure increment trend and the force and current conversion relationship corresponding to the driving unit of the injection molding actuator.

[0117] Optionally, the mold compensation device invokes a pre-stored force-current conversion relationship corresponding to the drive unit of the injection molding actuator. This conversion relationship refers to the correlation between the driving force output by the drive unit (including servo motors and hydraulic cylinders) and the input current, reflecting the magnitude of the driving force that the drive unit can generate under different input currents. The mold compensation device establishes a corresponding correlation between the output pressure increment trend and the force-current conversion relationship, converts the pressure increment trend into the corresponding driving force increment demand, and integrates the drive phase interval and screw propulsion direction to obtain a compensation driving force vector containing the magnitude, direction, and duration of the driving force, as described in steps 4041 to 4044.

[0118] The embodiments of the present invention can accurately determine the compensation driving force vector required by the injection molding actuator, ensuring accurate compensation, offsetting the changes in flow resistance caused by indexing drift, ensuring the stability of the plastic melt filling process, improving the product consistency of precision plastic parts, and maintaining the continuity of the production process.

[0119] Optionally, the processes of steps 4041 to 4044 include: Step 4041: Based on the trend and conversion relationship of output pressure increment, determine the direction of change of drive current in the drive phase interval of the injection molding actuator.

[0120] Optionally, the mold compensation device invokes pre-stored force-current conversion relationships corresponding to the drive units of the injection molding actuator. These relationships refer to the correlation between the driving force output by the drive unit (including servo motors and hydraulic cylinders) and the input current, reflecting the magnitude of the driving force that the drive unit can generate under different input currents. Specifically, the driving force and input current are positively correlated; that is, when the input current increases, the driving force output by the drive unit increases, thereby increasing the output pressure of the hydraulic cylinder, and vice versa. Further, the mold compensation device analyzes the correlation between the output pressure increment trend and the force-current conversion relationship: based on the pressure increment value at each moment in the output pressure increment trend, combined with the transmission relationship between the hydraulic cylinder pressure and the driving force (determined by parameters such as the piston area of ​​the hydraulic cylinder), the pressure increment value is converted into the corresponding driving force increment requirement; then, based on the force-current conversion relationship, the direction of the current increment required to meet the driving force increment requirement is determined.

[0121] Based on the above analysis, the mold compensation device determines the direction of the increase in drive current within the drive phase interval of the injection molding actuator's drive unit. The direction of drive current change refers to the direction and rhythm of the increase or decrease of the input current of the drive unit. Optionally, the determination logic of this embodiment is as follows: if the output pressure increment trend is that the pressure continues to increase, then the corresponding drive force increment demand continues to increase. Combining the positive correlation between force and current, the direction of drive current change is a continuous increase; if the output pressure increment trend is that the pressure first increases and then stabilizes, then the direction of drive current change is that it first increases and then remains constant; if the output pressure increment trend is that the pressure increases in stages, then the direction of drive current change is a staged increase. Each increase stage corresponds one-to-one with the pressure increase stage in time, ensuring that the current change can accurately match the pressure increment demand.

[0122] Step 4042: Based on the direction of change of the driving current and the main driving force output channel of the multi-axis coordinated drive of the injection molding actuator, determine the timing of the main driving force action of the injection molding actuator in the current molding cycle.

[0123] Optionally, the mold compensation device calls the pre-stored main driving force output channel parameters of the multi-axis collaborative drive of the injection actuator. Multi-axis collaborative drive refers to the driving method by which the injection actuator realizes the filling of plastic melt and the molding of plastic parts through the coordinated action of multiple drive axes (such as screw push shaft, mold closing shaft, ejection shaft, etc.). The main driving force output channel refers to the drive channel that undertakes the main melt filling driving force output task in the multi-axis collaborative drive, which usually corresponds to the drive unit of the screw push shaft. This parameter includes information such as the drive unit identifier, signal transmission path, and drive response delay time corresponding to the main driving force output channel.

[0124] Optionally, the mold compensation device analyzes the compatibility between the direction of change of the driving current and the driving response characteristics of the main driving force output channel. The driving response delay time refers to the time interval from when the main driving force output channel receives the current adjustment signal to when the actual output driving force of the driving unit changes. This time interval is predetermined by the driving unit performance test and incorporated into the parameters of the main driving force output channel.

[0125] Based on the above adaptation relationship, the mold compensation device determines the timing of the main driving force adjustment of the injection molding actuator in the current molding cycle. The main driving force timing refers to the time arrangement of the main driving force output channel outputting the adjusted driving force according to the direction of the driving current change, including the start time, adjustment duration, and adjustment rhythm of the driving force adjustment. The determination logic is as follows: taking the driving phase interval as a reference, combined with the driving response delay time of the main driving force output channel, the start time of the driving current change is advanced by the corresponding delay time as the start time of the main driving force adjustment; according to the rhythm of the driving current change, the adjustment rhythm of the main driving force is determined. If the current is continuously increasing, the main driving force is continuously increasing, and the increase rate matches the current increase rate; if the current is increasing in stages, the main driving force is increasing in stages, and the start time and duration of each increase stage are consistent with the current increase stage; the termination time of the main driving force adjustment is consistent with the termination time of the driving phase interval, ensuring that the main driving force timing can accurately cover the entire process of the melt flowing through the local resistance enhancement area, while avoiding conflicts with the action timing of other drive shafts.

[0126] Step 4043: Based on the timing of the main driving force and the spatial orientation of the reference driving force vector of the injection actuator in the standard filling stage, determine the direction of the compensation driving force superimposed by the injection actuator in the current molding cycle.

[0127] Optionally, the mold compensation device calls the pre-stored reference driving force vector of the injection actuator in the standard filling stage, which refers to the filling stage when the plastic melt has no displacement in the cavity and the flow resistance is normal.

[0128] Optionally, the reference driving force vector refers to the driving force parameter required by the main driving force output channel to maintain the standard filling rate during the standard filling stage. It includes the magnitude and spatial direction of the driving force. The spatial direction refers to the direction of the driving force, which is consistent with the screw propulsion direction of the injection molding actuator, that is, pointing into the cavity along the axis of the main runner.

[0129] Optionally, the mold compensation device analyzes the relationship between the timing of the main driving force and the vector spatial orientation of the reference driving force: the driving stage corresponding to the timing of the main driving force is a compensation stage set up to offset the increase in local resistance. The driving force adjustment in this stage is a superimposed adjustment based on the reference driving force. Its target is the same as that of the reference driving force, which is to push the plastic melt to fill smoothly along the filling path.

[0130] Based on the above correlation, the mold compensation device determines the direction of the compensation driving force superimposed by the injection molding actuator in the current molding cycle. The direction of the compensation driving force refers to the spatial direction of the additional compensation driving force. The determination logic is as follows: based on the spatial orientation of the reference driving force vector, the direction of the driving force is corrected by considering the influence of the spatial position of the local resistance enhancement area on the driving force direction; if the local resistance enhancement area is located in the center of the filling path, the direction of the compensation driving force is completely consistent with the direction of the reference driving force; if the local resistance enhancement area is located on one side of the filling path, the direction of the compensation driving force is slightly adjusted towards the resistance enhancement side according to the offset direction of the resistance enhancement area. The adjustment angle is determined by the offset distance of the resistance enhancement area. The larger the offset distance, the larger the adjustment angle, but the adjustment angle does not exceed five degrees to ensure that the compensation driving force can accurately act on the resistance enhancement area, while avoiding affecting the overall filling direction of the melt.

[0131] Step 4044: Determine the compensation driving force vector based on the direction of the compensation driving force and the boundary of the actual driving force output capability of the injection molding actuator within the driving phase interval.

[0132] Optionally, the mold compensation device calls the pre-stored actual driving force output capability boundary of the injection actuator within the driving phase interval. The actual driving force output capability boundary refers to the range of maximum and minimum driving force that the main driving force output channel of the injection actuator can stably output within the time corresponding to the driving phase interval. This boundary is determined by the performance parameters such as the rated power, rated torque, and rated pressure of the hydraulic cylinder of the drive unit, while also taking into account the thermal attenuation effect of the drive unit under continuous working conditions.

[0133] Furthermore, the mold compensation device analyzes the compatibility between the incremental demand for driving force and the boundary of the actual driving force output capability: it adds the reference driving force to the incremental demand for driving force to obtain the required total driving force, and determines whether the total driving force is within the boundary of the actual driving force output capability; if the total driving force is within the boundary, it is considered compatible; if the total driving force exceeds the maximum driving force boundary, the incremental demand for driving force needs to be reduced so that the total driving force does not exceed the maximum driving force; if the total driving force is lower than the minimum driving force boundary, the reference driving force needs to be adjusted to ensure that the total driving force meets the minimum driving demand.

[0134] Based on the above adaptability analysis and the direction of the compensating driving force, the mold compensation device determines the compensating driving force vector. The compensating driving force vector refers to the magnitude and direction parameters of the additional driving force that the injection molding actuator needs to apply to offset the impact of changes in flow resistance on molding quality. The determination logic is as follows: the increment of the adapted driving force is taken as the magnitude of the compensating driving force, and the direction of the compensating driving force is taken as the vector direction. Simultaneously, the timing information of the main driving force is incorporated into the vector parameters, forming a complete compensating driving force vector that includes magnitude, direction, and timing. This ensures that the vector can accurately offset the impact of increased local resistance while also conforming to the actual driving capability of the injection molding actuator.

[0135] The embodiments of the present invention can accurately determine the compensation driving force vector, ensure the accuracy of the compensation driving force output by the injection molding actuator, fully offset the changes in flow resistance caused by indexing drift, ensure the stability of the plastic melt filling process, improve the product consistency of precision plastic parts, and maintain the continuity of the production process.

[0136] Furthermore, the online mold wear compensation device for precision plastic parts production provided by the present invention will be described below. The online mold wear compensation device for precision plastic parts production described below can be referred to in correspondence with the online mold wear compensation method for precision plastic parts production described above.

[0137] Reference Figure 2 , Figure 2 This is a schematic diagram of the online mold wear compensation device for precision plastic parts production provided by the present invention. The online mold wear compensation device for precision plastic parts production includes: The trajectory drift analysis module 210 is used to obtain the actual indexing termination position of the mold indexing mechanism in the current molding cycle based on the position sensor signal after each demolding during the continuous production of precision plastic parts, and to determine the drift amount of the mold indexing trajectory in the current molding cycle based on the actual indexing termination position and the preset standard indexing termination position. The spatial displacement analysis module 220 is used to determine the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle based on the geometric mapping relationship between the drift amount and the mold cavity structure. The flow resistance analysis module 230 is used to determine the distribution of flow resistance changes experienced by the plastic melt in the current molding cycle based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity. The error compensation module 240 is used to determine the compensation driving force vector applied by the injection molding actuator in the current molding cycle based on the distribution of flow resistance variation and the driving response characteristics of the injection molding actuator, and to control the injection molding actuator to implement driving force output in the next molding cycle based on the compensation driving force vector.

[0138] This invention enables real-time sensing of mold indexing trajectory drift during continuous production without stopping the machine. It overcomes the limitations of compensation lag caused by reliance on manual intervention and periodic inspection, effectively addressing the indexing trajectory drift problem caused by nonlinear and non-uniform wear in continuous mold production. It achieves dynamic online compensation for molding errors, solving the problem of not being able to sense mold indexing trajectory drift in real time and dynamically compensate for molding errors online without stopping the machine, thus improving the product consistency and production continuity of precision plastic parts.

[0139] Please see Figure 3 , Figure 3 An embodiment diagram of an electronic device provided in accordance with the present invention. For example... Figure 3 As shown, this embodiment of the invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 311, it performs the following steps: Based on the position sensor signal after each demolding during the continuous production of precision plastic parts, the actual indexing termination position of the mold indexing mechanism in the current molding cycle is obtained, and the drift amount of the mold indexing trajectory in the current molding cycle is determined based on the actual indexing termination position and the preset standard indexing termination position. Based on the geometric mapping relationship between the drift amount and the mold cavity structure, the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle is determined. Based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity, the distribution of the flow resistance change of the plastic melt in the current molding cycle is determined. Based on the distribution of flow resistance variation and the driving response characteristics of the injection molding actuator, the compensation driving force vector applied by the injection molding actuator in the current molding cycle is determined, and the driving force output of the injection molding actuator in the next molding cycle is controlled based on the compensation driving force vector.

[0140] Please see Figure 4 , Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with an embodiment of the present invention is shown. Figure 4 As shown, this embodiment provides a computer-readable storage medium 400 on which a computer program 311 is stored. When the computer program 311 is executed by a processor, it performs the following steps: Based on the position sensor signal after each demolding during the continuous production of precision plastic parts, the actual indexing termination position of the mold indexing mechanism in the current molding cycle is obtained, and the drift amount of the mold indexing trajectory in the current molding cycle is determined based on the actual indexing termination position and the preset standard indexing termination position. Based on the geometric mapping relationship between the drift amount and the mold cavity structure, the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle is determined. Based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity, the distribution of the flow resistance change of the plastic melt in the current molding cycle is determined. Based on the distribution of flow resistance variation and the driving response characteristics of the injection molding actuator, the compensation driving force vector applied by the injection molding actuator in the current molding cycle is determined, and the driving force output of the injection molding actuator in the next molding cycle is controlled based on the compensation driving force vector.

[0141] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the online compensation method for mold wear in precision plastic parts production provided by the above methods, the method including: Based on the position sensor signal after each demolding during the continuous production of precision plastic parts, the actual indexing termination position of the mold indexing mechanism in the current molding cycle is obtained, and the drift amount of the mold indexing trajectory in the current molding cycle is determined based on the actual indexing termination position and the preset standard indexing termination position. Based on the geometric mapping relationship between the drift amount and the mold cavity structure, the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle is determined. Based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity, the distribution of the flow resistance change of the plastic melt in the current molding cycle is determined. Based on the distribution of flow resistance variation and the driving response characteristics of the injection molding actuator, the compensation driving force vector applied by the injection molding actuator in the current molding cycle is determined, and the driving force output of the injection molding actuator in the next molding cycle is controlled based on the compensation driving force vector.

[0142] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0143] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for online compensation of mold wear in precision plastic parts production, characterized in that, include: Based on the position sensor signal after each demolding during the continuous production of precision plastic parts, the actual indexing termination position of the mold indexing mechanism in the current molding cycle is obtained, and based on the actual indexing termination position and the preset standard indexing termination position, the drift amount of the mold indexing trajectory in the current molding cycle is determined. Based on the geometric mapping relationship between the drift amount and the mold cavity structure, the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle is determined. Based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity, the distribution of flow resistance changes experienced by the plastic melt in the current molding cycle is determined. Based on the flow resistance variation distribution and the driving response characteristics of the injection molding actuator, the compensation driving force vector applied by the injection molding actuator in the current molding cycle is determined, and the injection molding actuator is controlled to implement driving force output in the next molding cycle based on the compensation driving force vector.

2. The online compensation method for mold wear in precision plastic parts production according to claim 1, characterized in that, The steps for determining the local spatial displacement field include: Based on the spatial orientation relationship between the direction vector of the drift amount and the rotation axis of the mold indexing mechanism, the spatial direction of the drift of the mold indexing trajectory in the mold body coordinate system is determined. Based on the spatial action direction and the geometric layout relationship between each cavity unit in the mold cavity structure and the mold indexing center, the disturbed area of ​​each cavity unit under the drift of the mold indexing trajectory is determined. Based on the surface continuity characteristics of the disturbed region and the cavity walls of each cavity in the mold cavity structure, the normal projection path of each cavity wall in the disturbed region along the drift direction of the mold indexing trajectory is determined. Based on the normal projection path and the actual curvature distribution of each cavity wall surface in three-dimensional space in the mold cavity structure, the local spatial displacement field is determined.

3. The online compensation method for mold wear in precision plastic parts production according to claim 2, characterized in that, The determination of the local spatial displacement field based on the normal projection path and the actual curvature distribution of each cavity wall surface in three-dimensional space in the mold cavity structure includes: Based on the normal projection path and the actual curvature distribution of each cavity wall in the three-dimensional space, the local rigid body displacement trend of each cavity wall in the disturbed area due to the indexing trajectory drift is determined. Based on the local rigid body displacement trend and the structural connection constraint information between adjacent cavity units in the mold cavity structure, the boundary displacement transmission effect of each cavity unit in the disturbed area is determined. Based on the boundary displacement transmission effect and the geometric continuity characteristics of the mold cavity structure, the spatial displacement vectors of each local area of ​​the mold cavity caused by the indexing trajectory drift in the current molding cycle are determined. The local spatial displacement field is determined based on the relationship between the spatial displacement vector of each local region and the topological coverage of the mold cavity structure in three-dimensional space.

4. The online compensation method for mold wear in precision plastic parts production according to claim 1, characterized in that, The steps for determining the distribution of the flow resistance variation include: Based on the local spatial displacement field, the actual position offset vector of each cavity wall in the mold cavity in three-dimensional space is determined, and based on the spatial relative relationship between the actual position offset vector and the standard filling path in the cavity, the actual contact area between the plastic melt and each offset cavity wall during the filling process is determined. Based on the actual contact area and the mainstream direction of the plastic melt during the filling process, the local flow cross-sectional state of the plastic melt at each contact area is determined. Based on the local flow cross-sectional state and the flow channel geometric continuity information that the plastic melt depends on when flowing in the cavity, the streamline disturbance characteristics of the plastic melt at each contact area are determined. Based on the streamline disturbance characteristics and the viscous shear stress characteristics between the plastic melt and the cavity wall during flow in the cavity, the distribution of flow resistance variation is determined.

5. The online compensation method for mold wear in precision plastic parts production according to claim 4, characterized in that, The determination of the flow resistance variation distribution based on the streamline disturbance characteristics and the viscous shear stress characteristics between the molten plastic and the cavity wall during flow within the cavity includes: Based on the streamline disturbance characteristics and the viscous shear stress characteristics between the plastic melt and the cavity wall when the plastic melt flows in the cavity, the trend of wall friction effect of the plastic melt at each contact area is determined. Based on the trend of the wall friction effect and the flow connectivity constraints between adjacent regions of the plastic melt on the filling path, the pressure gradient perturbation distribution of the plastic melt in each segment of the filling path is determined. Based on the pressure gradient disturbance distribution and the local flow channel cross-sectional geometry of the plastic melt in each contact area, the change in cross-sectional flow area of ​​the plastic melt due to wall offset in each contact area is determined. The distribution of flow resistance variation is determined based on the change in cross-sectional flow area and the requirement for continuous flow of the plastic melt along the filling path.

6. The online compensation method for mold wear in precision plastic parts production according to claim 1, characterized in that, The steps for determining the compensation driving force vector include: Based on the distribution of flow resistance changes, the local resistance enhancement regions at various positions along the filling path of the injection molding actuator during the filling process are determined, and based on the spatial correspondence between the local resistance enhancement regions and the screw advance direction of the injection molding actuator, the axial travel range compensated by the injection molding actuator during the advance process is determined. Based on the time series of the axial travel range and the angular displacement feedback signal of the servo motor rotor of the injection actuator, the driving phase range of the injection actuator corresponding to the local resistance enhancement region in the current molding cycle is determined. Based on the transmission characteristic curves of displacement and pressure corresponding to the hydraulic cylinder piston rod of the injection molding actuator in the driving phase interval, the trend of output pressure increment of the injection molding actuator maintaining the standard filling rate increase in the driving phase interval is determined. Based on the trend of the output pressure increment and the force-current conversion relationship corresponding to the drive unit of the injection molding actuator, the compensation drive force vector is determined.

7. The online compensation method for mold wear in precision plastic parts production according to claim 6, characterized in that, The determination of the compensated driving force vector based on the output pressure increment trend and the force-current conversion relationship corresponding to the driving unit of the injection molding actuator includes: Based on the trend of the output pressure increment and the conversion relationship, the direction of the change in the drive current of the injection molding actuator's drive unit within the drive phase interval is determined. Based on the direction of the change in the driving current and the main driving force output channel in the multi-axis coordinated drive of the injection molding actuator, the timing sequence of the main driving force action of the injection molding actuator in the current molding cycle is determined. Based on the timing of the main driving force and the spatial orientation of the reference driving force vector of the injection actuator in the standard filling stage, the direction of the compensation driving force superimposed by the injection actuator in the current molding cycle is determined. The compensation driving force vector is determined based on the direction of the compensation driving force and the boundary of the actual driving force output capability of the injection molding actuator within the driving phase interval.

8. An online wear compensation device for molds used in the production of precision plastic parts, characterized in that, The method for online compensation of mold wear for precision plastic parts production, as described in any one of claims 1 to 7, is applied; the online compensation device for mold wear for precision plastic parts production comprises: The trajectory drift analysis module is used to obtain the actual indexing termination position of the mold indexing mechanism in the current molding cycle based on the position sensor signal after each demolding during the continuous production of precision plastic parts, and to determine the drift amount of the mold indexing trajectory in the current molding cycle based on the actual indexing termination position and the preset standard indexing termination position. The spatial displacement analysis module is used to determine the local spatial displacement field of the mold cavity caused by the indexing trajectory drift in the current molding cycle based on the geometric mapping relationship between the drift amount and the mold cavity structure. The flow resistance analysis module is used to determine the distribution of flow resistance changes experienced by the plastic melt in the current molding cycle based on the spatial coupling relationship between the local spatial displacement field and the filling path of the plastic melt in the cavity. The error compensation module is used to determine the compensation driving force vector applied by the injection molding actuator in the current molding cycle based on the flow resistance change distribution and the driving response characteristics of the injection molding actuator, and to control the injection molding actuator to implement driving force output in the next molding cycle based on the compensation driving force vector.

9. An electronic device, comprising: Memory, used to store computer software programs; A processor for reading and executing the computer software program, characterized in that, when the processor executes the computer software program, it implements the online compensation method for mold wear in precision plastic parts production as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, wherein a computer software program is stored therein, characterized in that, When the computer software program is executed by the processor, it implements the online compensation method for mold wear in the production of precision plastic parts as described in any one of claims 1 to 7.

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