Straight line machining surface machining path interpolation method based on multiple models and machine tool

Abstract

The invention discloses a multi-model-based straight line machining surface machining path interpolation method and a machine tool, machining path model information is generated based on workpiece straight line machining surface information, a cutter location point trajectory curve in the machining path information is associated with a straight line machining surface upper edge curve, and a cutter axis point trajectory curve is associated with a straight line machining surface lower edge curve; then geometric interpolation is carried out based on the machining path model information, machining speed setting is carried out based on the machining path model information, and the machining speed is set based on an interpolation cutter location point after geometric interpolation; calculating the position information of each physical axis from the position information of the interpolation cutter location point and the cutter axis vector information in an inverse solution manner, and storing the position information; interpolating information is arranged into a control command list, the control command list data is executed in sequence, and the interpolating information comprises the position information of each physical axis and the processing speed information. And accurate interpolation can be performed based on cutter axis point trajectory curves, cutter location points and cutter axis point correlation function information in multiple models, so that the bow height error is eliminated, and the interpolation precision is improved.

Description

Technical Field

[0001] The invention relates to the technical field of five-axis machine tool processing, and in particular to a multi-model-based ruled surface processing path interpolation method and a machine tool. Background Art

[0002] The processing equipment in the machining field usually uses a CNC system. The processing program generated after the processing path and process planning in the CAM software is usually input into the CNC system in the format of G and M codes. The processing of complex mechanical parts is usually processed in the machining center through multi-axis processing such as turning, milling, and drilling. The engine impeller is a typical complex part. The impeller is widely used in the fields of energy, aviation, and navigation.

[0003] The five-axis machining program usually includes three-dimensional linear motion (G1) and circular motion (G2) of the tool position point. The linear motion or circular motion here refers to the motion trajectory of the tool position point, and the direction of the tool axis is expressed in the NC program in the following two ways. One way is to use the three components of the tool axis vector. The other way is to use the angles of the two rotation axes of the five-axis machine tool.

[0004] After the NC program using the tool axis vector expression is imported into the CNC system, the program must be interpolated in the interpolator of the CNC system. Because the interpolator of the CNC system only has the mathematical model of the tool position point line segment (such as a circular arc) and the information of the tool axis vector at the starting point and the end point of the line segment, when the interpolator interpolates the line segment model, there is no reasonable method to interpolate the tool axis vector. An approximate method is to find a point on the tool axis vector at the starting point and the end point of the line segment, and then perform dense interpolation on the line connecting these two points. The number of interpolation points is consistent with the number of interpolation points of the tool position point trajectory line segment, and the direction of the line connecting the two corresponding interpolation points is used as the interpolated tool axis vector. Obviously, the shape of the workpiece cut in this way has a bow height error with the original processing surface, and for workpieces with higher precision requirements, the existing methods are difficult to meet the requirements. Summary of the invention

[0005] To solve the above problems, the purpose of the present invention is to provide a multi-model based ruled surface machining path interpolation method and machine tool, which can solve the problem of nonlinear bow height error caused by the interpolation scheme of the prior art.

[0006] The technical solution provided by the present invention is: a method for interpolating machining paths of ruled machined surfaces based on multiple models, comprising the following steps:

[0007] Generate machining path model information based on workpiece ruled surface information, the machining path information includes tool position point trajectory curve model information, tool axis point trajectory curve model information and tool position point and tool axis point correlation function information; wherein the tool position point trajectory curve is correlated with the upper edge curve of the ruled surface, and the tool axis point trajectory curve is correlated with the lower edge curve of the ruled surface;

[0008] Based on the machining path model information, geometric interpolation is performed to decompose each machining line segment on the machining path into interpolation steps, where the interpolation step data includes the tool position location and tool axis vector information, and the data of all interpolation steps are arranged into a list according to the machining sequence;

[0009] The machining speed is set based on the machining path model information, and the machining speed is set based on the interpolation tool position after geometric interpolation;

[0010] The position information of each physical axis is calculated and stored by inverse solution from the position information of the interpolated tool position and the tool axis vector information;

[0011] The interpolation information is arranged into a control command list, and the control command list data is executed sequentially, wherein the interpolation information includes position information of each physical axis and processing speed information.

[0012] Preferably, generating machining path model information based on workpiece straight-grained machining surface information further includes determining a tool axis point trajectory curve:

[0013] If the upper edge curve and the lower edge curve of the straight-grained machining surface are simple geometric curves of straight lines or arcs, the upper edge curve and the lower edge curve are perpendicular to the machining surface and offset outward by a tool radius; the offset of the arc curve is that the radius becomes larger or smaller by a tool radius; the offset upper edge curve is used as the trajectory curve of the tool position point, and the offset lower edge curve is used as the trajectory curve of the tool axis point;

[0014] If the upper edge curve and the lower edge curve of the ruled surface are not simple geometric curves, first discretize each ruled surface into a combination of straight generatrixes, and offset the upper point and the lower point of each straight generatrix perpendicular to the processing surface outward by a tool radius, fit the upper point of the offset straight generatrix group to the upper edge curve as the trajectory curve of the tool position point, and fit the lower point of the straight generatrix group to the lower edge curve as the trajectory curve of the tool axis point;

[0015] After the offset, the upper and lower edge curves of adjacent processing line segments need to be transitioned.

[0016] Preferably, generating the machining path model information based on the workpiece straight-grained machining surface information further includes determining the correlation function between the tool position point and the tool axis point:

[0017] Constructing the mathematical relationship between the arc length position of the tool position point on the trajectory curve and the arc length position of the tool axis point on the trajectory curve;

[0018] Or the discrete correspondence between the arc length position of the tool position point on the trajectory curve and the arc length position of the tool axis point on the trajectory curve is expressed in a list manner.

[0019] Preferably, a mathematical relationship between the arc lengths of the tool position point trajectory curve and the tool axis point trajectory curve is constructed by dividing the tool position point trajectory curve and the tool axis point trajectory curve into equal parts, and then constructing a mathematical relationship between the arc lengths of each divided tool position point trajectory curve and tool axis point trajectory curve.

[0020] Preferably, the method further comprises: the tool position point trajectory at the corner degenerates into a point, the tool position point trajectory at the corner corresponds to an arc length of a tool axis point trajectory curve in the list, and the arc angle step length is used during interpolation.

[0021] Preferably, generating machining path model information based on workpiece straight-grained machining surface information further includes:

[0022] The CAM module expresses the line segments of the generated machining path with a line segment class or structure of an object-oriented programming language, the entire machining path can be expressed with an object list of the line segment class or structure, a member variable representing the line segment type of the line segment class or structure is used to distinguish machining lines, cut-in and cut-out lines, and fast-forward lines, a member variable representing the machining speed of the line segment class or structure is used to express the theoretical machining speed, one or more member functions of the line segment class or structure that express the mathematical model of geometric curves are used to express the tool position point trajectory curve function, one or more member functions of the line segment class or structure that express the mathematical model of geometric curves are used to express the tool axis point trajectory curve function, and one or more member functions of the line segment class or structure that express the mathematical model of associated functions are used to express the associated function; the interpolation module obtains the machining path model information by sharing memory with the CAM module;

[0023] Alternatively, the processing path model information can be transferred from the CAM module to the interpolation module by passing modeling parameters. The modeling parameters include general parameters of path segments, model parameters of tool position point trajectory curves, and model parameters of tool axis point trajectory curves. The processing path model information expressed by modeling parameters can be transferred through text files or other data interaction methods. The processing path model information must include tool position point and tool axis point information at the origin of the processing path.

[0024] Preferably, setting the processing speed based on the processing path model information further includes:

[0025] Based on the processing path information, the process model is called to calculate the theoretical processing speed for each processing path segment and the endpoints of the path segment;

[0026] The process model includes a functional relationship with the curvature change of the path segment curve as the independent variable and the processing speed as the dependent variable. The greater the curvature change of the path segment curve, the slower the speed. When calculating the speed of the path segment endpoints, the greater the change in the path direction of two adjacent segments, the slower the speed.

[0027] Preferably, the method further comprises:

[0028] A zero-length line segment is added to each line segment connection point, and the zero-length line segment is used as a junction. The theoretical processing speed of the junction reflects the change in the tangential direction of the adjacent line segments of the junction. The greater the change in the tangential direction, the smaller the theoretical processing speed of the junction. The junction can also realize the transition of the tool axis vector direction of the adjacent line segments of the junction.

[0029] And / or, inserting a transition arc at a joint where the tangential direction of the machining path changes by more than a threshold value.

[0030] Preferably, the method further comprises:

[0031] Performing geometric interpolation: determining an interpolation step length, wherein the interpolation step length is calculated according to an interpolation cycle and a theoretical processing speed; or determining the interpolation step length according to control accuracy, and then calculating the number of interpolation cycles required for the interpolation step length according to the interpolation cycle and the theoretical processing speed; wherein for a zero-length line segment, the interpolation step length represents an arc angle of a change in the direction of a tool axis within an interpolation cycle or an arc angle determined according to arc angle control accuracy;

[0032] The interpolation step length is used to segment the tool position point trajectory curve of the machining path to obtain the interpolation tool position point. For the zero-length line segment, the arc angle of the tool axis direction change is segmented.

[0033] Find the interpolation point on the tool axis point trajectory curve through the tool position point and tool axis point correlation function, and obtain the tool axis point coordinates and tool axis vector information corresponding to the interpolation tool position point;

[0034] The interpolation point data is expressed by a step class or structure of an object-oriented programming language, and the entire machining path after interpolation is expressed by an object list of the step class or structure;

[0035] Perform speed interpolation on the object list of the stepper class or structure: Based on the acceleration limit of the machine, the acceleration limit of the specific process, and the acceleration and deceleration model, take the theoretical processing speed on the tool position point path segment as the maximum value, take the theoretical processing speed at the endpoint of the path segment as the starting point, and aim to obtain a continuous and smooth processing speed. Stepwisely adjust the theoretical processing speed corresponding to each interpolated tool position point in the direction of the midpoint of the path segment in both directions, and store the adjusted processing speed as a member variable of the stepper class or structure in the object list of the stepper class or structure.

[0036] Preferably, for the case where interpolation is performed inside the CAM or the interpolation module shares memory with the CAM module, the association function can be obtained from one or several member functions of the segment class or structure that express the mathematical model of the association function; for the case where interpolation is performed outside the CAM, the association function is limited to the case of equal division; for zero-length tool position point segments, no association function is required, and the tool axis point is determined by the arc angle interpolation step, which is independent of the tool position point; for the case where the tool axis point trajectory curve degenerates into a point, no association function is required to determine the tool axis point.

[0037] Preferably, the method further comprises: if the processing path model information is transferred from the CAM module to the interpolation module in the form of modeling parameters, then the modeling parameters in the interpolation module are restored to a mathematical model.

[0038] Preferably, the method further comprises: if the interpolation module and the control execution module do not share a memory, then the interpolated step list data is transmitted to the control execution module by means of data communication or text file data interaction.

[0039] Preferably, when the machining path model information is generated based on the workpiece straight-grain machining surface information, it is also necessary to calculate the offset required for reverse compensation based on the prediction mathematical model and the preset process parameters. The prediction mathematical model includes but is not limited to one or more of a cutting speed model, a slit taper model, a backlash model, and a machine tool random error model established based on the machining mechanism. The initial tool axis vector after the offset is optimized according to the reverse compensation offset to effectively compensate for the error caused during the machining process:

[0040] The first prediction mathematical model is called to calculate the drag amount of the cutting workpiece according to the target parameter information of the current position point, and then calculate the first angle that needs to be swung along the cutting feed direction to perform reverse compensation;

[0041] Acquire a first component of the initial tool axis vector along the cutting feed direction, and perform a first optimization according to the first angle to obtain a second component result of the optimized tool axis vector along the cutting feed direction;

[0042] The second prediction mathematical model is called to calculate the lateral taper generated by cutting the workpiece according to the target parameter information of the current position point, and then calculate the second angle that needs to be swung in the vertical direction along the cutting feed direction to perform reverse compensation;

[0043] Obtaining a third component of the initial tool axis vector in a direction perpendicular to the cutting feed direction, and performing a second optimization according to the second angle to obtain a fourth component result of the optimized tool axis vector perpendicular to the cutting feed direction;

[0044] According to the values ​​of the second component and the fourth component, the final optimized tool axis vector is synthesized.

[0045] Based on the same concept, the present invention also provides a machine tool, comprising:

[0046] A machining path generation module is used to generate machining path model information based on workpiece straight-grain machining surface information, wherein the machining path information includes tool position point trajectory curve model information, tool axis point trajectory curve model information, and information on tool position point and tool axis point correlation function; wherein the tool position point trajectory curve is correlated with the upper edge curve of the straight-grain machining surface, and the tool axis point trajectory curve is correlated with the lower edge curve of the straight-grain machining surface;

[0047] The geometric interpolation module is used to perform geometric interpolation, decompose each section of the processing path into interpolation steps, and arrange the data of all interpolation steps into a list according to the processing order;

[0048] The speed setting module is used to set the processing speed based on the interpolation tool position after geometric interpolation;

[0049] An inverse solution calculation module is used to inversely calculate the position information of each physical axis from the tool axis vector of the interpolation tool position and store it;

[0050] The execution module is used to arrange the interpolation information into a control command list and execute the control command list data in sequence.

[0051] Based on the same concept, the present invention also provides an electronic device, comprising:

[0052] A memory, the memory being used to store a processing program;

[0053] A processor, wherein when executing the processing program, the processor implements any one of the above-mentioned methods for interpolating machining paths of ruled machined surfaces based on multiple models.

[0054] Based on the same concept, the present invention also provides a readable storage medium, on which a processing program is stored. When the processing program is executed by a processor, any one of the above-mentioned methods for high-precision head reconstruction based on a single image is implemented.

[0055] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0056] 1. The technical solution of this embodiment introduces the tool position point trajectory curve, the tool axis point trajectory curve, and the tool position point and tool axis point correlation function into the processing path information before interpolation. That is to say, there are both mathematical models of the tool position point and the tool axis point. The tool position point and the tool axis point mathematical models are simultaneously transmitted to the interpolation module. Compared with the prior art which processes only based on the tool position point mathematical model, the interpolation module of this embodiment subsequently incorporates the tool axis point trajectory curve and the tool position point and tool axis point correlation function into the processing process when performing theoretical processing speed calculation, geometric interpolation and speed interpolation. The model information is more complete, which can avoid the occurrence of bow height error and improve the processing accuracy of the workpiece.

[0057] 2. The present invention adopts an iterative interpolation method, that is, based on the introduced tool position point trajectory curve, tool axis point trajectory curve, tool position point and tool axis point correlation function, process parameter model, etc., geometric interpolation is first performed, and then the speed of the interpolated short line segment is set. Here, a speed model that can adapt to the continuous change of line segment characteristics (such as change in movement direction) is required. When performing the next step of process parameter interpolation, a group of process parameter models (cutting seam taper model, back drag model, etc.) that can adapt to the change of line segment characteristics and continuous change of speed are required. Therefore, in the entire processing program, the process parameters can change with the actual working conditions, and the interpolation accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0059] Figure 1 A schematic diagram for generating machining paths in CAM software;

[0060] Figure 2 It is a schematic flow chart of a method for interpolating machining paths of ruled machined surfaces based on multiple models according to the present invention;

[0061] Figure 3 It is a schematic diagram of an embodiment in which the tool position point trajectory degenerates into a point at a corner;

[0062] Figure 4 This is an example of tool location path and theoretical processing speed;

[0063] Figure 5 An example of velocity distribution after interpolation. DETAILED DESCRIPTION

[0064] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0065] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0066] First embodiment

[0067] See also Figure 2 This embodiment provides a method for interpolating a machining path of a ruled surface based on multiple models, comprising the following steps:

[0068] Generate machining path model information based on workpiece ruled surface information, the machining path information includes tool position point trajectory curve model information, tool axis point trajectory curve model information and tool position point and tool axis point correlation function information; wherein the tool position point trajectory curve is correlated with the upper edge curve of the ruled surface, and the tool axis point trajectory curve is correlated with the lower edge curve of the ruled surface;

[0069] Based on the machining path model information, geometric interpolation is performed to decompose each machining line segment on the machining path into interpolation steps, where the interpolation step data includes the tool position location and tool axis vector information, and the data of all interpolation steps are arranged into a list according to the machining sequence;

[0070] The machining speed is set based on the machining path model information, and the machining speed is set based on the interpolation tool position after geometric interpolation;

[0071] The position information of each physical axis is calculated and stored by inverse solution from the position information of the interpolated tool position and the tool axis vector information;

[0072] The interpolation information is arranged into a control command list, and the control command list data is executed sequentially, wherein the interpolation information includes position information of each physical axis and processing speed information.

[0073] The technical solution of this embodiment introduces the tool position point trajectory curve, the tool axis point trajectory curve, and the tool position point and tool axis point correlation function into the processing path information before interpolation. That is to say, there are both mathematical models of the tool position point and the tool axis point, and the mathematical models of the tool position point and the tool axis point are simultaneously transmitted to the interpolation module. Compared with the prior art which processes only based on the mathematical model of the tool position point, the interpolation module of this embodiment subsequently incorporates the tool axis point trajectory curve and the tool position point and tool axis point correlation function into the processing process when performing theoretical processing speed calculation, geometric interpolation and speed interpolation. The model information is more complete, which can avoid the occurrence of bow height errors and improve the processing accuracy of the workpiece.

[0074] See also Figure 1 , using CAM software Figure 1 The workpiece shown is used as an example to generate the machining path. Figure 1 A represents the starting point and end point of the path, L represents the fast-forward line, M represents the discrete and offset main line, and R represents the cut-in and cut-out lines.

[0075] Preferably, generating machining path model information based on workpiece straight-grained machining surface information further includes determining a tool axis point trajectory curve:

[0076] If the upper edge curve and the lower edge curve of the straight-grained machining surface are simple geometric curves of straight lines or arcs, the upper edge curve and the lower edge curve are perpendicular to the machining surface and offset outward by a tool radius; the offset of the arc curve is that the radius becomes larger or smaller by a tool radius; the offset upper edge curve is used as the trajectory curve of the tool position point, and the offset lower edge curve is used as the trajectory curve of the tool axis point;

[0077] If the upper edge curve and the lower edge curve of the ruled surface are not simple geometric curves, first discretize each ruled surface into a combination of straight generatrixes, and offset the upper point and the lower point of each straight generatrix perpendicular to the processing surface outward by a tool radius, fit the upper point of the offset straight generatrix group to the upper edge curve as the trajectory curve of the tool position point, and fit the lower point of the straight generatrix group to the lower edge curve as the trajectory curve of the tool axis point;

[0078] After the offset, the upper and lower edge curves of adjacent processing line segments need to be transitioned.

[0079] In this embodiment, the lower point of the offset straight parent line group is fitted as the lower edge curve as the trajectory curve of the tool axis point. After the trajectory curve of the tool axis point is obtained, it is sent to the interpolation module together with other information in the model, so that the interpolation accuracy of the interpolation module is higher. The information contained in the model also includes: machining path tool position point (TCP) trajectory curve, tool axis point trajectory curve, tool position point and tool axis point position correlation function, machine tool structure model parameters, process parameter model, interpolation cycle parameters, control accuracy parameters, etc. Among them, the tool position point and tool axis point position correlation function refers to the distribution law of the tool position point and tool axis point on the trajectory curve. One of the simplest examples of correlation functions is equal division. A general correlation function refers to the mathematical relationship between the arc length position of the tool position point on its trajectory curve and the arc length position of the tool axis point on its trajectory curve. Correlation functions that do not form a mathematical law can also be expressed in the form of a list. For Figure 3 In the case shown, the tool position point trajectory degenerates into a point at the corner, and the trajectory curve of the tool axis point can be an arc curve like the 1-2-3-4-5 points, or a straight line like the 1'-2'-3'-4'-5' points, or other types of curves. However, because the arc length of the tool position point trajectory curve is zero, the association function cannot associate the arc length position of the tool position point on its trajectory curve with the arc length position of the tool axis point on its trajectory curve. In this case, the association function is not needed, and the arc angle step size can be used for interpolation. Figure 3On the contrary, it is possible that the trajectory of the tool axis point degenerates into a point at the corner, but there is a trajectory curve of the tool position point. In this case, the correlation function is also unnecessary because the position of the tool axis point is determined. Different processing technologies use different models. For example, water jet cutting includes cutting speed model, slit taper model, drag model, etc. Laser processing includes cutting parameter model, perforation parameter model, laser power / frequency curve, etc. Milling processing includes processing speed model, acceleration model, jerk model, feed model, cutting force model, etc.

[0080] Specifically, the generation of machining path information based on the workpiece straight-grained machining surface information also includes the determination of the correlation function between the tool position point and the tool axis point:

[0081] Constructing the mathematical relationship between the arc length position of the tool position point on the trajectory curve and the arc length position of the tool axis point on the trajectory curve;

[0082] Or the discrete correspondence between the arc length position of the tool position point on the trajectory curve and the arc length position of the tool axis point on the trajectory curve is expressed in a list manner.

[0083] By establishing the correlation function between the tool position point and the tool axis point, the position and posture of the tool can be precisely and synchronously controlled to ensure that the relative movement of the tool and the workpiece during the machining process meets the machining requirements. The determination of the correlation function can be a continuous mathematical relationship or a discrete list correspondence. This flexibility allows the machining strategy to be optimized according to the actual machining situation to adapt to complex machining tasks.

[0084] Preferably, a mathematical relationship between the arc lengths of the tool position point trajectory curve and the tool axis point trajectory curve is constructed by dividing the tool position point trajectory curve and the tool axis point trajectory curve into equal parts, and then constructing a mathematical relationship between the arc lengths of each divided tool position point trajectory curve and tool axis point trajectory curve.

[0085] By establishing precise mathematical relationships, the synchronous movement of the tool position point and tool axis point during machining can be ensured, which is essential for maintaining machining accuracy, especially in complex five-axis machining. Equally dividing the trajectory curve and establishing an arc length relationship can optimize the tool path and reduce unnecessary movement, thereby shortening machining time and improving production efficiency. By accurately controlling the position of the tool position point and tool axis point, machining errors caused by inaccurate tool positioning can be reduced, and the dimensional accuracy and surface quality of the machined part can be improved.

[0086] Preferably, the method further comprises: the tool position point trajectory at the corner degenerates into a point, the tool position point trajectory at the corner corresponds to an arc length of a tool axis point trajectory curve in the list, and the arc angle step length is used during interpolation.

[0087] When the tool position trajectory at the corner degenerates into a point, the arc angle step length is used for interpolation, which can better simulate the actual motion trajectory of the tool at the corner and further improve the machining accuracy. The arc angle step length is used for interpolation at the corner to make the tool movement smoother and reduce the machining defects caused by the incoherent tool movement.

[0088] Preferably, generating machining path model information based on workpiece straight-grained machining surface information further includes:

[0089] The CAM module expresses the line segments of the generated machining path with a line segment class or structure of an object-oriented programming language, the entire machining path can be expressed with an object list of the line segment class or structure, a member variable representing the line segment type of the line segment class or structure is used to distinguish machining lines, cut-in and cut-out lines, and fast-forward lines, a member variable representing the machining speed of the line segment class or structure is used to express the theoretical machining speed, one or more member functions of the line segment class or structure that express the mathematical model of geometric curves are used to express the tool position point trajectory curve function, one or more member functions of the line segment class or structure that express the mathematical model of geometric curves are used to express the tool axis point trajectory curve function, and one or more member functions of the line segment class or structure that express the mathematical model of associated functions are used to express the associated function; the interpolation module obtains the machining path model information by sharing memory with the CAM module;

[0090] Alternatively, the processing path model information can be transferred from the CAM module to the interpolation module by passing modeling parameters. The modeling parameters include general parameters of path segments, model parameters of tool position point trajectory curves, and model parameters of tool axis point trajectory curves. The processing path model information expressed by modeling parameters can be transferred through text files or other data interaction methods. The processing path model information must include tool position point and tool axis point information at the origin of the processing path.

[0091] By using object-oriented programming language to express the machining path, accurate machining path planning and control can be achieved, thereby optimizing the machining process and improving efficiency. When the machining path information is transmitted through modeling parameters, the correlation function is applicable to the equal division relationship between the tool position point trajectory curve and the tool axis point trajectory curve.

[0092] For example, each line segment of the generated machining path is expressed as a C++ class Entity, and the entire machining path can be represented by a C++ Entity list. <entity>To express, use the member variable m_dQuality of the Entity class to distinguish the processing line, cutting-in and cutting-out line, and fast-forward line;

[0093] For example, 1-5 represents level 5 processing quality, 9 represents cutting in and out, 10 represents fast forward in the idle stroke, and 13 represents the idle stroke transition line.

[0094] The processing path information is obtained by means of shared memory; or, the processing path information is expressed by means of a text file, wherein the processing path information text file contains general parameters of path segments, parameters of tool position point NURBS spline curves, parameters of tool axis point NURBS spline curves, and the text file (usually in the first line) shall give the tool position point and tool axis point information at the origin of the processing path: m_StartPt_TCP_X, m_StartPt_TCP_Y, m_StartPt_TCP_Z, m_StartPt_Axis_X, m_StartPt_Axis_Y, m_StartPt_Axis_Z.

[0095] If the interpolation module is placed inside the CAM software, the interpolation module can directly obtain the above path information. The example of class Entity is as follows:

[0096]

[0097]

[0098]

[0099] If the interpolation module is placed outside the CAM software, but on the same computer, the interpolation module can obtain the above path information through shared memory. If it is not on the same computer, the processing path information can be expressed in a text file. For example, the following example uses three lines in a text file.

[0100] (It can also be combined into one line, three lines are for easy reading) to express the information of a processing path segment. The entire processing path is a combination of the information of the above single processing path segments.

[0101] First row: m_nEntityNo,m_dQuality,m_dThickness,m_nOffset

[0102] Second line: m_nEntityType_TCP,m_EPt_TCP_X,m_EPt_TCP_Y,m_EPt_TCP_Z,m_dRadius_TCP,m_dLength_TCP,{P; (X,Y,Z,R;X,Y,Z,R;...;X,Y,Z,R;X,Y,Z,R);(K;...K)};

[0103] The third line: m_nEntityType_Axis,m_EPt_Axis_X,m_EPt_Axis_Y,m_EPt_Axis_Z,m_dRadius_Axis,m_dLength_Axis,{P; (X,Y,Z,R;X,Y,Z,R;...;X,Y,Z,R;X,Y,Z,R);(K;...K)};

[0104] The parameters in the first line are the common parameters of the path segment, which can be defined by referring to the definition of the Entity class example above.

[0105] The parameters in the second line, except for the parameters in {}, can also refer to the definition of the Entity class example above. When m_nEntityType_TCP is 4, the parameters in {} are used instead. The parameters in {} represent the parameters of the tool point NURBS spline curve (P is the level of the NURBS spline curve, X / Y / Z in the first () are the control point coordinates, R is the weight of the control point, and the number of control points is at least equal to the number of levels; K in the second () is the node vector parameter, and the number of node vector parameters must be equal to the number of control points plus the level).

[0106] The parameters in the third line can also refer to the definition of the Entity class example above, except for the parameters in {}. Only when m_nEntityType_Axis is 4, the parameters in {} are used instead. The parameters in {} represent the parameters of the NURBS spline curve of the tool axis point.

[0107] The text file (usually in the first line) should give the tool position point and tool axis point information at the origin of the machining path: m_StartPt_TCP_X, m_StartPt_TCP_Y, m_StartPt_TCP_Z, m_StartPt_Axis_X, m_StartPt_Axis_Y, m_StartPt_Axis_Z.

[0108] First import the path information in the text file into a list of Entities <entity>, and then passed to the interpolation module.

[0109] If the processing path model information is transferred from the CAM module to the interpolation module in the form of modeling parameters, the modeling parameters are restored to a mathematical model in the interpolation module.

[0110] Preferably, setting the processing speed based on the processing path model information further includes:

[0111] The process model is called based on the processing path information to calculate the theoretical processing speed for each processing path segment and the endpoint of the path segment, wherein the processing path information at least includes information on the change of process parameters including thickness information, and the thickness information is obtained by calculating the distance between the tool position point and the tool axis point or by the workpiece thickness parameter;

[0112] The process model includes a functional relationship with the curvature change of the path segment curve as the independent variable and the processing speed as the dependent variable. The greater the curvature change of the path segment curve, the slower the speed. When calculating the speed of the path segment endpoints, the greater the change in the path direction of two adjacent segments, the slower the speed.

[0113] Since the technical solution of the present invention introduces the tool position point trajectory curve, tool axis point trajectory curve, and tool position point and tool axis point correlation function, the cutting thickness information is the distance between the upper and lower points of the busbar. The actual cutting thickness affects the control of the processing speed, and the curvature change of the path curve, the change of the path direction of two adjacent line segments of the path, etc., jointly affect the control of the theoretical processing speed, so that under the technical concept of the present invention, the determination of the theoretical processing speed is more in line with the workpiece working conditions, and the processing accuracy is higher. The use of the process model enables the system to adapt to different processing conditions and workpiece materials, and improves the flexibility and adaptability of the processing system.

[0114] Preferably, the method further comprises:

[0115] A zero-length line segment is added to each line segment connection point, and the zero-length line segment is used as a junction. The theoretical processing speed of the junction reflects the change in the tangential direction of the adjacent line segments of the junction. The greater the change in the tangential direction, the smaller the theoretical processing speed of the junction. The junction can also realize the transition of the tool axis vector direction of the adjacent line segments of the junction.

[0116] And / or, insert transition arcs at the joints where the tangential direction of the machining path changes beyond a threshold value. This improves the smoothness of the motion speed, acceleration, and jerk, suppresses vibration and jitter, and improves machining efficiency. For high-speed and high-precision machining applications (such as laser cutting), it is necessary to insert transition arcs at the joints where the tangential direction of the machining path changes greatly to improve the smoothness of the motion speed, acceleration, and jerk, suppress vibration and jitter, and improve machining efficiency.

[0117] Preferably, the method further comprises:

[0118] Performing geometric interpolation: determining an interpolation step length, wherein the interpolation step length is calculated according to an interpolation cycle and a theoretical processing speed; or determining the interpolation step length according to control accuracy, and then calculating the number of interpolation cycles required for the interpolation step length according to the interpolation cycle and the theoretical processing speed; wherein for a zero-length line segment, the interpolation step length represents an arc angle of a change in the direction of a tool axis within an interpolation cycle or an arc angle determined according to arc angle control accuracy;

[0119] The interpolation step length is used to segment the tool position point trajectory curve of the machining path to obtain the interpolation tool position point. For the zero-length line segment, the arc angle of the tool axis direction change is segmented.

[0120] The interpolation point on the tool axis point trajectory curve is found through the tool position point and tool axis point association function, and the tool axis point coordinates and tool axis vector information of the corresponding interpolated tool position point are obtained; among them, for the case of interpolation inside the CAM, the association function can be obtained from the Entity class; for the case of interpolation outside the CAM, the association function can be limited to the case of equal division; for the zero-length tool position point line segment, no association function is required, and the tool axis point is determined by the arc angle interpolation step, which is independent of the tool position point; for the case where the tool axis point trajectory curve degenerates into a point, no association function is required to determine the tool axis point;

[0121] The interpolation point data is expressed by a step class or structure of an object-oriented programming language, and the entire machining path after interpolation is expressed by an object list of the step class or structure;

[0122] Perform speed interpolation on the object list of the stepper class or structure: Based on the acceleration limit of the machine, the acceleration limit of the specific process, and the acceleration and deceleration model, take the theoretical processing speed on the tool position point path segment as the maximum value, take the theoretical processing speed at the endpoint of the path segment as the starting point, and aim to obtain a continuous and smooth processing speed. Stepwisely adjust the theoretical processing speed corresponding to each interpolated tool position point in the direction of the midpoint of the path segment in both directions, and store the adjusted processing speed as a member variable of the stepper class or structure in the object list of the stepper class or structure.

[0123] For example, store the interpolation point data in the list list <pathstep>;

[0124] Here PathStep is a C++ class that collects the interpolation information of each interpolation point after interpolation. The following is an example of the PathStep class:

[0125]

[0126] In the step of geometric interpolation, the interpolation information mainly includes the geometric information of the interpolation points (m_StepPtS, m_StepPtE, m_nEntityNo, m_dOrientAngle, m_dLength, m_bDrive, m_sDrive).

[0127] Perform speed interpolation: Based on the acceleration limit of the machine, the acceleration limit of the specific process, and the acceleration and deceleration model, the theoretical processing speed on the tool position path is taken as the target, and the theoretical processing speed at the path endpoint is taken as the starting point. The theoretical processing speed corresponding to each interpolated tool position is gradually adjusted in both directions toward the midpoint of the path to obtain a continuous and smooth processing speed.

[0128] The acceleration and deceleration models include trapezoidal acceleration and deceleration, trigonometric function acceleration and deceleration, exponential acceleration and deceleration, S-curve acceleration and deceleration, cubic polynomial acceleration and deceleration, etc. Figure 4 This is an example of a tool location path. Different path segments have different theoretical processing speeds. Figure 5 This is an example of speed distribution after interpolation. The simplest trapezoidal acceleration and deceleration is used here. The speed smoothness can be improved by using S-curve acceleration and deceleration or other acceleration and deceleration models. Since acceleration and deceleration take time, the theoretical processing speed may not be achieved for shorter path segments. In the speed interpolation step, the interpolation information is saved in (m_dSpeed, m_bDelay, m_sDelay), where the delay Delay is calculated from m_dSpeed ​​and m_dLength.

[0129] The present invention adopts an iterative interpolation method, that is, based on the introduced tool position point trajectory curve, tool axis point trajectory curve, tool position point and tool axis point correlation function, process parameter model, etc., geometric interpolation is first performed, and then the speed of the interpolated short line segment is set. Here, a speed model that can adapt to the continuous change of line segment characteristics (such as change of movement direction) is required. When performing the next step of process parameter interpolation, a group of process parameter models (cutting seam taper model, back drag model, etc.) that can adapt to the change of line segment characteristics and continuous change of speed are required. Therefore, in the entire processing program, the process parameters can change with the actual working conditions, and the interpolation accuracy is higher.

[0130] Further, the IO command is inserted. For a specific processing technology, according to the properties of the processing path, the corresponding IO control command is inserted at the appropriate interpolation tool position, such as: for water jet cutting, the high pressure pump on / off command, nozzle on / off command, and abrasive on / off command are inserted. In this step, the interpolation information is saved in (m_bIO, m_sIO).

[0131] For specific processing techniques, see Figure 2 A process parameter interpolation step can be added to calculate process-related parameters at the interpolation tool position. If necessary, adjust the tool position and tool axis vector, or adjust the process parameters. For example: for water jet cutting, the current jet taper (m_dTE) and jet drag (m_dJL) are calculated at the interpolation tool position according to the kerf taper model and drag model and the speed of the current interpolation step. If the tool axis inclination causes a substantial change in the actual cutting thickness, the cutting speed (m_dSpeed) needs to be adjusted. For milling finishing, the current cutting force and the deformation between the tool and the workpiece are calculated at the interpolation tool position according to the three-dimensional model of the workpiece and the three-dimensional model of the tool, as well as the processing speed, feed rate, and cutting depth of the current interpolation step, and the position of the tool position is adjusted according to the deformation; for laser cutting, the current power / frequency is calculated at the interpolation tool position according to the laser power / frequency curve and the speed of the current interpolation step, and the output laser power / frequency is adjusted.

[0132] Preferably, when the machining path model information is generated based on the workpiece straight-grain machining surface information, it is also necessary to calculate the offset required for reverse compensation based on the prediction mathematical model and the preset process parameters. The prediction mathematical model includes but is not limited to one or more of a cutting speed model, a slit taper model, a backlash model, and a machine tool random error model established based on the machining mechanism. The initial tool axis vector after the offset is optimized according to the reverse compensation offset to effectively compensate for the error caused during the machining process:

[0133] The first prediction mathematical model is called to calculate the drag amount of the cutting workpiece according to the target parameter information of the current position point, and then calculate the first angle that needs to be swung along the cutting feed direction to perform reverse compensation;

[0134] Acquire a first component of the initial tool axis vector along the cutting feed direction, and perform a first optimization according to the first angle to obtain a second component result of the optimized tool axis vector along the cutting feed direction;

[0135] The second prediction mathematical model is called to calculate the lateral taper generated by cutting the workpiece according to the target parameter information of the current position point, and then calculate the second angle that needs to be swung in the vertical direction along the cutting feed direction to perform reverse compensation;

[0136] Obtaining a third component of the initial tool axis vector in a direction perpendicular to the cutting feed direction, and performing a second optimization according to the second angle to obtain a fourth component result of the optimized tool axis vector perpendicular to the cutting feed direction;

[0137] According to the values ​​of the second component and the fourth component, the final optimized tool axis vector is synthesized.

[0138] The calling prediction mathematical model for prediction includes:

[0139] Determine the current cutting speed in the water jet cutting scenario;

[0140] The cutting speed of each point on the cutting path is calculated based on the mathematical model corresponding to the ruled surface and the preset processing parameters.

[0141] Where, v is the cutting speed, Nm is the material machinability parameter, Pw is the water pressure, is the water flow rate, is the abrasive flow rate, Cs is the proportional factor, q is the cutting quality level, H is the material thickness, and D is the jet beam diameter. In the embodiment of the present application, Pw, The specific value corresponding to the superscript D is not limited in the embodiments of the present application, and the specific values ​​in the above formula are only examples.

[0142] The calling of the first prediction mathematical model to calculate the drag amount generated by cutting the workpiece according to the target parameter information of the current position point includes:

[0143] Get the current cutting speed, and combine the material thickness, material type, and process parameter information at the current position to calculate the drag amount caused by water jet cutting as follows:

[0144]

[0145] Among them, J(h) is the back-support amount, P is the water pressure, is the abrasive flow rate, h is the cutting depth, and v is the cutting speed. In the embodiment of the present application, the fixed values ​​of each parameter can be predetermined according to demand or experiment, etc., and the embodiment of the present application is not limited to this, and the specific values ​​in the above formula are only examples.

[0146] The calling of the second prediction mathematical model to calculate the lateral taper produced by cutting the workpiece according to the target parameter information of the current position point includes:

[0147] Get the current cutting speed and material thickness, and calculate the current lateral taper angle:

[0148]

[0149] Wherein, TA is the lateral taper produced by cutting, V is the cutting speed, and H is the thickness of the material being cut at the current cutting point. In the embodiment of the present application, the fixed values ​​of each parameter can be predetermined according to demand or experiment, etc., and the embodiment of the present application is not limited to this, and the specific values ​​in the above formula are only examples.

[0150] The core idea of ​​the present invention is to perform interpolation optimization on the machining path of the ruled surface based on multiple models. On the basis of the tool position point trajectory curve model, the tool axis point trajectory curve model, and the tool position point and tool axis point correlation function, iterative interpolation of the geometric model and the speed model, and appropriate optimization adjustment of the tool axis by the process adjustment mathematical model are comprehensively considered. The above multiple models are combined for optimization to improve the control accuracy of the interpolation and reduce the machining error.

[0151] In one embodiment, the initial tool axis vector is determined according to the generatrix of the ruled surface to be processed or the preset cutting direction, including: if the upper edge curve and the lower edge curve of the ruled surface are simple geometric curves, the upper edge curve and the lower edge curve are perpendicular to the processing surface and offset outward by a tool radius; if the upper edge curve and the lower edge curve of the ruled surface are not simple geometric curves, each ruled surface is discretized into a combination of straight generatrixes; the straight generatrix group is perpendicular to the processing surface and offset outward by a tool radius, and the upper point of the offset straight generatrix group is fitted as the upper edge curve as the trajectory curve of the tool position point, and the lower point of the straight generatrix group is fitted as the lower edge curve as the trajectory curve of the tool axis point. If the upper edge curve or the lower edge curve is a simple geometric curve, it is not necessary to determine its parameter equation by using a curve fitting method, but its parameters can be directly determined by using an existing function expression as its mathematical model. Among them, the special case of the mathematical model of a simple geometric curve is an arc, and the parameter equation of the arc is x(u)=cos(u), y(u)=sin(u). If the upper edge curve or the lower edge curve is not a simple geometric curve, but a complex curve, curve fitting is required. Specifically, any available method can be used to fit the upper edge curve and the lower edge curve to obtain their mathematical models, which is not limited in the embodiments of the present application. A special case of the mathematical model of a complex curve is the non-uniform rational B-splines (NonUniformRationalB-Splines, NURBS) curve parameter equation. From the above analysis, it can be seen that in the embodiments of the present application, the mathematical model of the upper edge curve and the mathematical model of the lower edge curve can correspond to a straight line or an arc or a spline curve, or can correspond to one or a group of other complex functions, or can correspond to a database, etc. Moreover, in actual applications, the upper edge curve and the lower edge curve corresponding to the same straight surface can be the same or different, which is not limited in the embodiments of the present application.

[0152] Furthermore, the machine tool inverse motion algorithm calculates the position information of each physical axis from the tool axis vector of the interpolated tool position. The position information can be incremental or absolute, and the interpolation information is stored in (m_StepPtS, m_StepPtE, m_bDrive, m_sDrive).

[0153] In order to reduce the amount of data, a data compression step can be added here. In the interpolation step data list generated in the above steps, adjacent interpolation steps with the same data are found and these interpolation steps are merged into an interpolation step that is repeated multiple times. The repetition information is saved in (m_bRepeat, m_sRepeat).

[0154] Arrange the above interpolation information (m_bIO, m_bDrive, m_bDelay, m_bRepeat) into a list of command control words. The command control word consists of 4 WORDs, 64 bits, or 8 bytes. The format is as follows:

[0155] "IO|Drive|Delay|Repeat"

[0156] The "IO" field occupies a 16-bit WORD

[0157] The "Drive" field occupies a 16-bit WORD

[0158] The "Delay" field occupies a 16-bit WORD

[0159] The "Repeat" field occupies 16 bits per WORD

[0160] If the interpolation is performed on the host computer, the above command control word list can be sent to the lower computer of the CNC system for processing. Because the amount of data after interpolation is relatively large, the method of sending data in batches can be used to send the data to the memory of the lower computer. If the interpolation is performed on the lower computer, the interpolation data is directly transferred to the memory. The function of the lower computer used in the next step is to cache the interpolation data and execute the motion commands and IO commands of each physical axis in the data in sequence.

[0161] For some motion commands and IO commands that need to be generated in real time, such as the cutting head height following function in water jet cutting, the lower computer needs to generate the compensation motion step command of the motion axis based on the height information fed back by the height following sensor, and insert the compensation motion step command in real time during the execution of the original interpolation data.

[0162] "IO" is used to control the IO port and calibrate special events. Bit0 to bit7 control the switch of 8 IO ports. Bit8 to bit11 are used to calibrate a multiple (1, 2, 4, 8, 16 times). Divide the multiple by the delay amount of Delay to get the delay amount when fast forward or fast rewind. Bit12 to bit15 are used to calibrate 16 special events:

[0163] 0001: Program starts

[0164] 0000: Program ends

[0165] 0011: Traversing starts (fast forward starts)

[0166] 0010: Traversing ends (fast forward ends)

[0167] 0101: Cutting starts

[0168] 0100: Cutting ends

[0169] 1011: Head-up Traversing starts

[0170] 1010: Head-up Traversing ends

[0171] "Drive" is used to control the movement of 8 axes. Bit0~bit7 control the pulses of 8 axes (1 means there is a pulse, 0 means there is no pulse), and bit8~bit15 control the direction of the corresponding axis (1 means positive direction, 0 means negative direction). The command control word format is as follows: Ex indicates the direction of the spare axis, ra|ry|rx indicates the direction of the three rotating axes, z2|z1 indicates the direction of the dual Z axis, and y|x indicates the direction of the Y and X axes; EX indicates the spare axis pulse, RA|RY|RX indicates the pulse of the three rotating axes, Z2|Z1 indicates the pulse of the dual Z axis, and Y|X indicates the pulse of the Y and X axes.

[0172] Ex|ra|ry|rx|z2|z1|y|x|EX|RA|RY|RX|Z2|Z1|Y|X

[0173] "Delay" indicates the motion delay. The delay is expressed by the number of cycles of the crystal oscillator of the lower computer (e.g. 45955 indicates a delay of 45955 crystal oscillator cycles). The speed of the motor can be controlled by this delay. The highest bit of Delay is used as a flag bit as the reference clock selection bit:

[0174] The definition of Delay

[15] ,

[0175] 1:2Mhz;

[0176] 0:7.8125Khz.

[0177] The remaining 15 bits are used as follows: When the frequency is 2MHz, use the values ​​100-32767 in the 15 bits (values ​​less than 100 are not used to avoid speed jumps) to represent the delay between 0.00005-0.016 seconds (the motor step is 0.0125 mm, and the corresponding speed is 15000-47mm / min). When the frequency is 7.8125kHz, use the values ​​125-32767 in the 15 bits to represent the delay between 0.016-2.55 seconds (the corresponding speed is 47-0.18mm / min). This can fully cover the speed range of 0.295-19200mm / min. Since an instruction is executed every 200 clock cycles at low speed (7.8125Khz), the delay will automatically increase by 0.0001 seconds (199 more clock cycles), which is less than 0.8% for the delay between 0.0125-2.55 seconds, and has little effect on the speed. When sending data to the lower computer, the delay needs to be converted into speed. Calculation method: 0.0125mm / time represents speed, time = 1 / Hz*delay, speed = (0.0125*2*10^6) / delay. You can also directly generate speed data when outputting interpolation data to replace delay data.

[0178] "Repeat" is used to represent the same command line (in order to compress the data volume). If the content of the command line is repeated n times; the value of n is stored in the 16 bits of Repeat, and the maximum value of n is 65535 (the number of executions is n, when n=1, it means 1 execution, and the maximum number of executions is 65535 times).

[0179] As an optional embodiment, if the interpolation module and the control execution module do not share a memory, the interpolated step list data is transferred to the control execution module through data communication or text file data interaction.

[0180] Based on the same concept, the present invention also provides a machine tool, comprising:

[0181] A machining path generation module is used to generate machining path model information based on workpiece straight-grain machining surface information, wherein the machining path information includes tool position point trajectory curve model information, tool axis point trajectory curve model information, and information on tool position point and tool axis point correlation function; wherein the tool position point trajectory curve is correlated with the upper edge curve of the straight-grain machining surface, and the tool axis point trajectory curve is correlated with the lower edge curve of the straight-grain machining surface;

[0182] The geometric interpolation module is used to perform geometric interpolation, decompose each section of the processing path into interpolation steps, and arrange the data of all interpolation steps into a list according to the processing order;

[0183] The speed setting module is used to set the processing speed based on the interpolation tool position after geometric interpolation;

[0184] An inverse solution calculation module is used to inversely calculate the position information of each physical axis from the tool axis vector of the interpolation tool position and store it;

[0185] The execution module is used to arrange the interpolation information into a control command list and execute the control command list data in sequence.

[0186] Based on the same concept, the present invention also provides an electronic device, comprising:

[0187] A memory, the memory being used to store a processing program;

[0188] A processor, wherein when executing the processing program, the processor implements any one of the above-mentioned methods for interpolating machining paths of ruled machined surfaces based on multiple models.

[0189] Based on the same concept, the present invention also provides a readable storage medium, on which a processing program is stored. When the processing program is executed by a processor, any one of the above-mentioned methods for interpolating machining paths of ruled machined surfaces based on multiple models is implemented.

[0190] Those skilled in the art can clearly understand that, for the sake of convenience and brevity in description, the identification content specifically executed by the above-described system and device can refer to the corresponding process in the aforementioned method embodiment.

[0191] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.< / pathstep> < / entity> < / entity>

Claims

1. A method for interpolating machining paths of ruled surfaces based on multiple models, characterized in that: The following steps are involved: Generate machining path model information based on workpiece ruled surface information, the machining path information includes tool position point trajectory curve model information, tool axis point trajectory curve model information and tool position point and tool axis point correlation function information; wherein the tool position point trajectory curve is correlated with the upper edge curve of the ruled surface, and the tool axis point trajectory curve is correlated with the lower edge curve of the ruled surface; Based on the machining path model information, geometric interpolation is performed to decompose each machining line segment on the machining path into interpolation steps, where the interpolation step data includes the tool position location and tool axis vector information, and the data of all interpolation steps are arranged into a list according to the machining sequence; The machining speed is set based on the machining path model information, and the machining speed is set based on the interpolation tool position after geometric interpolation; The position information of each physical axis is calculated and stored by inverse solution from the position information of the interpolated tool position and the tool axis vector information; The interpolation information is arranged into a control command list, and the control command list data is executed sequentially, wherein the interpolation information includes position information of each physical axis and processing speed information.

2. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The processing path model information generated based on the workpiece straight surface information also includes the determination of the tool axis point trajectory curve: If the upper edge curve and the lower edge curve of the straight-grained machining surface are simple geometric curves of straight lines or arcs, the upper edge curve and the lower edge curve are perpendicular to the machining surface and offset outward by a tool radius; the offset of the arc curve is that the radius becomes larger or smaller by a tool radius; the offset upper edge curve is used as the trajectory curve of the tool position point, and the offset lower edge curve is used as the trajectory curve of the tool axis point; If the upper edge curve and the lower edge curve of the ruled surface are not simple geometric curves, first discretize each ruled surface into a combination of straight generatrixes, and offset the upper point and the lower point of each straight generatrix perpendicular to the processing surface outward by a tool radius, fit the upper point of the offset straight generatrix group to the upper edge curve as the trajectory curve of the tool position point, and fit the lower point of the straight generatrix group to the lower edge curve as the trajectory curve of the tool axis point; After the offset, the upper and lower edge curves of adjacent processing line segments need to be transitioned.

3. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The processing path model information generated based on the workpiece straight surface information also includes the determination of the tool position point and tool axis point correlation function: Constructing the mathematical relationship between the arc length position of the tool position point on the trajectory curve and the arc length position of the tool axis point on the trajectory curve; Or the discrete correspondence between the arc length position of the tool position point on the trajectory curve and the arc length position of the tool axis point on the trajectory curve is expressed in a list manner.

4. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The mathematical relationship between the arc lengths of the tool position point trajectory curve and the tool axis point trajectory curve is constructed by dividing the tool position point trajectory curve and the tool axis point trajectory curve into equal parts, and then constructing the mathematical relationship between the arc lengths of each divided tool position point trajectory curve and tool axis point trajectory curve.

5. The method for interpolating machining paths of ruled surfaces based on multiple models according to claim 3 or 4, characterized in that: The method further comprises: the tool position point trajectory at the corner degenerates into a point, the tool position point trajectory at the corner corresponds to a section of the arc length of the tool axis point trajectory curve in the list, and the arc angle step length is used during interpolation.

6. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The machining path model information generated based on the workpiece straight-grained machining surface information also includes: The CAM module expresses the line segments of the generated machining path with a line segment class or structure of an object-oriented programming language, the entire machining path can be expressed with an object list of the line segment class or structure, a member variable representing the line segment type of the line segment class or structure is used to distinguish machining lines, cut-in and cut-out lines, and fast-forward lines, a member variable representing the machining speed of the line segment class or structure is used to express the theoretical machining speed, one or more member functions of the line segment class or structure that express the mathematical model of geometric curves are used to express the tool position point trajectory curve function, one or more member functions of the line segment class or structure that express the mathematical model of geometric curves are used to express the tool axis point trajectory curve function, and one or more member functions of the line segment class or structure that express the mathematical model of associated functions are used to express the associated function; the interpolation module obtains the machining path model information by sharing memory with the CAM module; Alternatively, the processing path model information can be transferred from the CAM module to the interpolation module by passing modeling parameters. The modeling parameters include general parameters of path segments, model parameters of tool position point trajectory curves, and model parameters of tool axis point trajectory curves. The processing path model information expressed by modeling parameters can be transferred through text files or other data interaction methods. The processing path model information must include tool position point and tool axis point information at the origin of the processing path.

7. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The processing speed setting based on the processing path model information further includes: Based on the processing path information, the process model is called to calculate the theoretical processing speed for each processing path segment and the endpoints of the path segment; The process model includes a functional relationship with the curvature change of the path segment curve as the independent variable and the processing speed as the dependent variable. The greater the curvature change of the path segment curve, the slower the speed. When calculating the speed of the path segment endpoints, the greater the change in the path direction of two adjacent segments, the slower the speed.

8. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The method further comprises: A zero-length line segment is added to each line segment connection point, and the zero-length line segment is used as a junction. The theoretical processing speed of the junction reflects the change in the tangential direction of the adjacent line segments of the junction. The greater the change in the tangential direction, the smaller the theoretical processing speed of the junction. The junction can also realize the transition of the tool axis vector direction of the adjacent line segments of the junction. And / or, inserting a transition arc at a joint where the tangential direction of the machining path changes by more than a threshold value.

9. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: The method further comprises: Performing geometric interpolation: determining an interpolation step length, wherein the interpolation step length is calculated according to an interpolation cycle and a theoretical processing speed; or determining the interpolation step length according to control accuracy, and then calculating the number of interpolation cycles required for the interpolation step length according to the interpolation cycle and the theoretical processing speed; wherein for a zero-length line segment, the interpolation step length represents an arc angle of a change in the direction of a tool axis within an interpolation cycle or an arc angle determined according to arc angle control accuracy; The interpolation step length is used to segment the tool position point trajectory curve of the machining path to obtain the interpolation tool position point. For the zero-length line segment, the arc angle of the tool axis direction change is segmented. Find the interpolation point on the tool axis point trajectory curve through the tool position point and tool axis point correlation function, and obtain the tool axis point coordinates and tool axis vector information corresponding to the interpolation tool position point; The interpolation point data is expressed by a step class or structure of an object-oriented programming language, and the entire machining path after interpolation is expressed by an object list of the step class or structure; Perform speed interpolation on the object list of the stepper class or structure: Based on the acceleration limit of the machine, the acceleration limit of the specific process, and the acceleration and deceleration model, take the theoretical processing speed on the tool position point path segment as the maximum value, take the theoretical processing speed at the endpoint of the path segment as the starting point, and aim to obtain a continuous and smooth processing speed. Stepwisely adjust the theoretical processing speed corresponding to each interpolated tool position point in the direction of the midpoint of the path segment in both directions, and store the adjusted processing speed as a member variable of the stepper class or structure in the object list of the stepper class or structure.

10. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 9, characterized in that: For the case where interpolation is performed inside the CAM or the interpolation module shares memory with the CAM module, the association function can be obtained from one or several member functions of the segment class or structure that express the mathematical model of the association function; for zero-length tool position point segments, no association function is required, and the tool axis point is determined by the arc angle interpolation step, which is independent of the tool position point; for the case where the tool axis point trajectory curve degenerates into a point, no association function is required to determine the tool axis point.

11. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 9, characterized in that: The method further includes: if the processing path model information is transferred from the CAM module to the interpolation module in the form of modeling parameters, then the modeling parameters are restored to a mathematical model in the interpolation module.

12. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 9, characterized in that: The method further includes: if the interpolation module and the control execution module do not share a memory, the interpolated step list data is transmitted to the control execution module through data communication or text file data interaction.

13. The method for interpolating a machining path of a ruled surface based on multiple models according to claim 1, characterized in that: When the machining path model information is generated based on the workpiece straight-grain machining surface information, it is also necessary to calculate the offset required for reverse compensation based on the prediction mathematical model and the preset process parameters. The prediction mathematical model includes but is not limited to one or more of a cutting speed model, a slit taper model, a backlash model, and a machine tool random error model established based on the machining mechanism. The initial tool axis vector after the offset is optimized according to the reverse compensation offset to effectively compensate for the error caused during the machining process: The first prediction mathematical model is called to calculate the drag amount of the cutting workpiece according to the target parameter information of the current position point, and then calculate the first angle that needs to be swung along the cutting feed direction to perform reverse compensation; Acquire a first component of the initial tool axis vector along the cutting feed direction, and perform a first optimization according to the first angle to obtain a second component result of the optimized tool axis vector along the cutting feed direction; The second prediction mathematical model is called to calculate the lateral taper generated by cutting the workpiece according to the target parameter information of the current position point, and then calculate the second angle that needs to be swung in the vertical direction along the cutting feed direction to perform reverse compensation; Obtaining a third component of the initial tool axis vector in a direction perpendicular to the cutting feed direction, and performing a second optimization according to the second angle to obtain a fourth component result of the optimized tool axis vector perpendicular to the cutting feed direction; According to the values ​​of the second component and the fourth component, the final optimized tool axis vector is synthesized.

14. A machine tool, characterized in that: include: A machining path generation module is used to generate machining path model information based on workpiece straight-grain machining surface information, wherein the machining path information includes tool position point trajectory curve model information, tool axis point trajectory curve model information, and information on tool position point and tool axis point correlation function; wherein the tool position point trajectory curve is correlated with the upper edge curve of the straight-grain machining surface, and the tool axis point trajectory curve is correlated with the lower edge curve of the straight-grain machining surface; The geometric interpolation module is used to perform geometric interpolation, decompose each section of the processing path into interpolation steps, and arrange the data of all interpolation steps into a list according to the processing order; The speed setting module is used to set the processing speed based on the interpolation tool position after geometric interpolation; An inverse solution calculation module is used to inversely calculate the position information of each physical axis from the tool axis vector of the interpolation tool position and store it; The execution module is used to arrange the interpolation information into a control command list and execute the control command list data in sequence.

15. An electronic device, characterized in that: include: A memory, the memory being used to store a processing program; A processor, wherein when executing the processing program, the processor implements the multi-model based ruled surface machining path interpolation method as described in any one of claims 1 to 13.

16. A readable storage medium, characterized in that: The readable storage medium stores a processing program, and when the processing program is executed by a processor, the multi-model-based ruled surface machining path interpolation method described in any one of claims 1 to 13 is implemented.

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