A device and method for long distance coaxial measurements

Abstract

The application discloses a device and method for long-distance coaxial measurement, and belongs to the field of manufacturing industry measurement and detection. The micrometric collimating telescope is used for measuring the position and direction of a measurement target relative to the main optical axis of the telescope; the CCD imaging reading system is used for acquiring the collimating image and positioning image measured by the micrometric collimating telescope to realize digital measurement; the installation and adjustment system is used for fixing the micrometric collimating telescope and adjusting the collimating aiming direction of the micrometric collimating telescope; the measurement target is used for coaxial reference leading of the measured coaxial position and cooperation with the micrometric collimating telescope to determine the position and posture of the measured coaxial position; the supporting tripod is used for portable stable support and height lifting adjustment of the whole device; and the data acquisition and processing system is used for acquisition and analysis processing of the measurement data of the CCD imaging reading system. The application can be used for measurement of the coaxial center position and posture of hollow shafts such as the bearing point of an aero-engine casing, and has the advantages of high measurement precision, high measurement efficiency and wide application range.

Description

TECHNICAL FIELD

[0001] The present application relates to a device and method for coaxial measurement at a distance, in particular to a device and method for measuring the coaxial center position and posture of a hollow shaft such as an aero-engine casing support point, and belongs to the field of manufacturing metrology. BACKGROUND

[0002] An engine is the heart of an airplane, and the performance of an airplane is largely determined by the engine selected. At present, military airplanes generally use aero gas turbine engines. The four main rotors of the low-pressure compressor, high-pressure compressor, high-pressure turbine and low-pressure turbine of the engine, as well as the corresponding casing and support point structure, are the key structures of the engine transmission shaft body. The coaxiality of the engine shaft body is one of the key characteristic parameters reflecting the assembly structure state, and the assembly precision has an important influence on the performance, safety and service life of the engine. At present, the coaxial measurement methods basically adopt the center alignment method, including the mechanical centering method and the laser centering method.

[0003] The traditional shaft centering methods at home and abroad are all manual operation and visual reading using mechanical instruments, and sometimes even manual calculation is required. The mechanical centering method mainly includes the chord line method, the telescope method and the micrometer method. The chord line method is to pull a string like a violin string and adjust it to be parallel to the measured object, and then use a gap gauge to measure the gap between the string and the object, or use an elongated steel shaft instead. This method is quite time-consuming and requires a lot of experience of the technical personnel, and in long distance measurement, the sag of the string or the "waist" of the shaft will result in a large measurement error. The telescope method is to use the optical axis of the telescope as the measurement reference, and adjust the center of the object by observing the deviation of the cross target center on the optical axis of the telescope. In long distance measurement, it can give accurate results, but reading error is inevitable due to parallax effect. The micrometer measurement method is one of the most widely used methods in China, which needs to be used with a righting support. During inspection, the shaft body needs to be rotated, and the center deviation of each shaft section is calculated according to the relative jump of the micrometer. The micrometer method can be divided into single table method, double table method and three table method according to the number of micrometers used.

[0004] With the emergence of light sensing PSD sensors, laser centering technology using laser combined with PSD sensors has been widely used in the installation and detection of shafts. The laser centering technology uses the light emitted by a collimating laser as a measurement reference, and installs a light sensing PSD sensor on the measured object. The light beam hits the PSD, and the position of the object shaft center can be detected according to the output deviation value of the PSD. According to the structure, it can be divided into outer contour shaft center measurement method and inner contour shaft center measurement method. This measurement method not only makes the measurement more accurate and less dependent on the experience of calibration personnel, but also is simpler and faster than the chord line method or the telescope method.

[0005] The biggest drawback of the above center alignment method is that it can only determine the center position of a certain cross section of the shaft, and cannot determine the normal vector of the shaft being measured. The normal vector of the entire shaft is composed of the various component shafts. If the normal vector directions of the end faces of the various component shafts are not the same, the axis of the combined shaft will become a curve, which will seriously affect the life of the shaft. Summary of the Invention

[0006] To address the problems of low digital measurement level, low accuracy, long measurement cycle, and significant influence of human intervention in the coaxial center position and attitude measurement of hollow shafts such as the engine casing pivot point in aero-engines, the main objective of this invention is to provide a device for long-distance coaxial measurement. This device is used for measuring the coaxial center position and attitude of hollow shafts such as the engine casing pivot point in aero-engines, as well as for coaxial measurement during the installation process of propellers in submarines and other ships. This invention has the advantages of high measurement accuracy, high measurement efficiency, and applicability to different types of coaxial measurement targets.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] The present invention discloses a device for long-distance coaxial measurement, which mainly consists of a micrometer collimating telescope, a CCD imaging reading system, an installation and adjustment system, a measurement target, a support tripod, and a data acquisition and processing system.

[0009] The micrometer collimating telescope is used to measure the position and orientation of the target relative to the telescope's principal optical axis; the CCD imaging reading system is used to acquire the collimated and positioning images measured by the micrometer collimating telescope to achieve digital measurement; the installation and adjustment system is used to fix the micrometer collimating telescope and adjust its collimating aiming direction; the target is used as a coaxial reference for the measured coaxial position and, in conjunction with the micrometer collimating telescope, to determine the position and attitude of the measured coaxial axis; the tripod is used for portable and stable support of the entire device and for height adjustment; the data acquisition and processing system is used for the acquisition and analysis of measurement data from the CCD imaging reading system.

[0010] The micrometer collimating telescope and CCD imaging reading system mainly comprises a micrometer collimating telescope, an image sensor CCD, an image sensor mounting cylinder and a primary positioning laser. The micrometer collimating telescope is a precision calibration tool, which is fixed on the mounting adjustment system through a telescope mounting frame and is mainly used for establishing a collimation line in large-size measurement and focusing at different distances from the mirror tube end face to infinity. The collimation line and the positioning image measured by the micrometer collimating telescope can be collected by the image sensor CCD, which has the functions of quantization, calibration and analysis. The primary positioning laser is installed on the mirror tube end face of the micrometer collimating telescope and can emit an indicating laser beam to guide the optical axis reference of the micrometer collimating telescope to achieve the primary positioning function.

[0011] The measurement target mainly comprises a coaxial reference guiding ring, a guide reference ring, a longitudinal adjustment ring, a transverse adjustment ring, a reference mirror and a reference mirror mounting ring. The reference mirror adopts a center line engraved plane mirror as the target for coaxial aiming and collimation measurement of the micrometer collimating telescope. The reference mirror is engraved with calibrated interval lines in the horizontal and vertical directions, which are used for displacement equivalent calibration of the image sensor CCD. Preferably, 1mm and 10mm interval lines are selected. The reference mirror is installed on the transverse adjustment ring through the reference mirror mounting ring, and the transverse adjustment ring is installed on the longitudinal adjustment ring. The longitudinal adjustment ring is provided with a guide table on the side surface, which is in small gap cooperation with the outer size of the transverse adjustment ring. The transverse displacement adjustment and guidance are realized by the threaded jacks installed on the guide reference ring. The longitudinal adjustment ring is further installed on the guide reference ring, which is also provided with a guide table on the longitudinal position. The guide table is in small gap cooperation with the longitudinal adjustment ring, and the longitudinal displacement adjustment and guidance are realized by the threaded jacks installed on the transverse guide table of the guide reference ring. Through adjustment, the coaxial reference guiding ring is realized in high-precision concentricity with the cross line reference of the reference mirror, and the concentric adjustment error is controlled to be less than 0.003mm, so as to achieve high-precision concentric reference guiding. The coaxial reference guiding ring is designed by adapting different measurement rings, which is used for coaxial reference guiding of the hollow long shaft hole of the measured aero-engine fulcrum, ship transmission shaft mounting seat and the like.

[0012] The installation and adjustment system mainly consists of a micrometer collimating telescope mounting bracket, a pitch and yaw adjustment mechanism, and a horizontal displacement adjustment mechanism. The system is mounted on a supporting tripod. The telescope mounting bracket uses two openable retaining rings to secure the telescope with locking screws. The telescope mounting bracket is mounted on the pitch and yaw adjustment mechanism via three-point support. The pitch and yaw adjustment mechanism has two supporting rotating shafts at its front end and a supporting screw at its rear end. A fine-tuning knob controls the raising and lowering of the supporting screw, which, in conjunction with the supporting rotating shafts, achieves pitch adjustment of the micrometer collimating telescope. A rotating shaft is embedded in the front end of the support base, and the yaw adjustment of the micrometer collimating telescope is achieved by adjusting the screws fixed to the outer frame. The pitch and yaw adjustment mechanism is fixed to the horizontal displacement adjustment mechanism with locking screws. The horizontal displacement adjustment mechanism uses a micrometer head to drive a threaded screw, which rotates to move the micrometer collimating telescope horizontally.

[0013] The supporting tripod mainly consists of a supporting tripod, a vertical precision adjustment mechanism, and a vertical coarse adjustment mechanism. The vertical precision adjustment mechanism drives a threaded screw via a micrometer head, causing the micrometer collimating telescope to move slightly in the vertical direction. The vertical coarse adjustment mechanism uses a handwheel to rotate a gear, causing the micrometer collimating telescope to move over a large range in the vertical direction. Through holes on the three feet of the supporting tripod are used to mount the entire device onto other stable support equipment.

[0014] The data acquisition and processing system consists of a computer and a measurement data processing module. It communicates with the image sensor CCD via a network cable or USB cable to acquire the aiming and collimation images of the micrometer collimating telescope and perform digital processing. Through pixel equivalent calibration, it accurately measures the positional offset of the target center relative to the optical axis and the angle between the target plane normal and the optical axis. Through data processing, it obtains the center position and attitude of the measured coaxial axis.

[0015] The operating method of the device for long-distance coaxial measurement disclosed in this invention is as follows:

[0016] Step 1: After precisely assembling the target and the reference axis of the coaxial component to be measured, place the coaxial measuring device at the front end of the coaxial component to be measured, turn on the laser beam of the initial positioning laser, and adjust the position of the support tripod and the height of the tripod lifting mechanism so that the laser beam hits the reference mirror of the target.

[0017] Step 2: Adjust the focus of the collimator telescope and the horizontal and vertical displacement mechanism of the installation adjustment system until the center of the crosshair on the reference mirror can be observed from the CCD, adjust the focus and the pitch and yaw mechanism until the axis of the collimator telescope is perpendicular to the reference mirror, adjust the focus and the horizontal and vertical displacement mechanism again so that the center of the crosshair on the reference mirror coincides with the center of the angle scale of the collimator telescope, at this time the main optical axis of the collimator telescope is collimated and centered with the reference mirror, then the center position of the reference shaft is P0(0, 0), the horizontal angle R x0 = 0, and the vertical angle R y0 = 0.

[0018] Step 3: Assemble the measurement target to the first measured shaft of the coaxial component to be measured, and measure the center position error and attitude error of the measured shaft relative to the reference shaft according to the following steps 3.1 and 3.2.

[0019] Step 3.1: Adjust the focus of the collimator telescope until the crosshair on the reference mirror of the measurement target is clearly observed from the CCD, rotate the measurement target so that the center line of the crosshair on the reference mirror is parallel to the center line of the angle scale of the collimator telescope, and calibrate the image displacement equivalent using the standard distance scale of the measurement target at this distance. Extract the pixel position P L1 (xL1, yL1) of the "0" position L1 = 0 mm of the crosshair on the reference mirror using the measurement data processing module, and then extract the pixel position P L2 (xL2, yL2) of the "10 mm" position L2 = 10 mm on the reference mirror, and obtain the displacement equivalent of the current target position Then the offset of the "0" position of the crosshair on the reference mirror relative to the center position of the main optical axis of the collimator telescope is d1. That is, the center position error of the measured shaft relative to the reference shaft is d1.

[0020] Step 3.2: Adjust the focus of the collimator telescope until the collimated image of the displacement scale of the collimator telescope is clearly observed from the CCD, and try to make the center of the collimated image of the displacement scale coincide with the center of the angle scale during adjustment. Measure the distance D from the reference mirror to the end face of the collimator telescope using a tape measure, and calibrate the image angle equivalent using the outer diameter of the concentric circle of the displacement scale at this distance. Move the cursor to the leftmost end of the circle marked "5" using the measurement data processing module, and record the horizontal pixel value P U1 (xU1, yU1) of the CCD, then move the cursor to the rightmost end of the circle marked "5", and record the horizontal pixel value P U2 (xU2, yU2) of the CCD, and obtain the angle equivalent of the current target position ( " / pixel). The collimated image ring center pixel value P is extracted by the measured data processing module U0 (xU0, yU0), the reference mirror normal is relative to the microlithographic collimating telescope main optical axis horizontal direction angle R x1 = xU0 * R alpha ( ° ), the vertical direction angle R y1 = yU0 * R alpha ( ° ), that is, the angle error of the measured shaft body relative to the reference shaft body horizontal direction is R x1 , the vertical angle error is R y1 .

[0021] Step 4: according to step 3, the center position error d i , the horizontal direction angle error R xi and the vertical direction angle error R yi of the second, third,..., i-th measured shaft body relative to the reference shaft body are measured in turn, wherein i is the actual measurement point number of the measured shaft body.

[0022] Step 5: the maximum value of the measured shaft body center error d i is twice 2d max , that is, the coaxial center position error value, the maximum value of the horizontal direction angle error R xi is twice 2R xmax , that is, the horizontal direction angle error value, the maximum value of the vertical direction angle error R yi is twice 2R ymax , that is, the vertical direction angle error value, that is, the long-distance coaxial measurement is realized.

[0023] Advantages:

[0024] 1. Compared with the method of coaxial measurement based on microlithographic collimating telescope commonly used at present, the device and method for long-distance coaxial measurement disclosed by the application, by modifying the human eye aiming system of the microlithographic collimating telescope, using the combination of microlithographic collimating telescope and image sensor CCD, realizing the image display and digital measurement of the microlithographic collimating telescope image plane, replacing the traditional human eye observation and manual drum adjustment measurement, the measurement is more convenient, more accurate and more stable.

[0025] 2. Compared with the method of aiming measurement of the plane reflective target commonly used at present, the device and method for long-distance coaxial measurement disclosed by the application, by using the semi-transparent half-mirror engraved with standard distance cross line as the measurement target, the pixel equivalent calibration of the collected image can be carried out at any distance, and the offset of the measured position can be directly measured accurately.

[0026] 3、Compared with the mechanical centering method and the laser centering method commonly used in the present stage coaxial measurement, the device and method for long-distance coaxial measurement disclosed by the application can determine the center position of the measured shaft body and the attitude of the measured shaft body. The method cooperates the optical reference with the measurement target, realizes the measurement of the center position of the measured target by aiming, and realizes the measurement of the attitude of the measured target by optical collimation. Since the optical aiming is combined with the image, the coaxial measurement at the farthest distance of 40m can be realized.

[0027] 4、The device and method for long-distance coaxial measurement disclosed by the application can directly lead out the coaxial reference of the measured position by high-precision concentricity of the outer ring mechanical reference provided with the measurement target and the cross line reference of the reference mirror, so that the measurement tool is simple and the operation is convenient.

[0028] 5、The device and method for long-distance coaxial measurement disclosed by the application are not only suitable for the measurement of the coaxial center position and the attitude of the hollow shaft such as the engine case support point of the aero-engine, and the coaxial measurement in the installation process of the propeller of the submarine and other ships, but also can be applied to the coaxial assembly measurement occasions in other fields by adapting the measurement target, so as to solve the related engineering technical problems. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the overall structure diagram of the special device for long-distance coaxial measurement of the application;

[0030] Figure 2 is the structure diagram of the measurement target of the application;

[0031] Figure 3 is the cross line diagram of the reference mirror of the measurement target of the application;

[0032] Figure 4 is the displacement pixel equivalent calibration diagram of the application;

[0033] Figure 5 is the angle pixel equivalent calibration diagram of the application.

[0034] Wherein: 1-micrometer collimating telescope, 2-CCD imaging reading system, 3-installation adjustment system, 4-measurement target, 5-supporting tripod, 7-image sensor CCD, 8-image sensor mounting cylinder, 9-primary positioning laser, 10-telescope mounting frame, 11-pitching and yawing adjustment mechanism, 12-horizontal displacement adjustment mechanism, 13-vertical precision adjustment mechanism, 14-clamp ring, 15-supporting rotating shaft, 16-supporting screw, 17-supporting base, 18-screw, 19-vertical coarse adjustment mechanism, 20-coaxial reference leading-out ring, 21-guiding reference ring, 22-longitudinal adjustment ring, 23-lateral adjustment ring, 24-reference mirror, 25-reference mirror mounting ring. DETAILED DESCRIPTION

[0035] The application will be described in detail below with reference to the accompanying drawings and embodiments.

[0036] Referring to the drawings Figure 1 As shown in the drawings, the device for long-distance coaxial measurement disclosed in the present embodiment mainly consists of five parts, namely, a micrometer collimation telescope 1, a CCD imaging reading system 2, a mounting and adjusting system 3, a measurement target 4, a supporting tripod 5, and a data acquisition and processing system. The micrometer collimation telescope 1 is used to measure the position and direction of the measurement target 4 relative to the main optical axis of the telescope; the CCD imaging reading system 2 is used to obtain the collimation image and positioning image measured by the micrometer collimation telescope 1 to realize digital measurement; the mounting and adjusting system 3 is used to fix the micrometer collimation telescope 1 and adjust the collimation and aiming direction of the micrometer collimation telescope 1; the measurement target 4 is used to lead out the coaxial reference of the measured coaxial position and cooperate with the micrometer collimation telescope 1 to determine the center position and attitude of the measured coaxial position; the supporting tripod 5 is used to stably support and adjust the height of the entire device; and the data acquisition and processing system is used to collect and analyze the measurement data of the CCD imaging reading system 2.

[0037] Referring to the drawings Figure 1 As shown in the drawings, the micrometer collimation telescope 1 and the CCD imaging reading system 2 mainly consist of the micrometer collimation telescope 1, an image sensor CCD 7, an image sensor mounting cylinder 8, and a primary positioning laser 9. The micrometer collimation telescope 1 is a precision calibration tool, which is fixed on the mounting and adjusting system 3 through a telescope mounting frame 10 and is mainly used to establish a collimation line during large-size measurement and can focus at different distances from the end face of the mirror tube to infinity. Through aiming measurement and optical collimation, the position offset of the target center of the measurement target 4 relative to the main optical axis of the micrometer collimation telescope 1 can be measured, and the included angle of the target plane normal relative to the main optical axis can also be measured. The image sensor CCD 7 is installed on the eyepiece of the micrometer collimation telescope 1 through the image sensor mounting cylinder 8, replaces the human eye observation system of the micrometer collimation telescope 1, can collect the collimation image and positioning image measured by the micrometer collimation telescope 1, and has the functions of quantization, calibration, and analysis. The primary positioning laser 9 is installed on the end face of the mirror tube of the micrometer collimation telescope 1 and can emit an indicating laser beam to lead out the optical axis reference of the micrometer collimation telescope 1 to achieve the primary positioning function.

[0038] Referring to the drawings Figure 2 , the drawings Figure 3As shown, the measurement target 4 is mainly composed of coaxial reference lead-out ring 20, guide reference ring 21, longitudinal adjustment ring 22, transverse adjustment ring 23, reference mirror 24 and reference mirror mounting ring 25. The reference mirror 24 uses a plane mirror with central scale as the target for coaxial aiming and collimation measurement of the micrometer collimation telescope 1. The reference mirror 24 is engraved with calibrated interval scale lines in horizontal and vertical directions, which are used for displacement equivalent calibration of the image sensor CCD, and 1mm and 10mm interval scale lines are selected. The reference mirror 24 is mounted on the transverse adjustment ring 23 through the reference mirror mounting ring 25, the transverse adjustment ring 23 is mounted on the longitudinal adjustment ring 22, and the longitudinal adjustment ring 22 is provided with a guide table on the side, which is in small gap cooperation with the outer size of the transverse adjustment ring 23, and the displacement adjustment and guidance in the transverse direction are realized through the threaded jackscrew mounted on the transverse guide table of the guide reference ring 21. The longitudinal adjustment ring 22 is further mounted on the guide reference ring 21, and the guide reference ring 21 is also provided with a guide table on the longitudinal position, which is in small gap cooperation with the longitudinal adjustment ring 22, and the displacement adjustment and guidance in the longitudinal direction are realized through the threaded jackscrew mounted on the longitudinal guide table of the guide reference ring 21. Through adjustment, the outer circle mechanical reference of the coaxial reference lead-out ring 20 is high-precision concentric with the cross scale reference of the reference mirror 24, and the concentric adjustment error is controlled within 0.003mm, so as to achieve high-precision concentric reference lead-out. The coaxial reference lead-out ring 20 is designed by adapting different measurement rings, which is used for coaxial reference lead-out of the hollow long shaft hole of the measured aero-engine fulcrum, ship transmission shaft mounting seat and the like.

[0039] Referring to the accompanying drawings Figure 1 As shown, the installation and adjustment system 3 is mainly composed of micrometer collimation telescope mounting frame 10, pitch and yaw adjustment mechanism 11, horizontal displacement adjustment mechanism 12. The installation and adjustment system 3 is installed on the supporting tripod 5. The telescope mounting frame 10 fixes the telescope through locking screws by means of two openable clamping rings 14. The telescope mounting frame 10 is installed on the pitch and yaw adjustment mechanism 11 through three-point support. The pitch and yaw adjustment mechanism 11 is provided with two support rotating shafts 15 at the front end and a support screw 16 at the rear end, the support screw is controlled to rise and fall through a fine adjustment knob, and the pitch adjustment of the micrometer collimation telescope is realized in cooperation with the support rotating shaft 15. The support base 17 is embedded with a rotating shaft at the front end, and the yaw adjustment of the micrometer collimation telescope is realized through the screw 18 fixed outside the frame. The pitch and yaw adjustment mechanism 11 is fixed on the horizontal displacement adjustment mechanism 12 through locking screws. The horizontal displacement adjustment mechanism 12 drives the micrometer collimation telescope 1 to move in the horizontal direction through the rotation of the differential head driving screw thread.

[0040] Referring to the accompanying drawings Figure 1As shown, the support tripod 5 is mainly composed of a support tripod 5, a vertical fine adjustment mechanism 13 and a vertical coarse adjustment mechanism 19. The vertical fine adjustment mechanism 13 drives the micro collimation telescope 1 to move in the vertical direction by rotating the screw rod through the differential head. The vertical coarse adjustment mechanism 19 drives the micro collimation telescope 1 to move in the vertical direction by rotating the gear through the hand wheel. The through holes on the three legs of the support tripod are used to install the whole device on other stable support equipment.

[0041] Referring to the accompanying drawings Figure 1 As shown, the data acquisition and processing system 6 is composed of a computer and a measurement data processing module, which communicates with the image sensor CCD 7 through a network port line or a USB line, acquires the aiming and collimation images of the micro collimation telescope 1 and performs digital processing, accurately measures the position offset of the target center relative to the optical axis and the angle between the normal of the target plane and the optical axis through pixel equivalent calibration, and obtains the center position and attitude of the measured coaxial part through data processing.

[0042] Referring to the accompanying drawings Figure 1 As shown, the data acquisition and processing system 6 is composed of a computer and a measurement data processing module, which communicates with the image sensor CCD 7 through a network port line or a USB line, acquires the aiming and collimation images of the micro collimation telescope 1 and performs digital processing, accurately measures the position offset of the target center relative to the optical axis and the angle between the normal of the target plane and the optical axis through pixel equivalent calibration, and obtains the center position and attitude of the measured coaxial part through data processing.

[0043] Referring to the accompanying drawings Figure 1 , the accompanying drawings Figure 4 , the accompanying drawings Figure 5 As shown, the working method of the device for long-distance coaxial measurement disclosed in the embodiment is as follows:

[0044] Step 1: After the measurement target is precisely matched and assembled with the reference axis body of the measured coaxial component, the coaxial measurement device is placed in front of the measured coaxial component, the initial positioning laser beam is turned on, the position of the support tripod and the height of the tripod lifting mechanism are adjusted, and the laser beam of the laser is adjusted to hit the reference mirror of the measurement target.

[0045] Step 2: The focal length of the micro collimation telescope and the horizontal and vertical displacement mechanisms of the installation adjustment system are adjusted until the center of the crosshair on the reference mirror can be observed from the CCD, the focal length and the pitch and yaw mechanisms are adjusted until the axis of the micro collimation telescope is perpendicular to the reference mirror, and the focal length and the horizontal and vertical displacement mechanisms are adjusted again so that the center of the crosshair of the reference mirror coincides with the center of the angle scale plate of the micro collimation telescope. At this time, the main optical axis of the micro collimation telescope is collimated and centered with the reference mirror, and the center position of the reference axis body is P0(0, 0), the horizontal angle R x0 = 0, and the vertical angle Ry0 =0.

[0046] Step 3: Assemble the measurement target onto the first shaft of the coaxial component to be measured, and measure the center position error and attitude error of the shaft relative to the reference shaft in sequence according to steps 3.1 and 3.2.

[0047] Step 3.1: Adjust the focal length of the micrometer collimating telescope until the crosshairs on the reference mirror of the measurement target are clearly observed in the CCD. Rotate the measurement target so that the center line of the crosshairs on the reference mirror is parallel to the center line of the angle reticle of the micrometer collimating telescope. At this distance, calibrate the image displacement equivalent using the standard distance scale on the measurement target. Use the measurement data processing module to extract the pixel position P at the center "0" position L1 = 0mm on the reference mirror. L1 (xL1, yL1), then extract the pixel position P at the horizontal "10mm" position L2 = 10mm on the reference mirror. L2 (xL2, yL2) is used to calculate the equivalent displacement of the current target position. The offset of the center "0" position of the crosshairs on the reference mirror relative to the center position of the principal optical axis of the micrometer collimating telescope. That is, the center position error of the measured shaft relative to the reference shaft is d1.

[0048] Step 3.2: Adjust the focal length of the micrometer collimating telescope until the collimated image of the displacement reticle of the micrometer collimating telescope is clearly observed in the CCD. During adjustment, try to make the center of the collimated image of the displacement reticle coincide with the center of the angle reticle. Measure the distance D from the reference mirror to the end face of the micrometer collimating telescope tube with a measuring tape. At this distance, use the outer diameter of the concentric circles of the displacement reticle to calibrate the image angle equivalent. Use the measurement data processing module to move the cursor to the leftmost end of the ring marked "5" and record the horizontal pixel value P of the CCD. U1 (xU1, yU1), then move the cursor to the rightmost end of the circle marked "5" and record the horizontal pixel value P of the CCD. U2 (xU2, yU2) is used to calculate the angular equivalent of the current target position. The center pixel value P of the collimated image inner ring is extracted using the measurement data processing module. U0 (xU0, yU0), then the angle R between the normal of the reference mirror and the horizontal direction of the principal optical axis of the micrometer collimating telescope. x1 =xU0*Rα(°), angle R in the vertical direction y1 =yU0*Rα(°), that is, the angular error of the measured shaft relative to the reference shaft in the horizontal direction is R. x1 The vertical angular error is R. y1 .

[0049] Step 4: Following Step 3, sequentially measure the center position error d of the 2nd, 3rd, ..., i-th measured shafts relative to the reference shaft. i Horizontal angular error R xi and vertical angular error R yi , where i is the actual number of measurement points on the measured shaft.

[0050] Step 5: Center error d of the measured shaft i 2d, twice the maximum value max That is, the coaxial center position error value and the horizontal angular error R. xi 2R, twice the maximum value xmax That is, the horizontal angular error value and the vertical angular error R. yi 2R, twice the maximum value ymax This refers to the vertical angular error value, which enables long-distance coaxial measurement.

[0051] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for long-distance coaxial measurement, characterized in that: It consists of a micrometer collimating telescope, a CCD imaging reading system, an installation and adjustment system, a measurement target, a support tripod, and a data acquisition and processing system. The micrometer collimating telescope is used to measure the position and orientation of the target relative to the telescope's principal optical axis; the CCD imaging reading system is used to acquire the collimated and positioning images measured by the micrometer collimating telescope to achieve digital measurement; the installation and adjustment system is used to fix the micrometer collimating telescope and adjust its collimating aiming direction; the target is used as a coaxial reference for the measured coaxial position and, in conjunction with the micrometer collimating telescope, determines the position and orientation of the measured coaxial axis. The supporting tripod is used for portable and stable support of the entire device and for height adjustment; the data acquisition and processing system is used for the acquisition and analysis of measurement data from the CCD imaging reading system. The measurement target consists of a coaxial reference lead-out ring, a guide reference ring, a longitudinal adjustment ring, a transverse adjustment ring, a reference mirror, and a reference mirror mounting ring. The reference mirror is a plane mirror with a central etched line, serving as the target for coaxial aiming and collimation measurement of the micrometer collimating telescope. The reference mirror has calibrated spacing lines engraved in both the horizontal and vertical directions; these spacing lines are used for displacement equivalent calibration of the image sensor CCD. The reference mirror is mounted to the transverse adjustment ring via the reference mirror mounting ring, and the transverse adjustment ring is mounted on the longitudinal adjustment ring. A guide platform is provided on the side of the longitudinal adjustment ring, and the guide platform is fitted with the outer dimension of the transverse adjustment ring with a small clearance. Lateral displacement adjustment and guidance are achieved through threaded set screws installed on the guide reference ring; a longitudinal adjustment ring is then installed on the guide reference ring, which also has a guide platform in the longitudinal position. The guide platform and the longitudinal adjustment ring are fitted with a small clearance, and longitudinal displacement adjustment and guidance are achieved through threaded set screws installed on the longitudinal guide platform of the guide reference ring; by adjustment, the mechanical reference of the outer ring of the coaxial reference lead-out ring and the cross-shaped datum of the reference mirror are made concentric with high precision, and the concentricity adjustment error is controlled to achieve high-precision concentric reference lead-out; the coaxial reference lead-out ring is adapted to different measuring rings to lead out the coaxial reference of the hollow long shaft hole to be measured; The installation and adjustment system consists of a micrometer collimating telescope mounting bracket, a pitch and yaw adjustment mechanism, and a horizontal displacement adjustment mechanism. The system is mounted on a supporting tripod. The telescope mounting bracket uses two openable retaining rings to secure the telescope with locking screws. The telescope mounting bracket is mounted on the pitch and yaw adjustment mechanism via three-point support. The pitch and yaw adjustment mechanism has two supporting rotating shafts at its front end and a supporting screw at its rear end. A fine-tuning knob controls the raising and lowering of the supporting screw, which, in conjunction with the supporting rotating shafts, allows for pitch adjustment of the micrometer collimating telescope. A rotating shaft is embedded in the front end of the support base, and the yaw adjustment of the micrometer collimating telescope is achieved by adjusting the screws fixed to the outer frame. The pitch and yaw adjustment mechanism is fixed to the horizontal displacement adjustment mechanism with locking screws. The horizontal displacement adjustment mechanism uses a micrometer head to drive a threaded screw, which in turn moves the micrometer collimating telescope horizontally.

2. The device for long-distance coaxial measurement as described in claim 1, characterized in that: The micrometer collimating telescope and CCD imaging reading system comprises a micrometer collimating telescope, an image sensor (CCD), an image sensor mounting tube, and a preliminary positioning laser. The micrometer collimating telescope, a precision calibration tool, is fixed to the mounting and adjustment system via a telescope mounting bracket. It is used to establish a collimation line during large-scale measurements and can focus at different distances from the end face of the telescope tube to infinity. Through aiming measurement and optical collimation, it can measure the positional offset of the target center relative to the telescope's principal optical axis and the angle between the target plane normal and the principal optical axis. The image sensor (CCD) is mounted on the eyepiece of the micrometer collimating telescope via the image sensor mounting tube, replacing the human eye observation system of the micrometer collimating telescope. It can acquire collimated and positioning images measured by the micrometer collimating telescope and has quantification, calibration, and analysis functions. The preliminary positioning laser is mounted on the end face of the micrometer collimating telescope tube and emits an indicator laser beam to guide the optical axis reference of the micrometer collimating telescope to achieve preliminary positioning.

3. The device for long-distance coaxial measurement as described in claim 1, characterized in that: Use 1mm and 10mm spacing for the scribing lines.

4. The device for long-distance coaxial measurement as described in claim 2, characterized in that: The supporting tripod consists of a supporting tripod, a vertical precision adjustment mechanism, and a vertical coarse adjustment mechanism. The vertical precision adjustment mechanism drives the threaded screw to rotate via a micrometer head, thereby causing the micrometer collimating telescope to move slightly in the vertical direction. The vertical coarse adjustment mechanism drives the micrometer collimating telescope to move over a wide range in the vertical direction via a handwheel rotating a gear. The three feet of the supporting tripod have through holes for mounting the entire device on other stable support equipment.

5. The device for long-distance coaxial measurement as described in claim 4, characterized in that: The data acquisition and processing system consists of a computer and a measurement data processing module. It communicates with the image sensor CCD via a network cable or USB cable to acquire the aiming and collimation images of the micrometer collimating telescope and perform digital processing. Through pixel equivalent calibration, it accurately measures the positional offset of the target center relative to the optical axis and the angle between the target plane normal and the optical axis. Through data processing, it obtains the center position and attitude of the measured coaxial axis.

6. A method for long-distance coaxial measurement, implemented based on the apparatus for long-distance coaxial measurement as described in claim 5, characterized in that: Includes the following steps, Step 1: After precisely assembling the target and the reference axis of the coaxial component to be measured, place the coaxial measuring device at the front end of the coaxial component to be measured, turn on the laser beam of the initial positioning laser, and adjust the position of the support tripod and the height of the tripod lifting mechanism so that the laser beam hits the reference mirror of the target. Step 2: Adjust the focal length of the micrometer collimating telescope and install the horizontal and vertical displacement mechanisms of the adjustment system until the center of the crosshairs on the reference mirror can be observed from the CCD. Adjust the focal length and pitch yaw mechanism until the axis of the micrometer collimating telescope is perpendicular to the reference mirror. Adjust the focal length and horizontal and vertical displacement mechanisms again until the center of the crosshairs on the reference mirror coincides with the center of the reticle of the micrometer collimating telescope. At this point, the principal optical axis of the micrometer collimating telescope is collimated and centered with the reference mirror. The center position of the reference axis is P0(0,0), and the horizontal angle R... x0 =0, vertical angle R y0 =0; Step 3: Assemble the measurement target onto the first shaft of the coaxial component to be measured, and measure the center position error and attitude error of the shaft relative to the reference shaft in sequence according to steps 3.1 and 3.

2. Step 3.1: Adjust the focal length of the micrometer collimating telescope until the crosshairs on the reference mirror of the measurement target are clearly observed in the CCD. Rotate the measurement target so that the center line of the crosshairs on the reference mirror is parallel to the center line of the angle reticle of the micrometer collimating telescope. At this distance, calibrate the image displacement equivalent using the standard distance scale of the measurement target. Use the measurement data processing module to extract the "0" position of the center of the crosshairs on the reference mirror. L Pixel position P = 0mm L1 ( xL 1, y L 1) Then extract the horizontal "10mm" position on the reference mirror. L Pixel position P = 10mm L2 ( xL 2, y L 2) Obtain the equivalent displacement of the current target position. The unit is mm / pixel; then the offset of the center "0" position of the crosshairs on the reference mirror relative to the center position of the principal optical axis of the micrometer collimating telescope is... The unit is mm, which means the center position error of the measured shaft relative to the reference shaft is d1; Step 3.2: Adjust the focal length of the micrometer collimating telescope until the collimated image of the displacement reticle of the micrometer collimating telescope is clearly observed from the CCD. During adjustment, try to make the center of the collimated image of the displacement reticle coincide with the center of the angle reticle. Use a measuring tape to measure the distance D from the reference mirror to the end face of the micrometer collimating telescope tube. At this distance, use the outer diameter of the concentric circles of the displacement reticle to calibrate the image angle equivalent. Use the measurement data processing module to move the cursor to the leftmost end of the ring marked "5" and record the horizontal pixel value P of the CCD. U1 ( xU 1, y U 1) Then move the cursor to the rightmost end of the circle marked "5" and record the horizontal pixel value P of the CCD. U2 ( xU 2, y U 2) Obtain the angular equivalent of the current target position. The unit is "″ / pixel"; the center pixel value P of the collimated image inner ring is extracted using the measurement data processing module. U0 ( xU 0, y U 0), then the angle between the reference mirror normal and the horizontal direction relative to the principal optical axis of the micrometer collimating telescope. Vertical angle That is, the angular error of the measured shaft relative to the reference shaft in the horizontal direction is R. x1 The vertical angular error is R. y1 ; Step 4: Following Step 3, sequentially measure the center position error d of the 2nd, 3rd, ..., i-th measured shafts relative to the reference shaft. i Horizontal angular error R xi and vertical angular error R yi , where i is the actual number of measurement points on the measured shaft; Step 5: Center error d of the measured shaft i 2d, twice the maximum value max That is, the coaxial center position error value and the horizontal angular error R. xi 2R, twice the maximum value x max That is, the horizontal angular error value and the vertical angular error R. yi 2R, twice the maximum value y max This refers to the vertical angular error value, which enables long-distance coaxial measurement.

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