Gear cutting machine tool shaft synchronization control method and system and machine tool

Abstract

The invention relates to the technical field of machine tool control, in particular to a tooth cutting machine tool shaft synchronous control method and system and a machine tool. The synchronous control method comprises the steps that the state of cuttings generated in the tooth cutting machining process is monitored; analyzing a synchronization error of the machine tool shaft based on the chip state; and regulating the rotation speed of the machine tool shaft based on the synchronization error. By the adoption of the synchronous control method, the problem of shaft synchronous errors caused by transmission side and cutting side factors in the prior art can be effectively solved, more accurate shaft synchronous control is achieved, and gear machining precision, surface quality and machining efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of machine tool control, and particularly relates to a synchronous control method, system and machine tool for the shafts of a shaving machine tool. Background Art

[0002] In the field of gear machining, shaving is a method of directly cutting the tooth profile from a blank using a gear-shaped tool. During machining, the workpiece shaft and the tool shaft operate at a set speed ratio, and their synchronism is the key to ensuring machining accuracy. Once the synchronism is out of adjustment, the tooth profile accuracy, surface quality and machining efficiency of the gear will be directly affected.

[0003] Currently, ensuring the precise synchronism between the workpiece shaft and the tool shaft mainly relies on the drive-side rotary encoder monitoring system. This system collects the rotational data of the drive sides of the workpiece shaft and the tool shaft in real time throughout the shaving process, and performs synchronous control measures after analyzing the data to obtain the error situation. However, this method has limitations: it is difficult to effectively map the shaft synchronous errors induced by the intermediate links (transmission side) of the transmission chain and the shaft synchronous errors caused by the cutting operation state (cutting side).

[0004] The causes of synchronous errors on the transmission side and the cutting side are complex and difficult to measure, and it is difficult to monitor. Adding a large number of sensors on the transmission side and the cutting side can effectively monitor the relevant shaft synchronous errors, but it will increase the structural complexity of the shaving machine tool, and at the same time greatly increase the manufacturing cost and maintenance cost of the machine tool. Summary of the Invention

[0005] To solve the above problems, the present invention provides a synchronous control method, system and machine tool for the shafts of a shaving machine tool, which are used to perform more precise synchronous control on the machine tool shafts based on the synchronous errors of the transmission side and the cutting side of the shaving machine tool.

[0006] On the one hand, the present invention provides a synchronous control method for the shafts of a shaving machine tool, including: Analyzing the synchronous error of the machine tool shaft based on the chip state generated during the shaving process; The chip state is the movement trajectory information of the chip after it is separated from the workpiece blank during the shaving process; the movement trajectory information is the trajectory passing points; by setting at least one induction area on the movement trajectory of the chip, monitoring the position information when the chip reaches the induction area, which is defined as the actual trajectory passing point; extracting the position information when the chip reaches the induction area in the theoretical movement trajectory, which is defined as the theoretical trajectory passing point; comparing the theoretical trajectory passing point with the actual trajectory passing point to analyze the synchronous error of the machine tool shaft; Adjusting the rotational speed of the machine tool shaft based on the synchronous error.

[0007] Further, the chip state includes a theoretical chip state and an actual chip state. The theoretical chip state is the theoretical motion trajectory information of the chip separated from the workpiece blank during the face hobbing process, and the actual chip state is the actual motion trajectory information of the chip separated from the workpiece blank during the face hobbing process. The acquisition method is as follows: Obtain the chip state generated when there is no synchronization error in the theoretical state, which is defined as the theoretical chip state, and monitor the chip state generated during the actual face hobbing process, which is defined as the actual chip state.

[0008] Further, monitor the actual chip state. When the difference between the actual chip state and the theoretical chip state is greater than the threshold, it is determined that there is a synchronization error in the machine tool axis, and the amount of synchronization error existing in the machine tool axis is proportional to the difference between the actual chip state and the theoretical chip state.

[0009] Further, before synchronous control, set the basic control amplitude; when there is a synchronization error in the machine tool axis, adjust the basic control amplitude based on the chip state difference generated when there is a synchronization error in the machine tool axis, randomly or according to the set priority, select the machine tool axis to be regulated, and output the adjusted basic control amplitude and the machine tool axis to be regulated as the first regulation strategy. After the first regulation strategy is executed, update the first regulation strategy based on the change of the synchronization error of the machine tool axis.

[0010] Further, using the chip state generated when there is a synchronization error in the machine tool axis and the operating parameters of the face hobbing machine as samples, construct and train a regulation strategy model using a machine learning algorithm or a deep learning algorithm. When there is a synchronization error in the machine tool axis, output a second regulation strategy through the regulation strategy model.

[0011] Further, collect the chip state and the operating parameters of the face hobbing machine, and output a pre-regulation strategy through the regulation strategy model.

[0012] Further, based on the accuracy requirement of the workpiece to be machined, set the synchronous control response sensitivity, and the synchronous control response sensitivity is proportional to the accuracy requirement of the workpiece to be machined.

[0013] Further, when the rotation encoder monitoring system does not detect a synchronization error on the driving side of the face hobbing machine and is not performing synchronous control, the machine tool axis is allowed to be regulated; when the rotation encoder monitoring system detects a synchronization error on the driving side of the face hobbing machine or is performing synchronous control, the regulation of the machine tool axis is terminated.

[0014] Further, analyze whether there is continuous coincidence of the actual chip state and the theoretical chip state regardless of time; if there is continuous coincidence of the actual chip state and the theoretical chip state within the preset time period regardless of time, it is determined that there is a rotational speed error in the machine tool axis; if there is no continuous coincidence of the actual chip state and the theoretical chip state within the preset time period regardless of time, it is determined that there is a rotational speed ratio error in the machine tool axis.

[0015] Further, the machine tool axis includes a workpiece axis and a tool axis; If there is a rotational speed error in the machine tool axis, synchronously regulate the workpiece axis and the tool axis; If there is a rotational speed ratio error in the machine tool axis, independently regulate the workpiece axis or the tool axis.

[0016] Further, the movement trajectory information of the chip is part or all of the movement trajectory from when the chip separates from the workpiece blank to before contacting any object.

[0017] Further, the induction area covers the movement trajectory of the chips generated during the skiving process, and a redundant induction area is set at the edge of the induction area.

[0018] Further, establish a monitoring coordinate system, convert each induction point in the induction area into the monitoring coordinate system, and adjust the position and angle of the induction area so that the theoretical movement trajectory of the chips during the entire skiving process passes through the induction area.

[0019] Further, establish a monitoring coordinate system, convert each induction point in the induction area into the monitoring coordinate system, and calculate the adjustment strategy for the induction area; the adjustment strategy is the adjustment positions and angles of several groups of induction areas; After the skiving process starts, adjust the induction area according to the adjustment strategy.

[0020] Further, calculate the generation moment of each chip based on the cutting model, define it as the theoretical chip moment, sort each chip generation moment within the time period when the chips are generated; construct a chip generation sequence according to the chip generation order; construct a chip trajectory sequence according to the theoretical movement trajectories of the chips corresponding to each chip in the chip generation sequence; establish a mapping relationship between the chip generation sequence and the chip trajectory sequence; Based on the moment after the skiving process starts, obtain the theoretical movement trajectory of the chips generated at the corresponding moment, and analyze the synchronization error of the machine tool axis by comparing the actual movement trajectory monitored at the same moment.

[0021] Further, construct a chip position sequence based on the theoretical positions where the chips corresponding to the theoretical movement trajectories in the chip trajectory sequence reach the induction area; establish a mapping relationship between the chip generation sequence, the chip trajectory sequence, and the chip position sequence; Based on the moment after the skiving process starts, obtain the theoretical position where the chips generated at the corresponding moment reach the induction area, and analyze the synchronization error of the machine tool axis by comparing the actual position reaching the induction area monitored at the same moment.

[0022] Further, send the regulation strategy to the rotary encoder monitoring system, and the rotary encoder monitoring system updates the normal rotational speed on the drive side of the machine tool axis.

[0023] On the other hand, the present invention provides a skiving machine tool axis synchronization control system, including: An error analysis module analyzes the synchronous error of the machine tool axis based on the chip state generated during the gear hobbing process; The chip state is the movement trajectory information of the chip after separation from the workpiece blank during the gear hobbing process; the movement trajectory information is the trajectory passing points; by setting at least one induction area on the movement trajectory of the chip, the position information when the chip reaches the induction area is monitored and defined as the actual trajectory passing point; the position information when the chip reaches the induction area in the theoretical movement trajectory is extracted and defined as the theoretical trajectory passing point; the synchronous error of the machine tool axis is analyzed by comparing the theoretical trajectory passing point with the actual trajectory passing point; A regulation module regulates the rotational speed of the machine tool axis based on the synchronous error.

[0024] Furthermore, the error analysis module is signal-connected to the rotary encoder monitoring system and the machine tool axis drive regulation device, and the error analysis module obtains the synchronous error condition of the drive side of the machine tool axis through the rotary encoder monitoring system; The regulation module is used to regulate the rotational speed of the machine tool axis based on the synchronous error when there is a synchronous error in the machine tool axis and there is no synchronous error on the drive side of the machine tool axis.

[0025] Furthermore, the error analysis module is used to monitor the trajectory passing points of the chips generated during the gear hobbing process. The error analysis module includes a movable monitoring surface, which is composed of several substrates. The adjacent substrates are hinged by a flexible connector. An angle adjustment mechanism for adjusting the angle of any substrate is integrated on the back of the substrate, and flexible film pressure sensors are arranged on the surfaces of the substrates.

[0026] Furthermore, the angle adjustment mechanism is used to adjust the substrate according to the theoretical movement trajectory of the chip so that the chip flows towards the collection area.

[0027] On the other hand, the present invention provides a gear hobbing machine tool, which includes a rotary encoder monitoring system and a machine tool axis drive regulation device, and integrates the above-mentioned gear hobbing machine tool axis synchronous control system. The gear hobbing machine tool axis synchronous control system is used to perform synchronous control on the machine tool axis.

[0028] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The present invention analyzes the synchronous error between the workpiece axis and the tool axis by monitoring the chip state generated during the gear hobbing process, and regulates the rotational speed accordingly, which can effectively solve the problem of axis synchronous error caused by factors on the transmission side and cutting side in the prior art, realize more accurate axis synchronous control, and improve the gear processing accuracy, surface quality and processing efficiency. It is applicable to various types of gear processing, including internal teeth, external teeth, straight teeth, helical teeth and other gear hobbing processes, and is not limited by specific types, with strong versatility and adaptability.

[0029] When performing synchronous monitoring and control on a gear hobbing machine, there is no need to add a large number of sensors on the driving side and the cutting side, which avoids the problems of increased complexity of the machine tool structure, significant increase in manufacturing costs and maintenance costs caused by adding sensors. While achieving high-precision synchronous control, the manufacturing and maintenance costs of the machine tool are reduced.

[0030] In addition, based on the output method of the regulation strategy of machine learning, it can quickly and accurately output the regulation strategy according to the collected chip arrival data, machine tool operation parameters, etc., realize efficient synchronous control, reduce the number of regulations, meet the requirements of high-quality and high-precision gear processing, and can also predict possible synchronous error situations, generate pre-regulation strategies in advance, and further improve the processing accuracy. Brief Description of the Drawings

[0031] Figure 1 It is the main flow chart of the shaft synchronous control method of the gear hobbing machine of the present invention; Figure 2 It is the gear hobbing principle diagram I of the embodiment of the shaft synchronous control method of the gear hobbing machine of the present invention; Figure 3 It is the gear hobbing principle diagram II of the embodiment of the shaft synchronous control method of the gear hobbing machine of the present invention; Figure 4 It is the detailed flow chart of the embodiment of the shaft synchronous control method of the gear hobbing machine of the present invention; Figure 5 It is the schematic diagram of the gear hobbing motion coordinate system of the embodiment of the shaft synchronous control method of the gear hobbing machine of the present invention; Figure 6 It is the schematic diagram of the expanded chip geometry model of the embodiment of the shaft synchronous control method of the gear hobbing machine of the present invention; Figure 7 It is the structural schematic diagram of the embodiment of the shaft synchronous control system of the gear hobbing machine of the present invention; Figure 8 It is the schematic diagram of the back of the movable monitoring surface of the embodiment of the shaft synchronous control system of the gear hobbing machine of the present invention; Figure 9 It is the schematic diagram of the front of the movable monitoring surface of the embodiment of the shaft synchronous control system of the gear hobbing machine of the present invention; Figure 10 It is the schematic diagram I of the monitoring principle of the movable monitoring surface of the embodiment of the shaft synchronous control system of the gear hobbing machine of the present invention; Figure 11 It is the schematic diagram II of the monitoring principle of the movable monitoring surface of the embodiment of the shaft synchronous control system of the gear hobbing machine of the present invention; Figure 12 It is the structural schematic diagram of the embodiment of the gear hobbing machine of the present invention.

[0032] The reference signs in the drawings of the specification include: 101, error analysis module; 102, regulation module; 103, rotary encoder monitoring system; 104, machine tool axis drive regulation equipment; 200, active monitoring surface; 201, substrate; 202, flexible connector; 203, angle adjustment mechanism; 204, flexible thin-film pressure sensor. Detailed implementation manners

[0033] The shaving machine tool is a device dedicated to gear processing. The gears processed by the shaving machine tool have high tooth surface accuracy and surface quality, and are commonly used for the processing of high-precision gears such as automotive gearboxes, planetary gearboxes, and industrial reducers. The shaving technology is different from other gear processing technologies. The machine tool axes of the shaving machine tool mainly include a workpiece axis and a cutter axis. Before shaving processing, the blank needs to be fixed to the workpiece axis, and the tool needs to be fixed to the cutter axis. During the shaving process, the workpiece axis and the cutter axis need to be inclined at a certain angle, and the two need to maintain a rotating state synchronously, and the workpiece needs to be fed synchronously in a small amount along the axis of the workpiece axis, so as to realize the shaving processing of the gear. The shaving processing is more flexible than traditional gear processing technologies such as gear shaping and hobbing, and can realize the processing of various gear products.

[0034] During the shaving process, the workpiece axis and the cutter axis need to rotate at a set speed ratio. If there is an error in the actual speed ratio of the workpiece axis and the cutter axis, it may affect the gear processing accuracy, the gear surface quality, the tool life, etc. Therefore, when the existing shaving machine tools perform shaving processing, they usually perform synchronous control of the cutter axis and the workpiece axis, and establish a coupling relationship between the workpiece axis and the cutter axis to ensure that the rotating speeds of the two can change synchronously and maintain the set speed ratio. When the existing shaving machine tools perform synchronous control, they collect the rotation data of the driving side (workpiece axis motor, cutter axis motor) as the basis for synchronous control, ignoring the influencing factors such as the transmission side (transmission chain) and the cutting side (tool wear, cutting heat). For the synchronous error brought by the driving side, the existing synchronous control methods can accurately perform synchronous control, while the synchronous errors brought by the transmission side and the cutting side cannot be accurately and effectively synchronously controlled.

[0035] The inventor combined the shaving theory and the actual operating state of the shaving machine tool, and found that when there is a synchronous error in any one or more of the driving side, the transmission side, and the cutting side, abnormal vibrations and abnormal chips will occur. Based on this, a synchronous control method for the shaving machine tool axis is proposed, which analyzes the synchronous error of the machine tool axis according to the chip state generated during the shaving process; and regulates the rotation speed of the machine tool axis based on the synchronous error.

[0036] The following will describe in detail the specific embodiments of the present invention with reference to the drawings. The synchronous control steps of the shaving machine tool axis in the embodiments of the present invention are divided into S11, S12, and S13, and the order of each step can be adjusted according to the actual situation. Preferably, reference can be made to Figure 1 , and the steps are as follows: S11. Monitor the chip state generated during the generation hobbing process. In the embodiments of the present invention, the chip state generated during the generation hobbing process is the discharge state of the chips. The discharge state is specifically the movement trajectory after separation from the workpiece blank being generation hobbed. The subsequent described chip movement trajectory corresponds to the chip state, the theoretical movement trajectory corresponds to the theoretical chip state, and the actual movement trajectory corresponds to the actual chip state. The technical solution of the present invention does not limit the type of generation hobbing of the workpiece, and is applicable to generation hobbing of internal teeth, external teeth, straight teeth, helical teeth, etc.

[0037] Refer to Figure 2 , the dotted filled area in the figure is the chip to be generated; during the generation hobbing process, the workpiece is fed microscopically along the axial direction, that is, the f direction in the figure; the rotation directions of the tool and the blank refer to the arrow directions indicated in the figure. Refer to Figure 3 , during the generation hobbing process, the cutting edge of the tool obliquely cuts into the bottom of the tooth groove from the right side of the blank, and then each point on the cutting edge participates in cutting in sequence. Under the extrusion of the cutting edge, the material in the tooth groove undergoes plastic deformation to form chips. The formed chips will not be immediately separated from the workpiece blank, but are continuously pushed by the rake face of the tool until the cutting edge completely leaves the tooth groove of the workpiece blank, and the chips are pushed and cut off by the rake face of the tool and discharged along the tooth profile direction. The finally discharged chip shape is similar to a "ji" shape, thereby realizing continuous and efficient tooth processing. The entire generation hobbing process is dry cutting, and the chips generated in adjacent tooth grooves are discharged from the tooth grooves one by one along the tooth profile. In the embodiments of the present invention, the movement trajectory of the chips after separation from the workpiece blank is used as the monitoring object to judge whether there are abnormal chips, and further judge whether there is a synchronous error between the current tool axis and the workpiece axis.

[0038] The detailed process of the embodiments of the present invention can be referred to Figure 4 , before officially monitoring the chip state, it is necessary to obtain the theoretical movement trajectory of the chips when there is no synchronous error between the tool axis and the workpiece axis based on the above generation hobbing principle, as the basis for judging the synchronous error after the actual movement trajectory of the chips is monitored subsequently. The acquisition of the theoretical movement trajectory of the chips depends on the basic parameters such as the mass, initial position, initial velocity, and chip cross-sectional area of each chip generated during generation hobbing when there is no synchronous error. In the embodiments of the present invention, the above basic parameters are obtained by establishing a cutting model and obtaining the chip geometric model of each chip therefrom, specifically as follows: S111. Obtain the generation hob tool model, the workpiece model to be machined, the tool running parameters and the workpiece blank running parameters through the numerical control machining program, and establish a cutting model based on the tool running parameters and the workpiece blank running parameters.

[0039] In the specific implementation, first, establish a generation hobbing motion coordinate system, refer to Figure 5 : The skiving process involves three motions: the rotational motion of the workpiece , the rotational motion of the tool and the feed motion along the axis of the workpiece . During the motion of the tool and the workpiece, there is always a shaft intersection angle between the tool axis and the workpiece axis . The differences between skiving internal gear workpieces and external gear workpieces lie in the center distance value and the tool axis direction

[0040] Coordinate system is the workpiece coordinate system, where the unit vector is ; Coordinate system is the tool coordinate system, where the unit vector is ; Coordinate system is the auxiliary coordinate system of coordinate system , where the unit vector is ; Coordinate system is the auxiliary coordinate system of coordinate system , where the unit vector is .

[0041] Coordinate system is used to establish the workpiece tooth surface model, and coordinate system is used to establish the tool model. The spatial positions of the auxiliary coordinate systems and are fixed and do not change with time. The center distance represents the perpendicular distance between the tool axis and the workpiece axis, and the shaft intersection angle represents the angle between the tool axis and the workpiece axis represents the angle by which the coordinate system rotates with respect to the position at time 0, represents the distance by which the coordinate system moves along the axis of the workpiece ( positive direction of the axis) with respect to the auxiliary coordinate system represents the angle by which the coordinate system rotates with respect to the position at time 0

[0042] The swept surface of the cutting edge is the swept surface formed by the cutting edge in the workpiece coordinate system , while the cutting edge of the skiving tool is usually represented in the tool coordinate system . In order to represent the swept surface of the cutting edge and thus establish the chip model in the workpiece coordinate system , a coordinate system transformation is required. The transformation matrix from coordinate system to coordinate system is:

[0043] In the formula, each matrix is a coordinate transformation matrix:

[0044]

[0045]

[0046] In the formula, represents the coordinate system to the coordinate system transformation matrix, represents the coordinate system to the coordinate system transformation matrix, represents the coordinate system to the coordinate system transformation matrix. and respectively represent the angular velocities of the workpiece and the tool during the shaving process.

[0047] represent the displacement of the workpiece or the tool along the axial direction of the workpiece:

[0048] and respectively represent the number of teeth of the workpiece and the tool, and satisfy the following relational expression:

[0049] Then, establish the flank-swept surface model: In order to obtain the flank-swept surface model, it is necessary to use the coordinate transformation matrix to transform the cutting edge in the tool coordinate system to the workpiece coordinate system :

[0050] In the formula, represents the point on the cutting edge, represents the distance from the point on the cutting edge of the th flank-swept surface in the tool coordinate system to the tool axis, , , respectively represent in the tool coordinate system in the axis, axis, axis components. After transforming the cutting edge to the workpiece coordinate system , the flank-swept surface can be obtained by calculating according to the following formula:

[0051] In the formula, represents a point on the rake face of the middle edge, represents the transformation matrix from the tool coordinate system to the workpiece coordinate system. Expanding Equation (8) gives the parametric equation of the rake face:

[0052] In the formula,

[0053] Then, a model of the rake face family is established: During the shaving process, a certain tooth on the tool will first contact and shave a certain tooth groove of the workpiece, performing the first rake face sweep. Let this tooth be Tooth No. 1. The rake face sweeping the tooth groove takes . When the workpiece rotates one week, the th tooth sweeps this tooth groove, that is, the second rake face sweep process. The rake face of the tooth relative to this tooth groove sweeps for . According to the periodicity of the shaving process, the following relationship is satisfied:

[0054] In the formula, represents taking the remainder. From this, it can be obtained that when the workpiece rotates the th week, that is, the th rake face sweep process, the rake face contacts the tooth groove at , satisfying:

[0055] According to the above formula, it can be deduced that when the workpiece rotates weeks, the included angle between Tooth No. 1 that shaves the tooth groove for the first time and the th tooth that shaves the tooth groove is:

[0056] Combining formulas (7) and (13), the parametric equation of the cutting edge on the th tooth of the shaving cutter can be obtained:

[0057]

[0057] Combining formulas (8) and (14), the The parameter equation of the blade sweep surface formed by the secondary scraping tooth groove is as follows:

[0058] Where,

[0059] According to equations (15) and (16), several blade sweep surfaces can be calculated, and their collection constitutes the blade sweep surface family.

[0060] Finally, the open chip model is established: Combined with the analysis of chip generation process, the expanded chip in the complete cutting state is a spatial geometric body surrounded by three surfaces, namely the tooth surface to be machined (The first one in the family of the previous cutting edge is swept by the The tooth surface is composed of three blade sweeps), the machined tooth surface (The first one in the family of edge sweeping in this machining process The blade sweeps of this machining process are composed of Blade sweep .

[0061]

[0062] Reference Figure 6 , through discrete cutting edges , the combined equations (15) and (17) can be used to solve the coordinates of the intersection point with the surface during the blade sweep process, that is, 、 、 Then, using curve fitting, we obtain the intersection lines A, B, and C of the three surfaces, which are the boundaries of the unfolded geometric chip. Based on this, we determine the boundaries of the machined tooth surface, the tooth surface to be machined, and the edge sweep surface that constitute the chip outline, and thus establish the chip geometric model.

[0063] S112, based on the chip geometry model obtained above, calculate the chip geometry model after the start of the gear cutting process. Cross-sectional area and volume of each chip: In the specific implementation, first, the chip is discretized into several chip elements, each chip element corresponds to a micro-segment cutting edge, and the length of the micro-segment cutting edge is defined as ,set up and They are the coordinate values of the two end points of a certain micro segment edge in the tool coordinate system. According to their position relationship, the length of any micro segment cutting edge on the cutting edge at time t can be obtained. , tool-chip contact edge length and the infinitesimal area :

[0064]

[0065]

[0066] Wherein, is the thickness of the differential chip, and the intersection point on the intersection line of the to-be-machined tooth surface and the machined tooth surface is used as the demarcation point to divide the chip cross-section into two regions, and the chip thicknesses are respectively represented by and . Thus, the thickness of the differential chip can be solved by the following formula:

[0067] Combining formulas (18), (19) and (20), the cross-sectional area of the th chip corresponding to the spatial trajectory of the cutting edge can be obtained:

[0068] Combining formulas (18), (19) and (20), the volume of the th chip corresponding to the spatial trajectory of the cutting edge can be obtained:

[0069] Wherein, , represents the initial contact time of the th blade sweep surface and the th blade sweep surface, represents the initial contact time of the th blade sweep surface and the tooth surface formed by the previous radial feed shaving, represents the initial contact time of the th blade sweep surface and the tooth surface formed by the previous radial feed shaving, and can both be obtained by formula (17).

[0070] S113. Based on the volume of the th chip, the mass of the th chip since the start of the self-shaving tooth machining can be calculated:

[0071] Wherein, is the metal density, i.e., the density of the workpiece blank; is the volume of the th chip since the start of the self-shaving tooth machining, which can be obtained by formula (23).

[0072] S114, and then obtain the initial position of the th chip and the initial velocity after the chip is separated from the workpiece blank, so as to calculate the theoretical movement trajectory of the th chip.

[0073] For the initial position of the th chip : In some embodiments, the initial position of the th chip in the workpiece coordinate system or the tool coordinate system is directly calculated with reference to the workpiece coordinate system or the tool coordinate system established above through the cutting model; in some other embodiments, the initial position of the th chip in the auxiliary coordinate system of the workpiece coordinate system or the auxiliary coordinate system of the tool coordinate system is directly calculated with reference to the auxiliary coordinate system of the workpiece coordinate system or the auxiliary coordinate system of the tool coordinate system established above through the cutting model; in still some other embodiments, an additional coordinate system is established, and the position of the mth chip in the workpiece coordinate system, the tool coordinate system, the auxiliary coordinate system of the workpiece coordinate system or the auxiliary coordinate system of the tool coordinate system is calculated with reference to the additional coordinate system through the cutting model established above, and then the position is converted into the additional coordinate system to obtain the initial position of the th chip in the additional coordinate system . It should be noted that the monitoring of the actual movement trajectory of the chip and the obtained initial position of the chip should be in the same coordinate system.

[0074] For the initial velocity of the th chip after it is separated from the workpiece blank ( ) can be calculated and obtained through the following method: In the embodiment of the present invention, first, calculate the cutting velocity when the cutting edge contacts the workpiece blank during the generation hobbing:

[0075] In the formula,

[0076] and respectively represent the vector and scalar of the rotational speed of the workpiece blank, and are respectively the vector and scalar of the rotational speed of the tool, and are respectively the vector and scalar of the feed rate, is the tooth surface of the workpiece in the workpiece coordinate system, is the conjugate surface in the tool coordinate system; , , are the unit vectors of the three coordinate axes of the workpiece coordinate system respectively. is the unit vector of the z-axis of the tool coordinate system. is the center distance between the tool and the workpiece blank.

[0077] Then, the initial velocity after the chip separates from the workpiece blank:

[0078]

[0079]

[0080]

[0081] In the formula, is the equivalent cross-section shear angle. is the equivalent cross-section rake angle. is the angle between the force direction at chip separation and the y-axis. The angle between the force direction at chip separation and the x-axis in the x-z plane.

[0082] S115. After obtaining the basic parameters such as the mass, initial position, initial velocity, and chip cross-sectional area of each chip, the theoretical motion trajectory of the chip can be calculated. Considering air resistance, the motion equations of each chip are as follows:

[0083] In the formula, is the air density, taking 1.225 ; is the acceleration due to gravity, taking 9.81 ; Define the derivative functions of velocity and position:

[0084]

[0085]

[0086]

[0087]

[0088]

[0089] Then, the numerical integration method is used to iteratively calculate the positions at each moment, and there is no closed-form solution; the theoretical chip motion trajectory is obtained. The numerical integration method adopted in the embodiment of the present invention is the Runge-Kutta method (fourth order), and the specific implementation is as follows:

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113] Update the chip speed and position:

[0114]

[0115]

[0116]

[0117]

[0118]

[0119] Wherein, is the time step; , and respectively represent the accelerations of the chip in the , and directions; , , respectively correspond to the rates of change of the velocity in the , and directions at the value of the current time step; , and at the next half time step; , , correspond to the rates of change of the velocity at the next half time step; , , correspond to another set of rates of change of the velocity at the next half time step; , , correspond to the rates of change of the velocity at the next full time step.

[0120] Through the above numerical integration method, the position of each chip at each time step can be obtained, and then the theoretical motion trajectory of each chip can be obtained.

[0121] In order to facilitate the subsequent comparison of the theoretical motion trajectory and the actual motion trajectory of a certain chip, in the embodiment of the present invention, based on the above cutting model, the generation time of each chip is calculated and defined as the chip theoretical time ; And calculate the generation time of the first chip in the entire workpiece processing time period, and the generation time of the last chip in the entire workpiece processing time period, and define them as the start time and the end time , the time period during which chips are generated . During the time period when chips are generated , sort each chip generation moment; assume a total of chips are generated, and mark their generation moments as respectively according to the chip generation order, and construct a chip generation sequence; mark their theoretical movement trajectories as respectively according to the chip generation order, and construct a chip trajectory sequence.

[0122] When subsequently comparing the theoretical movement trajectory and the actual movement trajectory of a certain chip, it is only necessary to find the chip that is being generated at the corresponding moment in the chip generation sequence based on the moment, and then obtain its corresponding theoretical movement trajectory. For example: the moment is , and the chip generated by the gear hobbing at this time is the th chip, and its theoretical trajectory is .

[0123] During the formal monitoring of the chip state process, it can be carried out through the trajectory monitoring method (the monitoring object is the trajectory path) and the point monitoring method (the monitoring object is the trajectory passing point). For the trajectory monitoring method, the trajectory path of the chip can be monitored by means of computer vision technology, laser tracking technology, infrared sensing technology, etc. For the point monitoring method, it can be realized by the fixed-point monitoring technology to monitor whether the chip passes through a certain point. No matter which of the above chip state monitoring methods is adopted, the collected chip movement trajectory information needs to be the movement trajectory information of the chip from the separation from the blank to the contact with any object. After the chip is separated from the blank, if it comes into contact with other objects, its movement trajectory is affected by various complex factors and is not suitable to be used as the basis for chip abnormality detection.

[0124] In some embodiments, computer vision technology is adopted, and its specific implementation method: capture the image sequence of the chip movement through a high-speed camera or a multi-camera system, and then use image processing algorithms (such as the optical flow method or feature point tracking in the OpenCV library) to determine the position change of the chip in the image, and then calculate its movement trajectory in the space coordinate system, and the monitoring result is directly output in the form of trajectory information. This method is suitable for the gear hobbing processing scenario with stable environmental light conditions to reduce the influence of environmental light conditions on the monitoring result.

[0125] In the embodiment of the present invention, the fixed-point monitoring technology is adopted, and its specific implementation method: after obtaining the theoretical movement trajectory of the chip during the gear hobbing process, set an induction component on its theoretical movement trajectory, and the induction area of the induction component needs to cover the movement trajectory of the chip, and set a certain redundant induction area to ensure that the chips moving along the theoretical movement trajectory and the error movement trajectory can be effectively covered and collected when reaching the induction area point, and the monitoring result is output in the form of position information.

[0126] In the embodiment of the present invention, a monitoring coordinate system is established specifically for judging whether there is an error in the chip trajectory, and the theoretical movement trajectory of the chip is transformed into the monitoring coordinate system, and each induction point in the induction area is transformed into the monitoring coordinate system. Subsequently, by adjusting the position and angle of the induction part once, the theoretical movement trajectory of the chip during the entire gear shaving process all passes through the induction area. If adjusting the position and angle of the induction part once cannot make the theoretical movement trajectory of the chip during the entire gear shaving process all pass through the induction area, then an adjustment strategy for the induction part is calculated. The adjustment strategy is to adjust the position and angle of the induction part multiple times, including the position and angle that the induction part should be in at a certain moment or time period. After the gear shaving process starts, the position and angle of the induction part are adjusted according to the adjustment strategy, so that the theoretical movement trajectories of the chips generated at each moment all pass through the induction area, ensuring that the positions where the chips reach within the induction area at each moment can be effectively obtained, and marking their theoretical positions when they theoretically reach the induction area in the order of chip generation as , a chip position sequence is constructed. The generation time, theoretical trajectory, and position passing through the induction area of each chip have a one-to-one mapping relationship Y in the chip generation sequence, chip trajectory sequence, and chip position sequence, that is: , , .

[0127] Since gear shaving may involve internal gear workpieces and external gear workpieces, to avoid the induction area of the induction part being too large and hindering gear shaving, the size of the induction part can be reduced, and the adjustment strategy of the induction part can be generated through the above steps. In some embodiments, the induction area of the induction part can be automatically adjusted in position and angle with the feeding of the workpiece blank. In short, it is only necessary to ensure that the generated chips all pass through the induction area.

[0128] S12. Analyze the synchronization error of the machine tool axes (workpiece axis and cutter axis) based on the chip state; In the actual gear shaving process, the synchronization error of the machine tool axes mainly includes: an error in the speed ratio between the workpiece axis and the cutter axis; or there is no error in the speed ratio between the workpiece axis and the cutter axis, but their speeds both deviate. For the former, it will directly affect the machining accuracy and surface quality of the workpiece, and there is a difference between the actual chip and the theoretical chip at a certain moment, and the movement trajectory of the discharged chip deviates from the theoretical movement trajectory; for the latter, it directly affects the machining efficiency of the workpiece, increases cutting heat or reduces the tool life, and there is a difference between the actual chip and the theoretical chip at a certain moment, and the movement trajectory of the discharged chip deviates from the theoretical movement trajectory, but only the generation time of the chip deviates. Since the start of gear shaving, the The movement trajectory of a chip will not deviate from its corresponding theoretical movement trajectory, but only the occurrence time of the actually monitored movement trajectory of the chip is shifted.

[0129] In the embodiments of the present invention, the chip state is the actual movement trajectory of the chip. In specific implementation, the above two cases of synchronous error are defined as speed ratio error and speed error.

[0130] The actual movement trajectories of the chips are sequentially recorded, and the point position monitoring method is used to record the positions where each chip actually reaches the induction area. Based on several moments included in the current moment or time period, and according to the mapping relationship Y, the deviation between the actual position and the theoretical position where the chip reaches the induction area is compared to determine whether the current workpiece axis and the tool axis are synchronized. When the workpiece axis and the tool axis are synchronized, the chip is normal; when the workpiece axis and the tool axis are synchronized, the chip is abnormal, and changes such as the chip shape, quality, initial position, and initial velocity occur. The actual movement trajectory after being discharged from the workpiece tooth groove is different from the theoretical movement trajectory, and the actual position where the chip reaches the induction area is different from the theoretical position where it reaches the induction area. Therefore, if the deviation between the actual position and the theoretical position where the chip reaches the induction area is greater than the allowable threshold, it is determined that there is a synchronous error between the current workpiece axis and the tool axis. In some embodiments, the allowable threshold is determined according to the cross-sectional area of the generated chip. When the chip with a smaller cross-sectional area reaches the induction area, the position error detected by the induction area is smaller, and vice versa. Therefore, the allowable threshold is positively correlated with the cross-sectional area of the chip. Secondly, the allowable threshold is also negatively correlated with the sensitivity of the required synchronous control response.

[0131] After determining the non-synchronous state of the current machine tool axis, it is necessary to judge the synchronous error situation in order to perform accurate synchronous control subsequently. For the speed ratio error, it is only necessary to separately control and adjust the driving side of the axis with the error. For the speed error, it is necessary to synchronously control and adjust the driving sides of the workpiece axis and the tool axis. According to the recorded positions where each chip actually reaches the induction area, first analyze whether the positions where each chip reaches the induction area are continuously coincident with the positions where each chip theoretically reaches the induction area in the chip position sequence without considering the arrival time. If there is continuous coincidence without considering the arrival time within the preset time period, it is determined that the current synchronous error situation is defined as speed error; if there is no continuous coincidence without considering the arrival time within the preset time period, it is determined that the current synchronous error situation is defined as speed ratio error.

[0132] After the synchronous error situation is determined, it is also necessary to determine the machine tool axis (workpiece axis or tool axis) for synchronous control and the regulation amount. Since the reasons for the synchronous errors on the transmission side and the cutting side are complex and difficult to accurately judge. Therefore, in the embodiments of the present invention, the synchronous error amounts of the workpiece axis and the tool axis are not accurately determined, and a fuzzy regulation method is adopted to assist the original encoder monitoring system of the gear hobbing machine to make up for the monitoring and regulation of the synchronous errors on the transmission side and the cutting side, so as to achieve more accurate synchronous control.

[0133] One implementation is the output mode of the basic regulation strategy (the first regulation strategy): Based on the accuracy requirements of the workpiece to be processed, the synchronous control response sensitivity and the basic control amplitude are set. Among them, the synchronous control response sensitivity is usually fixed, and the control amplitude is dynamically generated using a quasi-PID regulation method throughout the shaving process, that is, the larger the synchronous error between the workpiece axis and the cutter axis, the larger the control amplitude. The synchronous error amount between the workpiece axis and the cutter axis is proportional to the deviation between the actual position where the chip reaches the sensing area and the theoretical position where it reaches the sensing area. In addition to the synchronous control response sensitivity and the control amplitude, the regulation strategy also includes the axes to be regulated. In specific implementation, the workpiece axis and the cutter axis are regulated randomly or according to the set priority, so as to output a complete regulation strategy. For the rotational speed error: the workpiece axis and the cutter axis are regulated simultaneously according to the control amplitude; for the rotational speed ratio error: the workpiece axis or the cutter axis is selected randomly or according to the set priority for individual regulation.

[0134] After the regulation strategy is executed, continuously monitor the synchronous error between the workpiece axis and the cutter axis. Based on the synchronous error between the workpiece axis and the cutter axis after the regulation strategy is executed, generate the axes to be regulated, and dynamically generate the latest control amplitude. For example: if the synchronous error between the workpiece axis and the cutter axis decreases after the regulation strategy is executed, continue to regulate the axes to be regulated with a smaller control amplitude until the synchronous error between the workpiece axis and the cutter axis is eliminated.

[0135] Obviously, the output mode of the basic regulation strategy has the problem of multiple output and regulation of the regulation strategy, which is difficult to meet the shaving requirements of workpieces with extremely high quality and accuracy. Another implementation is the output mode of the regulation strategy (the second regulation strategy) based on machine learning algorithms or deep learning algorithms. In specific implementation, a machine learning algorithm is used: First of all, it is necessary to construct a regulation strategy model, and the regulation strategy model can be constructed based on existing machine learning models such as linear regression models, support vector machines, and neural network models.

[0136] Then, it is necessary to train the constructed machine learning model by collecting several groups of chip arrival data and the running parameters of the gear hobbing machine when there is a synchronous error between the workpiece axis and the cutter axis. In specific implementation, the chip arrival data includes: the actual position where the chip arrives at the induction area, the actual time when the chip arrives at the induction area, the deviation between the actual position where the chip arrives at the induction area and the theoretical position of arriving at the induction area (such as deviation amount, deviation direction, etc.), and the deviation between the actual position where the chip arrives at the induction area and the theoretical time of arriving at the induction area (such as advance amount, delay amount, etc.). The running parameters of the gear hobbing machine include: cutter axis rotational speed, workpiece axis rotational speed, feed speed, feed per tooth, the continuous running duration of the gear hobbing machine, the gear hobbing processing duration of the current workpiece, the type of workpiece gear, the normal module of the workpiece, etc. And when collecting the synchronous error between the workpiece axis and the cutter axis, collect the control amplitude data output according to the basic regulation strategy output method, as well as the corresponding synchronous control response sensitivity, the selection of the regulated axis (workpiece axis or cutter axis), and the change of the synchronous error after regulation, etc.

[0137] Clean the above - collected data to remove noise and outliers. Conduct feature extraction, using synchronous error, position deviation, etc. as input features, and control amplitude, regulated axis selection as output labels. At the same time, normalize or standardize the data to make it meet the input - output requirements of the model. Divide the pre - processed data into training set, validation set and test set. Input the training set data into the regulation strategy model and minimize the loss function through an optimization algorithm. For the output of the control amplitude, use regression loss functions such as mean square error; for the output of the regulated axis selection, use classification loss functions such as cross - entropy loss function. During the training process, calculate the output through forward propagation, and then use the backpropagation algorithm to calculate the gradient and update the model parameters. Evaluate the performance of the model on the validation set, and then use the test set to comprehensively test the model to obtain the trained regulation strategy model.

[0138] Based on the chip arrival data and the running parameters of the gear hobbing machine when there is a synchronous error between the workpiece axis and the cutter axis, the regulation strategy model can efficiently output accurate regulation strategies. The control amplitude and the regulated axis included in the regulation strategy are more accurate, and the number of regulations is low, which can efficiently and precisely perform the synchronous control of the workpiece axis and the cutter axis, meeting the requirements of gear hobbing processing of workpieces with extremely high quality and precision. In some embodiments, it can also predict the possible synchronous error situation between the workpiece axis and the cutter axis based on the chip arrival data and the running parameters of the gear hobbing machine when there is a synchronous error, so as to generate a pre - regulation strategy in advance and avoid the occurrence of some synchronous error situations, further improving the precision of gear hobbing processing.

[0139] S13, regulate the rotational speed of the machine tool axis (workpiece axis or / and cutter axis) based on the synchronous error; The cutter shaft of the gear hobbing machine is usually driven by a cutter shaft motor, and the workpiece shaft is usually driven by a workpiece shaft motor. The cutter shaft motor and the workpiece shaft motor are equipped with a rotary encoder monitoring system 103, which can monitor the synchronous error situation of the drives between the motors and perform timely synchronous control. Synchronous errors may still occur on the driving side and the cutting side of the workpiece shaft and the cutter shaft, mainly due to manufacturing errors of transmission components, assembly errors of transmission components, elastic deformation and clearance of transmission components after long-term use of the equipment, thermal deformation of transmission components, tool wear and deformation, etc.

[0140] The reasons for the synchronous error caused by the above reasons are complex and difficult to measure. However, as long as there is a synchronous error between the workpiece shaft and the cutter shaft, the chips generated by gear hobbing will be abnormal. By monitoring the chip abnormality through S11, and then judging the synchronous error situation of the workpiece shaft and the cutter shaft through S12, the corresponding regulation strategy is output. Executing the regulation strategy can regulate the synchronous error of the workpiece shaft and the cutter shaft on the driving side and the cutting side.

[0141] Before executing the regulation strategy, it is necessary to exclude the situation where the chip abnormality is caused by the synchronous error on the driving side, which can be judged by the monitoring data and synchronous control situation of the rotary encoder monitoring system 103. When the rotary encoder monitoring system 103 does not detect a synchronous error on the driving side and does not perform synchronous control, it is determined that the chip abnormality is caused by the synchronous error on the non-driving side, that is, the execution of the regulation strategy is allowed.

[0142] After the regulation strategy is executed, it finally acts on the workpiece shaft motor or / and the cutter shaft motor, mainly to regulate the rotational speeds of the two. The rotational speed control of the gear hobbing machine motor is usually realized by devices such as frequency converters, servo drivers, and DC speed regulation devices. Therefore, converting the execution of the strategy into an instruction that can be read by the above devices and letting the devices execute the instruction can complete the speed regulation of the machine tool motor.

[0143] During the execution stage of the regulation strategy, since the rotary encoder monitoring system 103 does not detect a synchronous error on the driving side, that is, the rotary encoder monitoring system 103 believes that the current workpiece shaft motor and cutter shaft motor have normal rotational speeds and there is no synchronous error. However, after the regulation strategy is executed, the rotational speed of the workpiece shaft motor or / and the cutter shaft motor will change. If the rotary encoder monitoring system 103 is not informed in advance, the change in the rotational speed of the workpiece shaft motor or / and the cutter shaft motor will be determined by the system as a synchronous error on the driving side, resulting in a conflict between the synchronous error control on the driving side and the synchronous error control on the driving side and the cutting side. Therefore, it is necessary to send the regulation strategy to the rotary encoder monitoring system 103, inform it of the rotational speed of the workpiece shaft motor or / and the cutter shaft motor after the execution of the regulation strategy, and let the rotary encoder monitoring system 103 update the normal rotational speeds of the workpiece shaft motor and the cutter shaft motor.

[0144] In specific implementation, when no control strategy is received, the normal rotation speeds of the workpiece shaft motor and the tool shaft motor stored in the rotary encoder monitoring system 103 are defined as the default driving speeds; when the rotation speeds of the workpiece shaft motor and the tool shaft motor deviate from the default driving speeds, the rotary encoder monitoring system 103 performs drive-side synchronization error control.

[0145] After receiving the control strategy for the first time, the default driving speed is updated to the first-time regulated driving speed; when the rotation speeds of the workpiece shaft motor and the tool shaft motor deviate from the first-time regulated driving speed, the rotary encoder monitoring system 103 performs drive-side synchronization error control.

[0146] After receiving the control strategy for the second time, the default driving speed is updated to the second-time regulated driving speed; when the rotation speeds of the workpiece shaft motor and the tool shaft motor deviate from the second-time regulated driving speed, the rotary encoder monitoring system 103 performs drive-side synchronization error control And so on until a single workpiece completes the gear shaving process, and the rotary encoder monitoring system 103 is reset. On the basis of achieving precise control of the drive-side synchronization error, it is further extended to the synchronization error compensation of the transmission side and the cutting side, and a comprehensive and high-precision synchronization control system is constructed, so as to ensure the precise coordinated operation of the workpiece shaft and the tool shaft throughout the gear shaving process, and comprehensively improve the overall accuracy and workpiece quality of the gear shaving process.

[0147] To enable those skilled in the art to better understand and implement the technical solution of the present invention, the following provides a detailed description of the system and the machine tool based on the above method: Referring to Figure 7 , an embodiment of the present invention further provides a gear shaving machine tool shaft synchronization control system, including an error analysis module 101 and a regulation module 102. The error analysis module 101 is used to monitor the chip state generated during the gear shaving process; analyze the synchronization error of the machine tool shafts (workpiece shaft and tool shaft) based on the chip state; the regulation module 102 is used to regulate the rotation speed of the machine tool shafts (workpiece shaft or / and tool shaft) based on the synchronization error.

[0148] In specific implementation, first, the error analysis module 101 collects the parameters of the workpiece to be machined and the cutting tool for machining the workpiece to be machined. These parameters can be obtained through the numerical control machining program to generate the corresponding theoretical state of the chip, which is the theoretical movement trajectory after the chip is discharged in the embodiment of the present invention. The skiving machining starts, and the error analysis module 101 collects the actual state of the chip, which is the actual movement trajectory after the chip is discharged in the embodiment of the present invention. The error analysis module 101 interacts with the regulation module 102, and the regulation module 102 interacts with the rotary encoder monitoring system 103. The error analysis module 101 compares the actual chip state with the theoretical chip state to determine whether the chip is abnormal, and further determines whether there is a synchronization error between the workpiece axis and the tool axis, and generates a corresponding regulation strategy. After receiving the regulation strategy, the regulation module 102 verifies whether there is a synchronization error on the current drive side from the rotary encoder monitoring system 103. If there is a synchronization error on the drive side, the regulation strategy is terminated, and the rotary encoder monitoring system 103 performs synchronization control. If there is no synchronization error on the drive side, the regulation strategy is sent to the rotary encoder monitoring system 103, and then the regulation strategy is executed. Both the regulation module 102 and the rotary encoder monitoring system 103 interact with the machine tool axis drive regulation device 104. The synchronization error control on the drive side is executed by the rotary encoder monitoring system 103 controlling the machine tool axis drive regulation device 104, and the synchronization error control on the transmission side and the cutting side is executed by the regulation module 102 controlling the machine tool axis drive regulation device 104.

[0149] In specific implementation, the error analysis module 101 is the sensing part in the above method. The error analysis module 101 corresponds to the data type of the chip state to be monitored. If the collected chip state is the actual movement trajectory of the chip, the error analysis module 101 can be a high-speed camera, an infrared camera, a multi-sensor fusion device, etc., which can collect the actual movement trajectory of the chip. If the collected chip state is the point where the chip arrives, the collection unit of the error analysis module 101 can be a photoelectric sensor, an inductive sensor and other sensing devices. However, the above devices as the collection units of the error analysis module 101 are all vulnerable to the interference of the complex environment of skiving machining. Therefore, the embodiment of the present invention proposes a collection unit of the error analysis module 101 adapted to the auxiliary environment of skiving machining, which is composed of the movable monitoring surface 200 and the flexible film pressure sensor 204.

[0150] Refer to Figure 8 and Figure 9, In specific implementation, the activity monitoring surface 200 is composed of six substrate plates 201. Adjacent substrate plates 201 are hinged through a flexible connector 202. The flexible connector 202 can achieve bending and torsion between the substrate plates 201 within a certain range. An angle adjustment mechanism 203 is integrated on the back of the substrate plate 201, and the angle adjustment mechanism 203 is used to adjust the angle of any substrate plate 201. In some embodiments, the angle adjustment mechanism 203 is designed with reference to the flexible finger structure of a flexible gripper, and it can adjust the angle of the substrate plate 201 by inflating and deflating. In other embodiments, the angle adjustment mechanism 203 is designed with a mechanical angle adjustment structure. Flexible thin-film pressure sensors 204 are arranged on the surfaces of the substrate plates 201, and the covered area of the flexible thin-film pressure sensors 204 is the induction area in the above method. The arrival position of the chip is detected through the pressure points on the surface of the flexible thin-film pressure sensors 204. Refer to Figure 10 , In specific implementation, control the angle adjustment mechanism 203 to adjust the angle of each substrate plate 201, and try to make the front surface of the substrate plate 201 face the incoming direction of the chip trajectory, so that the chip arrives perpendicularly at the surface of the flexible thin-film pressure sensor 204, which can improve the detection accuracy of the chip arrival position. Refer to Figure 11 , When the tooth groove of the workpiece blank reaches the dotted line position, the initial separation position of the chip from the workpiece blank is , The movement trajectory of the chip is along the arrow direction, and the position where it arrives at the surface of the flexible thin-film pressure sensor 204 is the circled position. At the same time, refer to Figure 10 and Figure 11 The bent activity monitoring surface 200 in, which is formed by the angle adjustment mechanism 203 according to the theoretical movement trajectory of the chip, is beneficial to collecting the chip, making the chip flow in the collection direction and reducing chip splashing.

[0151] Refer to Figure 12 , The embodiment of the present invention also provides a gear shaving machine tool, which is integrated with the above-mentioned gear shaving machine tool shaft synchronization control system. The acquisition unit of the error analysis module 101 in the embodiment of the present invention is arranged on the tool shaft device, and is equipped with a position adjustment mechanism and an angle adjustment mechanism 203. The acquisition unit of the error analysis module 101 can perform position and angle adjustments to make the theoretical movement trajectory of the chip during the gear shaving process pass through the induction area, so as to ensure effective monitoring of the chip state.

[0152] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A synchronous control method for a gear hobbing machine tool shaft, characterized in that, Including: Analyzing the synchronous error of the machine tool axis based on the chip state generated during the skiving process; The chip state is the movement trajectory information of the chip after it is separated from the workpiece blank during the skiving process; The movement trajectory information is the trajectory passing points; by setting at least one induction area on the movement trajectory of the chip, monitoring the position information when the chip reaches the induction area, which is defined as the actual trajectory passing point; extracting the position information when the chip reaches the induction area in the theoretical movement trajectory, which is defined as the theoretical trajectory passing point; comparing the theoretical trajectory passing point with the actual trajectory passing point to analyze the synchronous error of the machine tool axis; Regulating the rotational speed of the machine tool axis based on the synchronous error.

2. The synchronous control method for the gear hobbing machine tool shaft according to claim 1, wherein The chip state includes the theoretical chip state and the actual chip state. The theoretical chip state is the theoretical movement trajectory information of the chip after it is separated from the workpiece blank during the skiving process, and the actual chip state is the actual movement trajectory information of the chip after it is separated from the workpiece blank during the skiving process. The acquisition method is as follows: Obtaining the chip state generated when there is no synchronous error in the theoretical state, which is defined as the theoretical chip state, and monitoring the chip state generated during the actual skiving process, which is defined as the actual chip state.

3. The synchronous control method for the gear hobbing machine tool shaft according to claim 2, wherein, Monitoring the actual chip state. When the difference between the actual chip state and the theoretical chip state is greater than the threshold, it is determined that there is a synchronous error in the machine tool axis, and the amount of synchronous error in the machine tool axis is proportional to the difference between the actual chip state and the theoretical chip state.

4. The synchronous control method for the shaft of a gear shaper machine according to claim 1, wherein, Before synchronous control, setting a basic control amplitude; when there is a synchronous error in the machine tool axis, adjusting the basic control amplitude based on the chip state difference generated when there is a synchronous error in the machine tool axis, randomly or according to the set priority, selecting the machine tool axis to be regulated, and outputting the adjusted basic control amplitude and the machine tool axis to be regulated as the first regulation strategy. After the first regulation strategy is executed, updating the first regulation strategy based on the change of the synchronous error of the machine tool axis.

5. The synchronous control method for the gear shaper machine tool shaft according to claim 1, wherein Taking the chip state generated when there is a synchronous error in the machine tool axis and the running parameters of the skiving machine as samples, constructing and training a regulation strategy model using machine learning algorithms or deep learning algorithms. When there is a synchronous error in the machine tool axis, outputting a second regulation strategy through the regulation strategy model.

6. The synchronous control method for the gear shaper machine tool shaft according to claim 5, characterized in that, Collecting the chip state and the running parameters of the skiving machine, and outputting a pre-regulation strategy through the regulation strategy model.

7. The synchronous control method for the gear hobbing machine tool shaft according to any one of claims 1-6, characterized in that Based on the accuracy requirement of the workpiece to be machined, setting the synchronous control response sensitivity, and the synchronous control response sensitivity is proportional to the accuracy requirement of the workpiece to be machined.

8. The synchronous control method for the gear shaper machine tool shaft according to any one of claims 4-6, characterized in that When the rotary encoder monitoring system does not detect a synchronous error on the driving side of the skiving machine and is not performing synchronous control, allowing the regulation of the machine tool axis; when the rotary encoder monitoring system detects a synchronous error on the driving side of the skiving machine or is performing synchronous control, terminating the regulation of the machine tool axis.

9. The method for synchronously controlling a gear shaper machine tool shaft according to claim 2, characterized in that, Analyzing whether there is continuous coincidence regardless of time between the actual chip state and the theoretical chip state; if there is continuous coincidence regardless of time between the actual chip state and the theoretical chip state within the preset time period, it is determined that there is a rotational speed error in the machine tool axis; if there is no continuous coincidence regardless of time between the actual chip state and the theoretical chip state within the preset time period, it is determined that there is a rotational speed ratio error in the machine tool axis.

10. The gear hobbing machine shaft synchronization control method according to claim 9, characterized in that, The machine tool axis includes a workpiece axis and a tool axis; If there is a rotational speed error in the machine tool axis, synchronously regulate the workpiece axis and the tool axis; If there is a speed ratio error in the machine tool axis, independently regulate the workpiece axis or the tool axis.

11. The gear shaper machine tool shaft synchronization control method according to claim 1, characterized in that The movement trajectory information of the chip is part or all of the movement trajectory after the chip separates from the workpiece blank and before contacting any object.

12. The gear hobbing machine shaft synchronization control method according to claim 1, characterized in that, The induction area covers the movement trajectory of the chips generated during the skiving process, and a redundant induction area is set at the edge of the induction area.

13. The synchronous control method for the gear hobbing machine tool shaft according to claim 12, wherein Establish a monitoring coordinate system, convert each induction point in the induction area into the monitoring coordinate system, and adjust the position and angle of the induction area so that the theoretical movement trajectory of the chips during the entire skiving process passes through the induction area.

14. The method for synchronously controlling the shaft of a shaving machine tool according to claim 12, characterized in that, Establish a monitoring coordinate system, convert each induction point in the induction area into the monitoring coordinate system, and calculate the adjustment strategy for the induction area; the adjustment strategy is the adjustment positions and angles of several groups of induction areas; After the skiving process starts, adjust the induction area according to the adjustment strategy.

15. The gear hobbing machine shaft synchronization control method according to claim 1, characterized in that, Based on the cutting model, calculate the generation time of each chip, defined as the theoretical chip time, and sort the generation times of each chip within the time period when the chips are generated; Construct a chip generation sequence according to the chip generation order; construct a chip trajectory sequence according to the theoretical movement trajectories of the chips corresponding to each chip in the chip generation sequence; establish a mapping relationship between the chip generation sequence and the chip trajectory sequence; Based on the time after the skiving process starts, obtain the theoretical movement trajectory of the chips generated at the corresponding time, and analyze the synchronization error of the machine tool axis by comparing the actual movement trajectory monitored at the same time.

16. The gear hobbing machine shaft synchronization control method according to claim 15, wherein Construct a chip position sequence according to the theoretical positions where the chips corresponding to the theoretical movement trajectories in the chip trajectory sequence reach the induction area; establish a mapping relationship between the chip generation sequence, the chip trajectory sequence, and the chip position sequence; Based on the time after the skiving process starts, obtain the theoretical position where the chips generated at the corresponding time reach the induction area, and analyze the synchronization error of the machine tool axis by comparing the actual position reaching the induction area monitored at the same time.

17. The synchronous control method for the gear hobbing machine tool shaft according to any one of claims 4-6, characterized in that, Send the regulation strategy to the rotary encoder monitoring system, and the rotary encoder monitoring system updates the normal rotational speed of the drive side of the machine tool axis.

18. A synchronous control system for a gear hobbing machine tool shaft, characterized in that, Including: An error analysis module that analyzes the synchronization error of the machine tool axis based on the chip state generated during the skiving process; The chip state is the movement trajectory information of the chips generated during the skiving process after separating from the workpiece blank; The movement trajectory information is the trajectory passing points; by setting at least one induction area on the movement trajectory of the chip, monitor the position information when the chip reaches the induction area, defined as the actual trajectory passing point; extract the position information when the chip reaches the induction area in the theoretical movement trajectory, defined as the theoretical trajectory passing point; Analyze the synchronization error of the machine tool axis by comparing the theoretical trajectory passing point with the actual trajectory passing point; A regulation module that regulates the rotational speed of the machine tool axis based on the synchronization error.

19. The gear hobbing machine shaft synchronization control system according to claim 18, wherein, The error analysis module is signal-connected to the rotary encoder monitoring system and the drive regulation device of the machine tool axis. The error analysis module obtains the synchronization error situation of the drive side of the machine tool axis through the rotary encoder monitoring system; The regulation module is used to regulate the rotational speed of the machine tool axis based on the synchronization error when there is a synchronization error in the machine tool axis and there is no synchronization error on the drive side of the machine tool axis.

20. The gear hobbing machine shaft synchronization control system according to claim 18 or 19, characterized in that, The error analysis module is used to monitor the trajectory passing points of the chips generated during the gear hobbing process. The error analysis module includes a movable monitoring surface, which is composed of several substrates. The adjacent substrates are hinged by a flexible connector. An angle adjustment mechanism for adjusting the angle of any substrate is integrated on the back of the substrate, and flexible film pressure sensors are arranged on the surfaces of the substrates.

21. The gear shaper machine tool shaft synchronization control system according to claim 20, characterized in that, The angle adjustment mechanism is used to adjust the substrate according to the theoretical movement trajectory of the chips, so that the chips flow towards the collection area.

22. A shaving machine tool, comprising a rotary encoder monitoring system and a machine tool axis drive control device, characterized in that, Integrated with the gear hobbing machine shaft synchronization control system described in claim 18, the gear hobbing machine shaft synchronization control system is used to synchronously control the machine shafts.

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