A cylindrical workpiece spatial angle measurement system and method

Abstract

The present invention discloses a system and method for measuring the spatial angle of a cylindrical workpiece. The system comprises two support and rotation mechanisms spaced apart and configured to support and rotate a reference workpiece. The system comprises a reference workpiece measuring mechanism configured to detect the characteristic position of the reference workpiece. An axial limit mechanism is configured to axially secure the reference workpiece. A detection workpiece measuring mechanism is configured to detect the characteristic position of the detection workpiece. A detection workpiece posture adjustment mechanism is configured to support and adjust the posture of the detection workpiece. A control device is configured to control the movement of the axial limit mechanism, the reference workpiece measuring mechanism, the support and rotation mechanism, the detection workpiece posture adjustment mechanism, and the detection workpiece measuring mechanism, and to calculate the spatial phase angle between the reference workpiece feature and the detection workpiece feature. The above-mentioned measurement system improves work efficiency and measurement accuracy, and solves the problems of low work efficiency, low measurement accuracy, and poor detection quality consistency in traditional manual spatial phase angle measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial automation measurement, and in particular to a system and method for measuring the spatial angle of a cylindrical workpiece. Background Art

[0002] In recent years, with the rapid development of advanced manufacturing technologies and processes and the increase in the scale of mechanical manufacturing, large-scale assembly industrial sites have become characterized by large overall dimensions, complex and diverse target structures, harsh on-site assembly environments, multiple concurrent measurement tasks, and the need for high-efficiency and high-precision assembly. Consequently, higher requirements have been placed on on-site geometric measurement technology. During the assembly process, cylindrical workpieces such as ship pipes, weapons and ammunition require measurement and control of the spatial phase angles of each workpiece component. However, manual measurement is currently the primary method, resulting in low measurement accuracy and efficiency. Therefore, there is an urgent need to provide a system and method for measuring the spatial phase angle of large cylindrical workpieces to improve the detection efficiency and accuracy of the spatial phase angle during the assembly process. Summary of the Invention

[0003] In view of this, the present invention provides a system and method for measuring the spatial angle of a cylindrical workpiece. The measurement system improves work efficiency and measurement accuracy, and solves the problems of low work efficiency, low measurement accuracy, and poor detection quality consistency in traditional manual measurement of spatial phase angles.

[0004] The present invention adopts the following specific technical solutions:

[0005] The present invention provides a cylindrical workpiece spatial angle measurement system, which includes a base, two supporting rotation mechanisms, a reference workpiece measurement mechanism, an axial limit mechanism, a detection workpiece measurement mechanism, a detection workpiece posture adjustment mechanism and a control device;

[0006] The base is directly installed on the ground;

[0007] Along the length direction of the base, the axial limiting mechanism, the reference workpiece measuring mechanism, the supporting rotating mechanism, the detection workpiece posture adjusting mechanism and the detection workpiece measuring mechanism are sequentially slidably matched with the base;

[0008] The two supporting rotation mechanisms are spaced apart and are used to support the reference workpiece and drive the reference workpiece to rotate;

[0009] The reference workpiece measuring mechanism is used to detect a first characteristic position of the reference workpiece;

[0010] The axial limiting mechanism is used to axially fix the reference workpiece during the rotation process to prevent the reference workpiece from axial movement;

[0011] The detection workpiece measuring mechanism is used to detect a second characteristic position of the detection workpiece;

[0012] The detection workpiece posture adjustment mechanism is used to support the detection workpiece and adjust the posture of the detection workpiece;

[0013] The control device is used to control the actions of the axial limiting mechanism, the reference workpiece measuring mechanism, the supporting rotation mechanism, the detection workpiece posture adjustment mechanism and the detection workpiece measuring mechanism, and calculate the spatial phase angle between the first feature of the reference workpiece and the second feature of the detection workpiece according to the calibration results.

[0014] Furthermore, the base includes a front guide rail fixedly mounted on the base, a drive rack, a drive screw, a gantry column guide rail, two support rotation mechanism positioning blocks, a rear guide rail, a cylinder mounting plate and a detection mechanism positioning block;

[0015] The front guide rail and the rear guide rail both extend along the length direction of the base and are arranged at two ends of the base opposite to each other;

[0016] The two supporting and rotating mechanisms are respectively a first supporting and rotating mechanism and a second supporting and rotating mechanism;

[0017] The first supporting rotating mechanism and the detecting workpiece measuring mechanism are respectively slidably engaged with the front end guide rail via sliders;

[0018] The driving rack is meshed with the gear of the detection workpiece posture adjustment mechanism for transmission;

[0019] The driving screw is connected to the detection workpiece measuring mechanism through a connecting piece;

[0020] The gantry column guide rail is in sliding cooperation with the detection workpiece measuring mechanism;

[0021] The two support and rotation mechanism positioning blocks respectively fix the axial positions of the first support and rotation mechanism and the second support and rotation mechanism through positioning pins;

[0022] The second supporting rotation mechanism, the reference workpiece measuring mechanism and the axial limiting mechanism are respectively slidably engaged with the rear end guide rail via sliders;

[0023] The cylinder mounting plate is used to fix the driving cylinder of the axial limiting mechanism;

[0024] The detection mechanism positioning block fixes the axial position of the reference workpiece measuring mechanism in the form of a positioning pin.

[0025] Furthermore, each of the supporting rotating mechanisms includes a mounting bracket, a circular rotating motor and a reducer, a driving wheel and a driven wheel;

[0026] The mounting bracket of the first supporting rotating mechanism is mounted on the front guide rail in a sliding manner; the mounting bracket of the second supporting rotating mechanism is mounted on the rear guide rail in a sliding manner;

[0027] The circular rotating motor and the reducer are fixedly mounted on the mounting bracket;

[0028] The driving wheel and the driven wheel are rotatably mounted on the top of the mounting bracket;

[0029] The circular rotating motor and the reducer are connected to the driving wheel through a coupling, and are used to drive the driving wheel to rotate, and after the workpiece is placed, the driven wheel is driven to rotate through the workpiece.

[0030] Furthermore, the reference workpiece measurement mechanism includes a mounting plate, a support column, an upper endpoint laser displacement sensor, and a lower endpoint laser displacement sensor;

[0031] The mounting plate is mounted on the rear end guide rail in a sliding manner;

[0032] The bottom end of the supporting column is fixedly mounted on the mounting plate;

[0033] The upper endpoint laser displacement sensor and the lower endpoint laser displacement sensor are installed on the support column at intervals along the vertical direction, and are used to detect the first characteristic position on the circumferential surface of the reference workpiece.

[0034] Furthermore, the axial limiting mechanism further includes a connecting plate, a column and a limiting disc;

[0035] The driving cylinder is fixedly mounted on the cylinder mounting plate via a mounting bracket;

[0036] The two ends of the connecting plate are slidably engaged with the rear end guide rail through sliders, and the middle part is fixedly connected to the piston rod of the driving cylinder, and the connecting plate is driven to move axially by the driving cylinder;

[0037] The bottom end of the column is fixedly mounted on the connecting plate;

[0038] The limiting disc is rotatably mounted on the top end of the column, and the end surface of the limiting disc is used to contact the workpiece and rotate along with the workpiece.

[0039] Furthermore, the workpiece measurement mechanism includes a gantry stand, side guide rails, top guide rails, connecting columns, a three-dimensional vision sensor and a gantry crossbar;

[0040] The gantry frame includes a gantry column and a gantry crossbar that are fixedly connected to form a right-angle structure; the gantry column extends in a vertical direction, and the two sides of the bottom are slidably engaged with the gantry column guide rails through sliders, and the middle of the bottom is spirally engaged with the driving screw through the connecting block;

[0041] The gantry crossbar extends in the horizontal direction, one end of which is fixedly mounted on the top of the gantry column, and the other end forms a cantilever end;

[0042] A side guide rail is fixedly mounted on the side of the gantry crossbar, and a top guide rail is fixedly mounted on the top surface;

[0043] The top of the connecting column is slidably matched with the side guide rail and the top guide rail through a slider, and a protective box is installed at the bottom;

[0044] The three-dimensional vision sensor is installed in the protective box and is used to detect the spatial position of the second feature of the workpiece.

[0045] Furthermore, the detection workpiece posture adjustment mechanism also includes a drive assembly, a reducer, a first mounting base, a guide column, a lifting screw, a lifting mechanism, a second mounting base, a third mounting base, an end surface limiting mechanism, a rear left support wheel, a rear right support wheel, an adjusting screw, a slide rail, a front support wheel rocker, a front right support wheel, and a front left support wheel;

[0046] The drive assembly drives the gear to engage with the drive rack through the reducer to drive the detection workpiece posture adjustment mechanism to move axially;

[0047] The first mounting base is connected to the front guide rail via a slider;

[0048] The lifting screw drives the second mounting base plate to move upward and downward as a whole through the lifting mechanism, and the guide column maintains the lifting movement smoothly;

[0049] The rear left support wheel and the rear right support wheel jointly support the rear end of the workpiece;

[0050] The third mounting base is fixedly mounted on the second mounting base, and the axial position of the rear end face of the workpiece is limited by the end face limiting mechanism, and the position of the third mounting base is adjusted by the adjusting screw;

[0051] The front right support wheel and the front left support wheel jointly support the front end of the workpiece;

[0052] The front end support wheel rocker controls the front end right support wheel and the front end left support wheel to adjust the position of the front end of the workpiece through a screw drive, and is connected to the slide rail through a slider to achieve axial movement of the position of the front end of the workpiece.

[0053] Furthermore, the control device includes a programmable controller, a touch screen, a safety emergency stop switch button, a reference workpiece forward switch button, a reference workpiece reverse switch button, an axial limit forward button, an axial limit backward button, a start button, a stop button, a reset button, a circular rotation motor driver, an axial limit drive cylinder, and an audible and visual alarm indicator light;

[0054] The programmable controller is connected to the touch screen and the circular rotation motor driver through the PROFINET bus, and is connected to the safety emergency stop switch button, the reference workpiece forward switch button, the reference workpiece reverse switch button, the axial limit forward button, the axial limit backward button, the start button, the stop button, the reset button, the axial limit drive cylinder and the sound and light alarm indicator light through the switch input signal.

[0055] Furthermore, the driving component is a manual crank or a servo motor.

[0056] In addition, the present invention also provides a method for measuring the spatial angle of a cylindrical workpiece using the above-mentioned measurement system, the measurement method comprising the following steps:

[0057] Step 1: System calibration:

[0058] 1.1. Determine the base coordinate system O: Take the intersection of the reference workpiece's rotation axis and the axis of the first feature a as the origin; take the reference workpiece's rotation axis as the X-axis, with the direction pointing from the back end to the front end of the reference workpiece; take the projection direction of the axis of the first feature a in the plane perpendicular to the X-axis as the Y-axis, with the direction pointing from bottom to top; obtain the Z-axis by cross-producting the X-axis and the Y-axis.

[0059] 1.2. Calculate the arithmetic mean of the rigid body transformation matrix by measuring the base coordinate system O multiple times with the laser tracker, and establish the relationship calibration between the laser tracker coordinate system L and the base coordinate system O. Assume that the relationship matrix between the laser tracker coordinate system L and the base coordinate system O is

[0060] 1.3. The laser tracker and the 3D vision sensor are used to collect the sphere center data of the fixed sphere. The sphere center point set is aligned to realize the relationship calibration between the 3D vision sensor coordinate system S and the laser tracker coordinate system L. Assume that the relationship matrix between the 3D vision sensor coordinate system L and the 3D vision sensor coordinate system S is

[0061] 1.4. The relationship between the 3D vision sensor coordinate system S and the base coordinate system O is obtained through coordinate transformation, which is recorded as but It can be calculated by the following formula:

[0062]

[0063] 1.5. Use the 3D vision sensor to measure the center axis position coordinates of the second feature b of the workpiece, and multiply the center axis position coordinates by By performing coordinate transformation to the base coordinate system, the angle value of the second feature b of the detected workpiece in the base coordinate system O is obtained.

[0064] Step 2: Return all mechanisms to their original positions and hoist the workpiece for loading:

[0065] 2.1. The axial limit mechanism is driven back to its original position by the driving cylinder;

[0066] 2.2. The workpiece posture adjustment mechanism is driven by the drive assembly to return to its original position; the workpiece end face limit mechanism is manually completed and moved vertically upward to the limit position;

[0067] 2.3. Hoist the reference workpiece and place it on the supporting rotation mechanism, so that the first feature on the reference workpiece is within the detection range of the reference workpiece measurement mechanism;

[0068] 2.4. Hoist the inspection workpiece and place it on the inspection workpiece posture adjustment mechanism, and make the inspection workpiece end face fit with the inspection workpiece end face limit mechanism;

[0069] Step 3: Use the axial limiting mechanism to axially limit the reference workpiece. The reference workpiece rotates circumferentially, and the reference workpiece measuring mechanism detects the spatial position of the first circumferential feature a of the reference workpiece:

[0070] 3.1. The axial limit mechanism drives the cylinder to make the end surface of the limit disc contact the reference workpiece;

[0071] 3.2. The reference workpiece is rotated in a circular motion by a circular rotation motor. When the upper end point laser displacement sensor or the lower end point laser displacement sensor detects that the spatial position of the first feature a of the reference workpiece is within a set range, the circular rotation motor stops rotating.

[0072] Step 4: Adjust the spatial position of the workpiece through the workpiece posture adjustment mechanism so that the second feature b is within the measurement range of the workpiece measurement mechanism, and detect the spatial position of the second feature b through the workpiece measurement mechanism:

[0073] 4.1. Adjust the workpiece to ensure that the second feature b is within the measuring range of the workpiece measuring mechanism.

[0074] Step 5: The workpiece measuring mechanism measures the spatial position of the second feature b of the workpiece, calculates the spatial phase angle of the central axis of the second feature b of the workpiece, and makes the spatial phase angle within the set range:

[0075] 5.1. Scan and detect the coordinates of the central axis of the second feature b on the workpiece surface using the three-dimensional vision sensor in the workpiece measurement mechanism as p(x, y, z);

[0076] 5.2. The relationship matrix between the center axis position coordinates p(x, y, z) of the second feature b on the workpiece surface, the three-dimensional vision sensor coordinate system S and the base coordinate system O is Multiply them to get the spatial phase angle θ of the central axis of the second feature b;

[0077] 5.3. If the calculated spatial phase angle θ is within the set range, stop measuring. If the calculated spatial phase angle θ is not within the set range, repeat steps 3 and 4 until the spatial phase angle is within the set range.

[0078] Step 6: Complete the assembly of the reference workpiece and the inspection workpiece into a complete workpiece, and hoist the workpiece for unloading:

[0079] 6.1. Fine-tune the inspection workpiece posture adjustment mechanism to complete the assembly of the reference workpiece and the inspection workpiece;

[0080] 6.2. Lifting and unloading of workpieces.

[0081] Beneficial effects:

[0082] 1. The cylindrical workpiece spatial angle measurement system of the present invention adopts a modular structural design, including a supporting rotation mechanism for supporting a reference workpiece and driving the reference workpiece to rotate, a reference workpiece measuring mechanism for detecting the first feature position of the reference workpiece, an axial limiting mechanism for axially fixing the reference workpiece during rotation, a detection workpiece measuring mechanism for detecting the second feature position of the detection workpiece, a detection workpiece posture adjustment mechanism for supporting the detection workpiece and adjusting the posture, and a control device for calculating the spatial phase angle between the first feature of the reference workpiece and the second feature of the detection workpiece. It can realize the functions of circular rotation, axial limiting, feature position measurement, detection workpiece posture adjustment, feature position measurement and other functions of large cylindrical reference workpieces, and at the same time realize online measurement of the spatial angle of two cylindrical workpiece assembly features. It has the advantages of good flexibility, strong adaptability, high work efficiency and high measurement accuracy, and solves the problems of low work efficiency, low measurement accuracy and poor detection quality consistency in traditional manual measurement of spatial phase angles.

[0083] 2. The cylindrical workpiece spatial angle measurement system of the present invention uses a point laser displacement sensor and a three-dimensional vision sensor to detect the spatial position of the cylindrical workpiece features. The spatial phase angle between the reference workpiece and the detection workpiece is calculated through system calibration. It has the advantages of high measurement accuracy, high measurement efficiency and high degree of automation.

[0084] 3. The cylindrical workpiece spatial angle measurement method of the present invention establishes an intermediate coordinate system through a laser tracker, and establishes the coordinate relationship between the three-dimensional vision sensor and the base coordinate system through coordinate transformation, thereby realizing the systematic calibration and precise measurement of the spatial phase angle of large-size workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 Schematic diagram of the three-dimensional structure of the cylindrical workpiece spatial angle measurement system of the present invention;

[0086] Figure 2 Schematic diagram of the working state of the cylindrical workpiece spatial angle measurement system of the present invention;

[0087] Figure 3 for Figure 1 A schematic diagram of the partially enlarged structure of the front-end part;

[0088] Figure 4 for Figure 1 A schematic diagram of the partially enlarged structure of the middle and rear end parts;

[0089] Figure 5 for Figure 1 Schematic diagram of the three-dimensional structure of the central support rotating mechanism;

[0090] Figure 6 for Figure 1 Schematic diagram of the three-dimensional structure of the central reference workpiece measurement mechanism;

[0091] Figure 7 for Figure 1 Schematic diagram of the three-dimensional structure of the central axial limit mechanism;

[0092] Figure 8 for Figure 1 Schematic diagram of the three-dimensional structure of the workpiece measurement mechanism;

[0093] Figure 9 for Figure 1 Schematic diagram of the three-dimensional structure of the workpiece posture adjustment mechanism during detection;

[0094] Figure 10 This is a block diagram of the control device. DETAILED DESCRIPTION

[0095] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0096] Example 1

[0097] This embodiment provides a cylindrical workpiece space angle measurement system, such as Figure 1 and Figure 2As shown in the structure, the measuring system includes a base 1, two supporting rotating mechanisms 2, a reference workpiece measuring mechanism 3, an axial limiting mechanism 4, a detection workpiece measuring mechanism 5, a detection workpiece posture adjustment mechanism 6 and a control device 7;

[0098] The base 1 is directly mounted on the ground to support the entire measuring system. Along the length of the base 1, the axial limit mechanism 4, the reference workpiece measuring mechanism 3, the support rotation mechanism 2, the detection workpiece posture adjustment mechanism 6, and the detection workpiece measuring mechanism 5 are sequentially slidably engaged with the base 1.

[0099] The two supporting rotating mechanisms 2 are spaced apart and are used to jointly support the reference workpiece A and drive the reference workpiece A to rotate; the two supporting rotating mechanisms 2 have the same structure, namely the first supporting rotating mechanism 2 and the second supporting rotating mechanism 2. Figure 2 、 Figure 3 and Figure 4 As shown, the first supporting rotating mechanism 2 is supported at the front end of the reference workpiece A, and the second supporting rotating mechanism 2 is supported at the rear end of the reference workpiece A; in this embodiment, Figure 2 The end where the workpiece B is located is defined as the front end, and the end where the reference workpiece A is located is defined as the back end;

[0100] The reference workpiece measuring mechanism 3 is used to detect the first characteristic position of the reference workpiece A; Figure 2 As shown, the reference workpiece A has a first feature a;

[0101] The axial limiting mechanism 4 is used to axially fix the reference workpiece A during the rotation process to prevent the reference workpiece A from axial movement;

[0102] The workpiece measuring mechanism 5 is used to detect the second characteristic position of the workpiece B; Figure 2 As shown, the inspection workpiece B has a second feature b;

[0103] The detection workpiece posture adjustment mechanism 6 is used to support the detection workpiece B and adjust the posture of the detection workpiece B;

[0104] The control device 7 is used to control the movement of the axial limiting mechanism 4, the reference workpiece measuring mechanism 3, the supporting rotation mechanism 2, the detection workpiece posture adjustment mechanism 6 and the detection workpiece measuring mechanism 5, and calculates the spatial phase angle between the first feature a of the reference workpiece and the second feature b of the detection workpiece according to the calibration results.

[0105] The above-mentioned measurement system adopts a modular structural design, including a base 1, a supporting rotation mechanism 2 for supporting the reference workpiece A and driving the reference workpiece A to rotate, a reference workpiece measuring mechanism 3 for detecting the position of the first feature a of the reference workpiece, an axial limiting mechanism 4 for axially fixing the reference workpiece during rotation, a detection workpiece measuring mechanism 5 for detecting the position of the second feature b of the detection workpiece, a detection workpiece posture adjustment mechanism 6 for supporting the detection workpiece B and adjusting the posture, and a control device 7 for calculating the spatial phase angle between the first feature a of the reference workpiece and the second feature b of the detection workpiece. Through the various mechanisms installed on the base 1, the functions of circular rotation, axial limiting, feature position measurement, detection workpiece posture adjustment, and feature position measurement of large cylindrical reference workpieces can be realized, and the online measurement of the spatial angle of the assembly features of two cylindrical workpieces can be realized at the same time. It has the advantages of good flexibility, strong adaptability, high work efficiency, and high measurement accuracy, and solves the problems of low work efficiency, low measurement accuracy, and poor consistency of detection quality in traditional manual measurement of spatial phase angles.

[0106] In the above measurement system, Figure 3 and Figure 4As shown in the structure, the base 1 includes a front guide rail 8 fixedly mounted on the base 1, a driving rack 9, a driving screw 10, a gantry column guide rail 11, two support rotation mechanism positioning blocks 12, a rear end guide rail 13, a cylinder mounting plate 14 and a detection mechanism positioning block 15; the front guide rail 8 and the rear end guide rail 13 both extend along the length direction of the base 1 and are relatively arranged at both ends of the base 1, the front guide rail 8 is fixedly mounted on the front end of the base 1, and the rear end guide rail 13 is fixedly mounted on the rear end of the base 1, the extension direction of the front guide rail 8 and the extension direction of the rear end guide rail 13 are both consistent with the length direction of the base 1, and consistent with the arrangement direction of the reference workpiece and the detection workpiece; the front guide rail 8 and the rear end guide rail 13 both have two parallel tracks; the first support rotation mechanism 2 is connected to the front guide rail 8 through a slider; the detection workpiece measuring mechanism 5 is slidably matched with the gantry column guide rail 11 through a slider; the driving rack 9 is meshed with the gear 35 of the detection workpiece posture adjustment mechanism 6 for transmission; the driving screw 1 0 is connected to the inspection workpiece measuring mechanism 5 via a connector, which can be a component such as a nut that screws with the drive screw 10. The gantry column guide rail 11 slides with the inspection workpiece measuring mechanism 5. Two support and rotation mechanism positioning blocks 12 respectively fix the axial position of the first and second support and rotation mechanisms 2 using locating pins. That is, one support and rotation mechanism positioning block 12 corresponds to the first support and rotation mechanism 2 and is used to axially position the first support and rotation mechanism 2, while the other support and rotation mechanism positioning block 12 corresponds to the second support and rotation mechanism 2 and is used to axially position the second support and rotation mechanism 2. The second support and rotation mechanism 2, the reference workpiece measuring mechanism 3, and the axial limiting mechanism 4 each slide with the rear end guide rail 13 via sliders. The cylinder mounting plate 14 is used to securely install the drive cylinder 29 of the axial limiting mechanism 4. The inspection mechanism positioning block 15 fixes the axial position of the reference workpiece measuring mechanism 3 using locating pins. The drive screw 10 can be driven by a servo motor to achieve automatic axial movement of the inspection workpiece measuring mechanism 5.

[0107] like Figure 5 As shown, each supporting rotating mechanism 2 includes a mounting bracket 16, a circular rotating motor and reducer 17, a driving wheel 18 and a driven wheel 19; the mounting bracket 16 of the first supporting rotating mechanism 2 is slidably mounted on the front guide rail 8; the mounting bracket 16 of the second supporting rotating mechanism 2 is slidably mounted on the rear guide rail 13; the driving wheel 18 and the driven wheel 19 are rotatably mounted on the top of the mounting bracket 16; the circumferential rotating motor and reducer 17 are fixedly mounted on the mounting bracket 16; the circumferential rotating motor and reducer 17 are transmission-connected to the driving wheel 18 through a coupling, which is used to drive the driving wheel 18 to rotate, and drive the driven wheel 19 to rotate through the workpiece after the workpiece is placed.

[0108] like Figure 6As shown, the reference workpiece measuring mechanism 3 includes a mounting plate 25, a supporting column 26, an upper endpoint laser displacement sensor 27 and a lower endpoint laser displacement sensor 28; the mounting plate 25 is slidably mounted on the rear end guide rail 13; the mounting plate 25 can be slidably mounted with the rear end guide rail 13 through a slider; the bottom end of the supporting column 26 is fixedly mounted on the mounting plate 25, for supporting the upper endpoint laser displacement sensor 27 and the lower endpoint laser displacement sensor 28; the upper endpoint laser displacement sensor 27 and the lower endpoint laser displacement sensor 28 are installed on the supporting column 26 at intervals in the vertical direction, for detecting the first characteristic position on the circumferential surface of the reference workpiece.

[0109] like Figure 7 As shown, the axial limiting mechanism 4 includes a driving cylinder 29, a connecting plate 30, a column 31 and a limiting disc 32; the driving cylinder 29 is fixedly mounted on the cylinder mounting plate 14; the two ends of the connecting plate 30 are slidably matched with the rear end guide rail 13 through sliders, and the middle part is fixedly connected to the piston rod of the driving cylinder 29, and the connecting plate 30 is driven by the driving cylinder 29 to move axially; the bottom end of the column 31 is fixedly mounted on the connecting plate 30; the limiting disc 32 can be rotatably mounted on the top end of the column 31, and the end face of the limiting disc 32 is used to contact with the workpiece for axial limitation and can rotate with the workpiece.

[0110] like Figure 8 As shown, the workpiece measuring mechanism 5 includes a gantry frame, side guide rails 21, top guide rails 22, connecting columns 23 and a three-dimensional visual sensor 24; the gantry frame includes a gantry column 20 and a gantry crossbar that are fixedly connected to form a right-angled structure; the gantry column 20 extends in the vertical direction, and the two sides of the bottom are slidably matched with the gantry column guide rails 11 through sliders, and the middle of the bottom is spirally matched with the driving screw 10 through a connecting block; the gantry frame realizes position adjustment by the spiral match of the driving screw 10 and the connecting block, and the sliding match of the slider and the gantry column 20 guide rail 11 is realized. The gantry cross bar extends in the horizontal direction, with one end fixedly mounted on the top of the gantry column 20 and the other end forming a cantilever end; the side guide rail 21 is fixedly mounted on the side of the gantry cross bar, and the top guide rail 22 is fixedly mounted on the top surface; the top of the connecting column 23 slides with the side guide rail 21 and the top guide rail 22 respectively through a slider, and a protective box is installed at the bottom; the connecting column 23 is stably guided by the side guide rail 21 and the top guide rail 22; the three-dimensional vision sensor 24 is installed in the protective box to detect the spatial position of the workpiece features.

[0111] like Figure 9As shown, the detection workpiece posture adjustment mechanism 6 includes a drive assembly, a reducer 34, a gear 35, a first mounting base 36, a guide column 37, a lifting screw 38, a lifting mechanism 39, a second mounting base 40, a third mounting base 41, an end surface limiting mechanism 42, a rear end left support wheel 43, a rear end right support wheel 44, an adjusting screw 45, a slide rail 46, a front end support wheel rocker 47, a front end right support wheel 48, and a front end left support wheel 49; the drive assembly can be a manual rocker 33 or a servo motor; the drive assembly drives the gear 35 through the reducer 34 to engage with the drive rack 9 for driving the detection workpiece posture adjustment mechanism 6 to move axially; the first mounting base 36 is connected to the front end guide rail 8 through a slider; the lifting screw 38 The second mounting base plate 40 is driven to lift and lower as a whole by the lifting mechanism 39, and the lifting and lowering movement is kept smooth by the guide column 37; the rear end left support wheel 43 and the rear end right support wheel 44 jointly support the rear end of the workpiece; the third mounting base plate 41 is fixedly mounted on the second mounting base plate 40, and the axial limitation of the rear end face of the workpiece is performed by the end face limiting mechanism 42, and the position adjustment of the third mounting base plate 41 is achieved by adjusting the screw 45; the front end right support wheel 48 and the front end left support wheel 49 jointly support the front end of the workpiece; the front end support wheel rocker 47 controls the position adjustment of the front end of the workpiece supported by the front end right support wheel 48 and the front end left support wheel 49 through a screw drive, and is connected to the slide rail 46 through a slider to achieve axial movement of the position of the front end of the workpiece.

[0112] like Figure 10 As shown, the control device 7 includes a programmable controller, a touch screen, a safety emergency stop switch button, a reference workpiece forward switch button, a reference workpiece reverse switch button, an axial limit forward button, an axial limit backward button, a start button, a stop button, a reset button, a circular rotation motor driver and an audible and visual alarm indicator light; the circular rotation motor driver is provided with a first circular rotation motor driver corresponding to the first support rotation mechanism 2 and a second circular rotation motor driver corresponding to the second support rotation mechanism 2, and the circumferential rotation motors are respectively controlled by the corresponding circumferential rotation motor drivers;

[0113] The programmable controller is connected to the touch screen and the circular rotation motor driver through the PROFINET bus, and is connected to the safety emergency stop switch button, the reference workpiece forward switch button, the reference workpiece reverse switch button, the axial limit forward button, the axial limit backward button, the start button, the stop button, the reset button, the drive cylinder 29 and the sound and light alarm indicator light through the switch input signal.

[0114] The above-mentioned measurement system uses a point laser displacement sensor and a three-dimensional vision sensor 24 to detect the spatial position of the cylindrical workpiece feature, and calculates the spatial phase angle between the reference workpiece and the test workpiece through system calibration. It has the advantages of high measurement accuracy, high measurement efficiency and high degree of automation;

[0115] Example 2

[0116] This embodiment provides a method for measuring the spatial angle of a cylindrical workpiece using the above-mentioned measurement system. The measurement method includes the following steps:

[0117] Step 1: System calibration:

[0118] 1.1. Determine the base coordinate system O: Take the intersection of the rotation axis of the reference workpiece A and the axis of the first feature a as the origin; take the rotation axis of the reference workpiece A as the X-axis, with the direction pointing from the back end to the front end of the reference workpiece A; take the projection direction of the axis of the first feature a in the plane perpendicular to the X-axis as the Y-axis, with the direction pointing from bottom to top; obtain the Z-axis by cross-producting the X-axis and the Y-axis;

[0119] 1.2. Calculate the arithmetic mean of the rigid body transformation matrix by measuring the base coordinate system O multiple times with the laser tracker, and establish the relationship calibration between the laser tracker coordinate system L and the base coordinate system O. Assume that the relationship matrix between the laser tracker coordinate system L and the base coordinate system O is

[0120] 1.3. The laser tracker and the 3D vision sensor 24 are used to collect the sphere fitting center data of the fixed sphere. The sphere center point set is aligned to realize the relationship calibration between the 3D vision sensor 24 coordinate system S and the laser tracker coordinate system L. Assume that the relationship matrix between the 3D vision sensor 24 coordinate system L and the 3D vision sensor 24 coordinate system S is:

[0121] 1.4. The relationship between the 3D vision sensor 24 coordinate system S and the base coordinate system O is obtained through coordinate transformation, which is recorded as but It can be calculated by the following formula:

[0122]

[0123] 1.5. Use the three-dimensional vision sensor 24 to measure the center axis position coordinates of the second feature b of the workpiece, and multiply the center axis position coordinates by By performing coordinate transformation to the base coordinate system, the angle value of the second feature b of the detected workpiece in the base coordinate system O is obtained.

[0124] Step 2: Return all mechanisms to their original positions and hoist the workpiece for loading:

[0125] 2.1. The axial limiting mechanism 4 is driven back to its original position by the driving cylinder 29;

[0126] 2.2. The workpiece posture adjustment mechanism 6 is driven to return to its original position by the drive assembly; the workpiece end surface limiting mechanism 42 is manually completed and moves vertically upward to the limit position;

[0127] 2.3. Hoist the reference workpiece and place it on the supporting rotation mechanism 2 so that the first feature on the reference workpiece is within the detection range of the reference workpiece measuring mechanism 3;

[0128] 2.4. Hoist the inspection workpiece and place it on the inspection workpiece posture adjustment mechanism 6, so that the end face of the inspection workpiece is in contact with the inspection workpiece end face limiting mechanism 42;

[0129] Step 3: Use the axial limiting mechanism 4 to axially limit the reference workpiece. The reference workpiece rotates circumferentially, and the reference workpiece measuring mechanism 3 detects the spatial position of the first circumferential feature a of the reference workpiece:

[0130] 3.1. The axial limiting mechanism 4 drives the cylinder 29 to move so that the end surface of the limiting disc 32 contacts the reference workpiece;

[0131] 3.2. The reference workpiece is rotated in a circular motion by a circular rotation motor. When the upper end point laser displacement sensor 27 detects that the spatial position of the first feature a of the reference workpiece is within a set range, the circular rotation motor stops rotating.

[0132] Step 4: Adjust the spatial position of the inspection workpiece by the inspection workpiece posture adjustment mechanism 6 so that the second feature b is within the measurement range of the inspection workpiece measurement mechanism 5, and detect the spatial position of the second feature b by the inspection workpiece measurement mechanism 5:

[0133] 4.1. Adjust the inspection workpiece so that the position of its second feature b is within the measurement range of the inspection workpiece measuring mechanism 5;

[0134] Step 5: The workpiece measuring mechanism 5 measures the spatial position of the second feature b of the workpiece, calculates the spatial phase angle of the central axis of the second feature b of the workpiece, and makes the spatial phase angle within the set range:

[0135] 5.1. Scan and detect the central axis position coordinates of the second feature b on the workpiece surface by the three-dimensional vision sensor 24 in the workpiece measurement mechanism 5 as p(x, y, z);

[0136] 5.2. The relationship matrix between the center axis position coordinates p(x, y, z) of the second feature b on the workpiece surface, the three-dimensional vision sensor coordinate system S and the base coordinate system O is Multiply them to get the spatial phase angle θ of the central axis of the second feature b;

[0137] 5.3. If the calculated spatial phase angle θ is within the set range, stop measuring. If the calculated spatial phase angle θ is not within the set range, repeat steps 3 and 4 until the spatial phase angle is within the set range.

[0138] Step 6: Complete the assembly of the reference workpiece and the inspection workpiece into a complete workpiece, and hoist the workpiece for unloading:

[0139] 6.1. Fine-tune the inspection workpiece posture adjustment mechanism 6 to complete the assembly of the reference workpiece and the inspection workpiece;

[0140] 6.2. Lifting and unloading of workpieces.

[0141] The above measurement method establishes an intermediate coordinate system through a laser tracker, and establishes a coordinate relationship between the three-dimensional vision sensor 24 and the base coordinate system through coordinate transformation, thereby realizing systematic calibration and precise measurement of the spatial phase angle of large-scale workpieces.

[0142] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cylindrical workpiece spatial angle measurement system, characterized in that: It includes a base, two supporting rotation mechanisms, a reference workpiece measuring mechanism, an axial limiting mechanism, a detection workpiece measuring mechanism, a detection workpiece posture adjustment mechanism and a control device; The base is directly installed on the ground; Along the length direction of the base, the axial limiting mechanism, the reference workpiece measuring mechanism, the supporting rotating mechanism, the detection workpiece posture adjusting mechanism and the detection workpiece measuring mechanism are sequentially slidably matched with the base; The two supporting rotation mechanisms are spaced apart and are used to support the reference workpiece and drive the reference workpiece to rotate; The reference workpiece measuring mechanism is used to detect a first characteristic position of the reference workpiece; The axial limiting mechanism is used to axially fix the reference workpiece during the rotation process to prevent the reference workpiece from axial movement; The detection workpiece measuring mechanism is used to detect a second characteristic position of the detection workpiece; The detection workpiece posture adjustment mechanism is used to support the detection workpiece and adjust the posture of the detection workpiece; The control device is used to control the actions of the axial limiting mechanism, the reference workpiece measuring mechanism, the supporting rotation mechanism, the detection workpiece posture adjustment mechanism and the detection workpiece measuring mechanism, and calculate the spatial phase angle between the first feature of the reference workpiece and the second feature of the detection workpiece according to the calibration results.

2. The measurement system according to claim 1, wherein The base includes a front guide rail fixedly mounted on the base, a drive rack, a drive screw, a gantry column guide rail, two support rotation mechanism positioning blocks, a rear guide rail, a cylinder mounting plate and a detection mechanism positioning block; The front guide rail and the rear guide rail both extend along the length direction of the base and are arranged at two ends of the base opposite to each other; The two supporting and rotating mechanisms are respectively a first supporting and rotating mechanism and a second supporting and rotating mechanism; The first supporting rotation mechanism and the detection workpiece measuring mechanism are respectively slidably engaged with the front end guide rail via sliders; The driving rack is meshed with the gear of the detection workpiece posture adjustment mechanism for transmission; The driving screw is connected to the detection workpiece measuring mechanism through a connecting piece; The gantry column guide rail is in sliding cooperation with the detection workpiece measuring mechanism; The two support and rotation mechanism positioning blocks respectively fix the axial positions of the first support and rotation mechanism and the second support and rotation mechanism through positioning pins; The second supporting rotation mechanism, the reference workpiece measuring mechanism and the axial limiting mechanism are respectively slidably engaged with the rear end guide rail via sliders; The cylinder mounting plate is used to fix the driving cylinder of the axial limiting mechanism; The detection mechanism positioning block fixes the axial position of the reference workpiece measuring mechanism in the form of a positioning pin.

3. The measurement system according to claim 2, wherein: Each of the supporting rotating mechanisms includes a mounting bracket, a circular rotating motor and a reducer, a driving wheel and a driven wheel; The mounting bracket of the first supporting rotating mechanism is mounted on the front guide rail in a sliding manner; the mounting bracket of the second supporting rotating mechanism is mounted on the rear guide rail in a sliding manner; The circular rotating motor and the reducer are fixedly mounted on the mounting bracket; The driving wheel and the driven wheel are rotatably mounted on the top of the mounting bracket; The circular rotating motor and the reducer are connected to the driving wheel through a coupling, and are used to drive the driving wheel to rotate, and after the workpiece is placed, the driven wheel is driven to rotate through the workpiece.

4. The measurement system according to claim 3, wherein: The reference workpiece measurement mechanism includes a mounting plate, a support column, an upper end point laser displacement sensor and a lower end point laser displacement sensor; The mounting plate is mounted on the rear end guide rail in a sliding manner; The bottom end of the supporting column is fixedly mounted on the mounting plate; The upper endpoint laser displacement sensor and the lower endpoint laser displacement sensor are installed on the support column at intervals along the vertical direction, and are used to detect the first characteristic position on the circumferential surface of the reference workpiece.

5. The measurement system according to claim 4, wherein: The axial limiting mechanism also includes a connecting plate, a column and a limiting disc; The driving cylinder is fixedly mounted on the cylinder mounting plate via a mounting bracket; The two ends of the connecting plate are slidably engaged with the rear end guide rail through sliders, and the middle part is fixedly connected to the piston rod of the driving cylinder, and the connecting plate is driven to move axially by the driving cylinder; The bottom end of the column is fixedly mounted on the connecting plate; The limiting disc is rotatably mounted on the top end of the column, and the end surface of the limiting disc is used to contact the workpiece and rotate along with the workpiece.

6. The measuring system according to claim 5, wherein the workpiece measuring mechanism comprises a gantry frame, side guide rails, top guide rails, connecting columns and a three-dimensional vision sensor; The gantry frame includes a gantry column and a gantry crossbar that are fixedly connected to form a right-angle structure; the gantry column extends in a vertical direction, and the two sides of the bottom are slidably engaged with the gantry column guide rails through sliders, and the middle of the bottom is spirally engaged with the driving screw through the connecting block; The gantry crossbar extends in the horizontal direction, one end of which is fixedly mounted on the top of the gantry column, and the other end forms a cantilever end; A side guide rail is fixedly mounted on the side of the gantry crossbar, and a top guide rail is fixedly mounted on the top surface; The top of the connecting column is slidably matched with the side guide rail and the top guide rail through a slider, and a protective box is installed at the bottom; The three-dimensional vision sensor is installed in the protective box and is used to detect the spatial position of the second feature of the workpiece.

7. The measuring system according to claim 6, wherein the detection workpiece posture adjustment mechanism further comprises a drive assembly, a reducer, a first mounting base, a guide column, a lifting screw, a lifting mechanism, a second mounting base, a third mounting base, an end surface limiting mechanism, a rear left support wheel, a rear right support wheel, an adjusting screw, a slide rail, a front support wheel rocker, a front right support wheel, and a front left support wheel; The drive assembly drives the gear to engage with the drive rack through the reducer to drive the detection workpiece posture adjustment mechanism to move axially; The first mounting base is connected to the front guide rail via a slider; The lifting screw drives the second mounting base plate to move upward and downward as a whole through the lifting mechanism, and the guide column maintains the lifting movement smoothly; The rear left support wheel and the rear right support wheel jointly support the rear end of the workpiece; The third mounting base is fixedly mounted on the second mounting base, and the axial position of the rear end face of the workpiece is limited by the end face limiting mechanism, and the position of the third mounting base is adjusted by the adjusting screw; The front right support wheel and the front left support wheel jointly support the front end of the workpiece; The front end support wheel rocker controls the front end right support wheel and the front end left support wheel to adjust the position of the front end of the workpiece through a screw drive, and is connected to the slide rail through a slider to achieve axial movement of the position of the front end of the workpiece. 8 . The measuring system according to claim 7 , wherein the driving component is a manual crank or a servo motor.

9. The measuring system according to any one of claims 2 to 8, wherein the control device comprises a programmable controller, a touch screen, a safety emergency stop switch button, a reference workpiece forward rotation switch button, a reference workpiece reverse rotation switch button, an axial limit forward button, an axial limit backward button, a start button, a stop button, a reset button, a circular rotation motor driver, and an audible and visual alarm indicator light; The programmable controller is connected to the touch screen and the circular rotation motor driver through the PROFINET bus, and is connected to the safety emergency stop switch button, the reference workpiece forward switch button, the reference workpiece reverse switch button, the axial limit forward button, the axial limit backward button, the start button, the stop button, the reset button, the drive cylinder and the sound and light alarm indicator light through the switch input signal.

10. A method for measuring the spatial angle of a cylindrical workpiece using the measuring system of claim 9, comprising the following steps: Step 1: System calibration: 1.

1. Determine the base coordinate system O: Take the intersection of the reference workpiece's rotation axis and the axis of the first feature a as the origin; take the reference workpiece's rotation axis as the X-axis, with the direction pointing from the back end to the front end of the reference workpiece; take the projection direction of the axis of the first feature a in the plane perpendicular to the X-axis as the Y-axis, with the direction pointing from bottom to top; obtain the Z-axis by cross-producting the X-axis and the Y-axis. 1.

2. Calculate the arithmetic mean of the rigid body transformation matrix by measuring the base coordinate system O multiple times with the laser tracker, and establish the relationship calibration between the laser tracker coordinate system L and the base coordinate system O. Assume that the relationship matrix between the laser tracker coordinate system L and the base coordinate system O is 1.

3. The laser tracker and the 3D vision sensor are used to collect the sphere center data of the fixed sphere. The sphere center point set is aligned to realize the relationship calibration between the 3D vision sensor coordinate system S and the laser tracker coordinate system L. Assume that the relationship matrix between the 3D vision sensor coordinate system L and the 3D vision sensor coordinate system S is 1.

4. The relationship between the 3D vision sensor coordinate system S and the base coordinate system O is obtained through coordinate transformation, which is recorded as but It can be calculated by the following formula: 1.

5. Use the 3D vision sensor to measure the center axis position coordinates of the second feature b of the workpiece, and multiply the center axis position coordinates by Perform coordinate transformation to the base coordinate system, and then obtain the angle value of the second feature b of the workpiece in the base coordinate system O; Step 2: Return all mechanisms to their original positions and hoist the workpiece for loading: 2.

1. The axial limit mechanism is driven back to its original position by the driving cylinder; 2.

2. The workpiece posture adjustment mechanism is driven by the drive assembly to return to its original position; the workpiece end face limit mechanism is manually completed and moved vertically upward to the limit position; 2.

3. Hoist the reference workpiece and place it on the supporting rotation mechanism, so that the first feature a on the reference workpiece is within the detection range of the reference workpiece measurement mechanism; 2.

4. Hoist the inspection workpiece and place it on the inspection workpiece posture adjustment mechanism, and make the inspection workpiece end face fit with the inspection workpiece end face limit mechanism; Step 3: Use the axial limiting mechanism to axially limit the reference workpiece. The reference workpiece rotates circumferentially, and the reference workpiece measuring mechanism detects the spatial position of the first circumferential feature a of the reference workpiece: 3.

1. The axial limit mechanism drives the cylinder to make the end surface of the limit disc contact the reference workpiece; 3.

2. The reference workpiece is rotated in a circular motion by a circular rotation motor. When the upper end point laser displacement sensor or the lower end point laser displacement sensor detects that the spatial position of the first feature a of the reference workpiece is within a set range, the circular rotation motor stops rotating. Step 4: Adjust the spatial position of the workpiece through the workpiece posture adjustment mechanism so that the second feature b is within the measurement range of the workpiece measurement mechanism, and detect the spatial position of the second feature b through the workpiece measurement mechanism: 4.

1. Adjust the workpiece to ensure that the second feature b is within the measuring range of the workpiece measuring mechanism. Step 5: The workpiece measuring mechanism measures the spatial position of the second feature b of the workpiece, calculates the spatial phase angle of the central axis of the second feature b of the workpiece, and makes the spatial phase angle within the set range: 5.

1. Scan and detect the coordinates of the central axis of the second feature b on the workpiece surface using the three-dimensional vision sensor in the workpiece measurement mechanism as p(x, y, z); 5.

2. The relationship matrix between the central axis position coordinates p(x, y, z) of the second feature b on the workpiece surface, the three-dimensional vision sensor coordinate system S and the base coordinate system O is Multiply them to get the spatial phase angle θ of the central axis of the second feature b; 5.

3. If the calculated spatial phase angle θ is within the set range, stop measuring. If the calculated spatial phase angle θ is not within the set range, repeat steps 3 and 4 until the spatial phase angle is within the set range. Step 6: Complete the assembly of the reference workpiece and the inspection workpiece into a complete workpiece, and hoist the workpiece for unloading: 6.

1. Fine-tune the inspection workpiece posture adjustment mechanism to complete the assembly of the reference workpiece and the inspection workpiece; 6.

2. Lifting and unloading of workpieces.

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