CN-121977480-A - Catheter waviness measuring method and device based on auto-collimation laser tracker

Abstract

The invention relates to the technical field of precision measurement and detection in optics, in particular to a technology for detecting the surface shape precision of a catheter in neutron mirror optics, and provides a method and equipment for measuring the waviness of the catheter based on an auto-collimation laser tracker; the method comprises the steps of installing a high-precision laser tracker on a granite guide rail, placing a guide pipe to be measured on a marble table surface, sliding the laser tracker along the guide rail, obtaining space vector coordinates of a reflecting surface in a full-automatic auto-collimation mode, measuring the space vector coordinates for multiple times, and then guiding out data to a computer to calculate waviness parameters.

Inventors

• LI ZHUO
• LI HAIHUI
• PENG WENXIN
• WU YANYAN
• KANG LE
• WANG TONG
• KE ZHIYONG
• CAI ZEYING
• Xia shun
• YIN YUQIN
• LIU HANGBING

Assignees

• 散裂中子源科学中心
• 中国科学院高能物理研究所

Dates

Publication Date

20260505

Application Date

20251229

Claims (8)

1. 1. The catheter waviness measuring method based on the auto-collimation laser tracker is characterized by comprising the following steps of: s1, using a high-precision laser tracker as core measurement equipment, mounting the high-precision laser tracker on a granite guide rail, and placing a catheter to be measured on a stable marble table top; S2, the laser tracker slides at equal intervals along the guide rail, under a full-automatic auto-collimation mode, the emitted auto-collimation light beams irradiate the optical reflection surface of the side wall of the guide pipe, the tracker automatically adjusts the posture to enable the round-trip light rays to coincide, and meanwhile space vector coordinates of the reflection surface are obtained; S3, repeatedly measuring each measuring position for 3-5 times, pushing the tracker to the next measuring position, normally shifting by 50mm on the guide rail, and repeatedly measuring the space coordinates of auto-collimation tracking; And S4, exporting the measured data table, transmitting the exported data table to a computer for storage and analysis, and calculating the waviness parameter sigma serving as an index for measuring the surface shape machining precision of the reflecting surface.
2. 2. The method for measuring the waviness of a catheter based on an auto-collimation laser tracker according to claim 1, wherein the calculation formula of the waviness parameter sigma is as follows: wherein, alpha i,real (x) and alpha i,nominal (x) are the actual normal direction and the normal direction of the standard plane respectively, and n is the number of data points.
3. 3. The catheter waviness measurement method based on the auto-collimation laser tracker according to claim 1, wherein the performance index of the laser tracker is required to be within the range of an incident angle of +/-30 degrees, the measurement distance is more accurate than 10 μm, the angle measurement accuracy is more than 0.5'', and the 3'' accuracy requirement required by waviness measurement is met.
4. 4. The method for measuring the waviness of a catheter based on an auto-collimation laser tracker according to claim 1, wherein the waviness calculation method comprises: Calculating azimuth angles and elevation angles of vectors based on coordinate measurement results of a tracker, and firstly, calculating azimuth angles (horizontal angles) and elevation angles (vertical angles) of each vector in a spherical coordinate system; For a linear and conical neutron catheter, taking the normal of a first measuring point as the normal of a nominal surface; For curved neutron tubes, the relative surface normal deviations are accurately extracted from absolute coordinate measurements by optimizing the relative attitude parameters (slope k, origin offset xs, distance d) of the guide rail and the tube.
5. 5. The method for measuring the waviness of a tube based on an auto-collimation laser tracker according to claim 4, wherein the curved neutron tube comprises an elliptic tube, a circular tube and a parabolic tube, the waviness calculation is carried out by establishing a geometric model of a measuring system, converting mechanical installation parameters (k, xs, d) into variables which can be optimized mathematically, and the angle change trend of the theoretical model and the measured data is matched optimally through iterative calculation.
6. 6. A catheter waviness measurement device based on an auto-collimation laser tracker, comprising: The high-precision laser tracker is arranged on the granite guide rail and is used for measuring space vector coordinates of the reflecting surface of the side wall of the guide pipe; the granite guide rail is used for supporting and guiding the linear movement of the laser tracker; the marble table top is used for placing a conduit to be tested and has a shock insulation function; And the computer is used for storing and analyzing the data measured by the laser tracker and calculating the waviness parameter.
7. 7. The catheter waviness measurement device based on the auto-collimation laser tracker according to claim 6, wherein the laser tracker has a full-automatic auto-collimation function, can automatically adjust the posture to enable the round-trip light to coincide, and a person only needs to move the device along the guide rail and trigger measurement during measurement.
8. 8. A catheter waviness measurement device based on auto-collimation laser trackers according to claim 6, wherein the computer is equipped with special data processing software for performing conversion of coordinate data to angle data, data translation of relative changes, ray parameter optimization and finally obtaining waviness results based on waviness calculation formulas.

Description

Catheter waviness measuring method and device based on auto-collimation laser tracker Technical Field The invention relates to the technical field of precise measurement and detection in optics, in particular to a detection technology of surface shape accuracy of a catheter in the field of neutron mirror optics, and particularly relates to a catheter waviness measurement method and device based on an auto-collimation laser tracker. Background In the field of neutron mirror optics, critical optical elements such as neutron tubes, whose angle of incidence of reflected neutrons is typically in the very small range, typically between 0.1 ° and 1 °. Such a small angle of incidence means that the surface finish accuracy of the mirror or substrate must be extremely high. Because the actual surface profile and the ideal plane have even small deviations, the neutron reflection condition can be changed, thereby leading to neutron loss, and finally reducing neutron flux and affecting the performance of the whole optical system. At present, although some measuring methods for waviness exist, the prior art has a plurality of problems, on one hand, the equipment compatibility is seriously insufficient, and for example, an auto-collimation theodolite is taken as an example, the application surface is narrower, the domestic manufacturer of the come card stops producing and can only import from abroad at high price, related accessories are cut off or stop producing, and the configuration cost for measuring the accuracy of the catheter is very high. On the other hand, manual operation occupies a larger proportion in the prior measuring technology, so that the requirement on the professional skill of an operator is extremely high, and a tester is required to carefully aim at a collimating lens of the theodolite for a long time and finely adjust the posture of a theodolite base station to finish collimation, so that a larger error can occur in a measuring result due to slight carelessness. Therefore, the measuring efficiency is low and the labor intensity is high. Meanwhile, long-time repeated operation is easy to cause fatigue of operators, and the accuracy and the efficiency of measurement are further affected. Furthermore, the prior art data processing methods are not sufficiently stringent when faced with complex curved catheters. For the measurement of a curved catheter (such as ellipse, circle and parabola), the inherent problems of uncertain measurement starting points, unparallel relative postures of a guide rail and a curved surface, inaccurate determination of the distance from a measuring machine to the surface of the catheter to be measured and the like exist. The lack of rigorous mathematical treatment models to address these problems in the prior art results in lower reliability of measurement results and difficulty in accurately assessing the waviness performance of complex types of catheters and the effect of waviness on neutron reflection. Therefore, it is important to develop a catheter waviness measurement technique capable of solving the above-mentioned problems. Disclosure of Invention In order to solve the problems, the invention aims to provide a catheter waviness measurement method and device based on an auto-collimation laser tracker, which are particularly suitable for waviness measurement of optical elements requiring extremely high surface shape machining precision such as a neutron catheter and the like so as to meet strict control requirements on the surface shape precision in precision optical applications such as neutron reflection and the like. The technical scheme adopted by the invention is that the catheter waviness measuring method based on the auto-collimation laser tracker comprises the following steps: s1, using a high-precision laser tracker as core measurement equipment, mounting the high-precision laser tracker on a granite guide rail, and placing a catheter to be measured on a stable marble table top; S2, the laser tracker slides at equal intervals along the guide rail, under a full-automatic auto-collimation mode, the emitted auto-collimation light beams irradiate the optical reflection surface of the side wall of the guide pipe, the tracker automatically adjusts the posture to enable the round-trip light rays to coincide, and meanwhile space vector coordinates of the reflection surface are obtained; S3, repeatedly measuring each measuring position for 3-5 times, pushing the tracker to the next measuring position, normally shifting by 50mm on the guide rail, and repeatedly measuring the space coordinates of auto-collimation tracking; And S4, exporting the measured data table, transmitting the exported data table to a computer for storage and analysis, and calculating the waviness parameter sigma serving as an index for measuring the surface shape machining precision of the reflecting surface. A catheter waviness measurement method based on an auto-collimation laser tracker, wherein