A high-precision roller large ball base surface measuring device and method

Abstract

The application relates to the technical field of precision measuring instruments, and discloses a high-precision roller large ball base surface measuring device and method. The high-precision roller large ball base surface measuring device comprises a measuring instrument main body, a measuring head arranged on the measuring instrument main body, a clamping mechanism, an identification measuring mechanism and a control end. The clamping mechanism comprises a clamping piece, a rotary driving piece and a pre-supporting piece. The clamping piece is mainly used for clamping a roller to be measured. The rotary driving piece is connected with the clamping piece and is mainly used for driving the clamped roller to rotate around a theoretical axis. The application automatically identifies the size of the roller through machine vision and determines optimal clamping parameters. In combination with real-time calibration of the clamping posture through three-dimensional scanning, the application can dynamically generate an adaptive measuring path according to a measured deviation, effectively solves the system error problem caused by inconsistent clamping in traditional measurement, greatly shortens the single-piece measurement time, and realizes efficient and reliable measurement of the micron-level precision of the large ball base surface of the conical roller.

Description

Technical Field

[0001] This invention relates to the field of precision measuring instrument technology, and more specifically, to a high-precision roller ball base surface measuring device and method. Background Technology

[0002] Tapered rollers are one of the core components of bearings. Their ends are designed with a spherical structure, characterized by a short arc length and a large radius, and are commonly referred to as the "large spherical base surface." The machining accuracy of the large spherical base surface directly affects the bearing's rotational accuracy, load distribution, and service life; therefore, accurate measurement of its geometric parameters is crucial.

[0003] Currently, the industry primarily relies on general-purpose equipment such as coordinate measuring machines (CMMs) for measuring large spherical surfaces. While these devices possess multifunctional measurement capabilities, they still have limitations when dealing with the unique structure of large spherical surfaces. First, the clamping process heavily depends on the operator's experience and feel, making it difficult to guarantee consistency in clamping positions each time. Even micrometer-level misalignment or eccentricity of the roller within the fixture can be amplified into significant systematic errors in subsequent measurements, affecting the accuracy and reliability of the data. Second, existing measurement systems generally lack online judgment and compensation mechanisms for clamping quality. The equipment typically executes measurements according to a preset theoretical path, failing to identify reference offsets caused by clamping deviations. This results in measurement results that "accurately" reflect erroneous conditions, misleading process judgment and quality assessment. Furthermore, data fluctuations caused by inconsistent clamping also increase the uncertainty of measurement results, posing challenges to quality traceability and stability control in the production process.

[0004] Therefore, there is an urgent need for a dedicated measuring device that can automatically ensure clamping quality and has online evaluation and intelligent compensation functions, so as to fundamentally improve the measurement accuracy and efficiency of tapered roller spherical base surfaces. Summary of the Invention

[0005] The purpose of this invention is to provide a high-precision roller ball base surface measurement device and method to solve the above-mentioned technical problems.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions: This invention provides a high-precision roller ball base surface measuring device, comprising: a measuring instrument body, a measuring head disposed on the measuring instrument body, a clamping mechanism, an identification measuring mechanism, and a control terminal; The clamping mechanism includes: Clamping element, used to clamp the roller to be tested; A rotary drive component, connected to a clamping component, is used to drive the clamped roller to rotate about a theoretical axis. The pre-support member, located below the axis of the clamping member, has a telescopic linear function and is used to support the small end face of the roller before clamping. The identification and measurement mechanism is used to identify the external dimensions of the roller after it is placed on the pre-support; and to measure the actual positions of at least two reference features on the roller after it is clamped. The control terminal is communicatively connected to the clamping component, the rotary drive component, the pre-support component, and the identification and measurement mechanism, and is configured as follows: Receive the roller appearance dimension data sent by the identification and measurement mechanism, and generate the corresponding target clamping parameters based on the data; Based on the target clamping parameters, control the pre-support component to drive the roller to move, and control the clamping component to perform the clamping action; After clamping is completed, the actual position data of the reference feature sent by the identification and measurement mechanism is received, and the attitude deviation of the actual axis of the roller under test relative to the theoretical axis is calculated based on this. An adaptive measurement path is generated for the measurement head based on the attitude deviation.

[0007] Preferably, the clamping member is a three-jaw chuck structure, and the working surface of its jaws forms a V-shaped positioning surface that is adapted to the conical surface of the roller to be tested.

[0008] Preferably, the rotary drive component is a servo motor mounted on the working surface of the measuring instrument body, and its drive end is connected to the bottom of the three-jaw chuck structure.

[0009] Preferably, the pre-support member includes a support base and a telescopic drive source for driving the support base to extend and retract linearly.

[0010] Preferably, the identification and measurement mechanism is located on one side of the clamping member, and includes a visual identification sensor and a three-dimensional scanning sensor.

[0011] Preferably, the target clamping parameters include the lifting height of the pre-support member determined based on the roller size, the target clamping force of the clamping member, and the displacement.

[0012] Preferably, after calculating the attitude deviation, the control terminal determines whether it exceeds the preset software compensation tolerance; if it does, it outputs clamping abnormality information.

[0013] Preferably, when calculating the geometric parameters of the roller ball base surface to be measured, the control terminal establishes a virtual coordinate system based on the calculated actual axis.

[0014] A high-precision method for measuring the base surface of a large roller ball includes the following steps: Step S100: Identify the external dimensions of the rollers placed on the pre-support by the identification measuring mechanism; Step S200: The control terminal generates the corresponding target clamping parameters based on the external dimensions; Step S300: The control unit controls the pre-support member to rise and controls the clamping member to perform clamping actions according to the target clamping parameters; Step S400: After clamping is completed, the roller reference features are measured by the identification measuring mechanism; Step S500: Based on the actual position of the reference feature, the control end calculates the attitude deviation of the actual axis of the roller under test relative to the theoretical axis; Step S600: Generate an adaptive measurement path for the measurement head based on the attitude deviation; Step S700: Control the measuring head to scan the large spherical base surface along the adaptive measuring path; Step S800: Calculate the geometric parameters of the large sphere base surface based on the scan data and the actual axis.

[0015] The beneficial effects of this invention are as follows: This invention automatically identifies roller dimensions and determines optimal clamping parameters through machine vision, and combines 3D scanning to calibrate clamping posture in real time. It can dynamically generate adaptive measurement paths based on measured deviations, effectively solving the system error problem caused by inconsistent clamping in traditional measurements. It significantly shortens the measurement time for a single piece and achieves efficient and reliable measurement of the large spherical base surface of tapered rollers with micron-level accuracy, while significantly reducing the technical dependence on operators. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a high-precision roller ball base surface measuring device according to the present invention; Figure 2 This is a schematic diagram of the clamping mechanism in a high-precision roller ball base surface measuring device of the present invention; Figure 3 This is a schematic diagram of the internal structure of the clamping mechanism in a high-precision roller ball base surface measuring device of the present invention; Figure 4 This is a block diagram showing the relationship between the components in a high-precision roller ball base surface measuring device of the present invention; Figure 5 This is a flowchart of a high-precision roller ball base surface measurement method according to the present invention.

[0017] In the figure: 10, measuring instrument body; 20, measuring head; 30, clamping mechanism; 301, three-jaw chuck structure; 302, servo motor; 303, support base; 304, telescopic drive source; 40, identification and measuring mechanism. Detailed Implementation

[0018] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0019] Please refer to the following: Figures 1 to 5 A high-precision roller ball base surface measuring device includes: a measuring instrument body 10, a measuring head 20 disposed on the measuring instrument body 10, a clamping mechanism 30, an identification measuring mechanism 40, and a control terminal. The clamping mechanism 30 includes a clamping component, a rotary drive component, and a pre-support component; the clamping component is mainly used to clamp the roller to be measured; as a preferred embodiment, the clamping component can be a three-jaw chuck structure 301, whose jaw working surfaces form a V-shaped positioning surface adapted to the conical surface of the roller to be measured.

[0020] The rotary drive component is connected to the clamping component and is mainly used to drive the clamped roller to rotate around a theoretical axis (referring to the ideal rotation center axis preset by the equipment). The rotary drive component is a servo motor 302 installed on the working surface of the measuring instrument body 10, and its drive end is connected to the bottom of the three-jaw chuck structure 301.

[0021] The pre-support component is located below the axis of the clamping component and has a linear telescopic function. It is mainly used to support the small end face of the roller before clamping, so that it is initially positioned between the clamping components. The pre-support component includes a support base 303 and a telescopic drive source 304 for driving the linear telescopic extension and retraction of the support base 303. The support base 303 coincides with the center of the three-jaw chuck and has a groove on it to facilitate the insertion and positioning of the bottom end of the roller. The linear telescopic source can be a servo electric cylinder, which drives the support base 303 to rise and fall smoothly on the three-jaw chuck. A pressure sensor is also provided on the support base 303. During the measurement process, when the operator places the roller on the support base 303, the pressure sensor detects the load and sends a signal to the control terminal, causing the control terminal to start the clamping action.

[0022] The identification and measurement mechanism 40 is mainly used to identify the external dimensions of the roller after it is placed on the pre-support member; at the same time, after the roller to be tested is clamped, it measures the actual position of at least two reference features on the roller to be tested; the identification and measurement mechanism 40 is located on one side of the clamping member and includes a visual recognition sensor and a three-dimensional scanning sensor.

[0023] The control unit is an industrial PLC, which communicates with the clamping component, rotary drive component, pre-support component, and identification and measurement mechanism 40. An adaptive calibration module is configured within the control unit, which has two functions: determining appropriate clamping parameters and calibrating the attitude of the roller after clamping.

[0024] The function of determining clamping parameters mainly involves analyzing and calculating the received appearance parameters of the roller under test before clamping it. This determines appropriate clamping parameters (such as clamping force, clamping displacement, and lifting height of the pre-support) to achieve precise clamping and fixation of the roller under test, thereby ensuring the accuracy of subsequent measurements. The attitude calibration function primarily calibrates the attitude of the roller under test after clamping. If it is in a standard attitude, measurement operations can be performed directly; if it is in a non-standard attitude, the measurement strategy needs to be adaptively adjusted to ensure measurement accuracy.

[0025] The working process of the high-precision roller ball base surface measuring device designed in this invention is as follows: Step S100, clamping parameters determined: After the operator places the roller to be tested on the pre-support, the pressure sensor on it detects the load change and triggers the identification and measurement mechanism 40 to start working. The visual identification sensor in the identification and measurement mechanism 40 first collects the three views of the roller to be tested, and extracts the contour features through image processing algorithms (including: edge detection using the Canny operator, identification of end face contour using Hough circle transform, and fitting of geometric boundaries using the least squares method). Calculate key geometric parameters based on the extracted contour features: Large end diameter D1 = 2 × R1 × k calibration ; Small end diameter D2 = 2 × R2 × k calibration ; Roller length L=(z max -z min )×k calibration ; Cone angle α = arctan((D1-D2) / (2×L)); Based on the identified size parameters, the target clamping parameters are calculated using a preset mapping relationship: The lifting height H = 0.85 × L + 2.5 ± 0.1 mm; Clamping force F = 0.15 × D1 + 5 ± 1 N; Clamping displacement S = 0.8 × α + 0.5 ± 0.05 mm; Based on the calculated clamping parameters, the control end strictly executes the clamping action in sequence, controls the pre-support to smoothly lift the roller to height H at a preset speed (e.g., 5mm / s), and controls the clamping component to clamp and fix the roller under test according to the target clamping force and clamping displacement. Step S200, clamping attitude calibration: After clamping is completed, the attitude calibration process is started. The three-dimensional scanning sensor in the identification and measurement mechanism 40 collects 12 points at each of the three cross sections of the outer circle of the large end of the roller, 12 points at each of the two cross sections of the outer circle of the small end, and 8 points at equal intervals at the edge of the ball base surface. All measurement data are unified to the machine coordinate system through a pre-calibrated transformation matrix. The least squares method was used to fit the large-end circle and the small-end circle respectively: Objective function:

[0026] The coordinates of the center of the circle, O1(x1,y1,z1) and O2(x2,y2,z2), are obtained by solving the normal equation. Attitude deviation calculation: Axis direction vector:

[0027] Eccentricity: Where (x0, y0) are the projected coordinates of the theoretical axis in the XY plane; Inclination calculation (based on projection method): First, calculate the projection vectors of the axis direction vector onto the XZ and YZ planes:

[0028]

[0029] Then, calculate the angle between it and the positive Z-axis direction (0, 1):

[0030] Step S300, Measurement strategy decision: Automatically select the measurement strategy based on the attitude deviation results: A. Standard Measurement Mode: If |ΔX|<5μm, |ΔY|<5μm, |Δθx|<0.005°, |Δθy|<0.005°, and the deviation does not exceed the compensation capability, then the standard measurement strategy is executed: using the standard spiral scanning path, the standard sampling density, and the measurement speed of 10mm / s; B. Adaptive Measurement Mode: If the deviation exceeds the standard range but is within the equipment's compensation capability, a dynamic adjustment strategy will be implemented: Measuring speed Adaptive deceleration based on curvature; Sampling density Increase sampling based on tilt angle; C. Reloading mode: If the deviation exceeds the compensation capability, the specific direction and magnitude of the deviation will be output, and the operator will be prompted with a suggested method for re-clamping. The measurement process will be paused until the clamping problem is resolved. The theoretical path is transformed to the actual coordinate system using a transformation matrix:

[0031] Actual measurement point = T × theoretical measurement point. The control terminal multiplies the coordinates of all point cloud on the theoretical measurement path by the coordinate transformation matrix T to obtain the measurement path point sequence under the actual clamping posture, thereby compensating for the path offset caused by clamping deviation. During the measurement process, the system continuously monitors attitude changes and dynamically updates the transformation matrix. When a slight attitude change is detected, the system adjusts the measurement path in real time to ensure that the probe always moves along the optimal trajectory. Step 400, Real-time Measurement and Compensation: The control terminal sends a start command to the measuring head. The measuring head 20 scans the large sphere base surface along the planned path according to the selected measurement strategy (standard measurement mode, adaptive measurement mode). During the scanning process, the measuring head collects the three-dimensional coordinate data of each point on the large sphere base surface in real time and transmits these data to the control terminal. If in reclamping mode, after the operator reclamps the device, the subsequent process will start again from step S100 until the measurement is completed. Step S500: Determine the measurement result: Based on the collected point cloud data, the best sphere was fitted using the least squares method: Objective function:

[0032] Output: Center coordinates (a, b, c), radius of curvature R; Profile Calculation: Profile Calculation = max(d) i )-min(d i ), where d i This is the distance from the measuring point to the fitted sphere; Location evaluation:

[0033] As can be seen from the above scheme, the high-precision roller ball base surface measuring device designed in this invention has the following advantages compared with the prior art: First, by integrating the identification and measurement mechanism with the adaptive calibration module, this invention achieves intelligent determination of clamping parameters and real-time calibration of attitude deviations, solving the system error problem caused by inconsistent clamping in traditional measuring equipment and significantly improving the authenticity and reliability of measurement data. Secondly, this invention introduces a dynamic measurement strategy decision-making mechanism, which can automatically select the most suitable measurement mode based on the real-time calculated attitude deviation results. This mechanism not only improves the flexibility and adaptability of measurement, but also significantly enhances the compensation capability of the equipment. In the standard measurement mode, the equipment can perform efficient measurement according to the preset spiral scanning path. In the adaptive measurement mode, the equipment can dynamically adjust the measurement path and parameters according to the attitude deviation, ensuring that the measurement accuracy is not affected by the clamping deviation. In the reclamping mode, the equipment can promptly prompt the operator to reclamp and provide specific suggestions on the direction and magnitude of the deviation, thereby avoiding measurement failures and data fluctuations caused by clamping problems.

[0034] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A high-precision roller ball base surface measuring device, characterized in that, include: The measuring instrument body, the measuring head mounted on the measuring instrument body, the clamping mechanism, the identification measuring mechanism, and the control terminal; The clamping mechanism includes: A clamping component is used to clamp the roller to be tested. The clamping component is a three-jaw chuck structure, and the working surface of its jaws forms a V-shaped positioning surface that is adapted to the conical surface of the roller to be tested. A rotary drive component, connected to a clamping component, is used to drive the clamped roller to rotate about a theoretical axis. The pre-support member, located below the axis of the clamping member, has a telescopic linear function and is used to support the small end face of the roller before clamping. The identification and measurement mechanism is used to identify the external dimensions of the roller after it is placed on the pre-support; and to measure the actual positions of at least two reference features on the roller after it is clamped; the identification and measurement mechanism is located on one side of the clamping member and includes a visual recognition sensor and a three-dimensional scanning sensor. The control terminal is communicatively connected to the clamping component, the rotary drive component, the pre-support component, and the identification and measurement mechanism, and is configured as follows: Receive the roller appearance dimension data sent by the identification and measurement mechanism, and generate the corresponding target clamping parameters based on the data; Based on the target clamping parameters, control the pre-support component to drive the roller to move, and control the clamping component to perform the clamping action; After clamping is completed, the actual position data of the reference feature sent by the identification and measurement mechanism is received, and the attitude deviation of the actual axis of the roller under test relative to the theoretical axis is calculated based on this. Based on the attitude deviation, an adaptive measurement path is generated for the measurement head; When calculating the geometric parameters of the roller ball base surface to be measured, the control terminal establishes a virtual coordinate system based on the calculated actual axis.

2. The high-precision roller ball base surface measuring device according to claim 1, characterized in that, The rotary drive component is a servo motor mounted on the working surface of the measuring instrument body, and its drive end is connected to the bottom of the three-jaw chuck structure.

3. The high-precision roller ball base surface measuring device according to claim 2, characterized in that, The pre-support component includes a support base and a telescopic drive source for driving the support base to extend and retract linearly.

4. The high-precision roller ball base surface measuring device according to claim 1, characterized in that, The target clamping parameters include the lifting height of the pre-support member determined based on the roller size, the target clamping force of the clamping member, and the displacement.

5. The high-precision roller ball base surface measuring device according to claim 1, characterized in that, After calculating the attitude deviation, the control terminal determines whether it exceeds the preset software compensation tolerance; if it does, it outputs clamping abnormality information.

6. A high-precision roller ball base surface measurement method, employing a high-precision roller ball base surface measurement device as described in any one of claims 1-5, characterized in that, The following steps are included: Step S100: Identify the external dimensions of the rollers placed on the pre-support by the identification measuring mechanism; Step S200: The control terminal generates the corresponding target clamping parameters based on the external dimensions; Step S300: The control unit controls the pre-support member to rise and controls the clamping member to perform clamping actions according to the target clamping parameters; Step S400: After clamping is completed, the roller reference features are measured by the identification measuring mechanism; Step S5 00: Based on the actual position of the reference feature, the control end calculates the attitude deviation of the actual axis of the roller under test relative to the theoretical axis; Step S600: Generate an adaptive measurement path for the measurement head based on the attitude deviation; Step S700: Control the measuring head to scan the large spherical base surface along the adaptive measuring path; Step S800: Calculate the geometric parameters of the large sphere base surface based on the scan data and the actual axis.

7. The high-precision roller ball base surface measurement method according to claim 6, characterized in that, The control terminal determines the target clamping parameters corresponding to the appearance dimensions by querying a preset clamping parameter mapping table; the calculated attitude deviation is used to establish a virtual measurement coordinate system, the axis of which coincides with the actual axis of the roller to be measured.

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