Automatic Detection and Compensation Method for Five-Axis Precision of Impeller Motors with 45-Degree Sway Head

Abstract

This invention discloses an automatic five-axis accuracy detection and compensation method for a 45-degree tilting impeller machine, relating to the field of CNC technology. The method includes: installing and calibrating a multi-plane standard block on the outside of the C-axis of the worktable; driving the A and B axes to a specific angle; using a probe to touch the measuring surface of the standard block to collect the coordinates of the measuring points; calculating the deviation values ​​of RTCP in the Z and Y directions; collecting the spatial coordinates of the contact points of each measuring surface at different B-axis angles; obtaining the new zero point of the machine tool through two least-squares fitting operations; and then calculating the deviation values ​​of WRCS in the X, Y, and Z directions; inputting all the obtained deviation values ​​into the CNC system to complete the automatic compensation of the machine tool's RTCP and WRCS accuracy. This method significantly improves the adaptability, efficiency, and accuracy of five-axis accuracy detection for a 45-degree tilting impeller machine.

Description

Technical Field

[0001] This invention relates to the field of CNC technology, and in particular to a method for automatic detection and compensation of five-axis accuracy of a paddlewheel machine with a 45-degree tilting head. Background Technology

[0002] With the development of high-end equipment manufacturing industries such as aero-engines and gas turbines, bladed disks, as core components, have complex shapes and extremely high precision requirements. Five-axis CNC machine tools with a 45-degree tilting head structure, due to their unique kinematic configuration, can effectively avoid interference between the cutting tool and complex curved surfaces, and have become key equipment for the efficient and precise machining of bladed disks. The geometric and dynamic accuracy of the machine tool, especially the accuracy of the coordinated motion of the rotary and translational axes (often reflected through the RTCP function), directly determines the final machining quality of the bladed disk. Therefore, rapid, accurate, and comprehensive five-axis accuracy testing and diagnosis of such machine tools is a prerequisite for ensuring their machining capabilities and workpiece quality. Currently, there are various technical solutions in the industry for five-axis machine tool accuracy testing, mainly divided into traditional manual testing methods based on contact gauges and testing methods based on professional high-precision measuring instruments. The first method involves installing a ball-head gauge on the spindle, manually adjusting and aligning it using a dial indicator, and executing a fixed NC testing program to detect deviations in the X, Y, and Z directions step by step. While this method can detect the actual RTCP deviation in three spatial directions and correct it using system compensation, its core detection process heavily relies on manual operation. The second method designs specific five-axis linkage detection trajectories and uses high-precision displacement sensors (such as R-test) to collect error data in real time during machine tool movement. This data is then combined with error models (such as homogeneous coordinate transformation matrices) to calculate multiple accuracy indicators, including perpendicularity error. However, specialized instruments like R-test are expensive, non-standard professional equipment, and their widespread adoption is limited. Furthermore, the development of detection schemes (such as trajectory design) and complex subsequent data processing (such as error model calculation) require professional personnel, placing high demands on the user's technical skills and increasing operational complexity and maintenance costs.

[0003] While the aforementioned existing methods are effective for general-purpose five-axis machine tools, they face the following problems when applied to 45-degree slant head impeller machines:

[0004] Poor adaptability of the detection path: The 45-degree tilting head structure has a unique kinematic model, and its workspace and axis motion relationship are different from those of conventional orthogonal or angle tilting head machine tools. General detection path designs may not effectively cover its key working areas, or fail to consider its special structural interference characteristics, resulting in insufficient representativeness of detection points or a high risk of collision.

[0005] Low testing efficiency and automation: Whether it is the manual dial gauge method or the R-test method which requires complex station setup and data analysis, the entire testing process, from preparation and measurement to result analysis, is time-consuming and has a low degree of automation, making it difficult to meet the needs of the production site for rapid and frequent testing of machine tool accuracy.

[0006] Insufficient accuracy and specificity in error diagnosis: After acquiring data, existing methods often rely on general or simplified error models for calculation, which may not fully consider all geometric error elements and their coupling relationships of the 45-degree tilting head structure. This results in incomplete error identification and inaccurate diagnostic results, making it difficult to directly guide efficient and accurate compensation and maintenance for this type of specific machine tool.

[0007] In summary, existing technologies for five-axis precision inspection of 45-degree tilting impeller machines generally suffer from several drawbacks, including poor compatibility between the inspection scheme and the machine tool's unique structure, low automation and efficiency, reliance on expensive equipment or highly skilled personnel, and limited diagnostic accuracy due to the lack of specificity in the error model. Therefore, there is an urgent need to develop an automated, efficient, and accurate five-axis precision inspection and diagnostic method specifically designed for this type of machine tool. Summary of the Invention

[0008] This invention provides an automatic detection and compensation method for the five-axis accuracy of a bladed disk machine with a 45-degree tilting head, in order to overcome the above-mentioned technical problems.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] An automatic five-axis accuracy detection and compensation method for a 45-degree tilting impeller machine, applied to a six-axis five-linkage impeller machining center, includes:

[0011] S1: Install a standard block with multiple measuring planes on the outer circle side of the C-axis sub-disk of the worktable and perform position calibration;

[0012] S2: Construct a coordinate system based on the machine tool origin, control the B axis to rotate to a fixed angle position, drive the A axis to rotate to three set angle positions respectively, and at each angle position, control the X axis, Y axis or Z axis of the machine tool to move according to the set value so that the probe touches the measurement plane of the standard block, obtain the Y direction coordinate of the measurement point, and then obtain the RTCPZ direction deviation value and RTCPY direction deviation value;

[0013] S3: Control the A-axis to rotate to a fixed angle position, drive the B-axis to rotate to multiple different detection angle positions in sequence, set the measurement plane corresponding to each detection angle position; at each detection angle position, control the X-axis, Y-axis or Z-axis of the machine tool to move according to the set values ​​so that the probe touches the corresponding measurement plane, and collect the spatial coordinates of the touch points of each measurement surface;

[0014] S4: The spatial coordinates collected at each detection angle position are fitted using the least squares fitting algorithm to obtain the spatial center coordinates of the sphere at each detection angle position. The spatial center coordinates of the sphere at each detection angle position are then fitted twice using the least squares fitting algorithm to obtain the spatial center coordinates of the sphere after the second fitting. The new spatial center coordinates of the sphere are calculated based on the spatial center coordinates of the sphere after the second fitting and the probe length, and the new spatial center coordinates of the sphere are defined as the new zero point of the machine tool.

[0015] S5: Subtract the machine tool's new zero point from the machine tool's reference point to obtain the deviation values ​​in the WRCSX, WRCSY, and WRCSZ directions;

[0016] S6: Input the deviation values ​​of RTCPZ, RTCPY, WRCSX, WRCSY, and WRCSZ into the machine tool CNC system to compensate for the RTCP accuracy and WRCS accuracy of the machine tool.

[0017] S5: Using the virtual reference center as a reference, and combining the machine tool's theoretical motion model, calculate the various error indicators of the five-axis accuracy, and automatically compensate the calculated deviation values ​​to the machine tool's CNC system through the CNC system interface.

[0018] Furthermore, the measuring plane includes a first detection surface, a second detection surface, a third detection surface, a fourth detection surface, and a fifth detection surface;

[0019] The first detection surface is perpendicular to the Y-axis and close to the positive Y-axis direction; the second detection surface is perpendicular to the Z-axis direction; the third detection surface is perpendicular to the X-axis direction; the fourth detection surface is a 45-degree inclined surface machined at the intersection of the second and third detection surfaces; the fifth detection surface is located on the third detection surface and is symmetrical to the fourth detection surface.

[0020] Furthermore, a coordinate system is constructed based on the machine tool origin. The B-axis is controlled to rotate to a fixed angular position, and the A-axis is driven to rotate to three set angular positions. At each angular position, the X-axis, Y-axis, or Z-axis of the machine tool is controlled to move according to set values ​​so that the probe touches the measurement plane of the standard block, obtaining the Y-axis coordinate of the measurement point, and then obtaining the RTCPZ-axis deviation value and RTCPY-axis deviation value, including:

[0021] S21. Construct a coordinate system based on the machine tool origin, and set the angle when the B-axis is parallel to the Z-axis to 0 degrees, and the angle when the A-axis is parallel to the Y-axis to 0 degrees.

[0022] S22. Fix the B-axis to the 0-degree angle position, control the X-axis, Y-axis or Z-axis of the machine tool to move according to the value, so that the probe is positioned above the first detection surface of the standard block, and control the probe to move along the negative Y-axis to touch the first detection surface of the standard block.

[0023] The A-axis is rotated to 90 degrees and -90 degrees respectively. The Y-coordinates of the touch point are collected. The difference between the two Y-coordinates is taken as the average to obtain the RTCPZ deviation value.

[0024]

[0025] in, This represents the Y-coordinate of the touch point when the A-axis is rotated to a 90-degree angle. The Y-coordinate of the touch point when A-axis is rotated to a negative 90-degree angle position;

[0026] S23. Drive the A-axis to rotate to a 0-degree angle position, obtain the Y-direction coordinate at this angle, and calculate the RTCPY-direction deviation value based on the Y-direction coordinate and the RTCPZ-direction deviation value:

[0027]

[0028] in, This represents the Y-coordinate of the touch point when the A-axis is rotated to the 0-degree angle position. This refers to the probe length.

[0029] Furthermore, the detection angle of the B-axis mentioned in S3 covers a range of 0° to 180°, including at least horizontal, vertical, and 45° oblique positions, to verify the spatial coordinates of the swing head under different postures. Specifically, this means:

[0030] Fix axis A at 0 degrees, and drive axis B to rotate sequentially to 0 degrees, 45 degrees, 90 degrees, 135 degrees and 180 degrees.

[0031] When the B-axis rotates to the 0-degree, 90-degree, and 180-degree positions, the machine tool's X-axis, Y-axis, or Z-axis moves according to the set values, so that the probe touches the first, second, and third detection surfaces respectively, in order to collect the spatial coordinates of the contact points of each detection surface.

[0032] When the B-axis rotates to the 45-degree and 135-degree positions, the machine tool is controlled to move along the X, Y, or Z axes according to the set values, so that the probe touches the first, fourth, and fifth detection surfaces respectively, in order to collect the spatial coordinates of the contact points of each detection surface.

[0033] Furthermore, when the B-axis rotates to the 45-degree and 135-degree positions, the probe is controlled to move along the X, Y, or Z axes according to set values, including:

[0034] The machine tool is controlled to move along the X and Z axes according to the set values ​​to position the probe in front of the fourth detection surface parallel to the X axis. The probe is then controlled to move in the positive direction of the X axis to touch the fourth detection surface, and the spatial coordinates of the contact point of the fourth detection surface are obtained.

[0035] The machine tool is controlled to move again on the X and Z axes according to the set values ​​to position the probe in front of the fifth detection surface parallel to the Z axis. The probe is then controlled to move in the negative direction of the Z axis to touch the fifth detection surface, and the spatial coordinates of the contact point of the fifth detection surface are obtained.

[0036] Furthermore, the new spatial center coordinates are calculated based on the quadratic fitted spatial center coordinates and the probe length, including:

[0037] The X-coordinate of the new spatial sphere center is determined based on the X-coordinate of the spatial sphere center coordinates obtained from the quadratic fitting and the probe length:

[0038]

[0039] in, The x-coordinate is the coordinate of the center of the sphere in the quadratic fit. This refers to the probe length;

[0040] The new spatial center coordinates are formed by combining the X coordinate of the new spatial center with the Y and Z coordinates of the spatial center coordinates fitted in the second step.

[0041] Beneficial effects: This invention provides an automatic detection and compensation method for the five-axis accuracy of a paddlewheel motor with a 45-degree tilting head, which has the following advantages:

[0042] 1. The identification model measurement method based on the least squares method has high calculation accuracy and reliable error diagnosis results;

[0043] 2. For the unique kinematic model of the 45-degree slanted head impeller machine, an automatic detection path is designed. This path controls the probe to move along the X, Y, or Z axes according to set values. Within the set path, the probe collects measurement coordinates in different planes by touching a standard block, and then calculates the machine tool accuracy deviation. This improves the poor compatibility between general detection methods and the 45-degree slanted head impeller machine under this kinematic model, enhancing the adaptability, efficiency, and accuracy of the five-axis accuracy detection for the 45-degree slanted head impeller machine, and providing reliable technical support for ensuring the quality of impeller machining.

[0044] 3. By using a probe and a standard block in conjunction with corresponding measurement actions to detect the five-axis accuracy of the impeller machine, the maintenance cost of the equipment and the cost of updating the measuring instruments are reduced;

[0045] 4. By integrating the automatic detection program with the CNC system, the five-axis accuracy of the 45-degree tilting impeller machine can be automatically detected using only the operating system interface, effectively simplifying the operation steps and reducing reliance on the operator's technical skills. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 The flowchart of the automatic detection and compensation method for five-axis accuracy of impeller machine with 45-degree tilt head provided by the present invention;

[0048] Figure 2 This is a schematic diagram of the coordinate system of a 45° tilting impeller machine;

[0049] Figure 3 This is a schematic diagram showing the installation location of the standard block;

[0050] Figure 4 Top view schematic diagram of WRCS zero-point deviation detection for B-axis 0° and X-axis;

[0051] Figure 5 A top-view schematic diagram of the WRCS zero-point deviation detection for the B-axis (0°) and Z-axis.

[0052] Figure 6 A top-view schematic diagram of coordinate detection on an oblique plane parallel to the Z-axis at a 45° angle to the B-axis.

[0053] Figure 7 A top-view schematic diagram of coordinate detection on a 45° parallel X-axis inclined plane to the B-axis.

[0054] In the diagram, 1 is the first detection surface; 2 is the second detection surface; 3 is the third detection surface; 4 is the fourth detection surface; and 5 is the fifth detection surface. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] This embodiment provides an automatic detection and compensation method for the five-axis accuracy of an impeller motor with a 45-degree tilting head, such as... Figure 1 As shown,

[0057] S1: Install a standard block with multiple measuring planes on the outer circle side of the C-axis sub-disk of the worktable and perform position calibration;

[0058] S2: Construct a coordinate system based on the machine tool origin, control the B axis to rotate to a fixed angle position, drive the A axis to rotate to three set angle positions respectively, and at each angle position, control the X axis, Y axis or Z axis of the machine tool to move according to the set value so that the probe touches the measurement plane of the standard block, obtain the Y direction coordinate of the measurement point, and then obtain the RTCPZ direction deviation value and RTCPY direction deviation value;

[0059] S3: Control the A-axis to rotate to a fixed angle position, drive the B-axis to rotate to multiple different detection angle positions in sequence, set the measurement plane corresponding to each detection angle position; at each detection angle position, control the X-axis, Y-axis or Z-axis of the machine tool to move according to the set values ​​so that the probe touches the corresponding measurement plane, and collect the spatial coordinates of the touch points of each measurement surface;

[0060] S4: The spatial coordinates collected at each detection angle position are fitted using the least squares fitting algorithm to obtain the spatial center coordinates of the sphere at each detection angle position. The spatial center coordinates of the sphere at each detection angle position are then fitted twice using the least squares fitting algorithm to obtain the spatial center coordinates of the sphere after the second fitting. The new spatial center coordinates of the sphere are calculated based on the spatial center coordinates of the sphere after the second fitting and the probe length, and the new spatial center coordinates of the sphere are defined as the new zero point of the machine tool.

[0061] S5: Subtract the machine tool's new zero point from the machine tool's reference point to obtain the deviation values ​​in the WRCSX, WRCSY, and WRCSZ directions;

[0062] S6: Input the deviation values ​​of RTCPZ, RTCPY, WRCSX, WRCSY, and WRCSZ into the machine tool CNC system to compensate for the RTCP accuracy and WRCS accuracy of the machine tool.

[0063] Specifically, this invention adopts a general-purpose numerical control system (CNC) architecture and integrates a matching HMI (Hardware Interface) with an automatic precision measurement program for impeller machines, thereby achieving automatic measurement of the five-axis precision of the impeller machine. The CNC system is responsible for executing precise measurement commands, while the HMI interface provides operators with a parameter input interface, making parameter setting convenient and measurement results more intuitive.

[0064] like Figure 2As shown, a standard block is used as the detection tool. A standard block is installed on the worktable, and a coordinate system is constructed with the machine tool's inherent origin as the reference. Based on the unique kinematic model of the 45-degree tilting head structure, a dedicated automatic detection path is designed to ensure that the detection points fully cover the machine tool's working space and achieve collision-free and efficient detection. Based on the automatically collected detection data, the least squares method is used to calculate various accuracy indicators and complete error compensation.

[0065] In a specific embodiment, the scheme for installing a standard block with multiple measuring planes on the outer circumference side of the C-axis sub-disk of the worktable and performing position calibration is as follows:

[0066] The measuring plane includes a first detection surface 1, a second detection surface 2, a third detection surface 3, a fourth detection surface 4, and a fifth detection surface 5;

[0067] The first detection surface 1 is perpendicular to the Y-axis direction and close to the positive Y-axis direction; the second detection surface 2 is perpendicular to the Z-axis direction; the third detection surface 3 is perpendicular to the X-axis direction; the fourth detection surface 4 is a 45-degree inclined surface machined at the intersection of the second detection surface 2 and the third detection surface 3; the fifth detection surface 5 is provided on the third detection surface 3 and is symmetrical to the fourth detection surface 4.

[0068] Specifically, such as Figure 3 As shown, the standard block is a cuboid structure. The side of the standard block perpendicular to the Z-axis is installed on the outer circle of the C-axis sub-disk of the worktable. The side perpendicular to the Y-axis and opposite to the negative Y-axis direction is designated as the first detection surface 1. The side perpendicular to the Z-axis and not in contact with the C-axis sub-disk is designated as the second detection surface 2. The side perpendicular to the X-axis and away from the sub-disk surface is designated as the third detection surface 3. The 45-degree bevel formed by the edge of the second detection surface 2 and the third detection surface 3 is designated as the fourth detection surface. The 45-degree bevel formed by the edge of the side in contact with the C-axis sub-disk and the third detection surface is designated as the fifth detection surface 5. The fifth detection surface 5 is symmetrical to the fourth detection surface 4.

[0069] Manually calibrate the positional relationship between the standard block and the C-axis to ensure that the standard block is installed with acceptable accuracy;

[0070] In this solution, the installation and calibration of the workpiece or the detection block are common technical means for those skilled in the art, therefore this application will not describe the manual calibration in detail.

[0071] In this field, such as Figure 2 As shown, the definition of the X, Y, and Z axes and the A, B, and C axes of the machine tool is common knowledge to those skilled in the art. Those skilled in the art know the position and rotation method of each axis of the machine tool and there is no need to make specific limitations.

[0072] In this solution, a 45-degree inclined surface is machined on the standard block to adapt to the 45-degree oscillating head structure, thereby ensuring the accuracy of the 45-degree oscillating head detection.

[0073] In a specific embodiment, a coordinate system is constructed based on the machine tool origin. The B-axis is controlled to rotate to a fixed angular position, and the A-axis is driven to rotate to three set angular positions respectively. At each angular position, the X-axis, Y-axis, or Z-axis of the machine tool is controlled to move according to set values ​​so that the probe touches the measurement plane of the standard block to obtain the Y-axis coordinate of the measurement point, and then the RTCPZ-axis deviation value and RTCPY-axis deviation value are obtained.

[0074] S21. Construct a coordinate system based on the machine tool origin, and set the angle when the B-axis is parallel to the Z-axis to 0 degrees, and the angle when the A-axis is parallel to the Y-axis to 0 degrees.

[0075] Specifically, the CNC system constructs or calls a standard machine tool coordinate system (MCS) based on the machine tool's mechanical origin. Within this coordinate system, the angles of each rotary axis are defined:

[0076] Adjust the machine tool's swivel axis (B-axis) to a position where its rotation axis is parallel to the machine tool's Z-axis, and define the angle of the B-axis at this time as zero degrees (0°). Adjust the machine tool's base rotation axis (A-axis) to a position where its rotation axis is parallel to the machine tool's Y-axis, and define the angle of the A-axis at this time as zero degrees (0°).

[0077] S22. Fixing the B-axis to a 0-degree angle position simplifies the kinematic model of the machine tool to a single-axis rotation of the A-axis, eliminating the coupling error caused by the B-axis motion, and making the measurement and calculation logic clear and direct.

[0078] Control the probe to move on the X-axis, Y-axis or Z-axis according to the value to above the first detection surface 1 of the standard block, and move along the negative Y-axis so that the probe touches the first detection surface 1 of the standard block;

[0079] Specifically, a dedicated path for the probe to reach the plane is set within the CNC system, and measurement is performed through a built-in automatic measurement program:

[0080] First, control each translation axis (X, Y, Z axes) of the machine tool to move according to the values ​​input in the CNC system, so that the probe mounted on the A axis can be accurately positioned above the first detection surface 1 of the standard block at a preset safe position; drive the A axis to rotate to 90 degrees and -90 degrees respectively, and control the probe to slowly feed along the negative Y-axis of the machine tool until the probe ball contactes the first detection surface 1 of the standard block and triggers a signal. The CNC system locks and records the precise spatial coordinates of the probe ball center in the machine tool coordinate system at this moment; after acquisition, control the probe to retract along the positive Y-axis to the safe position;

[0081] Collect the Y-coordinate of the touch point, calculate the difference between the two Y-coordinates, and take the average to obtain the RTCPZ deviation value:

[0082]

[0083] in, This represents the Y-coordinate of the touch point when the A-axis is rotated to a 90-degree angle. The Y-coordinate of the touch point when A-axis is rotated to a negative 90-degree angle position;

[0084] S23. Drive the A-axis to rotate to a 0-degree angle position, control the probe to position itself above the first detection surface 1 of the standard block, and then feed it along the negative Y-axis until it is triggered. Obtain the Y-axis coordinate at this angle, and calculate the RTCPY-axis deviation value based on the Y-axis coordinate and the RTCPZ-axis deviation value:

[0085]

[0086] in, This represents the Y-coordinate of the touch point when the A-axis is rotated to the 0-degree angle position. This refers to the probe length.

[0087] CNC systems are commonly used in the field of machine tool processing. The points to be inspected may change depending on the inspection requirements. This solution only provides the path to the contact point. The specific values ​​of movement required for the X, Y, and Z axes shall be determined by the technicians based on the content and location of the inspection. This application does not impose any specific limitations.

[0088] In this solution, all axis movements, probe triggering, data acquisition, and calculations are automatically completed through a CNC program, completely avoiding the operational errors, subjective readings, and inefficiencies caused by the traditional manual use of dial indicators.

[0089] The model is highly targeted: the measurement path (fixed B-axis, changing the A-axis angle to touch the same plane) and calculation formula are specifically designed for the kinematic model of the 45-degree tilting head structure, ensuring the high adaptability of the detection method and the accuracy of the calculation results.

[0090] The results are directly usable: the calculated RTCPZ and RTCPY deviation values ​​are stored in the system in digital form and can be directly used to evaluate the machine tool's accuracy status, or automatically written into the compensation parameter table through the CNC system interface to achieve rapid accuracy correction, providing a reliable guarantee for subsequent high-precision bladed disk machining.

[0091] In a specific embodiment, the A-axis is controlled to rotate to a fixed angular position, and the B-axis is driven to rotate sequentially to multiple different detection angular positions. A measurement plane is set for each detection angular position. At each detection angular position, the X-axis, Y-axis, or Z-axis of the machine tool is controlled to move according to set values ​​so that the probe touches the corresponding measurement plane, and the spatial coordinates of the contact points of each measurement surface are collected.

[0092] The detection angle of the B-axis covers a range of 0° to 180°, including at least horizontal, vertical, and 45° oblique positions, to verify the spatial coordinates of the oscillating head under different postures, specifically including:

[0093] S31. Detection Attitude Configuration and Measurement Plane Mapping

[0094] This step is performed based on the known A-axis rotation center deviation (RTCP parameter) to eliminate the influence of A-axis error on subsequent B-axis detection.

[0095] Fixing the A-axis to a 0-degree angle position locks the rotation of the main shaft around the X-axis, allowing the detection process to focus on the movement of the B-axis and its linkage error with the X, Y, and Z translational axes.

[0096] According to the preset automatic detection program, the CNC system drives the B-axis to rotate sequentially to the 0-degree angle position, 45-degree angle position, 90-degree angle position, 135-degree angle position and 180-degree angle position; by setting the 45-degree angle position, the inclined surface on the standard block is activated for measurement, thereby detecting the unique error of the 45-degree inclined tilting head structure;

[0097] When the B-axis rotates to the 0-degree, 90-degree, and 180-degree positions, the machine tool's X-axis, Y-axis, or Z-axis moves according to the set values, so that the probe touches the first detection surface 1, the second detection surface 2, and the third detection surface 3 respectively, in order to collect the spatial coordinates of the contact points of each detection surface.

[0098] When the B-axis rotates to the 45-degree and 135-degree positions, the machine tool spindle will adopt a specific spatial posture due to the 45-degree tilting head structure. At this time, the specially designed fourth detection surface 4 and fifth detection surface 5 (i.e., two 45° tilting planes) on the standard block will be adjusted to be parallel to the X-axis and Z-axis of the machine tool, respectively. Therefore, when the B-axis rotates to the 45-degree and 135-degree positions, the machine tool is controlled to move on the X-axis, Y-axis, or Z-axis according to the set values, so that the probe touches the first detection surface 1, the fourth detection surface 4, and the fifth detection surface 5, respectively, to collect the spatial coordinates of the contact points of each detection surface.

[0099] S32, Automatic Acquisition of Multi-Angle Coordinate Data

[0100] At each predetermined B-axis detection angle position, the CNC system executes an automatic measurement cycle:

[0101] For the B-axis positions at 0 degrees, 90 degrees, and 180 degrees:

[0102] The system controls the X, Y, and Z axes of the machine tool to sequentially position the probe in front of the first detection surface 1, the second detection surface 2, and the third detection surface 3, ensuring a safe position. It then controls the probe to slowly feed along the corresponding machine tool coordinate axes (e.g., touching the first detection surface in the positive X direction, the second detection surface in the positive Y direction, and the third detection surface in the negative Z direction) until the probe is triggered. Figure 4 and Figure 5 As shown in the figure, this is a schematic diagram of the detection at the 0-degree angle position of axis B;

[0103] Each time it is triggered, the system immediately latches and records the spatial coordinates (X, Y, Z) of the current probe center.

[0104] For the B-axis positions at 45 degrees and 135 degrees:

[0105] The system first controls the machine tool, drives the probe to touch the first detection surface 1, and collects a set of orthogonal reference coordinates, in the same way as above;

[0106] The specific steps for measuring an inclined plane are as follows:

[0107] Step 1: The system coordinates the movement of the X and Z axes to precisely position the probe in front of the fourth detection surface 4 at a safe position, at which point the inclined surface is parallel to the X-axis;

[0108] Step 2: Control the probe to move along the positive X-axis until it touches the fourth detection surface and triggers, such as... Figure 6 As shown, record the spatial coordinates of this point;

[0109] Step 2: The system again coordinates the movement of the X and Z axes to position the probe in a safe position in front of the fifth detection surface 5 (which is now parallel to the Z-axis); the system then controls the probe to move along the negative Z-axis until it touches the fifth detection surface and triggers the operation. Figure 7 As shown, record the spatial coordinates of this point;

[0110] With this design, even in the tilted head posture, the probe can still perform measurements along the main translational axes (X and Z) of the machine tool, completely avoiding the collision risks or programming difficulties that may be caused by the probe needing to feed along complex vector directions. At the same time, the tilted face is extremely sensitive to angle errors and can effectively capture minute posture deviations.

[0111] In a specific embodiment, the spatial coordinates collected at each detection angle position are fitted using a least-squares fitting algorithm to obtain the spatial center coordinates of the sphere at each detection angle position. These spatial center coordinates are then subjected to a second fitting using the least-squares fitting algorithm to obtain the second-fitted spatial center coordinates. A new spatial center coordinate is calculated based on the second-fitted spatial center coordinates and the probe length, and this new spatial center coordinate is defined as the new zero point of the machine tool.

[0112] After all coordinate data has been collected, the system enters the automatic calculation phase:

[0113] Single-angle WRCS zero-point fitting: For each B-axis detection angle (e.g., 0°, 45°, etc.), the system calls the built-in least-squares fitting algorithm. The algorithm takes the spatial coordinates of all measurement points acquired at that angle as input, fits and solves for three mutually orthogonal optimal planes, and calculates the theoretical intersection point of these three planes. This intersection point is the zero-point estimate of the working coordinate system (WRCS) defined by the actual movement of the machine tool under that specific B-axis tilting posture. It represents the position where the tool center point should appear under that posture.

[0114] Global optimal reference point fitting: After obtaining the WRCS zero-point estimates for all detection angles, these points should coincide at a fixed point in the machine tool coordinate system (ideal spindle end face center or tool control point). However, due to geometric errors, they will be spatially dispersed.

[0115] The system then applies the least squares algorithm again to perform spatial sphere fitting or point cloud center fitting on the WRCS zero-point estimates for all angles, to find the globally optimal spatial point coordinates that minimize the overall deviation. This point is called the "comprehensive spatial reference point," which eliminates random errors from single measurements and accidental deviations at specific angles to the greatest extent possible.

[0116] The above-mentioned integrated spatial reference point is corrected based on the fixed structural parameters of the 45-degree tilting head, that is, the new spatial center coordinates are calculated based on the spatial center coordinates of the quadratic fitting and the probe length, including:

[0117] The X-coordinate of the new spatial sphere center is determined based on the X-coordinate of the spatial sphere center coordinates obtained from the quadratic fitting and the probe length:

[0118]

[0119] in, The x-coordinate is the coordinate of the center of the sphere in the quadratic fit. This refers to the probe length;

[0120] The new spatial center coordinates are formed by combining the X coordinate of the new spatial center with the Y and Z coordinates of the spatial center coordinates fitted in the second step.

[0121] The coordinates obtained after this geometric correction are defined as the "virtual reference center" for this inspection. This center point is a stable and high-precision calculation reference used for comparison with the theoretical values ​​of the machine tool.

[0122] This solution enables automated "check-up" of the linkage accuracy of a 45-degree slanted head impeller machine across its entire slant range. It not only improves the reliability of single-point measurements through multi-point fitting but also utilizes a standard block inclined plane to measure at key angles of 45 degrees and 135 degrees, achieving targeted excitation and high-precision capture of errors specific to this type of machine tool. This provides an irreplaceable data foundation for subsequent precise compensation. Throughout the process, the measurement path planning is entirely based on the machine tool's kinematic model, ensuring both efficiency and safety.

[0123] In a specific embodiment, the scheme for compensating the RTCP and WRCS accuracy of the machine tool by inputting the deviation values ​​of RTCPZ, RTCPY, WRCSX, WRCSY, and WRCSZ into the machine tool CNC system is as follows:

[0124] RTCP Compensation: Writes the RTCPZ-axis deviation value and RTCPY-axis deviation value into the parameter address used in the CNC system to define the offset of the "spindle end face center" or "tool center point (TCP)".

[0125] WRCS Compensation: Write the deviation values ​​of WRCSX, WRCSY, and WRCSZ into the parameter area used to define the zero-point offset or geometric error compensation of the working coordinate system. This can be used to directly correct the zero point of a specific working coordinate system (such as G54), or to write it into the system's spatial error compensation table for real-time dynamic compensation of the X, Z (and Y) axis positions.

[0126] This invention, through the aforementioned integrated detection and compensation method, brings significant technical improvements to the 45-degree tilting impeller compressor:

[0127] The accuracy and reliability of the detection have been fundamentally improved:

[0128] Eliminating human error: Fully automated measurement path execution, data acquisition and calculation completely avoid subjective errors introduced by traditional manual operation due to meter matching, reading and recording.

[0129] Accurate Model: The measurement path and error calculation formula, specifically designed for a 45-degree tilting head structure, ensure a high degree of compatibility between the detection method and the object being measured, and the diagnostic results truly reflect the inherent errors of the machine tool.

[0130] Detection efficiency has been significantly improved:

[0131] One-click operation: From measurement to compensation, the entire process is automatically controlled by the program, reducing the time taken from several hours in traditional methods to tens of minutes.

[0132] Parallel data acquisition: The system continuously and automatically completes data acquisition of dozens or even hundreds of spatial points, which is far more efficient than manual single-point recording.

[0133] The compensation effect is direct and significant:

[0134] Root cause compensation: By compensating for RTCPZ and RTCPY, the positional deviation of the A-axis rotation center is directly corrected, fundamentally improving the trajectory accuracy of the tool when rotating around the A-axis.

[0135] Systematic compensation: By compensating for WRCSX and WRCSZ, the drift of the working coordinate system caused by the combined geometric errors such as B-axis oscillation, perpendicularity of each axis, and straightness is corrected, thereby improving the spatial positioning consistency of the machine tool under different postures.

[0136] Machining quality assurance: After compensation, when the machine tool performs complex five-axis linkage impeller machining, the deviation between the actual tool trajectory and the theoretical program is greatly reduced, which directly improves the contour accuracy and surface quality of the impeller surface and reduces the amount of subsequent manual grinding and finishing work.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for 45-degree swing head blisk machine five-axis precision automatic detection and compensation, applied to a six-axis five-linkage blisk machining center, characterized in that, include: S1: Install a standard block with multiple measuring planes on the outer circle side of the C-axis sub-disk of the worktable and perform position calibration; S2: Construct a coordinate system based on the machine tool origin, control the B axis to rotate to a fixed angle position, drive the A axis to rotate to three set angle positions respectively, and at each angle position, control the X axis, Y axis or Z axis of the machine tool to move according to the set value so that the probe touches the measurement plane of the standard block, obtain the Y direction coordinate of the measurement point, and then obtain the RTCPZ direction deviation value and RTCPY direction deviation value; S3: Control the A-axis to rotate to a fixed angle position, drive the B-axis to rotate to multiple different detection angle positions in sequence, set the measurement plane corresponding to each detection angle position; at each detection angle position, control the X-axis, Y-axis or Z-axis of the machine tool to move according to the set values ​​so that the probe touches the corresponding measurement plane, and collect the spatial coordinates of the touch points of each measurement surface; S4: The spatial coordinates collected at each detection angle position are fitted using the least squares fitting algorithm to obtain the spatial center coordinates of the sphere at each detection angle position. The spatial center coordinates of the sphere at each detection angle position are then fitted twice using the least squares fitting algorithm to obtain the spatial center coordinates of the sphere after the second fitting. The new spatial center coordinates of the sphere are calculated based on the spatial center coordinates of the sphere after the second fitting and the probe length, and the new spatial center coordinates of the sphere are defined as the new zero point of the machine tool. S5: Subtract the machine tool's new zero point from the machine tool's reference point to obtain the deviation values ​​in the WRCSX, WRCSY, and WRCSZ directions; S6: Input the deviation values ​​of RTCPZ, RTCPY, WRCSX, WRCSY, and WRCSZ into the machine tool CNC system to compensate for the RTCP accuracy and WRCS accuracy of the machine tool.

2. The method for automatic detection and compensation of five-axis accuracy of a bladed disk machine with a 45-degree tilting head as described in claim 1, characterized in that, The measuring plane includes a first detection surface (1), a second detection surface (2), a third detection surface (3), a fourth detection surface (4), and a fifth detection surface (5); The first detection surface (1) is perpendicular to the Y-axis direction and close to the positive Y-axis direction, the second detection surface (2) is perpendicular to the Z-axis direction, the third detection surface (3) is perpendicular to the X-axis direction, the fourth detection surface (4) is a 45-degree inclined surface formed by machining at the intersection of the second detection surface (2) and the third detection surface (3); the fifth detection surface (5) is set on the third detection surface (3) and is symmetrical to the fourth detection surface (4).

3. The method for automatic detection and compensation of five-axis accuracy of a bladed disk machine with a 45-degree tilting head as described in claim 2, is characterized in that, A coordinate system is established based on the machine tool origin. The B-axis is controlled to rotate to a fixed angular position, and the A-axis is driven to rotate to three set angular positions. At each angular position, the X-axis, Y-axis, or Z-axis of the machine tool is controlled to move according to set values ​​so that the probe touches the measurement plane of the standard block, obtaining the Y-axis coordinate of the measurement point, and then obtaining the RTCPZ-axis deviation value and RTCPY-axis deviation value, including: S21. Construct a coordinate system based on the machine tool origin, and set the angle when the B-axis is parallel to the Z-axis to 0 degrees, and the angle when the A-axis is parallel to the Y-axis to 0 degrees. S22. Fix the B-axis to the 0-degree angle position, control the X-axis, Y-axis or Z-axis of the machine tool to move according to the value, so that the probe is positioned above the first detection surface (1) of the standard block, and control the probe to move along the negative Y-axis to touch the first detection surface (1) of the standard block. The A-axis is rotated to 90 degrees and -90 degrees respectively. The Y-coordinates of the touch point are collected. The difference between the two Y-coordinates is taken as the average to obtain the RTCPZ deviation value. in, This represents the Y-coordinate of the touch point when the A-axis is rotated to a 90-degree angle. The Y-coordinate of the touch point when A-axis is rotated to a negative 90-degree angle position; S23. Drive the A-axis to rotate to a 0-degree angle position, obtain the Y-direction coordinate at this angle, and calculate the RTCPY-direction deviation value based on the Y-direction coordinate and the RTCPZ-direction deviation value: in, This represents the Y-coordinate of the touch point when the A-axis is rotated to the 0-degree angle position. This refers to the probe length.

4. The method for automatic detection and compensation of five-axis accuracy of a bladed disk machine with a 45-degree tilting head as described in claim 2, characterized in that, The detection angle of the B-axis mentioned in S3 covers a range of 0° to 180°, including at least horizontal, vertical, and 45° oblique positions, to verify the spatial coordinates of the oscillating head under different postures. Specifically, this means: Fix axis A at 0 degrees, and drive axis B to rotate sequentially to 0 degrees, 45 degrees, 90 degrees, 135 degrees and 180 degrees. When the B-axis rotates to the 0-degree angle position, 90-degree angle position and 180-degree angle position, the machine tool X-axis, Y-axis or Z-axis are controlled to move according to the set value, so that the probe touches the first detection surface (1), the second detection surface (2) and the third detection surface (3) respectively, so as to collect the spatial coordinates of the touch point of each detection surface; When the B-axis rotates to the 45-degree and 135-degree positions, the machine tool is controlled to move on the X-axis, Y-axis or Z-axis according to the set values, so that the probe touches the first detection surface (1), the fourth detection surface (4) and the fifth detection surface (5) respectively, so as to collect the spatial coordinates of the contact points of each detection surface.

5. The method for automatic detection and compensation of five-axis accuracy of a bladed disk machine with a 45-degree tilting head as described in claim 4, characterized in that, When the B-axis rotates to the 45-degree and 135-degree positions, the probe is controlled to move along the X, Y, or Z axes according to set values, including: The machine tool is controlled to move on the X-axis and Z-axis according to the set values ​​to position the probe in front of the fourth detection surface (4) parallel to the X-axis. The probe is then controlled to move in the positive direction of the X-axis to touch the fourth detection surface (4) and the spatial coordinates of the touch point of the fourth detection surface (4) are obtained. The machine tool is controlled to move again on the X and Z axes according to the set values ​​to position the probe in front of the fifth detection surface (5) parallel to the Z axis. The probe is then controlled to move in the negative direction of the Z axis to touch the fifth detection surface (5) and the spatial coordinates of the contact point of the fifth detection surface (5) are obtained.

6. The method for automatic detection and compensation of five-axis accuracy of a bladed disk machine with a 45-degree tilting head as described in claim 1, characterized in that, The calculation of the new spatial center coordinates based on the spatial center coordinates of the quadratic fitting and the probe length includes: The X-coordinate of the new spatial sphere center is determined based on the X-coordinate of the spatial sphere center coordinates obtained from the quadratic fitting and the probe length: in, The x-coordinate is the coordinate of the center of the sphere in the quadratic fit. This refers to the probe length; The new spatial center coordinates are formed by combining the X coordinate of the new spatial center with the Y and Z coordinates of the spatial center coordinates fitted in the second step.

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