A machining method, system and apparatus with automatic tool height compensation

Abstract

The application provides a machining method, system and equipment with automatic tool height compensation, the method comprises the following steps: a host computer performs rough interpolation operation on a profile curve of a machining workpiece to obtain a plurality of continuous first profile line segments of the machining workpiece; the host computer performs primary fine interpolation operation on the machining workpiece again to obtain a plurality of continuous second profile line segments of the machining workpiece; then the host computer drives a lower computer to measure the height of the start and end points of the first profile line segments in sequence; the host computer adaptively calculates machining path height compensation data of the tool at the start and end points of the plurality of first profile line segments; then the host computer performs secondary fine interpolation operation on the machining path according to the machining path height of the tool after compensation to generate a cutting program; finally, the lower computer executes the cutting program to realize cutting operation. Through the application, the tool can maintain a constant distance with the surface of the machining workpiece during cutting movement, high-precision cutting operation is realized, and tool and workpiece collision is avoided.

Description

Technical Field

[0001] This invention belongs to the field of CNC machining technology, and in particular relates to a machining method, system and equipment with automatic tool height compensation. Background Technology

[0002] In the field of CNC machining, especially when cutting workpieces requiring high precision, maintaining a constant distance between the tool and the workpiece during machining is a crucial technical aspect. Various factors can cause variations in this distance, such as inherent unevenness on the workpiece surface, non-parallelism between the workpiece's mounting surface and the machine tool's motion control plane, or dynamic deformation of the workpiece during machining due to thermal stress and the release of pre-existing internal stresses.

[0003] In existing technologies, dynamic real-time height tracking is mainly used to control the constant distance between the cutting tool and the workpiece. For example, in fiber laser cutting and plasma arc cutting, capacitive sensors can be used to detect the distance between the cutting tool and the workpiece (usually metal) in real time, and then the Z-axis movement amplitude of the cutting tool can be dynamically adjusted to maintain a constant distance between the tool and the workpiece. However, the capacitive sensor solution is only suitable for processing materials with conductive properties. Since the materials being cut in waterjet cutting include non-conductive materials such as glass, ceramics, and plastics, and the water jet is a weakly conductive medium, the capacitive sensor solution cannot be applied to waterjet cutting. In waterjet cutting, mechanical displacement sensors are commonly used. These sensors have contacts that directly contact the workpiece surface to detect the distance between the tool and the workpiece in real time. However, mechanical displacement sensors suffer from poor reliability and stability. During waterjet cutting, the precision structure of these sensors is easily jammed by abrasive particles in the water. Furthermore, the annular contacts of mechanical displacement sensors are unsuitable for workpieces with significant slopes (greater than 10°), resulting in poor applicability. Existing tool path adjustment methods also exhibit poor accuracy and control stability, making it difficult to achieve high-precision cutting of precision-machined workpieces. Summary of the Invention

[0004] The present invention provides a machining method, system, and equipment with automatic tool height compensation to solve the technical problem that existing machining methods, systems, and equipment cannot achieve high-precision automatic compensation of tool height.

[0005] To solve the above problems, the technical solution of the present invention is: a machining method with automatic tool height compensation, comprising the following steps:

[0006] S1: The host computer performs a coarse interpolation operation on the contour curve of the workpiece with the first interval as the interpolation distance, obtains several continuous first contour line segments of the workpiece, and saves the set of the first contour line segments in the processing path line segment list.

[0007] S2: The host computer performs an initial fine interpolation operation on the contour curve of the workpiece with the second interval as the interpolation distance, obtains several continuous second contour line segments of the workpiece, and saves the set of the second contour line segments in the height measurement program.

[0008] S3: The host computer inserts a height measurement command into the second contour line segment according to the start and end points of the first contour line segment, and the height measurement command is stored in the height measurement program;

[0009] S4: The lower-level machine reads and executes the height measurement program, takes the first spacing as the detection distance, and sequentially measures the height of the beginning and end points of the first contour line segment, and saves several height measurement data of the first contour line segment in the height measurement array;

[0010] S5: The host computer reads the height measurement array, takes the first spacing as a height adjustment unit, adaptively calculates the height compensation data of the start and end points of the machining path within the first contour line segment, and saves this height compensation data in the machining path line segment list.

[0011] S6: The host computer reads the list of machining path segments again, adjusts the height of the tool machining path according to the height compensation data, that is, performs a second fine interpolation operation on the contour curve of the workpiece with the second spacing as the interpolation distance based on the compensated tool machining path height, generates cutting program data and saves it in the cutting program.

[0012] S7: The lower-level machine reads and executes the cutting program to achieve the effect of maintaining a constant distance between the tool and the upper surface of the workpiece during the processing.

[0013] Preferably, in steps S2 and S6, the host computer performs initial and secondary fine interpolation operations on the contour curve of the workpiece with the second interpolation distance as the interpolation distance, further including the following steps:

[0014] Set the speed and acceleration parameters of the tool in the second contour segment.

[0015] Preferably, the first spacing is calculated as follows: a preset interpolation distance is set according to the total length of a single contour curve of the workpiece, the total length of the single contour curve is divided by the preset interpolation distance and rounded to obtain the number of interpolation points of the single contour curve, and the length value of the first spacing is obtained by dividing the total length of the single contour curve by the number of interpolation points again.

[0016] Preferably, the interpolation preset distance is set to 1-100mm, and the second spacing is set to the minimum movement distance of the servo drive motor or stepper motor.

[0017] Preferably, step S2, which involves performing an initial fine interpolation operation on the contour curve of the workpiece processed by the host computer with the second interpolation distance as the interpolation distance, further includes the following steps:

[0018] The host computer reads the set of the first contour lines stored in the processing path line segment list, and sequentially performs initial fine interpolation operations on the contour curves of the workpieces contained in a number of the first contour lines.

[0019] Preferably, in step S5, the host computer adaptively calculates the height compensation data for the start and end points of the machining path within the first contour segment, and further includes the following steps:

[0020] The host computer reads the height measurement array to obtain the starting and ending height data of the tool within the first contour segment. Based on the difference between the actual height measurement data of the tool and the standard height data, it adaptively calculates the height compensation data of the tool at the beginning and end points of the first contour segment.

[0021] Preferably, during the process of adjusting the tool machining path height based on the height compensation data in S6, the following steps are further included:

[0022] During the secondary fine interpolation process, the host computer adaptively calculates the machining path height of the tool within the second contour segment after compensation, based on the height data of the tool after compensation at the beginning and end points of the first contour segment, using a linear interpolation method.

[0023] Preferably, before the host computer measures the height of the start and end points of the first contour line segment in S4, the following steps are also included:

[0024] The host computer performs a second confirmation on the height measurement task process of the first contour line segment. If confirmed, the height measurement task process of the first contour line segment is executed. If cancelled, the height measurement task process of the first contour line segment is stopped, and the processing path line segment list and the height measurement program are deleted.

[0025] Based on the same concept, the present invention also provides a machining system with automatic tool height compensation, comprising:

[0026] The host computer module is used to output height measurement instructions for the contour curve of the workpiece being processed, and to integrate the height measurement data with the processing path to form a height measurement program and a cutting program.

[0027] The lower-level machine module is used to drive the processing equipment to perform height measurement and cutting operations, as well as height compensation during the cutting operation;

[0028] An interpolation module, located in the host computer module, is used to perform coarse interpolation, initial fine interpolation, and secondary fine interpolation operations on the contour curve of the workpiece.

[0029] Based on the same concept, the present invention also provides a machining device with automatic tool height compensation, characterized in that it includes: a tool body, a height measuring component, and a motion component;

[0030] The tool body is used to apply cutting force to the workpiece, and the axis of the tool body forms a first intersection with the plane of the workpiece. During the tool height measurement process, the height measuring component is configured such that its measuring end extends to the second intersection with the plane of the workpiece, which coincides with the first intersection, and is used to indirectly measure the distance from the tool tip of the tool body to the plane of the workpiece.

[0031] Both the tool body and the height measuring component can be detachably mounted on the motion component, and the two form a rigid connection during the height measurement process. The motion component is used to drive the tool body and the height measuring component to move synchronously in three dimensions.

[0032] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

[0033] (1) In the processing equipment with automatic tool height compensation provided by the present invention, the height measuring device can be a laser height measuring instrument, which is not limited by the conductivity of the processing material. Combined with water jet cutting process, it can be used for cutting workpieces of different materials and is not easily affected by the processing environment. Compared with fiber laser cutting or plasma arc cutting with capacitive sensor and water cutting with mechanical displacement sensor to cut workpieces, the present invention has better accuracy and stability and is more suitable for the three-dimensional five-axis high-precision machining requirements of workpieces.

[0034] (2) In the machining method with automatic tool height compensation provided by this invention, multiple interpolation operations are performed on the contour curve of the workpiece, including coarse interpolation, primary fine interpolation, and secondary fine interpolation. Coarse interpolation divides the contour curve of the workpiece into first contour segments with a first spacing, facilitating the subsequent insertion of height measurement commands. Simultaneously, the first contour segment formed by coarse interpolation also serves as the unit distance for height detection. By analyzing the height error at the beginning and end points of the first contour segment, adaptive adjustment of the tool height is achieved, thus compensating for and correcting the tool height. Primary and secondary fine interpolation further refine the segmentation of the workpiece's contour curve, thereby generating the final machining path of the tool based on the minimum movement distance of the servo drive motor or stepper motor, enabling height measurement and high-precision cutting of the workpiece.

[0035] (3) In the machining system with automatic tool height compensation provided by the present invention, there is an upper computer module, a lower computer module and an interpolation module. The interpolation module is used to implement various interpolation operations. The interpolation module is set in the upper computer module. The upper computer can easily upgrade and optimize the interpolation algorithm built into the interpolation module and quickly debug it. Compared with the lower computer interpolation scheme that requires customized hardware, the software-based interpolation function reduces the need for dedicated hardware and reduces hardware costs. At the same time, the upper computer has better computing power and can improve the controllability and smoothness of the interpolation algorithm operation or interpolation operation execution. Attached Figure Description

[0036] Figure 1 The present invention provides a flowchart a of a machining method with automatic tool height compensation;

[0037] Figure 2 The present invention provides a flowchart b of a machining method with automatic tool height compensation;

[0038] Figure 3 The present invention provides a schematic diagram a of a machining equipment with automatic tool height compensation.

[0039] Figure 4 The present invention provides a schematic diagram (b) of a machining equipment with automatic tool height compensation.

[0040] Explanation of reference numerals in the attached drawings: 1: Tool body; 2: Tool head; 3: Height measuring component; 4: Moving component; 5: Workpiece being machined. Detailed Implementation

[0041] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a machining method, system, and device with automatic tool height compensation according to the present invention. The advantages and features of the present invention will become clearer from the following description and claims.

[0042] First Embodiment

[0043] See Figure 1 This embodiment provides a machining method with automatic tool height compensation, which enables the tool to adaptively adjust the machining path during the machining process, so that the TCP center point of the tool can maintain a constant distance from the surface of the workpiece. This automatically eliminates the tilt of the workpiece or machine tool itself during the movement, thereby meeting the technical requirement of constant distance between the tool and the workpiece in high-precision cutting.

[0044] A machining method with automatic tool height compensation specifically includes the following steps:

[0045] S1: Import the 3D model of the workpiece into the CNC operating system, and perform CAM programming based on the 3D model to determine the initial tool movement path. The host computer performs coarse interpolation on the workpiece's contour curve with a first interpolation distance, cutting the contour curve into several continuous first contour segments. Simultaneously, a list of machining path segments is generated. The set of first contour segments is saved in the machining path segment list, which is further stored in memory for later retrieval. It is worth noting that the machining path segment list mentioned in this step and subsequent steps, as well as the height measurement program, height measurement array, and cutting program mentioned later, can also be stored in a file. The host computer and slave computer can then access and store data by reading and writing files.

[0046] S2: The host computer directly reads the set of first contour lines stored in the list of machining path lines from memory, and performs initial fine interpolation operation on the first contour lines formed by coarse interpolation with the second interval as the interpolation distance. That is, the contour curve of the workpiece is cut into several continuous second contour lines. The distance between the second contour lines should be much smaller than the distance between the first contour lines. At the same time, a height measurement program is generated and the set of second contour lines is stored in this height measurement program. The height measurement program is also directly stored in memory.

[0047] S3: The host computer inserts a height measurement command into the second contour line segment based on the start and end points of the first contour line segment. The height measurement command is also directly stored in the height measurement program.

[0048] S4: The lower-level machine reads and executes the height measurement program. Then, the lower-level machine uses the first spacing as the detection distance and measures the height of the beginning and end points of several first contour line segments in turn according to the height measurement instructions. The set of height measurement data of the beginning and end points of several first contour line segments is stored in a height measurement array, which is also stored in memory.

[0049] S5: The host computer reads the height measurement array, takes the first spacing as a height adjustment unit, and adaptively calculates the height compensation data of the tool at the beginning and end points of different machining paths within several first contour segments. This ensures that the tool maintains the same spacing between itself and the workpiece surface at the beginning and end points within different first contour segments. The height compensation data of the tool at the beginning and end points of the machining path is saved in the machining path segment list. This height compensation data is used to construct the compensated tool machining path in the future.

[0050] S6: The host computer reads the list of machining path segments again and performs a second fine interpolation operation on the contour curve of the workpiece with the second interval as the interpolation distance. During the second fine interpolation process, the height compensation data of the tool at the beginning and end points of the machining path is further linearly interpolated with the machining path to generate cutting program data with completed tool height compensation correction, and this cutting program data is saved in a cutting program.

[0051] S7: The lower-level machine reads and executes the cutting program, thereby driving the motors of each axis and the IO module to perform the cutting operation of the tool on the workpiece, and ensuring that the tool and the upper surface of the workpiece maintain a constant distance during the cutting process.

[0052] Therefore, this embodiment provides a machining method with automatic tool height compensation. It performs a three-step interpolation operation on the contour curve of the workpiece. Coarse interpolation divides the contour curve of the workpiece into a relatively long first contour segment, which serves as the interpolation object for subsequent fine interpolation and the measurement interval for height measurement. Specifically, the initial fine interpolation performs another interpolation operation on the divided first contour segment, further dividing it into second contour segments at a second interval. Height measurement commands are inserted into the second contour segments based on the start and end points of the first contour segments, generating a height measurement program.

[0053] Meanwhile, in this embodiment, the first contour line segment serves as the smallest unit of height measurement. That is, by measuring the distance between the tool and the workpiece surface at the beginning and end points within a certain first contour line segment, the deviation height between the tool and the workpiece within the first contour line segment is determined. During the secondary fine interpolation process, the tool movement path height is linearly interpolated and adjusted based on the height measurement data of the beginning and end points of the first contour line segment. This allows the tool to adaptively compensate and correct its height parameters throughout the overall machining path, ensuring that it maintains a constant distance from the workpiece surface. The final cutting program data is then formed using the height-compensated tool movement path.

[0054] During the coarse interpolation operation, the overall machining path for the workpiece can be constructed using a list of machining path segments in C#. <entity>To illustrate, an example of the Entity class is as follows:

[0055] public class Entity

[0056] {

[0057] public int m_nEntityType; / / 0=Point,1=Straight Line,2=Arc

[0058] public int m_nEntityNo;

[0059] public int m_nStepCount;

[0060] public Point3d m_SPt; / / entity start point

[0061] public Point3d m_EPt; / / entity end point

[0062] public Point3d m_CPt; / / arc entity center point

[0063] public double m_dQuality; / / 1-5 are cuts, 9 is cut-in / cut-out, 10 and above are fast forwards without a stop.

[0064] public double m_dThickness;

[0065] public double m_dStartAngle;

[0066] public double m_dEndAngle;

[0067] public int m_nJetDir; / / m_nJetDir is the cutting direction, 1 for the line from start to finish, and 0 for the line from end to end.

[0068] public int m_nOffset;

[0069] public double m_dHeadStartHight = 0; / / Initial height of the blade head

[0070] public double m_dHeadEndHight = 0; / / Cutting head end height

[0071] public double m_dNozzleStartAngle = 0; / / Longitudinal start angle

[0072] public double m_dNozzleEndAngle = 0; / / Longitudinal end angle

[0073] public double m_dBulge; / / positive value indicates ccw rotation from start to end of arc; 1=semi-circle; 0=straight line.

[0074] public double m_dIncludedAngle; / / included angle of arc

[0075] public double m_dOrientationAngle; / / CCW angle (from X axis) of the line connecting start to end pts

[0076] public double m_dOrientationAngleS; / / CCW angle (from X axis) of the tangent line at the start pt of arc

[0077] public double m_dOrientationAngleE; / / CCW angle (from X axis) of the tangent line at the end pt of arc

[0078] public double m_dRadius; / / radius of arc

[0079] public double m_dDistance; / / distance from start to end of arc

[0080] public double m_dLength; / / arc length

[0081] public double m_dSpeed;

[0082] public double m_dSepSpeed;

[0083] }

[0084] Preferably, before performing the coarse interpolation operation with the first interval as the interpolation distance on the contour curve of the workpiece in S1, it is necessary to set the preset interpolation distance based on the total length of a single contour curve of the workpiece, and to judge the contour curve of the workpiece, that is, to traverse the list according to the set preset interpolation distance. <entity>For each Entity interpolation point, if m_nEntityType = 0, or m_dLength is less than the interpolation preset distance, that is, if the total length of a single contour curve is less than the interpolation preset distance set by coarse interpolation, then it is determined that the contour curve does not meet the coarse interpolation conditions, and the coarse interpolation operation for the contour curve is skipped.

[0085] Furthermore, for the contour curves that meet the coarse interpolation conditions, the first spacing is determined. The first spacing is calculated by dividing the total length of a single contour curve of the workpiece by the preset interpolation distance and rounding it to the nearest integer to obtain the number of entity interpolation points N. Then, the total length of a single contour curve is divided by the number of interpolation points N again to obtain the length value of the first spacing. The length value of the first spacing is then updated in the list of machining path segments. <entity>In the list.

[0086] Furthermore, the preset interpolation distance can be set from 1 to 100 mm depending on the type of workpiece and machining accuracy. The second interval is set to the minimum movement distance of the servo drive motor or stepper motor (e.g., 0.01 mm). The second interval is the interpolation interval between the initial and secondary fine interpolations. Limiting the second interval to the minimum movement distance of the servo drive motor or stepper motor ensures that the tool movement reaches the highest control accuracy of the servo drive motor or stepper motor. The data generated after the fine interpolation operation can be represented by a list of PathStep machining paths in C#. <pathstep>is expressed as follows, an example of the PathStep class is shown below:

[0087] public class PathStep:ICloneable

[0088] {

[0089] public int ID = 0;

[0090] public string m_sIO{get;set;}

[0091] public string m_sDrive{get;set;}

[0092] public string m_sDelay{get;set;}

[0093] public string m_sRepeat{get;set;}

[0094] public string m_sNote{get;set;}

[0095] public BitArray m_bIO = new BitArray(16);

[0096] public BitArray m_bDrive = new BitArray(16);

[0097] public BitArray m_bDelay = new BitArray(16);

[0098] public BitArray m_bRepeat = new BitArray(16);

[0099] public PathPoint6d m_StepPtS = new PathPoint6d();

[0100] public PathPoint6d m_StepPtE = new PathPoint6d();

[0101] public int m_ndx,m_ndy,m_ndz1,m_ndz2,m_nda,m_ndb,m_ndc,m_nde;

[0102] public int m_ndxdir,m_ndydir,m_ndz1dir,m_ndz2dir,m_ndadir,m_ndbdir,m_ndcdir,m_ndedir;

[0103] public int m_nEntityNo;

[0104] public double m_dOrientAngle;

[0105] public double m_dLength; / / mm

[0106] public double m_dSpeed; / / mm / min

[0107] public double m_dDelay; / / second

[0108] public int m_nDelay;

[0109] public int m_nRepeat;

[0110] public double m_dQ;

[0111] public double m_dTE; / / mm

[0112] public double m_dJL; / / mm

[0113] public double m_dKW; / / mm

[0114] public TiltingHead1 m_TiltHd;

[0115] public TiltingHead2 m_TiltHd2;

[0116] }

[0117] Preferably, in S2 and S6, during the initial and secondary fine interpolation operations of the upper computer on the contour curve of the workpiece with the second interval as the interpolation distance, the following steps are further included: setting the movement speed and acceleration parameters of the tool in the second contour line segment respectively. Specifically, the movement speed of the tool during the height measurement process is faster than its movement speed during the cutting process, thereby shortening the time consumed in the height measurement process and improving the overall efficiency of the tool operation. Adjusting the acceleration parameters of the tool during the movement process can effectively prevent the tool or height measuring instrument from shaking, thereby improving the height measurement accuracy and the machining accuracy of the tool.

[0118] Preferably, in S5, the adaptive compensation of the machining path height of the tool within the first contour segment further includes the following steps: the host computer reads the height measurement array to obtain the starting position height and ending position height data of the tool within the first contour segment, and adaptively calculates the height compensation data of the tool at the beginning and end points of the first contour segment based on the difference between the actual height measurement data of the tool and the standard height data.

[0119] Furthermore, in S6, during the process of adjusting the tool machining path height based on the height compensation data, the host computer further includes the following steps: during the secondary fine interpolation process, the host computer adaptively adjusts the tool's running path within the first contour segment using linear interpolation based on the height data of the tool after compensation at the start and end points of the first contour segment, thus obtaining the compensated machining path height of the tool within the first contour segment. The height compensation algorithm described in this embodiment is not limited to linear interpolation; it is only used as an example of a superior processing method to demonstrate the feasibility of tool height compensation adjustment in this embodiment. Specifically, firstly, the starting and ending heights of the tool within the first contour segment are adjusted according to the set standard height data. The starting position coordinates of the tool after height compensation correction within the first contour segment are set as P1(x1,y1), and the ending position coordinates are set as P2(x2,y2). The tool movement path between the compensated starting and ending positions corresponds to the continuous and smooth linear transition path constructed between P1 and P2. The mathematical expression for linear interpolation is:

[0120]

[0121] Using the linear interpolation formula described above, for each small step size d within the range from x1 to x2... x (i.e., the second contour line segment with the second spacing as the interpolation distance), calculate the corresponding tool height y, thereby generating a series of continuous height data points. The connection of several height data points constitutes the machining path after the tool height is compensated within the first contour line segment.

[0122] In this embodiment, the tool's machining path height compensation data can be directly updated to the machining path segment list. <entity>The following two members are variables:

[0123] public double m_dHeadStartHight; / / Starting height of the tool head

[0124] public double m_dHeadEndHight; / / Cutting head end height of the tool

[0125] The variables m_dHeadStartHight and m_dHeadEndHight directly reflect the distance compensation values ​​between the tool and the workpiece surface at the beginning and end points of the first contour line segment. During the secondary fine interpolation process, the m_ndz1 and m_ndz1dir parameters of the Z-axis motor in the PathStep machining path can be adjusted by linear interpolation calculation of the two variables m_dHeadStartHight and m_dHeadEndHight. That is, during the entire macro machining process, the tool height can be continuously and linearly adjusted according to the surface inclination or concavity of the workpiece, so that the center point of the tool and the surface of the workpiece maintain a constant distance.

[0126] Preferably, before measuring the height of the start and end points of the first contour line segment in S2, the following steps are also included: A pop-up prompt on the CNC operating system's display interface confirms the height measurement task process a second time. Selecting "OK" executes the height measurement task process for the first contour line segment; selecting "Cancel" cancels the height measurement task process and deletes the machining path line segment list and the height measurement program. Similarly, after the height measurement task process for the first contour line segment is completed and the height measurement data is output, before cutting, a pop-up prompt on the CNC operating system's display interface confirms the cutting task process a second time. Selecting "OK" generates and outputs the cutting program to the lower-level machine; selecting "Cancel" cancels the generation and output of the cutting program and deletes the machining path line segment list, the height measurement program, and the height measurement array. This pop-up prompt setting makes the overall machining process control more flexible and safer. The CNC operating system can stop in time under different unexpected situations, improving the controllability of the machining process.

[0127] In this embodiment, the lower-level machine is not involved in the implementation of the interpolation function. It only serves to buffer multi-axis motion commands and IO control commands and send them sequentially to the drivers and IO modules of each motor. The interpolation module is set up entirely in the upper-level machine module. The upper-level machine can easily upgrade, optimize and quickly debug the interpolation algorithm built into the interpolation module. Compared with the lower-level machine interpolation scheme that requires customized hardware, the software-implemented interpolation module function reduces the need for dedicated hardware and lowers hardware costs. At the same time, the upper-level machine has better computing power, which can improve the controllability and smoothness of the interpolation algorithm operation or interpolation job execution.

[0128] Second Embodiment

[0129] This embodiment provides a machining system with automatic tool height compensation, including a host computer module, a slave computer module, and a coarse interpolation module. The host computer module is responsible for the control, management, and data processing of the entire CNC machining system. In this embodiment, it specifically outputs commands for measuring the height of the workpiece's contour curve, receives height deviation data for several first contour segments after measurement, and integrates the height measurement data with the tool machining path to form a height measurement program and a cutting program. The slave computer module is responsible for real-time fine interpolation and control of the underlying machining equipment. In this embodiment, it specifically drives the machining equipment to perform height measurement and cutting operations, achieving a constant distance between the tool and the upper surface of the workpiece during the cutting process.

[0130] In one embodiment, the coarse interpolation module is located in the host computer module and is used to perform coarse interpolation operations on the contour curve of the workpiece. A series of height measurement points are formed through the coarse interpolation operation, and then height measurement instructions are inserted at the height measurement points to generate a height measurement program.

[0131] See Figure 2 The interpolation module in the host computer module performs coarse interpolation on the contour curve of the workpiece at a first interval, constructing a list of machining path segments. Then, the host computer module inserts height measurement commands within the first contour segments formed by the coarse interpolation to detect the distance between the tool and the workpiece surface, generating a height measurement program. This program is transmitted to the slave computer module, which performs initial fine interpolation. The resulting motion and I / O control commands drive a multi-axis motor and I / O module, simultaneously collecting height data from the tool to the workpiece surface into a height measurement array, which is then uploaded back to the host computer module. The host computer module compensates for and corrects the machining path height at the start and end points of any first contour segment along the tool's path based on the height measurement array, forming the final cutting program. The slave computer module reads the cutting program and performs secondary fine interpolation. The resulting motion and I / O control commands drive the multi-axis motor and I / O module, thereby controlling the tool to perform the cutting operation and maintaining a constant distance between the tool and the workpiece surface during the cutting process.

[0132] See Figure 2 In this embodiment, the lower-level machine is involved in implementing the fine interpolation function and serves as a buffer for multi-axis motion commands and IO control commands, which are then sent sequentially to the drivers and IO modules of each motor. The coarse interpolation module is located in the upper-level machine module, which facilitates the insertion of height measurement commands into the machining path. The advantage of this embodiment is that the data volume of the height measurement and cutting programs without fine interpolation is small, the read / write time is short, and the transmission is convenient. However, the fine interpolation algorithm is not easy to upgrade and maintain.

[0133] See Figure 2 Taking the example of setting the coarse interpolation module in the host computer module and the fine interpolation module in the slave computer module, the coarse interpolation module in the host computer module performs coarse interpolation operation on the contour curve of the workpiece with the first interval to construct a list of machining path segments. Then, the host computer module inserts a height measurement command for detecting the distance between the tool and the surface of the workpiece in the first contour segment formed by coarse interpolation and generates a height measurement program. The height measurement program is transmitted to the lower-level computer module. The fine interpolation module in the lower-level computer module performs an initial fine interpolation operation on the contour curve of the workpiece. The motion and IO control commands generated after fine interpolation drive the multi-axis motor and IO module to perform movement and collect the height data of the tool from the surface of the workpiece, generating a height data array. The height data array is then uploaded to the upper-level computer module. The upper-level computer module compensates and corrects the machining path height of the tool at any starting and ending points within the first contour line segment, generating a cutting program. After the cutting program is imported into the lower-level computer, the fine interpolation module of the lower-level computer module performs a second fine interpolation operation. The motion and IO control commands generated after fine interpolation drive the multi-axis motor and IO module to work, thereby controlling the tool to achieve the cutting operation. During the cutting process, the tool maintains a constant distance from the upper surface of the workpiece.

[0134] Third Embodiment

[0135] See Figures 3 to 4 This embodiment provides a processing device with automatic tool height compensation, including a tool body 1, a height measuring component 3 and a motion component 4. The tool body 1 is used to apply a cutting force to the workpiece 5. The tool body 1 is configured to generate a certain displacement along its axial direction or to generate a certain angle rotation between its axial direction and the plane of the workpiece, so as to flexibly adjust the distance between the tool body 1 and the surface of the workpiece 5 and the cutting angle.

[0136] During height measurement, the height measuring component 3 is configured such that its measuring end can extend to the intersection of the axis of the tool body 1 and the plane of the workpiece 5, indirectly measuring the distance from the tool head 2 to the plane of the workpiece 5. When the tool is not measuring height, the height measuring component 3 is configured such that there is an offset distance between the intersection of its measuring end and the workpiece surface and the intersection of the tool body axis and the workpiece plane; that is, the height measuring component 3 can produce a certain displacement along the x-axis and y-axis directions, or its measuring end can produce a certain angle rotation. Before height measurement, the axis of the measuring end of the height measuring component 3 is moved to a position relative to the tool... The intersection point of the axis of the tool body 1 and the plane of the workpiece 5 is aligned, and then height measurement is performed. When the tool body 1 is not in height measurement mode, the height measuring component 3 can be moved horizontally or its measuring end can be rotated to offset the measuring end of the height measuring component 3 from the cutting point of the tool body 1. Through the adjustable assembly of the height measuring component 3 and the tool body 1, when changing the tool body 1 or the height measuring component 3, the position of the intersection point of the measuring end axis of the height measuring component 3 and the surface of the workpiece can be further precisely adjusted according to the actual setting position of both, ensuring high accuracy of subsequent height measurement operations. To protect the height measuring component 3 from damage caused by liquid and solid splashes during the cutting process, the height measuring component 3 can be removed or wrapped before the cutting operation.

[0137] Both the tool body 1 and the height measuring component 3 can be detachably mounted on the motion component 4, and the two form a rigid connection during the height measurement process, ensuring that the intersection of the measuring end axis of the height measuring component 3 with the plane of the workpiece 5 and the intersection of the axis of the tool body 1 with the plane of the workpiece 5 are stably coincident. The motion component 4 is used to drive the tool body 1 and the height measuring component 3 to move synchronously in three dimensions, thereby completing the high-precision measurement of the tool height.

[0138] Preferably, in this embodiment, the tool body 1 adopts a water jet device, and the cutting operation is carried out by water jet cutting as an example. There is a water jet distance between the tool head 2 and the surface of the workpiece 5. During the lateral movement of the tool relative to the workpiece, due to the unevenness of the surface of the workpiece 5 or the tilting of the workpiece when fixed on the machine tool, the water jet distance cannot be maintained at a constant distance. Therefore, during the movement of the tool, by compensating and adjusting the height of the tool movement path, the distance between the tool head 2 and the surface of the workpiece 5 is maintained at a constant distance, thereby ensuring the precision of the cutting and avoiding collision between the tool head 2 and the workpiece.

[0139] In this embodiment, the height measuring component 3 preferably uses a laser height measuring instrument. The measuring laser emitted by the laser height measuring instrument is emitted to the intersection of the axis of the tool body 1 and the plane of the workpiece 5, and the distance between the tool body 1 and the workpiece 5 is measured indirectly. The laser height measuring instrument has high accuracy and reliability and can be applied to most processing environments. The height measuring component 3 can also be a mechanical displacement sensor. If the workpiece is a conductive material, the height measuring component 3 can also use a capacitive sensor. When using a mechanical displacement sensor or a capacitive sensor, after the height measurement is completed, the sensor needs to be removed or offset before further cutting operations can be carried out.

[0140] The embodiments of the present invention have been described in detail above with reference to 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 shall still fall within the protection scope of the present invention.< / entity> < / pathstep> < / entity> < / entity> < / entity>

Claims

1. A machining method with automatic tool height compensation, characterized in that, Includes the following steps: S1: The host computer performs a coarse interpolation operation on the contour curve of the workpiece with the first interval as the interpolation distance, obtains several continuous first contour line segments of the workpiece, and saves the set of the first contour line segments in the processing path line segment list. S2: The host computer performs an initial fine interpolation operation on the contour curve of the workpiece with the second interval as the interpolation distance, obtains several continuous second contour line segments of the workpiece, and saves the set of the second contour line segments in the height measurement program. S3: The host computer inserts a height measurement command into the second contour line segment according to the start and end points of the first contour line segment, and the height measurement command is stored in the height measurement program; S4: The lower-level machine reads and executes the height measurement program, takes the first spacing as the detection distance, and sequentially measures the height of the beginning and end points of the first contour line segment, and saves several height measurement data of the first contour line segment in the height measurement array; S5: The host computer reads the height measurement array, takes the first spacing as a height adjustment unit, adaptively calculates the height compensation data of the start and end points of the machining path within the first contour line segment, and saves this height compensation data in the machining path line segment list. S6: The host computer reads the list of machining path segments again, adjusts the height of the tool machining path according to the height compensation data, that is, performs a second fine interpolation operation on the contour curve of the workpiece with the second spacing as the interpolation distance based on the compensated tool machining path height, generates cutting program data and saves it in the cutting program. S7: The lower-level machine reads and executes the cutting program to achieve the effect of maintaining a constant distance between the tool and the upper surface of the workpiece during the processing.

2. The machining method with automatic tool height compensation as described in claim 1, characterized in that, In S2 and S6, during the initial and secondary fine interpolation operations performed by the host computer on the contour curve of the machined workpiece with the second interpolation distance as the interpolation distance, the following steps are further included: Set the speed and acceleration parameters of the tool in the second contour segment.

3. The machining method with automatic tool height compensation as described in claim 2, characterized in that, The first spacing is calculated as follows: The interpolation preset distance is set according to the total length of a single contour curve of the workpiece. The total length of the single contour curve is divided by the interpolation preset distance and rounded to obtain the number of interpolation points of the single contour curve. The length value of the first spacing is obtained by dividing the total length of the single contour curve by the number of interpolation points again.

4. The machining method with automatic tool height compensation as described in claim 3, characterized in that, The interpolation preset distance is set to 1-100mm, and the second spacing is set to the minimum movement distance of the servo drive motor or stepper motor.

5. The machining method with automatic tool height compensation as described in claim 4, characterized in that, S2 performs an initial fine interpolation operation on the contour curve of the workpiece processed by the host computer with the second interval as the interpolation distance, and further includes the following steps: The host computer reads the set of the first contour lines stored in the processing path line segment list, and sequentially performs initial fine interpolation operations on the contour curves of the workpieces contained in a number of the first contour lines.

6. The machining method with automatic tool height compensation as described in claim 1, characterized in that, In S5, the host computer adaptively calculates the height compensation data for the start and end points of the machining path within the first contour segment that the tool needs to cover, and further includes the following steps: The host computer reads the height measurement array to obtain the starting and ending height data of the tool within the first contour segment. Based on the difference between the actual height measurement data of the tool and the standard height data, it adaptively calculates the height compensation data of the tool at the beginning and end points of the first contour segment.

7. The machining method with automatic tool height compensation as described in claim 1, characterized in that, In the process of adjusting the tool machining path height based on height compensation data in S6, the following steps are further included: During the secondary fine interpolation process, the host computer adaptively calculates the machining path height of the tool within the second contour segment after compensation, based on the height data of the tool after compensation at the beginning and end points of the first contour segment, using a linear interpolation method.

8. The machining method with automatic tool height compensation as described in claim 1, characterized in that, Before the host computer measures the height of the beginning and end points of the first contour line segment in S4, the following steps are also included: The host computer performs a second confirmation on the height measurement task process of the first contour line segment. If confirmed, the height measurement task process of the first contour line segment is executed. If cancelled, the height measurement task process of the first contour line segment is stopped, and the processing path line segment list and the height measurement program are deleted.

9. A machining system with automatic tool height compensation, characterized in that, The machining system, configured to perform the machining method with automatic tool height compensation as described in any one of claims 1-8, comprises: The host computer module is used to output height measurement instructions for the contour curve of the workpiece being processed, and to integrate the height measurement data with the processing path to form a height measurement program and a cutting program. The lower-level machine module is used to drive the processing equipment to perform height measurement and cutting operations, as well as height compensation during the cutting operation; An interpolation module, located in the host computer module, is used to perform coarse interpolation, initial fine interpolation, and secondary fine interpolation operations on the contour curve of the workpiece.

10. A machining equipment with automatic tool height compensation, characterized in that, The machining equipment, configured to perform the machining method with automatic tool height compensation as described in any one of claims 1-8, comprises: a tool body, a height measuring component, and a motion component; The tool body is used to apply cutting force to the workpiece, and the axis of the tool body forms a first intersection with the plane of the workpiece. During the tool height measurement process, the height measuring component is configured such that its measuring end extends to the second intersection with the plane of the workpiece, which coincides with the first intersection, and is used to indirectly measure the distance from the tool tip of the tool body to the plane of the workpiece. Both the tool body and the height measuring component can be detachably mounted on the motion component, and the two form a rigid connection during the height measurement process. The motion component is used to drive the tool body and the height measuring component to move synchronously in three dimensions.

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