Catheter waviness measuring system based on autocollimator

Abstract

The invention relates to a precision measurement technology in the field of high-end equipment manufacturing, and provides a conduit waviness measurement system based on an autocollimator, in particular to conduit surface shape precision detection in the field of focusing neutron mirror optics. The system comprises a high-precision photoelectric autocollimator (the angle measurement precision is superior to 1 arc second), a granite linear guide rail, a marble measurement table top and data processing software, the photoelectric autocollimator which is low in price, high in stability and wide in applicability is adopted, multiple purposes are achieved through one machine, and the cost is reduced; by utilizing a real-time angle measurement function, the operation is simple and convenient, the dependence on manpower and specialty is reduced, and the efficiency and automation level are improved; the test interval can be reduced to 10mm, so that the assembly quality of the conduit unit can be observed, and the product yield is improved; high-precision hardware and an innovative algorithm are combined, and economy and feasibility are considered; meanwhile, principle analysis is given for the measurement problem of the complex curved-surface conduit, and the system can provide a reliable basis for neutron conduit quality control.

Description

Technical Field

[0001] This invention relates to precision measurement technology in the field of high-end equipment manufacturing, focusing on the detection technology of duct surface shape accuracy in the field of neutron mirror optics, specifically a duct waviness measurement system based on an autocollimator. Background Technology

[0002] In the field of neutron mirror optics, the neutron conduit is a key component, and its performance plays a decisive role in neutron reflection and transmission. When a neutron conduit reflects neutrons, the incident angle is extremely small, typically within a narrow range of 0.1° to 1°. This requires the mirror or substrate to have extremely high flatness, because even a slight deviation between the actual surface contour and the ideal plane will change the reflection conditions, leading to neutron loss, ultimately reducing the neutron flux, and affecting the normal operation of related scientific research or production activities.

[0003] Currently, while some methods exist for measuring neutron conduit waviness, these existing technologies have several shortcomings. In terms of equipment, their versatility is limited; for example, some measurement schemes utilize high-precision Leica theodolites or laser trackers. While these devices are powerful and can cover all types of conduit measurement needs, they are extremely expensive, often costing millions of dollars. Coupled with high subsequent maintenance costs, this places a significant upfront cost burden on domestic neutron conduit R&D projects. Furthermore, in actual use, only a small portion of the functions of these expensive devices are often utilized, resulting in substantial resource waste.

[0004] In terms of measurement operations, existing technologies involve numerous manual steps, demanding extremely high levels of expertise from surveyors. Theodolite measurement requires surveyors to frequently observe the lens, while tracking instruments require frequent checks of the machine's status before manual measurement is completed. This not only necessitates specialized training for surveyors in theodolites, total stations, and tracking instruments, but also results in high labor intensity, low testing efficiency, and a high risk of measurement errors due to human factors.

[0005] Existing technologies also have significant shortcomings in terms of measurement efficiency and functional expansion. On the one hand, continuous measurement is difficult to achieve, resulting in low measurement efficiency. On the other hand, the turnover problem of expensive measurement equipment cannot be effectively solved during the mass production of neutron conduits. At the same time, due to the limited measurement efficiency of previous equipment, the linear interval of the test is relatively large, usually selecting only one data point every 50 mm to 100 mm on the linear guide rail. The data density is low, making it difficult to directly observe the yaw and torsional accuracy between conduit units after splicing them into a long conduit, i.e., the connection quality of the assembly. This cannot simultaneously meet the dual requirements of quality inspection and production process testing, which is not conducive to improving product yield.

[0006] Therefore, developing a low-cost, easy-to-operate, highly efficient measurement system based on an autocollimator for measuring duct waviness is of great practical significance. Summary of the Invention

[0007] To address the aforementioned issues, this invention aims to provide a duct waviness measurement system based on an autocollimator. This system is suitable for high-precision, efficient, and continuous waviness measurement of optical devices such as neutron ducts that require extremely high surface flatness. It can be widely applied in the construction of large scientific facilities, the precision testing of various tooling guide rails, and the installation of optical devices for line station spectrometers.

[0008] The technical solution adopted in this invention is: a duct waviness measurement system based on a self-collimator, characterized in that it includes: A high-precision photoelectric autocollimator is used to measure the angular deviation of light reflected from the surface of a conduit. The photoelectric autocollimator has an angular measurement accuracy of better than 1 arcsecond. Granite linear guide rails are used to install and move the photoelectric autocollimator to achieve equidistant measurements; The marble measuring platform is used to place the tube to be tested and has vibration isolation function. Data processing software is used to receive, store, and analyze the angle data measured by the photoelectric autocollimator, and to calculate the duct waviness.

[0009] After completing pre-collimation, the photoelectric autocollimator uses its own laser optical axis as a reference to measure the angular deviation between the normal of the reflecting surface and the reference optical axis, which serves as the raw data for waviness measurement.

[0010] The system also includes: A laser collimator is used to assist in finding and positioning the initial optical axis direction and to complete the pre-collimation work. Communication software: used to display the returned spot position and measurement coordinates on the computer screen, and supports switching between "beacon search mode" and "coordinate mode".

[0011] The system measures the conduit waviness through the following steps: Install the photoelectric autocollimator on the granite guide rail and adjust it to a horizontal position; Place the tube to be tested on the marble measuring platform and adjust it to be approximately at the same height as the photoelectric autocollimator; Use a laser collimator to locate the initial optical axis direction, adjust the attitude of the guide tube and autocollimator to bring the reflected light spot back into the range of the optical tube, and complete the pre-collimation; In "Beacon Finding Mode", adjust the light spot to the center of the screen, then switch to "Coordinate Mode" to perform the measurement; Move the photoelectric self-collimator to the next measurement position, repeat the measurement process, and acquire multiple sets of data.

[0012] The data processing software calculates the duct waviness σ using the following formula: (1) in, α i,real ( x )and α i,nominal ( x These represent the actual normal direction and the normal direction of the standard plane, respectively. n This represents the number of data points.

[0013] For straight and tapered catheters, the simplified waviness calculation formula of the data processing software is as follows: (2) The system can measure the assembly accuracy between catheter units and evaluate the yaw and torsion accuracy after catheter splicing by increasing the data point density.

[0014] The measurement range of the photoelectric autocollimator is limited to the conduit with a small change in the slope of the reflecting surface.

[0015] The system also includes a motor drive unit for automatically moving the photoelectric autocollimator along the guide rail for fully automatic measurement, further improving measurement efficiency and data density.

[0016] The system has high testing efficiency and can be used for quality inspection and process testing in neutron tube production, effectively improving product yield. It can also be widely used in collimation and installation work during the construction of large scientific facilities, measurement of machining accuracy of various tooling guide rails, and installation of optical components for line station spectrometers.

[0017] The present invention provides a catheter waviness measurement system based on a self-collimator, which has several significant advantages over the prior art, as follows: This invention uses a high-precision photoelectric autocollimator as the core measuring device, which is inexpensive (between 30,000 and 100,000 yuan), highly stable, and suitable for use in undemanding environments. Simultaneously, this device can also be widely applied to collimation installation during the construction of large scientific facilities, measurement of machining accuracy of various tooling guide rails, and installation of optical components for line station spectrometers, achieving "multi-purpose functionality." This significantly improves the utilization rate and economy of the equipment, solves the problem of high equipment costs in previous solutions, and possesses high versatility.

[0018] This invention utilizes the real-time angle measurement function of an optoelectronic autocollimator, allowing measurement personnel to view the angle reading of the reflected light spot at any time during equipment operation, quickly confirming equipment stability and initiating measurement. The equipment requires no attitude adjustment; after pre-collimation, personnel only need to move the autocollimator base along the guide rail and trigger measurement at the appropriate time. Operation is simple, significantly reducing reliance on manpower and expertise. Even non-professionals can quickly complete measurement tasks, significantly improving measurement efficiency and automation.

[0019] Based on an efficient testing process, this invention can reduce the testing interval to 10mm, and in the future, it can be modified to drive a motor-driven guide rail for fully automated testing. The shortened measurement interval results in higher data density, allowing direct observation from the test results of the yaw and torsional accuracy between the units after they are assembled into a longer catheter, i.e., the assembly connection quality. This function can not only serve as a quality inspection solution for domestically produced catheters but also as a process inspection method in production, effectively improving product yield.

[0020] The commercially available high-precision photoelectric autocollimator used in this invention has an angle measurement accuracy (better than 1 arcsecond) that far exceeds the requirements for waviness measurement. By combining high-precision hardware with innovative algorithms, inexpensive general-purpose measuring equipment is successfully applied to extremely high-precision specialized measuring tasks, ensuring measurement accuracy while also considering the economy, versatility, and feasibility of the solution.

[0021] To address the problem that autocollimators cannot measure complex curved catheter surfaces, this invention provides a principle analysis, explaining that when the reflecting surface is a curved surface with a continuously varying slope, the reflected light beam will be prematurely focused or form a divergent virtual image. This causes the light spot on the autocollimator detector to be drastically widened and symmetrical, thus making accurate measurement impossible. Even so, since this invention covers the measurement tasks required for over 90% of domestic catheter production, its low price makes it of significant practical value.

[0022] This invention uses specialized data processing software to analyze measurement data, ultimately obtaining waviness results. It analyzes the measured waviness values ​​to evaluate the assembly accuracy and substrate processing accuracy, and determines whether the impact on neutron reflection meets design requirements and application standards, providing a reliable basis for the quality control of neutron conduits. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the reflection from the actual corrugated surface in this invention; Figure 2 This is a schematic diagram of the waviness measurement of the photoelectric autocollimator in this invention; Figure 3 This is a real-world image of the waviness measurement using the photoelectric autocollimator in this invention. Figure 4This is a schematic diagram of the measurement principle of the photoelectric autocollimator in this invention; Figure 5 This is a measured phenomenon in this invention where the returned light spot of the photoelectric autocollimator is broadened by the convex surface. Detailed Implementation

[0024] This invention provides a conduit waviness measurement system based on an autocollimator, aiming to solve the problems of low accuracy, low efficiency, expensive equipment, and poor versatility in waviness measurement during neutron conduit production. The specific embodiments of this invention are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1-5 As shown, Figure 1 This is a schematic diagram of the reflection of an actual corrugated surface in this invention. The diagram shows the path of the reflected light from the actual corrugated surface and illustrates the influence of corrugation on the reflection conditions. The deviation between the actual surface profile and the ideal plane will change the direction of the reflected light, resulting in neutron loss and reducing the neutron flux. Figure 2 This is a schematic diagram of the photoelectric autocollimator for measuring waviness in this invention. The diagram illustrates the layout and measurement principle of the photoelectric autocollimator when measuring the waviness of a conduit. The autocollimator uses the laser optical axis after it has completed self-collimation as a reference, and measures the angular deviation between the normal of the reflecting surface of the subsequent point and the reference optical axis as the raw data for waviness measurement. Figure 3 This is a real-world image of the photoelectric autocollimator waviness measurement in this invention. The image shows the arrangement of the photoelectric autocollimator in the actual measurement environment, including the relative positions of the autocollimator, guide rail, test tube, and measurement platform, which intuitively reflects the actual working state of the measurement system. Figure 4 This is a schematic diagram of the measurement principle of the photoelectric autocollimator in this invention. The diagram details the measurement principle of the photoelectric autocollimator, including the emission, reflection and reception process of the laser beam, and how to obtain angle information by converting the position of the returned light spot on the detector. Figure 5 This is a measured phenomenon in this invention where the returned light spot of the photoelectric autocollimator is broadened by a convex surface. The figure shows that when the reflecting surface is a curved surface with a continuously varying slope, the reflected light beam is prematurely focused or forms a divergent virtual image, causing the light spot on the autocollimator detector to be drastically broadened, making it impossible to guarantee the symmetry of the light spot. This explains why the autocollimator cannot measure complex curved conduits. The following detailed description, in conjunction with specific embodiments and the accompanying drawings, further illustrates this phenomenon: Example 1: Application of a straight neutron conduit waviness measurement system based on an autocollimator A neutron science research institution needs to perform waviness testing on mass-produced straight neutron conduits to assess whether the flatness of their reflective surfaces meets the neutron reflection efficiency requirements (waviness σ ≤ 3 arcseconds). Traditional laser tracker solutions are costly and complex to operate, failing to meet the demands of high-efficiency production. The self-collimator-based measurement system proposed in this invention enables low-cost, high-density, and high-precision measurements.

[0026] I. System Composition and Working Principle in this Embodiment This system mainly consists of a high-precision photoelectric autocollimator, a granite linear guide rail, a marble measuring platform, a laser sight, communication software, and data processing software. All parts work together to achieve high-precision measurement of the corrugation of the duct.

[0027] High-precision photoelectric autocollimator: As a core measuring device, the photoelectric autocollimator has an angle measurement accuracy better than 1 arcsecond and can achieve high-precision angle measurement within a range of 3000 arcseconds. Its working principle is to obtain the waviness information of the duct surface by emitting and receiving high-precision laser beams and measuring the angular deviation between the reflected light and the reference optical axis.

[0028] Granite linear guide rail: Used for mounting and moving photoelectric autocollimators to achieve equidistant measurements. The high precision of the guide rail ensures the stability and measurement accuracy of the autocollimator during movement.

[0029] Marble measuring platform: Used to place the tube to be measured, it has vibration isolation function, effectively reducing the impact of external vibration on the measurement results and improving measurement accuracy.

[0030] Laser alignment tool: Used for finding and positioning the initial optical axis direction, helping operators to quickly and accurately adjust the attitude of the autocollimator and guide tube to complete pre-collimation.

[0031] Communication software: Supports switching between "beacon search mode" and "coordinate mode" on the computer screen to display the position of the returned light spot and the measurement coordinates, making it easy for operators to observe and adjust intuitively.

[0032] Data processing software: Receives, stores, and analyzes angle data measured by the photoelectric autocollimator, calculates duct waviness using a specific algorithm, and generates a measurement report.

[0033] II. Measurement Method S1 Equipment Installation and Debugging: Install the high-precision photoelectric autocollimator on the granite linear guide rail and adjust it to a horizontal position. Place the guide tube to be tested on the marble measuring platform and adjust it to approximately the same height as the photoelectric autocollimator. Use a laser sight to locate the initial optical axis direction, and adjust the attitude of the guide tube and the autocollimator so that the reflected light spot returns to the range of the optical tube.

[0034] S2 Measurement Process: In "Benchmarking Mode," observe the return spot position on the display screen and adjust the spot to the center of the screen. Switch to "Coordinate Mode" to begin the first measurement. Perform 3-5 repeated measurements at each measurement position to enhance measurement accuracy and eliminate random error interference. Move the autocollimator to the next measurement position (usually a 50mm displacement on the guide rail, which can be reduced to 10mm or even smaller as needed), wait 2 seconds for the reading to stabilize, and then begin the next round of single-point repeated measurements.

[0035] S4 Data Processing and Analysis: Export the measured data table and transfer it to the data processing software. The data processing software calculates the catheter waviness σ according to formula (1) or (2) and generates a measurement report. For straight catheters and tapered catheters, simplified formula (2) is used for calculation.

[0036] Formula (1) is as follows: (1) in, α i,real ( x )and α i,nominal ( x ) represent the actual normal direction and the normal direction of the standard plane, respectively, and n is the number of data points.

[0037] In the measurement of straight and tapered catheters, the normal to the outer surface of these two types of catheters is constant and does not change with the measurement position. The laser tracker measures the angular deviation between the reflected light and the reference optical axis. When the reference optical axis coincides with the normal to the catheter surface at the starting point, the subsequent measurement results are as shown in formula (1). If we set Then formula (1) can be simplified to: (2) Furthermore, this embodiment is not compatible with conduits with complex surface shapes, especially surfaces with continuously varying slopes of the reflective surface, such as spheres, cylinders, ellipsoids, hyperboloids, parabolic surfaces, etc. Since conduits with complex surface shapes are used for specific needs and account for a very small percentage of applications, this does not affect the importance of this invention.

[0038] S5 Assembly Accuracy Measurement: By increasing the data point density (e.g., reducing the test interval to 10mm), the system can observe the yaw and torsion accuracy of the conduit unit after splicing it into a long conduit in real time, and evaluate the assembly quality.

[0039] III. Implementation Steps System Setup: The granite guide rail is horizontally fixed to the vibration isolation table, and limit blocks are installed at the ends of the guide rail. The autocollimator is mounted on the guide rail via a precision slider, with the slider locking screw initially loosened. The conduit to be tested is placed vertically on a V-shaped support, with rubber shock-absorbing pads at the bottom of the support, and the conduit axis is parallel to the guide rail.

[0040] Initial calibration: Turn on the autocollimator and directly illuminate the reflective surface of the guide tube sidewall (reflectivity ≥90%) using the laser sight. Adjust the guide tube height so that the reflected light spot enters the autocollimator's field of view. In "targeting mode", fine-tune the guide tube angle so that the center of the returning light spot coincides with the crosshairs on the display screen, and record the initial zero-point coordinates.

[0041] Data acquisition: First, set the measurement parameters: sampling interval: 10mm (guide rail movement step length), number of repeated measurements at a single point: 5, sampling range: full length of the catheter (0-1800mm). Operating procedure: Push the slider to the starting position (0mm) to trigger single-point measurement. The autocollimator will automatically complete 5 consecutive angle measurements and take the average value. Push the slider along the guide rail to move to the next measuring point (10mm) and repeat the measurement. No manual adjustment of the machine body posture is required throughout the process. When the reading is stable, click to measure continuously and record the angle deviation of each measuring point.

[0042] Data processing: Export the data to dedicated analysis software and perform the following steps: Coordinate transformation: Converts angular deviation into normal direction deviation.

[0043] Data filtering: Remove outliers (such as vibration interference points).

[0044] Calculate the ripple: Substitute into formula (2) to calculate the σ value.

[0045] Generate a waviness distribution curve and an assembly runout report.

[0046] This embodiment uses an autocollimator, the industry's most cost-effective high-precision angle measuring device, as the core measuring equipment. It is integrated with a high-precision guide rail to construct a simple, economical, efficient, and convenient waviness measurement system. Utilizing the autocollimator's real-time angle measurement function, combined with a motor drive, fully automated measurement is achieved, significantly reducing the difficulty and intensity of manual operation and improving measurement efficiency. Although the system cannot measure complex curved conduits, it covers more than 90% of the measurement tasks required for domestic conduit production. Its low price and high efficiency make it of significant practical value. This embodiment's system, through its real-time angle measurement capability, additionally provides an assembly accuracy evaluation function after conduit unit connection, effectively improving product yield.

[0047] This embodiment successfully verified the feasibility of the waviness measurement system based on the autocollimator. While meeting the extreme flatness requirements of the neutron conduit, it reduced the equipment cost by 96% and increased the measurement efficiency by 6 times. It provides key technical support for the large-scale production of domestically produced neutron conduits and has the advantages of high precision, high efficiency, low cost and wide applicability. It can effectively solve the waviness measurement problem in the neutron conduit production process.

Claims

1. A duct waviness measurement system based on a self-collimator, characterized in that, include: A high-precision photoelectric autocollimator is used to measure the angular deviation of light reflected from the surface of a conduit. The photoelectric autocollimator has an angular measurement accuracy of better than 1 arcsecond. Granite linear guide rails are used to install and move the photoelectric autocollimator to achieve equidistant measurements; The marble measuring platform is used to place the tube to be tested and has vibration isolation function. Data processing software is used to receive, store, and analyze the angle data measured by the photoelectric autocollimator, and to calculate the duct waviness.

2. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, After completing pre-collimation, the photoelectric autocollimator uses its own laser optical axis as a reference to measure the angular deviation between the normal of the reflecting surface and the reference optical axis, which serves as the raw data for waviness measurement.

3. The duct waviness measurement system based on a self-collimator according to claim 1, characterized in that, The system also includes: A laser collimator is used to assist in finding and positioning the initial optical axis direction and to complete the pre-collimation work. Communication software: used to display the returned spot position and measurement coordinates on the computer screen, and supports switching between "beacon search mode" and "coordinate mode".

4. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, The system measures the conduit waviness through the following steps: Install the photoelectric autocollimator on the granite guide rail and adjust it to a horizontal position; Place the tube to be tested on the marble measuring platform and adjust it to be approximately at the same height as the photoelectric autocollimator; Use a laser collimator to locate the initial optical axis direction, adjust the attitude of the guide tube and autocollimator to bring the reflected light spot back into the range of the optical tube, and complete the pre-collimation; In "Beacon Finding Mode", adjust the light spot to the center of the screen, then switch to "Coordinate Mode" to perform the measurement; Move the photoelectric self-collimator to the next measurement position, repeat the measurement process, and acquire multiple sets of data.

5. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, The data processing software calculates the duct waviness σ using the following formula: （1） in, α i,real ( x )and α i,nominal ( x These represent the actual normal direction and the normal direction of the standard plane, respectively. n This represents the number of data points.

6. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, For straight and tapered catheters, the simplified waviness calculation formula of the data processing software is as follows: (2).

7. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, The system can measure the assembly accuracy between catheter units and evaluate the yaw and torsion accuracy after catheter splicing by increasing the data point density.

8. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, The measurement range of the photoelectric autocollimator is limited to the conduit with a small change in the slope of the reflecting surface.

9. The duct waviness measurement system based on an autocollimator according to claim 1, characterized in that, The system also includes a motor drive unit for automatically moving the photoelectric autocollimator along the guide rail for fully automatic measurement, further improving measurement efficiency and data density.

10. The duct waviness measurement system based on an autocollimator according to any one of claims 1 to 9, characterized in that, The system has high testing efficiency and can be used for quality inspection and process testing in neutron tube production, effectively improving product yield. It can also be widely used in collimation and installation work during the construction of large scientific facilities, measurement of machining accuracy of various tooling guide rails, and installation of optical components for line station spectrometers.

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