Numerical control multi-axis interpolation control method, device and electronic equipment for ordinary lathe

Abstract

The application provides a multi-axis interpolation control method, device and electronic equipment for numerical control of a general lathe, and the method comprises the following steps: firstly, acquiring machine tool shafting configuration data and process data, and establishing a synchronous proportional relationship of a main shaft and a longitudinal shaft and a slot sequence starting angle offset; secondly, generating a reference control sequence of longitudinal and transverse feed shafts by taking the main shaft phase as a driving source; then, calculating the local boundary activity of the transverse feed shaft, and generating an execution control sequence by using a second-order difference to correct the reference sequence; finally, performing weighted correction on a tracking deviation according to the slot execution progress, and outputting a final instruction to control the movement of the machine tool. Through the multi-axis interpolation and dynamic correction mechanism, the application solves the problems of dependence on a hanging wheel, large error accumulation and poor slot quality when the general lathe processes a spiral slot of a roller, and realizes high-precision flexible processing of low-cost equipment.

Description

Technical Field

[0001] This invention belongs to the field of machine tool control technology, and particularly relates to a method, device and electronic equipment for CNC multi-axis interpolation control of ordinary lathes. Background Technology

[0002] Ordinary lathes have long been widely used in the manufacturing, repair, and refurbishment of roller parts, especially rubber processing rollers, due to their mature structure, large number of machines in use, and low purchase and maintenance costs. However, as rubber processing equipment places higher demands on the groove accuracy, lead range, number of heads, processing length, and processing efficiency of the spiral grooves on the roller surface, the method of relying solely on the original mechanical transmission chain and manual operation of ordinary lathes is becoming increasingly difficult to meet actual production needs.

[0003] Existing, relatively similar technical approaches fall into two categories. One involves continuing to use conventional lathes with changeover wheels, indexing, and manual tool retraction to machine helical grooves. While this method has lower equipment barriers, it heavily relies on operator experience in areas such as lead conversion, indexing value determination, changeover wheel assembly, and clamping reversal. Slight errors in calculation and operation can lead to inaccurate groove spacing, phase misalignment, or even scrapping of the entire part. Furthermore, the number of changeover wheels, gear ratio, and installation space limit the range of machinable leads, making it difficult to adapt to the flexible production requirements of rollers with different diameters, numbers of heads, and rotation directions. The other approach utilizes dedicated CNC milling and turning composite equipment or higher-configuration multi-axis CNC machine tools. While these machines offer higher levels of automation and machining capabilities, they require significant initial investment and have high replacement costs. They are also incompatible with existing conventional lathes, making them less economically viable for companies primarily engaged in repair, refurbishment, and small-batch production of various specifications. Especially in the machining of spiral grooves on rollers, spindle rotation, longitudinal feed, transverse cutting and retraction, indexing and reversal, and groove connection do not occur in isolation, but need to be continuously coordinated according to the established geometric relationship and process sequence. Transmission error, clearance error, cumulative position error, or manual connection error in any link will be continuously amplified in long stroke, multi-groove, and multi-head machining, ultimately manifesting as discontinuous spiral lines, inconsistent groove depths, uneven groove transitions, accumulated indexing errors, excessive auxiliary time, and poor machining consistency. Summary of the Invention

[0004] This invention discloses a CNC multi-axis interpolation control method, device, and electronic equipment for ordinary lathes, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the first aspect of the present invention provides a CNC multi-axis interpolation control method for a conventional lathe, applicable to a CNC system of a conventional lathe including a spindle rotation axis, a longitudinal feed axis, and a transverse feed axis. The method includes the following steps: Obtain machine tool axis configuration data and process data for roller spiral groove machining task; determine the synchronization ratio between spindle rotation axis and longitudinal feed axis based on the machine tool axis configuration data; and determine the starting angle offset corresponding to each spiral groove based on the number of heads in the process data. Based on the synchronization ratio and the starting angle offset, the cumulative angular position of the spindle rotation axis is used as the driving variable to generate the reference position sequence of the longitudinal feed axis and the reference position sequence of the transverse feed axis. The position increment ratio of adjacent cycles in the reference position sequence of the transverse feed axis is calculated to obtain the local boundary activity. The local boundary activity is then used to perform second-order difference correction on the reference position sequences of the longitudinal feed axis and the transverse feed axis to generate the execution control sequence. During the machining process, the in-slot execution progress is calculated based on the cumulative angular position of the current spindle rotation axis. The tracking deviation of the previous interpolation cycle is weighted based on the in-slot execution progress, and the execution control sequence is corrected using the weighted tracking deviation to obtain the final execution command to control the movement of the longitudinal feed axis and the transverse feed axis.

[0006] Further, determining the synchronization ratio between the spindle rotation axis and the longitudinal feed axis based on the machine tool axis configuration data includes: Obtain the lead parameters and the number of encoder pulses per revolution corresponding to the spindle rotation axis from the process data; Calculate the ratio of the lead parameter to the number of pulses per revolution of the encoder, and use the ratio as the synchronization ratio to characterize the displacement of the longitudinal feed axis when the spindle rotation axis increases by one counting unit.

[0007] Further, the step of generating the reference position sequence for the longitudinal feed axis and the reference position sequence for the transverse feed axis based on the synchronization ratio and the starting angle offset includes: In each interpolation cycle, the real-time cumulative count value of the spindle rotation axis is read, and the target position of the longitudinal feed axis is calculated by combining the starting angle offset and the synchronization ratio. Based on the normalized progress of the current interpolation cycle within the current spiral groove, the target position of the transverse feed axis is calculated using a cubic polynomial interpolation function, so that the transverse feed axis forms a smooth entry and exit trajectory in the entry and exit sections of the spiral groove.

[0008] Further, the second-order difference correction of the reference position sequence of the longitudinal feed axis and the reference position sequence of the transverse feed axis using the local boundary activity includes: For the current interpolation cycle, read the reference positions of the longitudinal feed axis and the transverse feed axis for three consecutive cycles; Calculate the second difference between the current position and the positions of the previous two cycles; The correction amount is obtained by multiplying the second-order difference value by the local boundary activity, and then subtracting the correction amount from the reference position of the current cycle to obtain the corrected execution control sequence.

[0009] Further, the step of calculating the ratio of position increments between adjacent cycles in the reference position sequence of the lateral feed axis to obtain the local boundary activity includes: Calculate the absolute value of the difference between the reference position of the lateral feed axis in the current cycle and that in the previous cycle as the numerator; The denominator is the sum of the absolute value of the difference between the reference position of the longitudinal feed axis in the current cycle and the previous cycle and a preset small positive number. Calculate the ratio of the numerator to the denominator, which is used to characterize whether the current machining point is in the transition zone of the groove boundary or the stable zone of the main cutting.

[0010] Furthermore, the weighting of the tracking deviation of the previous interpolation cycle based on the execution progress within the slot includes: The difference between the actual execution position vector of the previous interpolation cycle and the target execution vector of the previous interpolation cycle is obtained as the tracking error; The execution progress within the slot is processed using a quadratic weight function, such that the weight increases when the execution progress within the slot approaches the endpoint of the interval, and decreases when the execution progress within the slot approaches the midpoint of the interval. Multiplying the tracking deviation by the processed weights yields a correction vector used to compensate for the dynamic lag during the slot entry and exit phases.

[0011] Furthermore, the method also includes: When the cumulative angular position of the main spindle rotation axis advances to the starting angular offset range corresponding to the next spiral groove, it automatically switches to the starting angular offset of the next spiral groove, and uses the same groove execution progress calculation logic and boundary reinforcement execution strategy to complete the continuous processing of all spiral grooves on the entire roller.

[0012] In a second aspect of the present invention, a CNC multi-axis interpolation control system for a conventional lathe is provided. The system includes: a data configuration module for acquiring machine tool axis configuration data and process data for the machining task of the roller spiral groove, determining the synchronous ratio between the spindle rotation axis and the longitudinal feed axis, and the starting angle offset corresponding to each spiral groove. The reference generation module is used to generate a reference position sequence for the longitudinal feed axis and a reference position sequence for the transverse feed axis based on the synchronization ratio and the starting angle offset, with the cumulative angular position of the spindle rotation axis as the driving variable. The trajectory correction module is used to calculate the local boundary activity of the reference position sequence of the lateral feed axis, and use the local boundary activity to perform second-order difference correction on the reference position sequence to generate an execution control sequence. The execution control module is used to weight the tracking deviation of the previous interpolation cycle according to the execution progress in the slot, and use the weighted tracking deviation to correct the execution control sequence, and output the final execution command to control the machine tool movement.

[0013] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of the CNC multi-axis interpolation control method for a conventional lathe as described above.

[0014] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the steps of the conventional lathe CNC multi-axis interpolation control method as described above.

[0015] The beneficial technical effects of the present invention are at least as follows: To address the aforementioned problems, this invention provides a CNC multi-axis interpolation control method, device, and electronic equipment for conventional lathes. It unifies workpiece geometry requirements, groove sequence relationships, and machine tool axis capabilities into directly callable control inputs, which are then transformed into a multi-axis interpolation reference control process based on the spindle phase. This eliminates the need for manual disassembly and repeated calculations for spindle rotation, longitudinal feed, transverse infeed, and tool retraction; instead, it automatically forms a continuous and systematic control sequence according to the current groove phase relationship and machining range. Addressing common issues after conventional lathe modification such as groove impact, abrupt trajectory changes in boundary sections, long-stroke cumulative errors, and unstable inter-groove switching, this invention further constructs an execution control correction mechanism around the boundary activity sections and in-groove execution progress in the reference control process. This enables the control system to perform targeted local shaping and execution compensation for longitudinal feed and transverse infeed retraction while maintaining stable lead and groove sequence relationships, thereby improving trajectory consistency, groove smoothness, and overall machining accuracy during multi-groove, multi-head, and anti-directional spiral groove machining. This invention enables conventional lathes to maintain their original cost and equipment advantages while possessing better flexible machining capabilities, lower reliance on manual labor, and higher machining stability. Attached Figure Description

[0016] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0017] Figure 1 This is a flowchart of the CNC multi-axis interpolation control method for ordinary lathes according to the present invention.

[0018] Figure 2 This is a framework diagram of the CNC multi-axis interpolation control system for a conventional lathe according to the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In one or more embodiments, such as Figure 1 As shown, a CNC multi-axis interpolation control method for a conventional lathe is disclosed, the method comprising the following: S1: Obtain machine tool axis configuration data and process data for roller spiral groove machining task; determine the synchronization ratio between spindle rotation axis and longitudinal feed axis based on the machine tool axis configuration data; and determine the starting angle offset corresponding to each spiral groove based on the number of heads in the process data.

[0021] Specifically, in this step, the control program first loads the machine tool axis configuration data from the CNC system of a conventional lathe, then receives the process data for this roller spiral groove machining task, and organizes the two into a control input set that can be directly called upon for subsequent multi-axis interpolation motion control. The machine tool axis configuration data comes from the CNC system parameter area and servo driver registers: the cumulative angular position information of the spindle rotation axis is provided by the incremental encoder installed at the spindle end. The encoder output pulses enter the CNC system through the high-speed counting interface, forming a cumulative count value in the system variable area; the positions of the longitudinal feed axis and the transverse feed axis are provided by the position registers of their respective servo drivers. The control program reads the current position through the drive bus and writes it into the control variables; the definition of each axis direction, upper and lower limits of travel, control resolution, etc., come from the parameter table after the machine tool's CNC retrofit is completed. These parameters are loaded by the system once before machining begins. The process data is input by the operator in the parameter interface, including the roller outer diameter, effective length, lead, number of heads, direction of rotation, number of slots, slot depth, and machining start and end positions. After these data enter the designated variable area, they, together with the axis configuration data, constitute the original input for this step. After entering the control processing process, the system uniformly converts the cumulative count of the spindle encoder into the expression of the spindle cumulative angular position, uniformly converts the longitudinal servo position into the expression of the longitudinal cumulative displacement, and uniformly converts the transverse servo position into the expression of the radial position. After this processing, the three original signals from different sources are normalized into three basic quantities under the same control semantics, laying the foundation for establishing the synchronization relationship between the spindle rotation axis and the longitudinal feed axis, as well as the cutting state switching relationship of the transverse feed axis.

[0022] The direct physical basis for the formation of the helical groove comes from the classical helical motion geometry, namely, that for every full rotation of the workpiece, the tool advances one lead along the axial direction. Therefore, this step directly establishes the synchronization ratio between the cumulative angular position of the spindle and the cumulative longitudinal displacement during the input processing stage. This relationship originates from the basic kinematic expression of the cylindrical helix. After discretizing "one full rotation corresponds to one lead" to the encoder counting scale, the longitudinal displacement ratio corresponding to each additional count of the spindle can be obtained. The control program calculates the synchronization ratio relationship according to the following formula: ; in, The longitudinal displacement ratio corresponding to each additional encoder count in the cumulative angular position of the main spindle is calculated by the control program. For the guide, the operator enters the information based on the workpiece drawing or process card; The total encoder count corresponding to one full revolution of the spindle is given by the spindle encoder configuration parameters. The left side of the formula represents the ratio of displacement to count, and the right side is calculated by dividing one lead by the number of counts corresponding to one full revolution. Essentially, it discretizes the classic helical "one revolution, one lead" relationship according to the encoder resolution, thus the calculation logic is consistent with the laws of mechanical motion. Taking a typical set of inputs as an example, if the lead... The total count corresponds to one full revolution of the spindle encoder. Then the control program calculates... This result indicates that as the cumulative angular position of the principal axis increases... When counting, the longitudinal feed axis increases accordingly. The displacement; if the spindle cumulatively increases If the count is 1, the longitudinal feed axis will increase accordingly. The displacement. In this way, when generating the multi-axis interpolation motion control reference control scheme, it is only necessary to call the already formed synchronous proportional relationship, and there is no need to recalculate the lead and spindle synchronization relationship.

[0023] In multi-slot, multi-head spiral groove scenarios, synchronization ratio alone is insufficient to support subsequent control, because the starting spindle angle position for each slot needs to be clearly defined during the input stage. The calculation in this step is based on the classic principle of equal circumference: if multiple starting heads exist on the same cross-section, they are distributed at equal angles within a full circumference of the spindle; in the encoder counting space, this equal angular distribution can be directly represented as an equal counting interval distribution. Based on this principle, the system calculates the corresponding starting angle offset for each slot according to its slot number, expressed as: ; in, For the first The spindle starting count offset corresponding to the slot is calculated by the control program and written into the slot sequence array; The slot number is automatically generated by the control program in sequence according to the number of slots. The total encoder count corresponding to the spindle completing one full revolution is taken from the encoder configuration parameters; The number of heads is entered by the operator according to process requirements. This formula indicates that the slot sequence is first generated in order of slot number, and then each slot is cyclically mapped to the corresponding starting head, so that slots on the same head inherit the same starting phase. Continuing with the above typical input, if the number of heads... Then the odd number of slots corresponds to Even-numbered slots correspond to ;If the number of heads The initial offset of each slot is as follows: , , , The slots are allocated sequentially and cyclically. In the actual program implementation, the system first generates a slot number sequence based on the number of slots, and then writes the corresponding slot number to each slot according to the above formula. In this way, when subsequent steps generate multi-axis interpolation motion control reference control schemes in slot number order, the system reads... This always indicates the starting count offset corresponding to the current groove. Simultaneously, the transverse feed axis defines the cutting state around the groove depth and the safety position: the groove depth is written to the control variable via the operation interface, and the safety position is taken from the transverse axis configuration parameters. The program binds these two to the status flags of the cutting and retraction phases, respectively. Thus, the control input set... This includes the control quantities expressed in a unified manner across the three axes, and the synchronization ratio between the main axis and the longitudinal axis. The starting angle offset corresponding to the multi-head distribution And the cutting state definition of the transverse feed axis. Subsequent steps can be directly based on... A multi-axis interpolation motion control reference control scheme is generated for the input, and the relevant lead relationship, split relationship and cutting state relationship have been clearly written in this step.

[0024] S2: Based on the synchronization ratio and the starting angle offset, using the cumulative angular position of the spindle rotation axis as the driving variable, generate the reference position sequence of the longitudinal feed axis and the reference position sequence of the transverse feed axis.

[0025] Specifically, in this step, the control input set formed in step one is used directly. As input, the already structured expressions for the principal axis cumulative angular position, longitudinal cumulative displacement, lateral position, and synchronization ratio are used. Slot sequence start angle offset The cutting state definition is expanded into a continuous multi-axis interpolation motion control baseline control scheme. The core of this expansion process is to unify the kinematic relationship of the classical cylindrical helix with the encoder counting system already discretized in step one, making the spindle rotation axis the sole driving variable for the entire interpolation process, and generating target control quantities for the longitudinal and transverse feed axes in each interpolation cycle. Since the proportional conversion between lead and encoder count, as well as the pre-calculation of slot sequence and starting angle offset, have already been completed in step one, this step directly inherits these results, transforming them into a continuous control sequence advancing according to the spindle phase. This avoids performing lead conversion or indexing derivation again in the control stage, ensuring consistency of the control logic at the execution layer.

[0026] The fundamental relationship in helical groove machining originates from the parametric equation of a cylindrical helix in spatial geometry, which is essentially a linear proportional relationship between angular and axial displacement. In a continuous form, this relationship can be expressed as axial displacement being proportional to angular displacement. In this scheme, since the spindle angular displacement is obtained through discrete counting by an encoder, it is necessary to discretize the continuous relationship into a counting-based expression. Step one has already given the proportional relationship. This ratio comes from the lead. The encoder count corresponds to one full revolution of the spindle. The ratio. This step introduces the slot sequence start angle offset based on this. The overall spiral trajectory is decomposed into several sub-trajectories that unfold from different phase starting points, allowing each slot to be generated independently under the same control framework. This yields the... The formula for calculating the target position of the longitudinal feed axis under one interpolation cycle is as follows: ; in, For the first The target position of the longitudinal feed axis within one interpolation cycle is calculated by the control program and written into the position instruction register of the longitudinal servo driver. This is the axial starting position of the current groove. This value comes from the machining start point parameter input in step one and is in the control input set. Save in; The proportionality coefficient between the spindle count and the longitudinal displacement is determined by step one based on the lead. and encoder counting Calculated; For the first The cumulative count value of the spindle read in each interpolation cycle is provided in real time by the spindle encoder through the high-speed counting interface; This is the starting angular offset corresponding to the current slot number, generated in step one based on the number of heads and slot sequence, and written into an array structure. This expression is a discrete form obtained by introducing discrete counting variables and slot sequence offsets, based on the classic helix's "axial displacement is proportional to angular displacement" principle. Both sides represent axial position quantities, consistent with practical control meaning. The specific calculation process will be explained below. When the lead ratio has been determined in step one... Current slot start point Current slot offset Spindle cumulative count At that time, it can be obtained When the spindle continues to rotate to Updated to By updating the calculation results cycle by cycle, the longitudinal feed axis remains synchronized with the spindle rotation throughout the entire machining process, thus forming a spatial helical trajectory.

[0027] Regarding transverse feed axis control, this step, based on the groove depth and safety position defined in step one, and combined with the current groove's advance progress throughout the entire axial machining range, constructs a smooth entry, stable cutting, and smooth retraction process. This process is based on the classical cubic polynomial interpolation function, whose original form comes from curve interpolation theory, used to generate a transition curve with continuous first derivatives under given boundary conditions. This step first determines the axial starting point of the current groove. Axial endpoint Synchronization ratio and starting angle offset Calculate the cumulative count at the end of the current slot. To satisfy The normalized progress within the current slot during the current interpolation cycle is then defined as... And generate the target position of the transverse feed axis according to the following formula: ; in, For the first The target position of the transverse feed axis within one interpolation cycle is written to the position instruction register of the transverse servo drive. The lateral safety position is derived from the machine tool axis configuration parameters in step one; The transverse cutting position is determined by the groove depth parameter input in step one; This represents the normalized progress within the current slot during the current interpolation cycle, calculated from the current spindle's cumulative count. Current slot starting angle offset Cumulative count at the end of the current slot Calculated; This represents the normalized proportion of the entry and retraction sections within the entire groove. This value is pre-calculated and written into the control variables during program initialization based on the groove depth and machining cycle time. The expression originates from a cubic interpolation function. Its characteristic is that and When the derivative is zero, this step replaces the interpolation variable with the normalized progress within the current slot, allowing the transverse feed axis to smoothly enter the slot at the beginning, maintain stable cutting in the middle, and smoothly retract at the end. For example, when... , , , , At that time, if the current spindle count ,but ,thereby Substituting, we can get If the current spindle count ,but ,at this time If the current spindle count ,but ,have Substituting them in yields the same result. Through this calculation process, the transverse feed axis forms a continuously varying radial motion trajectory at the inlet and outlet of the helical groove, while maintaining a constant cutting depth in the middle of the groove.

[0028] Driven by the two core calculation relationships mentioned above, the control program synchronously generates target control quantities for the spindle, longitudinal, and transverse axes in each interpolation cycle, and advances the machining process according to the slot sequence array. When the cumulative spindle count exceeds the machining range corresponding to the current slot, the program automatically switches to the next slot and loads a new starting angle offset. This allows subsequent control cycles to continue along the same computational logic. The resulting baseline control scheme manifests in the control system as a multi-axis target position sequence arranged according to the interpolation cycle. The principal axis phase serves as a unified driving variable, the longitudinal feed axis advances synchronously according to a proportional relationship, and the lateral feed axis achieves smooth entry and exit according to a phase window. This scheme directly inherits the control input set formed in step one. Furthermore, the lead relationship, slot sequence relationship, and cutting state are transformed into a continuous control process, enabling multi-axis interpolation motion control to have a clear calculation path and executability under the CNC conditions of ordinary lathes.

[0029] S3: Calculate the ratio of position increments of adjacent cycles in the reference position sequence of the transverse feed axis to obtain the local boundary activity. Use the local boundary activity to perform second-order difference correction on the reference position sequences of the longitudinal feed axis and the transverse feed axis to generate the execution control sequence.

[0030] Specifically, step three directly reads the multi-axis interpolation motion control reference control scheme generated in step two, and extracts the main axis cumulative count sequence arranged according to the interpolation period. Vertical target location sequence Horizontal target position sequence Slot sequence start angle offset and the current slot end cumulative count This serves as the complete input for generating the execution control. Step two has already processed the control input set formed in step one. The control trajectory is expanded to match the geometric relationship of the helical groove. Therefore, this step does not reorganize the lead, groove sequence, and cutting state. Instead, it focuses on the three positional segments that most easily affect the actual machining quality in a CNC lathe scenario: the entry segment, the retraction segment, and the inter-groove switching segment. The common characteristic here is that the lateral target position changes rapidly, while the longitudinal target position continues to advance. Therefore, the tool is most prone to asynchronous actual feed, local impact at the groove opening, and uneven inter-groove transitions in these segments. Based on this, this step extracts "local boundary activity" within the reference control scheme and uses it as the sole weight for the correction intensity in the execution control. The correction effect is limited to segments with high boundary activity, ensuring that the main cutting stability zone maintains the ideal helical relationship established in step two. The original basis of this approach comes from the proportional measurement method of local change intensity in discrete signal processing. In this embodiment, it is rewritten as the ratio of adjacent cycle position increments suitable for the helical groove machining scenario, used to identify the critical stages of the tool's radial entry and exit from the workpiece. The control program in step... The local boundary activity is calculated within one interpolation cycle using the following formula: ; in, Indicates the first The local boundary activity of each interpolation cycle is calculated in real time by the CNC system and written into the cache register in the current interpolation cycle; and These represent the current and previous cycle horizontal target positions generated in step two, respectively, and are read from the horizontal reference control sequence according to the current slot number and the current cycle index. and These represent the current and previous cycle longitudinal target positions generated in step two, respectively, and are read from the longitudinal reference control sequence using the same index. This represents a preset, small positive number, written into the control parameter area to ensure the denominator remains valid. The derivation logic is as follows: within the stable zone of the main cutting of the spiral groove, the lateral position hardly changes, while the longitudinal position continuously advances. Therefore, the numerator is very small, and the denominator mainly consists of the longitudinal increment. Naturally close to zero; within the cutting or retraction segment, the lateral position changes significantly, and the molecules rapidly increase in size. Automatically approaching point one, thus identifying these segments from the entire slot trajectory. Taking three consecutive points in a set of debugging records as an example, if two adjacent cycles of the current slot satisfy... , , , , Then there is , Thus obtain This indicates that the control point is located in a clear boundary transition zone; if another adjacent period satisfies , , , ,but This corresponds to the main cutting stability zone. Therefore, the output of step two is... and In this step, the sequence is automatically divided into "boundary sensitive points" and "stable cutting points," which provides a clear calculation basis for local corrections in the execution control scheme.

[0031] In obtaining Subsequently, the control program synchronously applies second-order difference corrections to the longitudinal and lateral target position sequences generated in step two, forming the corrected sequence in the execution control scheme. This correction relationship originates from the second-order finite difference shaping method in numerical analysis. The original idea is to characterize the local curvature using the second-order difference between the current point and the preceding and following points, and then suppress local abrupt changes through weights; here, this idea is rewritten for the multi-axis interpolation scenario of a spiral groove, using the same weights. Simultaneous action is applied to both longitudinal and transverse control variables, ensuring continuous tool trajectory during slot entry, slot exit, and inter-slot phase switching, while maintaining the spindle phase and lead advance relationship established in step two. The control program is generated according to the following formula: Execution control points for each interpolation cycle: ; in, Indicates the first The longitudinal target position, corrected after one interpolation cycle, is calculated by the control program and written into the position instruction register of the longitudinal servo driver. Indicates the first The corrected lateral target position after one interpolation cycle is calculated by the control program and written into the position instruction register of the lateral servo drive. , , These are the three consecutive longitudinal target positions generated in step two, which are read sequentially from the reference control sequence corresponding to the current slot; , , These are three consecutive horizontal target positions generated in step two, and they are read in the same way. The local boundary activity is obtained from the previous equation. The derivation logic of this equation is: the term in parentheses is the second-order difference between the current position and the positions of the previous two cycles, which describes the local bending intensity of the reference trajectory at the current point; when When the value is very small, it indicates that the current region is in the main cutting stable zone, and the control point is basically equal to the reference control point, ensuring that the lead and groove relationship are not disturbed by additional factors; when... When the value increases, it indicates that the current position is in the cutting, retraction, or slot switching zone. The second-order difference term will be amplified and subtracted from the reference control point, thereby suppressing local abrupt changes and making the execution trajectory smoother under CNC conditions on a conventional lathe. The calculation process is further illustrated using a set of continuous debugging data: assuming the current three cycles satisfy... , , , , , And from the previous equation, we get Then the longitudinal second difference is divided into The transverse second difference is divided into Based on this, we can obtain , This result indicates that in the section where the tool rapidly enters the workpiece radially, the control scheme slightly converges the longitudinal feed while allowing the transverse feed to approach the cutting position more smoothly, thereby reducing local impact at the notch; if the current position is in the main cutting stability zone, the previous calculation yields... Then there is directly , The baseline spiral relationship generated in step two is completely preserved.

[0032] The sequence organization at the execution level still follows the slot sequence structure established in step two. The CNC system offsets the current slot by the starting angle corresponding to the current slot. For indexing, read continuously within the same slot , , And calculate , and When the spindle's cumulative count advances to the starting angle offset range corresponding to the next slot, the control program switches to the next slot buffer area, according to the new slot number and new... The same correction process is restarted. The resulting execution control scheme consists of five parts: the first part is the main axis cumulative count sequence that maintains the phase-driven relationship from step two. The second part is the longitudinal position sequence after local boundary activity weighting correction. The third part is the horizontal position sequence, which has also been adjusted with the same weights. The fourth part is the starting angle offset that follows the slot sequence organization relationship. The fifth part is the cumulative count at the end of the current slot. The entire process transforms the ideal multi-axis interpolation geometry established in step two into a control sequence suitable for the actual execution of CNC machining on ordinary lathes. This enables the machining of roller spiral grooves to simultaneously ensure groove shape accuracy, groove smoothness, and groove continuity stability under conditions of long stroke, multiple grooves, and multiple head switching.

[0033] S4: During the machining process, the in-slot execution progress is calculated based on the cumulative angular position of the current spindle rotation axis. The tracking deviation of the previous interpolation cycle is weighted based on the in-slot execution progress, and the execution control sequence is corrected using the weighted tracking deviation to obtain the final execution command to control the movement of the longitudinal feed axis and the transverse feed axis.

[0034] Specifically, step four directly reads the execution control scheme generated in step three, and uses the spindle cumulative count sequence arranged according to the interpolation period. Corrected longitudinal target position sequence Corrected lateral target position sequence and the starting angle offset of the slot sequence organization This serves as the complete execution basis for the current machining cycle. Step one has already organized the machine tool axis capabilities and the roller spiral groove machining task into a control input set. Step two has expanded the control input set into a reference control scheme that satisfies the helical geometry. Step three further transforms the reference control scheme into an execution control scheme more suitable for the actual operation of a conventional lathe CNC system. Therefore, this step is responsible for stably implementing the control logic formed in the previous three steps onto the physical device, ensuring that the spindle rotation axis, longitudinal feed axis, and transverse feed axis complete the entry, main cutting, retraction, and slot switching according to the predetermined phase relationship in each interpolation cycle. During execution, the CNC system first reads the corresponding starting angle offset based on the current slot number. Then retrieve the current cycle corresponding to the execution control scheme. , and These target values ​​are then loaded into the interpolation buffer. The spindle encoder continuously provides cumulative counts, while the longitudinal and transverse servo drives continuously return their respective actual execution positions. The control program aligns these feedback quantities with the target sequence in the execution control scheme cycle by cycle, ensuring that each slot completes independent and continuous execution within its own phase interval.

[0035] To ensure that the execution process maintains the geometric relationships established in step three while adapting to the dynamic stability requirements of slot entry, exit, and slot switching in a conventional lathe CNC scenario, this step first constructs an in-slot execution progress quantity within the current slot. The original source of this quantity is the linear normalization concept in analytical geometry, which maps the current position within an interval to a dimensionless progress value between zero and one. In this scheme, it is applied to the spindle cumulative count interval corresponding to the current slot, ensuring that subsequent execution corrections always revolve around the position within the current slot without interfering with cross-slot movements. The control program calculates the [further details omitted]. The execution progress of each interpolation cycle within the current slot: ; in, Indicates the first The execution progress of each interpolation cycle within the current slot is calculated in real time by the control program and stored in the current cycle cache; This indicates the cumulative count value returned by the spindle encoder in the current cycle, which is acquired by the spindle encoder via the high-speed counting interface; This indicates the starting angle offset of the current slot, which comes from the slot sequence organization result used in step three. This represents the cumulative count value at the end of the execution control scheme for the current slot. This value is directly given by the end count of the current slot execution sequence generated in step three. The derivation of this formula involves dividing the current slot's counting interval... Perform linear scaling to make the starting point correspond The endpoint corresponds to The relative position within the interval corresponding to any execution point in the middle. This is explained in detail with a specific calculation process, if the starting angle of the current slot is offset... The cumulative count at the end of this slot Current spindle cumulative count Then we can obtain This indicates that the current control point is located in the area preceding the start of the slot; if the spindle cumulative count advances to... ,but This corresponds to the middle region of the current slot; if the spindle's cumulative count advances to... ,but This corresponds to the end region of the slot. Through this progress amount, the execution control scheme output in step three is further organized into the "slot-sensitive area" and the "slot-stable area" in this step, providing a clear phase position basis for execution layer correction.

[0036] In obtaining Subsequently, the control program applies an in-groove phase-weighted execution correction to the corrected position sequence output from step three, forming the final execution command actually issued to the servo drive in this cycle. This correction relationship originates from the property of the classical quadratic weight function, which takes a large value at both ends of the interval and a small value in the middle of the interval. Its original application is commonly seen in interval weighting and boundary reinforcement. In this scheme, it is combined with the tracking deviation of the previous cycle to construct an in-groove boundary reinforcement execution strategy for CNC spiral groove machining on ordinary lathes. The reason for this design is that the groove entry and exit stages are most sensitive to instantaneous execution deviations, while the main cutting stage in the groove emphasizes maintaining the ideal execution trajectory formed in step three. Therefore, the correction amount should be increased near the groove opening and decreased in the middle of the groove. The control program in the... Each interpolation cycle generates the final execution instruction vector according to the following formula: ; in, Indicates the first The execution command vector ultimately sent to the servo driver in each interpolation cycle contains the vertical and horizontal execution positions of the current cycle. This indicates the generation of the third step. The control vector is executed every interpolation cycle, and it contains the current cycle's control vector. and It is directly read by the execution control scheme; This represents the actual execution position vector of the previous interpolation cycle. It contains the actual longitudinal position fed back by the longitudinal servo driver and the actual lateral position fed back by the lateral servo driver in the previous cycle. The control program reads this in real time through the driver communication interface. This indicates that the execution control vector generated in step three for the previous interpolation cycle is directly read from the cache of the previous cycle of the execution control scheme. The in-slot execution progress is calculated using the previous formula. The derivation logic of this formula is as follows: first, the difference between the actual execution position vector of the previous cycle and the target execution vector of the previous cycle represents the current machine tool's tracking deviation at the execution layer; then... The deviation is weighted by the in-slot position. Because when near or close to At that time, the weight is close to This indicates that the area is in the slot entry or exit zone, requiring stronger absorption of the execution deviation from the previous cycle; when At that time, the weight is This indicates that the cutting is in a stable cutting region within the groove. At this point, the final executed command maintains the execution control vector output in step three, maximizing the geometric accuracy of the central part of the helical groove. A specific calculation example is as follows: If the current groove satisfies... , , Then from the previous equation, we get And thus If step three gives the execution control vector in the current cycle The corresponding vertical and horizontal positions are respectively and The actual execution position vector of the previous cycle The corresponding positions are respectively and The control vector was executed in the previous cycle. The corresponding positions are respectively and Then the tracking deviation vector of the previous cycle is Multiply by weight The correction vector is then obtained. Therefore, the final instruction vector executed in this cycle is This result indicates that in the initial region of the slot, the longitudinal execution position is slightly retracted and the transverse execution position is slightly slowed down, thereby reducing the local impact caused by machine tool lag when the tool enters the workpiece. If the current spindle cumulative count is in the middle of the slot, making If the weighting coefficient is zero, the final execution instruction vector of this cycle is directly equal to the execution control vector output in step three, ensuring that the main cutting segment maintains a stable helical trajectory.

[0037] The control program executes the above calculation sequence in each interpolation cycle: first based on... and Calculate the current execution progress within the slot, and then generate the final execution instruction vector based on the execution progress and the tracking deviation of the previous cycle. Then, the longitudinal and transverse execution positions are written to the corresponding servo driver's position instruction register, while the current cumulative count and current slot number of the spindle are stored in the interpolation buffer. As the spindle continues to rotate, when... When entering the starting angle offset range corresponding to the next slot, the control program switches to the next group. and The same in-slot progress calculation and boundary reinforcement execution strategy are used to complete the control of the next slot. Thus, the control input set formed in step one... The baseline control scheme formed in step two and the execution control scheme formed in step three are fully implemented in this step as actual multi-axis coordinated motion on the CNC system of a conventional lathe, ultimately completing the continuous machining of the entire roller spiral groove. This process enhances execution stability in the groove opening area and maintains geometric accuracy in the groove middle area, ensuring consistency between the spiral groove lead and the branching relationship while adapting to the actual dynamic characteristics of the conventional lathe after CNC machining.

[0038] In one or more embodiments, such as Figure 2 As shown, a CNC multi-axis interpolation control system for a conventional lathe is disclosed, the system comprising: The data configuration module is used to acquire machine tool axis configuration data and process data for the roller spiral groove machining task, determine the synchronous ratio between the spindle rotation axis and the longitudinal feed axis, and the starting angle offset of each spiral groove. The reference generation module is used to generate a reference position sequence for the longitudinal feed axis and a reference position sequence for the transverse feed axis based on the synchronization ratio and the starting angle offset, with the cumulative angular position of the spindle rotation axis as the driving variable. The trajectory correction module is used to calculate the local boundary activity of the reference position sequence of the lateral feed axis, and use the local boundary activity to perform second-order difference correction on the reference position sequence to generate an execution control sequence. The execution control module is used to weight the tracking deviation of the previous interpolation cycle according to the execution progress in the slot, and use the weighted tracking deviation to correct the execution control sequence, and output the final execution command to control the machine tool movement.

[0039] It is worth noting that the specific workflow of the CNC multi-axis interpolation control system for ordinary lathes provided in this embodiment of the invention is the same as that of the CNC multi-axis interpolation control method for ordinary lathes described in the above embodiments, and will not be repeated here.

[0040] This invention also provides a CNC multi-axis interpolation control device for a conventional lathe, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the steps described in the above embodiments of the CNC multi-axis interpolation control method for a conventional lathe, for example... Figure 1 The steps S1 to S4 described above; or, when the processor executes the computer program, it implements the functions of each module in the above system embodiments.

[0041] For example, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the CNC multi-axis interpolation control device of the ordinary lathe.

[0042] The CNC multi-axis interpolation control device for a conventional lathe can be a desktop computer, laptop, handheld computer, or cloud server, etc. This device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the CNC multi-axis interpolation control device for a conventional lathe may also include input / output devices, network access devices, buses, etc.

[0043] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the conventional lathe's CNC multi-axis interpolation control equipment, connecting all parts of the equipment via various interfaces and lines.

[0044] The memory can be used to store the computer program and / or modules. The processor realizes various functions of the CNC multi-axis interpolation control device for the ordinary lathe by running or executing the computer program and / or modules stored in the memory and calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created according to the operation of the controller, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital card (SD card), flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0045] The modules integrated into the CNC multi-axis interpolation control equipment for ordinary lathes, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0046] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0047] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for CNC multi-axis interpolation control of a conventional lathe, characterized in that, The method, applied to a CNC system for a conventional lathe including a spindle rotary axis, a longitudinal feed axis, and a transverse feed axis, comprises the following steps: Obtain machine tool axis configuration data and process data for roller spiral groove machining task; determine the synchronization ratio between spindle rotation axis and longitudinal feed axis based on the machine tool axis configuration data; and determine the starting angle offset corresponding to each spiral groove based on the number of heads in the process data. Based on the synchronization ratio and the starting angle offset, the cumulative angular position of the spindle rotation axis is used as the driving variable to generate the reference position sequence of the longitudinal feed axis and the reference position sequence of the transverse feed axis. The position increment ratio of adjacent cycles in the reference position sequence of the transverse feed axis is calculated to obtain the local boundary activity. The local boundary activity is then used to perform second-order difference correction on the reference position sequences of the longitudinal feed axis and the transverse feed axis to generate the execution control sequence. During the machining process, the in-slot execution progress is calculated based on the cumulative angular position of the current spindle rotation axis. The tracking deviation of the previous interpolation cycle is weighted based on the in-slot execution progress, and the execution control sequence is corrected using the weighted tracking deviation to obtain the final execution command to control the movement of the longitudinal feed axis and the transverse feed axis.

2. The CNC multi-axis interpolation control method for a conventional lathe according to claim 1, characterized in that, Determining the synchronization ratio between the spindle rotary axis and the longitudinal feed axis based on the machine tool axis configuration data includes: Obtain the lead parameters and the number of encoder pulses per revolution corresponding to the spindle rotation axis from the process data; Calculate the ratio of the lead parameter to the number of pulses per revolution of the encoder, and use the ratio as the synchronization ratio to characterize the displacement of the longitudinal feed axis when the spindle rotation axis increases by one counting unit.

3. The CNC multi-axis interpolation control method for a conventional lathe according to claim 1, characterized in that, The step of generating the reference position sequence for the longitudinal feed axis and the reference position sequence for the transverse feed axis based on the synchronization ratio and the starting angle offset includes: In each interpolation cycle, the real-time cumulative count value of the spindle rotation axis is read, and the target position of the longitudinal feed axis is calculated by combining the starting angle offset and the synchronization ratio. Based on the normalized progress of the current interpolation cycle within the current spiral groove, the target position of the transverse feed axis is calculated using a cubic polynomial interpolation function, so that the transverse feed axis forms a smooth entry and exit trajectory in the entry and exit sections of the spiral groove.

4. The CNC multi-axis interpolation control method for a conventional lathe according to claim 1, characterized in that, The second-order difference correction of the reference position sequence of the longitudinal feed axis and the reference position sequence of the transverse feed axis using the local boundary mobility includes: For the current interpolation cycle, read the reference positions of the longitudinal feed axis and the transverse feed axis for three consecutive cycles; Calculate the second difference between the current position and the positions of the previous two cycles; The correction amount is obtained by multiplying the second-order difference value by the local boundary activity, and then subtracting the correction amount from the reference position of the current cycle to obtain the corrected execution control sequence.

5. The CNC multi-axis interpolation control method for a conventional lathe according to claim 1, characterized in that, The calculation of the ratio of position increments between adjacent cycles in the reference position sequence of the lateral feed axis to obtain the local boundary activity includes: Calculate the absolute value of the difference between the reference position of the lateral feed axis in the current cycle and that in the previous cycle as the numerator; The denominator is the sum of the absolute value of the difference between the reference position of the longitudinal feed axis in the current cycle and the previous cycle and a preset small positive number. Calculate the ratio of the numerator to the denominator, which is used to characterize whether the current machining point is in the transition zone of the groove boundary or the stable zone of the main cutting.

6. The CNC multi-axis interpolation control method for a conventional lathe according to claim 1, characterized in that, The weighting of the tracking deviation of the previous interpolation cycle based on the execution progress within the slot includes: The difference between the actual execution position vector of the previous interpolation cycle and the target execution vector of the previous interpolation cycle is obtained as the tracking error; The execution progress within the slot is processed using a quadratic weight function, such that the weight increases when the execution progress within the slot approaches the endpoint of the interval, and decreases when the execution progress within the slot approaches the midpoint of the interval. Multiplying the tracking deviation by the processed weights yields a correction vector used to compensate for the dynamic lag during the slot entry and exit phases.

7. The CNC multi-axis interpolation control method for a conventional lathe according to claim 1, characterized in that, The method further includes: When the cumulative angular position of the main spindle rotation axis advances to the starting angular offset range corresponding to the next spiral groove, it automatically switches to the starting angular offset of the next spiral groove, and uses the same groove execution progress calculation logic and boundary reinforcement execution strategy to complete the continuous processing of all spiral grooves on the entire roller.

8. A CNC multi-axis interpolation control device for a conventional lathe, characterized in that, include: The data configuration module is used to acquire machine tool axis configuration data and process data for roller spiral groove machining tasks, determine the synchronization ratio between the spindle rotation axis and the longitudinal feed axis, and the starting angle offset of each spiral groove. The reference generation module is used to generate a reference position sequence for the longitudinal feed axis and a reference position sequence for the transverse feed axis based on the synchronization ratio and the starting angle offset, with the cumulative angular position of the spindle rotation axis as the driving variable. The trajectory correction module is used to calculate the local boundary activity of the reference position sequence of the lateral feed axis, and use the local boundary activity to perform second-order difference correction on the reference position sequence to generate an execution control sequence. The execution control module is used to weight the tracking deviation of the previous interpolation cycle according to the execution progress in the slot, and use the weighted tracking deviation to correct the execution control sequence, and output the final execution command to control the machine tool movement.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the CNC multi-axis interpolation control method for a conventional lathe as described in any one of claims 1 to 7.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the CNC multi-axis interpolation control method for a conventional lathe as described in any one of claims 1 to 7.

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