Methods, devices, and machine tools for measuring and compensating runout error of moving parts in machine tools

Abstract

This invention discloses a method, apparatus, and machine tool for measuring and compensating for runout error of a moving part of a machine tool. The method includes: acquiring, in real time, the relative position parameters of the moving part relative to a fixed guide reference using at least two detection units disposed on the moving part; arranging the at least two detection units at intervals along the movement direction of the moving part; calculating in real time the difference between the relative position parameters acquired by the at least two detection units to obtain a runout characterization; and determining the runout compensation amount of the moving part in real time based on the runout characterization and the geometric mapping relationship between the spacing between the at least two detection units and the span of the fixed guide reference. This invention utilizes detection units disposed on the moving part to acquire the position change relative to a fixed reference in real time, and combines this with the geometric mapping relationship to calculate the runout amount, thereby achieving real-time, accurate quantification and compensation for the dynamic runout error of the moving part.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tool machining accuracy control technology, and in particular to a method, device and machine tool for measuring and compensating for runout error of moving parts of a machine tool. Background Technology

[0002] Currently, five-axis CNC machine tools are widely used in aerospace, automotive manufacturing, and other fields for machining complex curved surface parts. The crossbeam and slide, as key structural components of the machine tool, are prone to runout during movement due to factors such as gravity, thermal deformation, and external loads, leading to machining errors. Existing technologies often employ offline detection methods for measuring such runout errors, such as using a coordinate measuring machine (CMM) for stop-motion inspection. This method is not only inefficient, severely impacting production cycle time, but also fails to capture real-time runout data during dynamic operation. Furthermore, existing compensation algorithms are often based on idealized machine tool models, neglecting the complex and variable dynamic runout factors during actual machining, resulting in limited compensation effectiveness and failing to meet the demands of high-precision machining. While some existing technologies attempt to introduce additional hardware for online monitoring, these often suffer from high costs and difficult installation and maintenance, hindering large-scale application. Therefore, there is an urgent need for a method that can measure and compensate for the runout errors of machine tool moving parts in real time, accurately, and efficiently. Summary of the Invention

[0003] The purpose of this invention is to provide a method, device, and machine tool for measuring and compensating the runout error of moving parts in a machine tool. This invention utilizes a detection unit mounted on the moving part to acquire the positional change relative to a fixed reference in real time, and calculates the runout amount by combining geometric mapping relationships, thereby achieving real-time, accurate quantification and compensation of the dynamic runout error of the moving part.

[0004] The technical solution of the present invention: a method for measuring and compensating for runout error of moving parts of a machine tool, comprising:

[0005] The relative position parameters of the moving component with respect to the fixed guide reference are acquired in real time by at least two detection units disposed on the moving component; the at least two detection units are arranged at intervals along the movement direction of the moving component.

[0006] The difference between the relative position parameters acquired by the at least two detection units is calculated in real time to obtain the yaw characterization quantity;

[0007] Based on the yaw characterization quantity and the geometric mapping relationship between the distance between at least two detection units and the span of the fixed guide reference, the yaw compensation amount of the moving component is determined in real time, and then the motion trajectory of the moving component is compensated based on the yaw compensation amount.

[0008] The aforementioned method for measuring and compensating for runout error of machine tool moving parts includes a fixed guide reference, which may be the side of the machine tool guide rail, the column reference surface, or an independent reference structure rigidly connected to the guide rail.

[0009] The aforementioned method for measuring and compensating for runout error of machine tool moving parts, wherein the geometric mapping relationship satisfies the following formula:

[0010] △1 = L1 / L2 × △0;

[0011] Wherein, △1 ​​is the sway compensation amount, △0 is the sway characterization amount, L1 is the span of the fixed guide reference, and L2 is the distance between the at least two detection units.

[0012] The aforementioned method for measuring and compensating for runout error of moving parts in machine tools further includes:

[0013] Compare the yaw rate with a preset threshold;

[0014] If the yaw rate is greater than or equal to the preset threshold, the motion trajectory of the moving part is compensated based on the yaw compensation amount.

[0015] In the aforementioned method for measuring and compensating for runout error of moving parts of a machine tool, the preset threshold is dynamically adjusted according to the operating parameters of the moving parts, including load status, temperature parameters, or movement speed.

[0016] The dynamic adjustment of the preset threshold satisfies the following formula:

[0017]

[0018] The aforementioned method for measuring and compensating for runout error of moving parts in machine tools further includes:

[0019] A time series forecasting model is established based on historical skewness characteristic data;

[0020] Based on the time series prediction model, predict the sway characteristics at future times;

[0021] If the predicted sway characterization is greater than or equal to the preset threshold, a compensation instruction is generated in advance.

[0022] The aforementioned method for measuring and compensating for runout error of machine tool moving parts, wherein compensating for the motion trajectory of the moving parts based on the runout compensation amount includes:

[0023] The yaw compensation amount is decomposed into multiple progressive compensation steps, each progressive compensation step being smaller than the preset maximum single compensation amount.

[0024] The plurality of progressive compensation steps are executed step by step according to the preset compensation frequency.

[0025] The aforementioned method for measuring and compensating for runout error of machine tool moving parts, wherein the moving parts include the machine tool's crossbeam and / or slide.

[0026] A device for measuring and compensating for runout error of moving parts in a machine tool, comprising:

[0027] The detection module is configured to acquire, in real time, the relative position parameters of the moving component with respect to a fixed guide reference through at least two detection units disposed on the moving component; the detection units are arranged at intervals along the movement direction of the moving component.

[0028] The processing module is configured to calculate the difference in relative position parameters obtained by the detection unit in real time to obtain the yaw characterization quantity; based on the yaw characterization quantity and the geometric mapping relationship between the distance between at least two detection units and the span of the fixed guide reference, the yaw compensation amount of the moving part is determined in real time.

[0029] A CNC machine tool includes a machine tool body and a device for measuring and compensating for runout error of the moving parts of the machine tool, as described above.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. This invention detects the relative position change of a moving part relative to a fixed guide reference in real time by arranging detection units on the moving part, and converts the detected small displacement difference into a yaw compensation amount by using geometric mapping relationship. This achieves real-time and accurate measurement and compensation of the dynamic yaw error of the moving part, effectively eliminates the processing error caused by factors such as gravity and thermal deformation, and significantly improves the processing accuracy.

[0032] 2. This invention abandons the traditional offline detection method and realizes online real-time monitoring of the runout error of machine tool moving parts; at the same time, it accurately converts the displacement difference detected by the sensor into the runout compensation amount through the geometric mapping model. Not only is the calculation logic simple and the response speed fast, but it also does not require a lot of modification to the machine tool structure. It can be realized using existing sensors and control systems, which has the advantages of low cost and easy implementation.

[0033] 3. This invention introduces a threshold judgment mechanism to determine whether a decision triggers compensation, avoiding over-compensation or under-compensation and improving system stability and reliability. The preset threshold can be dynamically adjusted based on operating parameters (load state, temperature parameters, and movement speed), achieving adaptive compensation for different operating conditions and improving the accuracy and flexibility of compensation. Furthermore, this invention introduces an adaptive threshold adjustment algorithm, establishing a nonlinear mapping function between operating parameters and thresholds, and introducing weighting coefficients and correction factors. This enables the system to intelligently adjust the compensation strategy according to actual processing conditions, ensuring high-precision processing while avoiding system instability caused by over-compensation, significantly improving the machine tool's intelligence level and processing quality.

[0034] 4. This invention introduces an error prediction algorithm to establish a time series prediction model based on historical yaw characteristic data, predicting the yaw characteristic at future moments to achieve advance compensation. This improves the system's response speed and compensation effect, and reduces processing errors. Furthermore, by introducing a compensation amount optimization algorithm, the yaw compensation amount is decomposed into multiple progressive compensation steps, and compensation is executed gradually. This avoids system oscillations caused by excessively large single compensation amounts, improving the stability and reliability of the compensation. Attached Figure Description

[0035] Figure 1 This is a front view of the overall structure of the CNC machine tool according to an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the installation position of the crossbeam and detection unit according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the installation position of the slide block and detection unit according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the geometric model of the beam yaw in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the geometric model of the ram's deflection according to an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the yaw measurement and compensation control principle according to an embodiment of the present invention.

[0041] Figure Labels

[0042] 100. Base; 200. Column; 201. Y-axis ball screw; 202. Y-axis linear guide rail; 300. Slide ram; 301. Z-axis ball screw; 302. Z-axis linear guide rail; 303. Distance sensor C; 304. Distance sensor D; 400. Crossbeam; 500. Slide ram box; 401. Distance sensor A; 402. Distance sensor B; 403. Y-axis rail slider 1; 404. Y-axis rail slider 2; 405. X-axis linear guide rail; 406. X-axis ball screw. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0044] Example 1: This example provides a method for measuring and compensating for the runout error of a machine tool moving part. The core concept of this method is to establish a relative motion measurement model of "moving part, sensor and fixed reference", and to invert its own runout attitude by capturing the position change of the moving part relative to the fixed reference system.

[0045] First, the machine tool structure used in this embodiment will be described. For example... Figure 1 As shown, the machine tool adopts a gantry-type structure layout, mainly including core components such as the base 100, columns 200, crossbeam 400, ram 300, and ram box 500. The base 100 serves as the basic support platform for the machine tool, fixedly set on the foundation, with two parallel columns 200 fixedly mounted on its upper surface. The columns 200 extend along the Y-axis, and a Y-axis linear guide rail 202 is fixedly mounted on their sides. Driven by the Y-axis ball screw 201, the crossbeam 400 can perform linear reciprocating motion along the Y-axis. The crossbeam 400 is horizontally mounted between the two columns 200 along the X-axis, and an X-axis linear guide rail 405 is fixedly mounted on its upper surface. Driven by the X-axis ball screw 406, the ram box 500 can perform linear reciprocating motion along the X-axis. The slide box 500 is equipped with a Z-axis linear guide rail 302. Driven by the Z-axis ball screw 301, the slide 300 can perform vertical linear movement along the Z-axis. A tool assembly is mounted at the lower end of the slide 300 for cutting the workpiece. The above mechanisms together constitute the X, Y, and Z-axis linear motion structure of the machine tool, realizing the three-axis linkage function of the machine tool.

[0046] Furthermore, such as Figure 2 As shown, distance sensor A 401 and distance sensor B 402 are fixedly installed below the body of the crossbeam 400. The probe of distance sensor A 401 points vertically towards the Y-axis rail slider 1. Figure 2The detection reference surface (403) is used to detect the straight-line distance between the mounting point of sensor A and this reference surface in real time; the probe of distance sensor B 402 points perpendicularly to the Y-axis rail slider 2. Figure 2 The detection reference plane (404) is used to detect the linear distance between the sensor B mounting point and this reference plane in real time. Similarly, as... Figure 3 As shown, distance sensors C 303 and D 304 are fixedly mounted on the body of the ram 300, with their probes pointing to the corresponding detection reference planes of the Z-axis linear guide rail 302, respectively, to detect the positional changes of the ram 300 during movement. This sensor arrangement constitutes the detection unit of this embodiment, providing the hardware foundation for subsequent yaw error measurement.

[0047] Specifically, such as Figure 1 and Figure 2 As shown, the method includes the following steps:

[0048] Step S100: The relative position parameters of the moving component with respect to a fixed guide reference are acquired in real time using at least two detection units mounted on the moving component; the at least two detection units are arranged at intervals along the movement direction of the moving component. The fixed guide reference includes the side of the machine tool's guide rail, the reference surface of the column, or an independent reference structure rigidly connected to the guide rail. In this embodiment, the moving component is taken as the machine tool's crossbeam 400, and the detection units are specifically implemented as distance sensors (such as sensor A401 and sensor B402). These sensors are fixedly mounted on the body of the crossbeam 400 and move with the crossbeam 400. The target object of detection is the "fixed guide reference," such as the side of the guide rail 202 fixed on the machine tool bed or column. The probes of sensor A401 and sensor B402 are perpendicularly pointed to the side of the guide rail 202, thereby measuring the straight-line distance between the sensor mounting point and the side of the fixed guide rail in real time.

[0049] Step S200: The difference in relative position parameters acquired by at least two detection units is calculated in real time to obtain the yaw characterization quantity. When the crossbeam 400 yaws during movement, the distances from sensors A 401 and B 402, installed at different positions on the crossbeam 400, to the side of the guide rail 202 will change inconsistently. This invention establishes... Figure 4The mathematical model of beam sway is shown below. Point A is the position of distance sensor A401, point B is the position of distance sensor B402, C is the reference plane position of Y-axis rail slider 1 (403), D is the reference plane position of Y-axis rail slider 2 (404), and E is the position of distance sensor B402 after sway. Lm2 is the distance from distance sensor A401 to the reference plane position of Y-axis rail slider 1 (403), Lm1 is the distance from distance sensor B402 to the reference plane position of Y-axis rail slider 2 (404), Δ0 is the actual sway coefficient of the beam (the difference between the distance from sensor A to the slider's reference plane and the distance from sensor B to the slider's reference plane), L2 is the distance between distance sensors 401, 402, and B, and L1 is the span between the two rails of the X-axis linear guide 405. In this embodiment, the difference between the distance data detected by the two sensors (e.g., Δ0 = Lm2 - Lm1) is calculated, and this difference is defined as the sway characterization quantity.

[0050] Step S300: Based on the yaw characterization quantity and the geometric mapping relationship between the spacing between at least two detection units and the span of the fixed guide reference, the yaw compensation amount of the moving part is determined in real time. Figure 4 As shown, the mapping relationship is established based on the principle of similar triangles and satisfies the following formula: △1=L1 / L2×△0; where △1 is the sway compensation amount, △0 is the sway characterization amount, L1 is the span of the fixed guide reference, and L2 is the distance between at least two detection units.

[0051] The physical meaning of this formula is that the sensor installation position is usually limited by structural space, and its spacing L2 is often smaller than the guide rail span L1. Using this formula, the system amplifies the tiny displacement difference Δ0 detected by the sensor within a local area into a linear displacement compensation amount Δ1 over the entire motion stroke, proportional to the span. For example, if the guide rail span L1 is 10 times the sensor spacing L2, then a displacement difference of 0.01mm detected by the sensor means that a linear displacement error of 0.1mm needs to be compensated within the guide rail span.

[0052] Similarly, a mathematical model for the pendulum of the 30° slide is established, such as... Figure 5As shown, point F is the detection point position of distance sensor C303, point G is the position of distance sensor D304, H is the position of distance sensor C303, K is the detection point position of distance sensor D304, and N is the detection point position of distance sensor D304 after the sway occurs. Lm4 is the distance from distance sensor C303 to the detected point on the Z-axis linear guide rail 302, Lm3 is the distance from distance sensor D304 to the detected point on the Z-axis linear guide rail 302, △2 is the actual sway coefficient of the beam (the difference between the actual detected data of the distance from distance sensor C303 to the detected point on the Z-axis linear guide rail 302 and the distance from distance sensor D304 to the detected point on the Z-axis linear guide rail 302), L4 is the distance between distance sensor A401 and distance sensor B402, and L3 is the span of the detected surfaces of the two guide rails on the Z-axis linear guide rail 302. In this embodiment, the difference between the distance data detected by the two sensors (e.g., △3 = Lm4 - Lm3) is calculated, and this difference is defined as the sway characterization quantity. Then calculate and determine the yaw compensation of the moving parts: △4 = L3 / L4 × △3.

[0053] It should be noted that the geometric mapping model (△1 = L1 / L2 ×△0) established based on the principle of similar triangles implies the following assumptions: the yaw of the moving parts (beams or rams) is mainly manifested as rigid body rotation, and its elastic bending deformation in the direction of motion is negligible. This assumption holds true under the following conditions: 1. The length-to-diameter ratio (span to section height ratio) of the moving parts is less than 20; 2. The material of the parts has sufficient rigidity (such as high-strength cast iron or welded steel plate structures); 3. The bending deformation caused by the load does not exceed 5% of the yaw compensation. If the elastic deformation of the moving parts cannot be ignored in practical applications (e.g., ultra-long stroke beams or heavy-duty rams), then the geometric mapping relationship needs to be nonlinearly corrected. The correction method is as follows: obtain the bending deformation curves under different loads through finite element analysis or experimental calibration, and correct the original formula to △1 = (L1 / L2) × (1 + ε)·△0, where ε is the bending deformation correction coefficient, with a value range of 0.05~0.15. For the sake of simplicity, this embodiment uses a rigid body yaw model as an example. In actual applications, a correction coefficient can be introduced depending on the specific working conditions.

[0054] Furthermore, this embodiment also introduces a compensation triggering mechanism: comparing the yaw rate with a preset threshold; if the yaw rate is greater than or equal to the preset threshold, then the motion trajectory of the moving part is compensated based on the yaw compensation amount.

[0055] Specifically, during actual machining, machine tools inevitably experience minor vibrations or measurement noise. The system calculates the runout characteristic Δ0 in real time and compares it with a preset threshold. Only when Δ0 exceeds this threshold does the system determine that the current runout error has affected machining accuracy and trigger a compensation procedure. This threshold-based logic effectively filters out normal measurement noise and balances compensation accuracy with system stability.

[0056] This embodiment, through the above-described scheme, utilizes a fixed guiding benchmark as the measurement reference system, successfully avoiding the logical flaw in traditional schemes where the detection benchmark deforms along with the moving parts, making it impossible to measure relative runout. This method achieves online, real-time capture of the dynamic runout error of the moving parts, providing reliable data support for subsequent real-time compensation.

[0057] Example 2: Based on the above examples, this example further introduces intelligent compensation algorithms, including adaptive threshold adjustment algorithm, error prediction algorithm and compensation amount optimization algorithm, to improve the intelligence level and compensation effect of the system.

[0058] First, this embodiment introduces an adaptive threshold adjustment algorithm. The preset threshold is dynamically adjusted based on the operating parameters of the moving parts, including load status, temperature parameters, or movement speed.

[0059] Specifically, the dynamic adjustment of the preset threshold satisfies the following formula:

[0060]

[0061] In actual machining, the operating conditions of machine tools are dynamically changing. For example, when the machine tool is under heavy-duty cutting, the rigid deformation of moving parts increases, requiring a more relaxed preset threshold to avoid frequent compensation triggering. When the machine tool is under finishing conditions, higher precision is required, necessitating a tighter preset threshold to improve compensation sensitivity. This embodiment establishes a nonlinear mapping relationship between operating parameters and preset thresholds by real-time monitoring of machine tool operating parameters. The values ​​of weighting coefficients w1, w2, and w3 are determined based on the structural characteristics of the machine tool and machining accuracy requirements. For example, for high-precision machine tools, w1, w2, and w3 can be 0.4, 0.3, and 0.3 respectively; for heavy-duty machine tools, w1, w2, and w3 can be 0.5, 0.2, and 0.3 respectively. The specific forms of the correction functions f(L), g(T), and h(V) are obtained by fitting experimental data. For example, f(L) can be a linear function f(L) = 1 + k1·(L - L0), where k1 is the load influence coefficient and L0 is the reference load; g(T) can be a quadratic function g(T) = 1 + k2·(T - T0). 2Where k2 is the temperature influence coefficient and T0 is the reference temperature; h(V) can be expressed as an exponential function h(V)=1+k3·exp(V-V0), where k3 is the velocity influence coefficient and V0 is the reference velocity.

[0062] Secondly, this embodiment introduces an error prediction algorithm. The method also includes: establishing a time series prediction model based on historical skewness characteristic data; predicting the skewness characteristic at future times according to the time series prediction model; and generating a compensation instruction in advance if the predicted skewness characteristic is greater than or equal to a preset threshold.

[0063] Specifically, in actual machining processes, runout error often exhibits a certain temporal regularity. For example, when a machine tool performs reciprocating motion, the runout error shows periodic changes; when the machine tool temperature gradually increases, the runout error shows a trend change. By establishing a time series prediction model, the system can predict future runout trends in advance, thereby generating compensation commands ahead of time, reducing compensation delays, and improving compensation effectiveness. This embodiment uses the sliding window averaging method to establish the time series prediction model. The system maintains a historical data window of length N, recording the runout characteristics Δ0(t-N+1), Δ0(t-N+2), ..., Δ0(t) of the most recent N samples. The prediction model uses a weighted average method to predict the runout characteristics at future times as follows:

[0064] △0_ pred (t+1)=Σ(w i ·△0(t-i+1));

[0065] Where w i Let w be the weighting coefficient, satisfying Σwi=1. The weighting coefficient can be determined based on the timeliness of the historical data; for example, data closer to the current time has a greater weight, and a linearly decreasing weight w can be used. i =(N-i+1) / [N·(N+1) / 2]. Furthermore, this embodiment can also use exponential smoothing to establish the prediction model. The prediction formula is:

[0066] △0_ pred (t+1)=α·△0(t)+(1-α)·△0_ pred (t);

[0067] Where α is the smoothing coefficient.

[0068] Finally, this embodiment introduces a compensation amount optimization algorithm. The motion trajectory of the moving part is compensated based on the yaw compensation amount, including: decomposing the yaw compensation amount into multiple progressive compensation steps, each progressive compensation step being smaller than a preset maximum single compensation amount; and executing multiple progressive compensation steps step by step according to a preset compensation frequency.

[0069] Specifically, in actual machining, if the single compensation amount is too large, it can cause the machine tool servo system to suddenly move, potentially leading to system oscillation and affecting the quality of the machined surface. Therefore, this embodiment introduces a progressive compensation mechanism, decomposing the runout compensation amount △1 into multiple progressive compensation steps △1_1, △1_2, ..., △1_ m Each progressive compensation step is smaller than the preset maximum single compensation amount Δmax. For example, if the calculated runout compensation amount Δ1 = 0.10 mm and the maximum single compensation amount Δmax = 0.02 mm, then Δ1 is decomposed into 5 progressive compensation steps, each with a step size of 0.02 mm. The execution frequency of the progressive compensation step is determined based on the response characteristics of the machine tool servo system and the machining accuracy requirements. For example, for high-speed machining scenarios, the compensation frequency can be set to 100 Hz, meaning a progressive compensation step is executed every 10 ms; for precision machining scenarios, the compensation frequency can be set to 50 Hz, meaning a progressive compensation step is executed every 20 ms.

[0070] Through the synergistic effect of the three intelligent compensation algorithms mentioned above, the system can intelligently adjust the compensation strategy according to the actual processing conditions, which not only ensures high-precision processing, but also avoids system instability caused by over-compensation, thus significantly improving the intelligence level of the machine tool and the processing quality.

[0071] Example 3: Based on the above examples, this example further introduces a multi-component collaborative compensation mechanism to achieve systematic error elimination. Specifically, this method is applied to a machine tool including a crossbeam and a slide, with at least two detection units respectively provided on the crossbeam and the slide. The method also includes: collaboratively adjusting the motion trajectory of the machine tool based on the runout compensation amount of the crossbeam and the runout compensation amount of the slide.

[0072] Specifically, such as Figure 1 As shown, in a five-axis CNC machine tool, the crossbeam 400 (Y-axis moving part) and the slide 300 (Z-axis moving part) are two key moving parts, both of which may generate runout errors during movement. If only one part is compensated while ignoring the runout of the other part, the overall error will not be completely eliminated.

[0073] This embodiment uses detection units (such as sensors A401 and B402 on the crossbeam, and sensors C303 and D304 on the slide) to measure the runout characteristics of the two components in real time, and calculates the runout compensation amounts △1 (crossbeam) and △3 (slide) respectively. The control system integrates these two compensation amounts to generate a coordinated compensation command. For example, when both the crossbeam and slide run out of space simultaneously, the system can calculate the comprehensive position error of the tool center point based on the direction and magnitude of the runout, generate a corresponding multi-axis linkage compensation command, and simultaneously adjust the motion trajectories of the Y-axis and Z-axis.

[0074] Taking the crossbeam 400 as an example, distance sensors A 401 and B 402, installed on the body of the crossbeam 400, operate in real time. Sensor A 401 measures the distance Lm2 from its probe to the side of the guide rail where the Y-axis rail slider 1 (403) is fixed on the column 200, and sensor B 402 measures the distance Lm1 from its probe to the side of the guide rail where the Y-axis rail slider 2 (404) is located. Assume that at a certain moment, the reading of sensor A 401 is 500.05mm and the reading of sensor B 402 is 500.00mm. The system calculates the runout characteristic Δ0 = Lm2 - Lm1 = 0.05mm. It is known that the installation distance L2 between the two sensors is 1000mm, while the span L1 of the X-axis rail slider (405) of the machine tool is 2000mm. Based on the geometric mapping formula △1=L1 / L2×△0, the system calculates the runout compensation amount △1=2000 / 1000×0.05=0.10mm. If this value exceeds the preset threshold, the control system will output a compensation command to adjust the motion trajectory of the Y-axis servo motor and correct the runout error.

[0075] Similarly, as a Z-axis moving component, the slide 300 is prone to lateral sway during vertical movement due to changes in the center of gravity of the slide box. Distance sensors C 303 and D 304 are installed on the slide 300. Sensor C 303 measures the distance Lm4 from its probe to the side of the guide rail where the Z-axis slide block is located, and sensor D 304 measures the distance Lm3 from its probe to the other side of the guide rail. Assuming the reading of sensor C 303 is 300.02 mm and the reading of sensor D 304 is 300.00 mm, the system calculates the sway characteristic Δ2 = Lm4 - Lm3 = 0.02 mm. Given that the distance L4 between sensors C and D is 800 mm and the guide rail span L3 is 1500 mm, according to the formula Δ3 = L3 / L4 × Δ2, the system calculates the sway compensation Δ3 = 1500 / 800 × 0.02 ≈ 0.0375 mm. The system corrects the Z-axis motion trajectory in real time based on this value.

[0076] This multi-component collaborative compensation mechanism can eliminate systematic errors, avoid error transfer or accumulation caused by compensation of a single component, and further improve the overall machining accuracy of the machine tool. Especially in the machining of complex curved surfaces, the collaborative compensation of the crossbeam and the slide can ensure that the tool always moves along the ideal trajectory, significantly improving the surface quality and dimensional accuracy of the machined surface.

[0077] Example 4: This example provides a device for measuring and compensating for runout error of machine tool moving parts, and a CNC machine tool. This device is a hardware implementation based on the methods described in the above examples, aiming to achieve automated monitoring and compensation for runout error of machine tool moving parts through a modular functional architecture.

[0078] Specifically, combined Figure 6 The control principle diagram shown illustrates that the device mainly comprises two core functional units: a detection module and a processing module. The detection module is configured to acquire the relative position parameters of the moving part relative to a fixed guide reference in real time using at least two detection units positioned on the moving part; these at least two detection units are spaced apart along the direction of movement of the moving part. The processing module is configured to have a controller that collects data and then calculates the difference between the relative position parameters acquired by the at least two detection units in real time to obtain a runout characterization. Based on the runout characterization and the geometric mapping relationship between the spacing between the at least two detection units and the span of the fixed guide reference, the runout compensation amount of the moving part is determined in real time. Finally, by comparing the runout characterization with a preset threshold, if the runout characterization is greater than or equal to the preset threshold, the movement trajectory of the moving part is compensated based on the runout compensation amount; otherwise, the machine tool operates normally.

[0079] At the hardware level, the detection module is specifically implemented as at least two distance sensors, which are mounted on the moving part and configured to detect the displacement data of the moving part relative to the fixed guide reference as a relative position parameter.

[0080] Specifically, combined Figure 2 and Figure 6 As shown, the hardware implementation of the detection module consists of distance sensors A401, B402 (for the crossbeam 400), C303, and D304 (for the slide 300). These distance sensors are rigidly mounted on the moving parts via mechanical fixing methods (such as threaded connections, snap-fits, or welding). Taking the crossbeam 400 as an example, sensors A401 and B402 are fixed to the side or bottom of the crossbeam 400 and reciprocate along the Y-axis with the crossbeam 400. During installation, the sensor probe direction must be strictly controlled so that it points perpendicularly to the side of the guide rail 202, which serves as the fixed guide reference. This physical connection ensures that the sensors and the moving parts are on the same rigid body, and when the moving parts wobble, the sensors can synchronously sense the change in distance relative to the side of the fixed guide rail.

[0081] It should be understood that the distance sensor described in this embodiment can be a contact-type distance sensor (such as a linear variable differential transformer LVDT) or a non-contact-type distance sensor (such as a laser distance sensor or an eddy current sensor). Non-contact sensors, due to the absence of mechanical wear, are more suitable for high-precision measurement scenarios involving high-frequency reciprocating motion, such as machine tools. For example, when using an eddy current sensor, its probe faces the side of a metal guide rail, and the air gap distance between the probe and the guide rail surface is accurately measured by detecting changes in the eddy current. This air gap distance is the relative position parameter described in this embodiment.

[0082] The processing module is the "computing brain" of the entire device. At the hardware level, it is typically implemented as the core controller of the machine tool's CNC system, or a dedicated compensation controller independent of the CNC system (such as a PLC module or industrial computer). The processing module establishes a signal connection with the detection module via a data bus (such as a fieldbus or Ethernet). Internally, it pre-configures the geometric mapping algorithm (i.e., Δ1 = L1 / L2 × Δ0) and threshold determination logic described in the previous embodiments. When the processing module receives the relative position parameters uploaded by the detection module, it automatically performs a series of calculations, including difference calculation, geometric mapping transformation, and threshold comparison, ultimately generating the runout compensation amount. This compensation amount is then converted into servo drive commands and sent to the machine tool's feed axis driver, thereby achieving closed-loop compensation control.

[0083] This embodiment also provides a CNC machine tool. The CNC machine tool includes a machine tool body and the device for measuring and compensating for the runout error of the machine tool moving parts described in the above embodiment.

[0084] Specifically, combined Figure 1 As shown, the machine tool body constitutes the basic hardware platform of the CNC machine tool. The device for measuring and compensating for the runout error of the machine tool's moving parts is integrated into the machine tool body as a functional module. The detection module of this device, namely distance sensors A 401, B 402, C 303, and D 304 in the aforementioned embodiments, is respectively installed on the bodies of the crossbeam 400 and the slide 300, facing the fixed guide rail side. The displacement data collected in real time constitutes the feedback source of the machine tool's closed-loop control system. The processing module of this device can be integrated inside the machine tool's CNC system controller, or it can be connected to the CNC controller via a bus as an independent compensation control unit. The processing module calculates the runout compensation amount in real time according to the geometric mapping algorithm described in the aforementioned embodiments and sends compensation commands to the machine tool's servo drive unit.

[0085] It should be understood that the CNC machine tool described in this embodiment is not limited to the five-axis linkage gantry milling machine structure shown in the accompanying drawings. Any machine tool with linear motion axes (such as X, Y, and Z axes) that experiences runout risk during operation and requires precision compensation falls within the scope of this embodiment. For example, the machine tool could also be a floor-type boring and milling machine, a vertical machining center, or a large grinding machine. By integrating the aforementioned measurement and compensation devices into the complete machine tool product, the machine tool product possesses the ability to autonomously sense and eliminate dynamic runout errors, thereby maintaining high-precision machining performance during factory delivery and subsequent use, significantly enhancing the product's market competitiveness.

[0086] This embodiment constructs a complete hardware architecture for perception, decision-making, and execution through the collaborative work of the aforementioned detection and processing modules. This device architecture design enables machine tools to autonomously perceive and eliminate dynamic runout errors without relying on manual intervention or external detection equipment. Furthermore, embedding the method logic within the hardware modules not only improves the system's response speed and reliability but also facilitates modular production and modification of the device as an independent product, giving it significant market potential.

[0087] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for measuring and compensating for runout errors of a machine tool motion component, characterized in that, include: The relative position parameters of the moving part with respect to the fixed guide reference are acquired in real time by using at least two detection units set on the moving part. The at least two detection units are arranged at intervals along the direction of movement of the moving component; The difference between the relative position parameters acquired by the at least two detection units is calculated in real time to obtain the sway characterization quantity; Based on the yaw characterization quantity and the geometric mapping relationship between the distance between at least two detection units and the span of the fixed guide reference, the yaw compensation amount of the moving component is determined in real time, and then the motion trajectory of the moving component is compensated based on the yaw compensation amount.

2. The method of claim 1, wherein, The fixed guide reference includes the side of the machine tool guide rail, the column reference surface, or an independent reference structure rigidly connected to the guide rail.

3. The method of claim 1, wherein, The geometric mapping relationship satisfies the following formula: △1 = L1 / L2 × △0; Wherein, △1 ​​is the sway compensation amount, △0 is the sway characterization amount, L1 is the span of the fixed guide reference, and L2 is the distance between the at least two detection units.

4. The method for measuring and compensating for runout error of machine tool moving parts according to claim 1, characterized in that, The method further includes: Compare the yaw rate with a preset threshold; If the yaw rate is greater than or equal to the preset threshold, the motion trajectory of the moving part is compensated based on the yaw compensation amount.

5. The method for measuring and compensating for runout error of machine tool moving parts according to claim 4, characterized in that, The preset threshold is dynamically adjusted according to the operating parameters of the moving parts, including load status, temperature parameters, or movement speed. The dynamic adjustment of the preset threshold satisfies the following formula:

6. The method for measuring and compensating for runout error of machine tool moving parts according to claim 4, characterized in that, The method further includes: A time series forecasting model is established based on historical skewness characteristic data; Based on the time series prediction model, predict the sway characteristics at future times; If the predicted sway characterization is greater than or equal to the preset threshold, a compensation instruction is generated in advance.

7. The method for measuring and compensating for runout error of machine tool moving parts according to claim 4, characterized in that, The compensation of the motion trajectory of the moving component based on the yaw compensation amount includes: The yaw compensation amount is decomposed into multiple progressive compensation steps, each progressive compensation step being smaller than the preset maximum single compensation amount. The plurality of progressive compensation steps are executed step by step according to the preset compensation frequency.

8. The method for measuring and compensating for runout error of machine tool moving parts according to any one of claims 1 to 7, characterized in that, The moving parts include the machine tool's crossbeam and / or slide.

9. A device for measuring and compensating for runout error of moving parts in a machine tool, characterized in that, include: The detection module is configured to acquire, in real time, the relative position parameters of the moving component with respect to a fixed guide reference through at least two detection units disposed on the moving component; the detection units are arranged at intervals along the movement direction of the moving component. The processing module is configured to calculate the difference in relative position parameters obtained by the detection unit in real time to obtain the yaw characterization quantity; based on the yaw characterization quantity and the geometric mapping relationship between the distance between at least two detection units and the span of the fixed guide reference, the yaw compensation amount of the moving part is determined in real time.

10. A CNC machine tool, comprising a machine tool body, characterized in that, It also includes the device for measuring and compensating for runout error of machine tool moving parts as described in claim 9.

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