Complex curved surface profile calculation method, system and terminal based on multi-laser sensor calibration

Abstract

The complex curved surface profile calculation method, system and terminal based on multi-laser sensor calibration of the present application obtain the profile data of the complex curved surface collected by each laser sensor respectively; based on the local sensor coordinate system conversion relationship of each laser sensor obtained by the multi-laser sensor calibration method, the profile data is converted from the corresponding sensor coordinate system to a local sensor coordinate system respectively, then based on the measurement device global coordinate system conversion relationship obtained by the multi-laser sensor calibration method, the local sensor coordinate profile data is converted from the local sensor coordinate system to the measurement device global coordinate system, and the measurement device global coordinate system profile data of each laser sensor obtained is spliced to obtain the corresponding complex curved surface profile. The present application realizes the calibration of the multi-laser sensor coordinate system and the global coordinate system, and realizes the online real-time calibration, which ensures that the calibration can be quickly and accurately completed before each measurement, and the profile calculation is carried out on the basis of the calibration method, which greatly improves the accuracy of the profile measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of profile measurement, in particular to a complex curved surface profile calculation method, system and terminal based on multi-laser sensor calibration. BACKGROUND

[0002] The aero-engine occupies a crucial position in the field of aviation, and the blade is the core part of the aero-engine, which has the characteristics of complex structure, strict manufacturing standard, etc., and the shape profile error of the blade affects the performance of the whole engine. Therefore, the detection of the surface profile of the blade, especially the compressor blade, has always been the focus and difficulty of the manufacture of aero-engine. The cross-section profile measurement method based on multi-laser sensor can ensure the measurement accuracy of the blade in the process of quickly measuring the profile of the blade. The profiler can effectively reduce the measurement error and improve the accuracy of the whole measurement system through accurate calibration. At present, the commonly used calibration method is to calibrate the profiler by installing a fine adjustment mechanism and a sensor. This method is complex for each calibration process, and cannot be calibrated online, which is not convenient and simple. The method of calibrating the profiler by a single calibration gauge can only calibrate the sensor, and lacks the multi-sensor calibration method. In order to adapt to a three-dimensional blade profile detection device which adopts three or more multi-sensors, can quickly scan the cross-section of the blade, and automatically analyzes the parameters of the blade, a system calibration method which is online, simple and meets the requirements of precise detection is needed, and a complex curved surface profile calculation method calibrated by multi-laser sensor is needed. SUMMARY

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a complex curved surface profile calculation method, system and terminal based on multi-laser sensor calibration, which is used to solve the problems of the above-mentioned prior art.

[0004] To achieve the above object and other related objects, the present application provides a complex curved surface profile calculation method for multi-laser sensor calibration, which is applied to a complex curved surface profile measurement device, the device comprising: a rotary table for driving a complex curved surface to be measured to rotate around the Z-axis in the system coordinate system; a first motion mechanism for driving the rotary table fixed thereon to move along the Y-axis in the system coordinate system; at least three laser sensors covering a range of view angles, with the laser planes perpendicular to the Z-axis, for collecting profile data of the complex curved surface to be measured; and a second motion mechanism for driving the laser collection system fixed thereon to move along the Z-axis, the method comprising: collecting profile data of the complex curved surface to be measured collected by each laser sensor respectively; converting the profile data of the complex curved surface to be measured collected by each laser sensor from the corresponding sensor coordinate system to a local sensor coordinate system based on the local sensor coordinate system conversion relationship of each laser sensor obtained by the multi-laser sensor calibration method, and obtaining local sensor coordinate profile data corresponding to each laser sensor; converting the local sensor coordinate profile data corresponding to each laser sensor from the local sensor coordinate system to the measurement device global coordinate system based on the measurement device global coordinate system conversion relationship obtained by the multi-laser sensor calibration method, and obtaining measurement device global coordinate system profile data corresponding to each laser sensor; and splicing the measurement device global coordinate system profile data of each laser sensor to obtain the corresponding complex curved surface profile.

[0005] In an embodiment of the present application, the multi-laser sensor calibration method comprises: a local coordinate system XY-axis calibration method, a local coordinate system Z-axis calibration method, a measurement device global coordinate system rotation calibration method, and a measurement device global coordinate system translation calibration method; wherein the local coordinate system XY-axis calibration method is used to obtain the local coordinate system XY-axis conversion relationship for converting the profile data of the complex curved surface to be measured collected by each laser sensor to the XY-axis data in the same local sensor coordinate system; the local coordinate system Z-axis calibration method is used to obtain the local coordinate system Z-axis conversion matrix for converting the profile data of the complex curved surface to be measured collected by each laser sensor to the Z-axis data in the local sensor coordinate system; the measurement device global coordinate system rotation calibration method is used to obtain the measurement device global coordinate system rotation conversion relationship for converting the measurement device global coordinate system profile data corresponding to each laser sensor to the rotation conversion in the measurement device global coordinate system; and the measurement device global coordinate system translation calibration method is used to obtain the measurement device global coordinate system translation conversion relationship for converting the measurement device global coordinate system profile data corresponding to each laser sensor to the translation conversion in the measurement device global coordinate system.

[0006] In an embodiment of the present application, the local coordinate system XY axis calibration method is used to obtain the local coordinate system XY axis transformation relationship based on the profile data of the gauge block collected by each sensor during calibration; the local coordinate system Z axis calibration method is used to obtain the local coordinate system Z axis transformation matrix based on the profile data of the gauge with Z axis direction cross section gradient variation collected by each sensor during calibration; the measurement device global coordinate system rotation calibration method is used to obtain the measurement device global coordinate system rotation conversion relationship based on the profile data of the gauge block collected by a sensor at multiple Y axis positions during calibration; and the measurement device global coordinate system translation calibration method is used to obtain the measurement device global coordinate system translation conversion relationship based on the profile data of the gauge collected by a sensor at multiple rotation angle positions during calibration.

[0007] In an embodiment of the present application, the local coordinate system XY axis calibration method comprises: obtaining the profile XY axis data of the gauge block at different angles placed on the rotary table collected by each laser sensor; wherein the collection mode of the profile XY axis data of the gauge block at different angles comprises: collecting the XY axis data of the gauge block placed at the corresponding position in the corresponding sensor coordinate system by using at least two laser sensors arranged adjacently; linearly fitting the profile feature data of the corresponding gauge block according to each profile XY axis data, respectively; and calculating the local coordinate system XY axis transformation matrix of each laser sensor based on the fitted profile feature data.

[0008] In an embodiment of the present application, the local coordinate system Z axis calibration method comprises: obtaining the profile Z axis data of the gauge with Z axis direction cross section gradient variation placed on the rotary table collected by each laser sensor at the corresponding height; calculating the Z axis variation data of each laser sensor based on each profile Z axis data and the cross section profile data of the gauge with Z axis direction cross section gradient variation, so as to obtain the Z axis transformation matrix of each laser sensor.

[0009] In an embodiment of the present application, the measurement device global coordinate system rotation calibration method comprises: obtaining the corresponding profile data collected by a laser sensor when the rotary table is kept stationary and the gauge is moved to multiple Y axis positions along the Y axis direction by moving the first motion mechanism; and obtaining the rotation conversion matrix based on the included angle data between the connecting line of the same vertex of the gauge block and the Y axis obtained by linearly fitting the same vertex of the gauge block from each profile data.

[0010] In an embodiment of the present application, the measurement device global coordinate system translation calibration method comprises: acquiring profile data corresponding to a plurality of rotation angle positions of a gauge which does not have a Z-axis direction cross-section gradient variation, under the condition that the first motion mechanism remains stationary and the gauge is rotated by rotating the rotary table; and calculating a corresponding translation conversion matrix based on a center position of a profile fitted by a profile center of each profile data.

[0011] In an embodiment of the present application, the gauge comprises a plug gauge and a cube gauge.

[0012] To achieve the above object and other related objects, the present application provides a complex curved surface profile calculation system based on multi-laser sensor calibration, which is applied to a complex curved surface profile measurement device, the device comprising: a rotary table for rotating a complex curved surface to be measured about a Z-axis in a system coordinate system; a first motion mechanism for moving the rotary table fixed thereon along a Y-axis in the system coordinate system; at least three laser sensors covering a viewing angle range, with laser surfaces perpendicular to the Z-axis, for acquiring profile data of the complex curved surface to be measured; and a second motion mechanism for moving a laser acquisition system fixed thereon along the Z-axis, the system comprising: a profile data acquisition module for acquiring profile data of the complex curved surface to be measured acquired by each laser sensor respectively; a local coordinate system conversion module connected to the profile data acquisition module, for converting the profile data of the complex curved surface to be measured acquired by each laser sensor from a corresponding sensor coordinate system to a local sensor coordinate system based on a local sensor coordinate system conversion relationship of each laser sensor obtained through multi-laser sensor calibration, and obtaining local sensor coordinate profile data of each laser sensor; a measurement device global coordinate profile module connected to the local coordinate system conversion module, for converting the local sensor coordinate profile data of each laser sensor from the local sensor coordinate system to a measurement device global coordinate system based on a measurement device global coordinate system conversion relationship obtained through multi-laser sensor calibration, and obtaining measurement device global coordinate system profile data of each laser sensor; and a profile splicing module connected to the measurement device global coordinate profile module, for splicing the measurement device global coordinate system profile data of each laser sensor to obtain a corresponding complex curved surface profile.

[0013] To achieve the above object and other related objects, the present application provides a complex curved surface profile calculation terminal based on multi-laser sensor calibration, comprising: a memory for storing a computer program; and a processor for executing the complex curved surface profile calculation method based on multi-laser sensor calibration.

[0014] As described above, the present application is a complex curved surface profile calculation method, system and terminal based on multi-laser sensor calibration, which has the following beneficial effects: the present application obtains the profile data of the complex curved surface measured by each laser sensor; based on the local sensor coordinate system conversion relationship of each laser sensor obtained by the multi-laser sensor calibration method, the profile data is converted from the corresponding sensor coordinate system to the local sensor coordinate system; based on the measurement device global coordinate system conversion relationship obtained by the multi-laser sensor calibration method, the local sensor coordinate profile data is converted from the local sensor coordinate system to the measurement device global coordinate system, and the measurement device global coordinate system profile data of each laser sensor is spliced to obtain the corresponding complex curved surface profile. The present application realizes the calibration of the multi-laser sensor coordinate system and the global coordinate system, and realizes online real-time calibration, which ensures that the calibration can be quickly and accurately completed before each measurement. Based on the calibration method, the profile calculation is carried out, which greatly improves the accuracy of profile measurement. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A structure schematic diagram of a complex curved surface profile measurement device in an embodiment of the present application is shown.

[0016] Figure 2 A flow schematic diagram of a complex curved surface profile calculation method based on multi-laser sensor calibration in an embodiment of the present application is shown.

[0017] Figure 3 A standard gauge schematic diagram in an embodiment of the present application is shown.

[0018] Figure 4 A structure schematic diagram of a complex curved surface profile calculation system based on multi-laser sensor calibration in an embodiment of the present application is shown.

[0019] Figure 5 A structure schematic diagram of a complex curved surface profile calculation terminal based on multi-laser sensor calibration in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be described in detail below with specific reference to the drawings. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied by different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0021] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the above context clearly dictates otherwise. Spatially relative terms, such as "upper," "lower," "left," "right," "bottom," "top," "horizontal," "vertical," and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be further understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described is turned over in use, a relative physical property previously described as on the bottom surface can now be

[0022] Throughout this specification, when it is said that a certain part is "connected" to another part, it includes not only the case of "direct connection" but also the case of "indirect connection" in which other elements are interposed therebetween. In addition, when it is said that a certain part "includes" a certain constituent element, other constituent elements are not excluded unless specifically stated to the contrary, and it means that other constituent elements can be further included.

[0023] The terms first, second, third, etc. that are mentioned herein are used to explain various parts, components, regions, layers and / or sections, but are not limited thereto. These terms are used only to distinguish a certain part, component, region, layer or section from other parts, components, regions, layers or sections. Thus, the first part, component, region, layer or section described below can be referred to as the second part, component, region, layer or section within the scope of the present application.

[0024] Further, as used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and / or "including," when used herein, specify the presence of stated features, operations, elements, components, items, and / or objects, but do not preclude the presence or addition of one or more other features, operations, elements, components, items, and / or objects. As used herein, the term "or" and "and / or" is construed to be inclusive, or to mean "either" or "any combination of the items." Thus, "A, B, or C" or "A, B, and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B, and C." This definition also applies to other common terms such as "at least one of," "one, but not both," and "one, or the other, but not both."

[0025] The application provides a complex curved surface profile calculation method based on multi-laser sensor calibration.

[0026] The application will be described in detail below with reference to the accompanying drawings, and the skilled in the art of the application can easily implement the application according to the embodiments of the application. The application can be embodied in various forms, and is not limited to the embodiments described herein.

[0027] As shown in Figure 1 The application is applied to a complex curved surface profile measurement device, and the device comprises: a rotary table 11 for driving a to-be-measured complex curved surface 10 to rotate around a Z axis in a system coordinate system; wherein a horizontal reference surface of the to-be-measured complex curved surface 10 is perpendicular to the Z axis; a first movement mechanism 14 for driving the rotary table 11 fixed thereon to move along a Y axis in the system coordinate system; preferably, a moving track extending along the Y axis is arranged on the first movement mechanism, and the rotary table is arranged on the moving track and driven by the first movement mechanism to move along the Y axis; at least three laser sensors covering a visual angle range, with laser surfaces perpendicular to the Z axis, for collecting profile data of the to-be-measured complex curved surface; and a second movement mechanism 12 for driving a laser collecting system 13 fixed thereon to move along the Z axis; preferably, a moving track extending along the Z axis is arranged on the second movement mechanism, and the laser collecting system 13 is arranged on the moving track and driven by the second movement mechanism to move along the Z axis.

[0028] As shown in Figure 2 A flowchart of a complex curved surface profile calculation method based on multi-laser sensor calibration in an embodiment of the application is shown.

[0029] The method comprises:

[0030] Step S1: acquiring profile data of a to-be-measured complex curved surface collected by each laser sensor respectively.

[0031] Step S2: based on the local sensor coordinate system conversion relationship of each laser sensor obtained by the multi-laser sensor calibration method, the profile data of the complex surface to be measured collected by each laser sensor is converted from the corresponding sensor coordinate system to the local sensor coordinate system, and the local sensor coordinate profile data corresponding to each laser sensor is obtained;

[0032] Step S3: based on the measurement device global coordinate system conversion relationship obtained by the multi-laser sensor calibration method, the local sensor coordinate profile data corresponding to each laser sensor is converted from the local sensor coordinate system to the measurement device global coordinate system, and the measurement device global coordinate system profile data corresponding to each laser sensor is obtained.

[0033] Step S4: the measurement device global coordinate system profile data of each laser sensor is spliced to obtain the corresponding complex surface profile.

[0034] In an embodiment, the multi-laser sensor calibration method comprises:

[0035] a local coordinate system XY axis calibration method, a local coordinate system Z axis calibration method, a measurement device global coordinate system rotation calibration method, and a measurement device global coordinate system translation calibration method;

[0036] The local coordinate system XY axis calibration method is used to obtain the local coordinate system XY axis transformation relationship for XY axis data conversion of the profile data of the complex surface to be measured collected by each laser sensor in the local sensor coordinate system.

[0037] The local coordinate system Z axis calibration method is used to obtain the local coordinate system Z axis transformation matrix for Z axis data conversion of the profile data of the complex surface to be measured collected by each laser sensor in the local sensor coordinate system.

[0038] The measurement device global coordinate system rotation calibration method is used to obtain the measurement device global coordinate system rotation conversion relationship for rotation conversion of the measurement device global coordinate system profile data corresponding to each laser sensor in the measurement device global coordinate system.

[0039] The measurement device global coordinate system translation calibration method is used to obtain the measurement device global coordinate system translation conversion relationship for translation conversion of the measurement device global coordinate system profile data corresponding to each laser sensor in the measurement device global coordinate system.

[0040] In an embodiment, the local coordinate system XY axis calibration method is used to obtain the local coordinate system XY axis transformation relationship based on the profile data of the gauge block collected by each sensor for calibration; wherein the gauge block is a regular cuboid shape, and preferably the gauge block comprises a plug gauge and a cube gauge block.

[0041] The local coordinate system Z-axis calibration method is used to obtain the local coordinate system Z-axis transformation matrix based on the profile data of the gauge with Z-axis direction cross section gradient variation acquired by each sensor for calibration.

[0042] The measurement device global coordinate system rotation calibration method is used to obtain the measurement device global coordinate system rotation conversion relationship based on the profile data of the gauge at multiple Y-axis positions acquired by a sensor for calibration.

[0043] The measurement device global coordinate system translation calibration method is used to obtain the measurement device global coordinate system translation conversion relationship based on the profile data of the gauge without Z-axis direction cross section gradient variation at multiple rotation angle positions acquired by a sensor for calibration.

[0044] In a specific embodiment, the local coordinate system XY-axis calibration method comprises:

[0045] Obtaining profile XY-axis data of the gauge at different angles placed on the rotary table acquired by each laser sensor; wherein the acquisition method of the profile XY-axis data of the gauge at different angles includes: using at least two adjacent laser sensors to acquire the XY-axis data of the gauge placed at the same position in the corresponding sensor coordinate system;

[0046] Linearly fitting the profile feature data of the corresponding gauge according to each profile XY-axis data, and calculating the local coordinate system XY-axis transformation matrix of each laser sensor based on the fitted profile feature data and the actual profile feature data of the gauge.

[0047] Specifically, the gauge placed on the rotary table can be placed at different positions, wherein the positions ensure that at least two adjacent laser sensors can capture the gauge at the same position to ensure that all profiles of the gauge are captured. That is, the profile XY-axis data of the gauge at different angles placed on the rotary table acquired by each laser sensor constitutes a complete profile. Linearly fitting the profile feature data of the corresponding gauge according to each profile XY-axis data, obtaining the long side and the short side obtained by fitting to obtain the slope of the long side and the intersection of the long side and the short side, and calculating the rotation and translation matrix between the sensor coordinate systems of each laser sensor to convert the sensor coordinate system to the same local sensor plane coordinate system.

[0048] Preferably, the rotation and translation matrix between the sensor coordinate system of each laser sensor is obtained by using the Rodrigues formula.

[0049] In an embodiment, the local coordinate system Z-axis calibration method comprises:

[0050] Obtaining profile Z-axis data of the gauge with Z-axis direction cross-section gradient variation placed on the rotary table collected by each laser sensor at a corresponding height;

[0051] Based on the profile Z-axis data and the cross-section profile data of the gauge with Z-axis direction cross-section gradient variation, a Z-axis transformation matrix corresponding to each laser sensor is obtained.

[0052] Specifically, cross-section point cloud data of the gauge with Z-axis direction cross-section gradient variation placed on the rotary table collected by each laser sensor at a corresponding height is obtained, and based on the cross-section profile data of the gauge with Z-axis direction cross-section gradient variation, the Euclidean distance of the repeated point cloud collected by each sensor projected onto the X-Y plane at each cross-section is calculated, and the height difference between the two cross-sections with the smallest distance is calculated to obtain the Z-axis transformation matrix corresponding to each laser sensor.

[0053] In the above description, the cross-section profile data of the gauge placed at a corresponding position is collected by each laser sensor in a corresponding sensor coordinate system; alternatively, the gauge placed on the rotary table can be placed at different positions, wherein the positions ensure that at least two adjacent laser sensors can capture the gauge at the same position. Taking the collection of two adjacent laser sensors as an example, the Euclidean distance of the repeated point cloud of the two sensors projected onto the X-Y plane at each cross-section is calculated, and the height difference between the two cross-sections with the smallest distance is calculated to eliminate the error caused by the different heights of different sensors.

[0054] In an embodiment, the measurement device global coordinate system rotation calibration method comprises:

[0055] Obtaining profile data corresponding to the case that the gauge is moved to a plurality of Y-axis positions along the Y-axis direction by moving the first motion mechanism while the rotary table remains stationary, by a laser sensor;

[0056] Based on the angle change data of the line connecting the same vertex of the gauge obtained by linear fitting of each profile data and the Y-axis, a measurement device global coordinate system rotation conversion matrix is obtained.

[0057] Specifically, the laser sensor collects profile data corresponding to the case that the rotary table is kept stationary and the gauge is moved to a plurality of Y-axis positions along the Y-axis direction by moving the first motion mechanism; each profile data is fitted to obtain position information of the same vertex of the gauge, and each position information is fitted to obtain a connecting line and an included angle data with the Y-axis, and the steps are repeated to calculate a rotation matrix for calibrating the profile data to be parallel to the Y-axis.

[0058] In an embodiment, the measurement device global coordinate system translation calibration method comprises:

[0059] The laser sensor collects profile data corresponding to the case that the first motion mechanism is kept stationary and the gauge is rotated to a plurality of rotation angle positions by rotating the rotary table; it should be noted that the laser sensor is the same sensor as the laser sensor used in the measurement device global coordinate system rotation calibration.

[0060] Based on the center position of the profile fitted by the same gauge profile center linearly fitted from each profile data, a corresponding translation conversion matrix is calculated and obtained.

[0061] Specifically, the laser sensor collects circular arc point cloud data corresponding to the case that the first motion mechanism is kept stationary and the gauge is rotated to a plurality of rotation angle positions by rotating the rotary table; the preprocessing of the point cloud data includes adaptive point cloud removal, guided filtering, etc., and then the circle center is fitted by the least square method, a circle is fitted based on the obtained each circle center, the center coordinates of the circle are obtained, the coordinates are the translation vector, the sensor height is changed by the Z-axis motion mechanism, the calibration is repeated for several times, and the function of the change of the translation vector at different heights is fitted to obtain the corresponding translation conversion matrix.

[0062] Preferably, a three-dimensional translation rotation matrix is obtained based on the rotation conversion matrix obtained by the measurement device global coordinate system rotation calibration method and the translation conversion matrix obtained by the measurement device global coordinate system translation calibration method.

[0063] In order to better describe the complex curved surface profile calculation method of the multi-laser sensor calibration, specific embodiments are provided.

[0064] Embodiment 1: A multi-laser sensor calibration method.

[0065] The detection device applied in the embodiment comprises: four profile measurement sensors I-IV distributed at certain angles in the same plane to simultaneously collect cross-section profile data; a precision rotary table and Y-axis and Z-axis motion mechanisms to generate three-axis relative motion between the measured curved surface and the multiple laser sensors. The measured curved surface can rotate with the rotary table. The rotary table moves on the Y-axis motion mechanism. The four profile measurement sensors are installed on the Z-axis motion mechanism and can move in the Z direction.

[0066] As shown in Figure 3 , a series of standard gauges (plug gauges 11, standard cones 12, standard cylinders 13) are used to realize calibration and unification of the motion mechanism and the rotary table coordinate system to the multiple profile measurement sensor coordinate system, compensation of geometric errors of the motion mechanism and the rotary table during movement, and compensation of height differences of different sensors.

[0067] The embodiment takes measurement of a blade, a three-dimensional free curved surface, as an example, and the specific measurement steps are as follows:

[0068] Step (1) The calibration method is realized by means of the standard gauge plug gauges 11, and the measurement device global coordinate system and the local sensor coordinate system are converted to the same local sensor plane coordinate system.

[0069] After fixing the plug gauges, the long and short edges of the plug gauges 11 are measured at different angles, and the data of the profile measurement sensors I-IV are collected. Linear fitting is performed on the data of the sensors, the rotation and translation between the coordinate systems of the sensors III, IV, I and II are calculated using the slope of the long edge and the intersection of the long and short edges obtained by fitting, and the rotation and translation matrices of the sensors III, IV, I and II are obtained using the Rodrigues formula.

[0070] Step (2) The height calibration of different sensors in the Z-axis direction is realized by means of the standard gauge with gradient variation of the standard cone 12. The error caused by the different heights of different sensors is eliminated.

[0071] The Z-axis motion mechanism is moved in steps of 0.01 mm, and 100 cross-section point cloud data are obtained by scanning the standard cone 12. The repeated point cloud data is taken out, separated according to the cross-section and the sensor, and taken as an example of calibrating the sensors III and IV. The Euclidean distance of the repeated point cloud of the sensors III and IV projected onto the X-Y plane at each cross-section is calculated, and the height difference between the two cross-sections with the smallest distance is calculated.

[0072] Step (3) The calibration of the motion direction is realized by means of the standard gauge plug gauges 11. The rotation coefficient of the local sensor coordinate system and the actual motion direction of the first motion mechanism is obtained.

[0073] Move the feeler gauge on the Y-axis motion mechanism, get the direction vector of the feeler gauge moving in the sensor III coordinate system, and calculate the included angle between the direction vector and the y-axis of the sensor III coordinate system to obtain the rotation matrix.

[0074] Step (4) The calibration of the rotation axis of the turntable is realized by means of the standard cylindrical gauge 13. The translation coefficient of the local sensor coordinate system and the actual motion direction of the first motion mechanism is obtained, and finally the sensor coordinate system is unified with the global coordinate system.

[0075] Fix the Y-axis motion mechanism, and the sensors I-IV scan the standard cylindrical gauge to obtain point cloud data of the circular arc. The point cloud data is preprocessed, including adaptive removal of repeated point clouds, directional filtering, etc. Then the center of the circle is fitted by the least square method. The turntable is continuously rotated clockwise by 15 degrees, and the center of the circle is repeatedly obtained. The center coordinates of the circle at different positions are fitted into a circle to obtain the center coordinates of the circle. The coordinates are the translation vector. The rotation and translation matrix at this height is calculated by the rotation matrix of step (3) and the translation vector. The height of the sensor is changed by the Z-axis motion mechanism, and the above steps of step (4) are repeated to fit the function of the change of the translation vector at different heights to obtain a three-dimensional rotation and translation matrix.

[0076] The embodiment realizes the calibration method of unifying the coordinate system of the multiple laser sensors and the global coordinate system. In the fitting of the rotation axis, the repeated point clouds are adaptively removed, and the filtering processing is performed to improve the accuracy of the fitted center of the circle and improve the calibration accuracy. In the conversion from the local coordinate system to the global coordinate system, a three-dimensional rotation and translation matrix is obtained to eliminate the error caused by the non-perpendicular axis. Online real-time calibration is realized to ensure that the calibration can be quickly and accurately completed before each measurement to achieve the measurement accuracy.

[0077] Similar to the principle of the above embodiment, the application provides a complex curved surface profile calculation system based on multiple laser sensor calibration.

[0078] The specific embodiments are provided in combination with the accompanying drawings as follows:

[0079] As Figure 4 A structure schematic diagram of a complex curved surface profile calculation system based on multiple laser sensor calibration in the embodiment of the application is shown.

[0080] The application is applied to a complex curved surface profile measurement device, and the device comprises: a turntable for driving a complex curved surface to be measured to rotate around the Z-axis in the system coordinate system; a first motion mechanism for driving the turntable fixed thereon to move along the Y-axis direction in the system coordinate system; at least three laser sensors covering a visual angle range, with laser surfaces perpendicular to the Z-axis, for collecting profile data of the complex curved surface to be measured; and a second motion mechanism for driving the laser collection system fixed thereon to move along the Z-axis direction, and the system comprises:

[0081] a profile data acquisition module 41, configured to acquire profile data of the complex surface to be measured collected by each laser sensor respectively;

[0082] a local coordinate system conversion module 42, connected to the profile data acquisition module 41, configured to convert the profile data of the complex surface to be measured collected by each laser sensor from a corresponding sensor coordinate system to a local sensor coordinate system based on a local sensor coordinate system conversion relationship of each laser sensor obtained through multi-laser sensor calibration, and obtain local sensor coordinate profile data of each laser sensor;

[0083] a measurement device global coordinate profile module 43, connected to the local coordinate system conversion module 42, configured to convert the local sensor coordinate profile data of each laser sensor from the local sensor coordinate system to a measurement device global coordinate system based on a measurement device global coordinate system conversion relationship obtained through multi-laser sensor calibration, and obtain measurement device global coordinate system profile data of each laser sensor;

[0084] a profile splicing module 44, connected to the measurement device global coordinate profile module 43, configured to splice the measurement device global coordinate system profile data of each laser sensor to obtain a corresponding complex surface profile.

[0085] Since the implementation principle of the complex surface profile calculation system based on multi-laser sensor calibration has been described in the foregoing embodiments, it will not be repeated here.

[0086] In an embodiment, the multi-laser sensor calibration method includes a local coordinate system XY axis calibration method, a local coordinate system Z axis calibration method, a measurement device global coordinate system rotation calibration method, and a measurement device global coordinate system translation calibration method. The local coordinate system XY axis calibration method is used to obtain a local coordinate system XY axis transformation relationship for XY axis data conversion of the profile data of the complex surface to be measured collected by each laser sensor in a local sensor coordinate system. The local coordinate system Z axis calibration method is used to obtain a local coordinate system Z axis transformation matrix for Z axis data conversion of the profile data of the complex surface to be measured collected by each laser sensor in a local sensor coordinate system. The measurement device global coordinate system rotation calibration method is used to obtain a measurement device global coordinate system rotation conversion relationship for rotation conversion of the measurement device global coordinate system profile data of each laser sensor in a measurement device global coordinate system. The measurement device global coordinate system translation calibration method is used to obtain a measurement device global coordinate system translation conversion relationship for translation conversion of the measurement device global coordinate system profile data of each laser sensor in a measurement device global coordinate system.

[0087] In an embodiment, the local coordinate system XY axis calibration method is used to obtain the local coordinate system XY axis transformation relationship based on the profile data of the gauge block collected by each sensor for calibration; the local coordinate system Z axis calibration method is used to obtain the local coordinate system Z axis transformation matrix based on the profile data of the gauge with Z axis direction cross section gradient variation collected by each sensor for calibration; the measurement device global coordinate system rotation calibration method is used to obtain the measurement device global coordinate system rotation conversion relationship based on the profile data of the gauge block collected by a sensor at multiple Y axis positions for calibration; and the measurement device global coordinate system translation calibration method is used to obtain the measurement device global coordinate system translation conversion relationship based on the profile data of the gauge without Z axis direction cross section gradient variation collected by a sensor at multiple rotation angle positions for calibration.

[0088] In an embodiment, the local coordinate system XY axis calibration method comprises: obtaining profile XY axis data of the gauge block at different angles placed on the rotary table collected by each laser sensor; wherein the collection mode of the profile XY axis data of the gauge block at different angles comprises: using at least two adjacent laser sensors to collect XY axis data of the gauge block placed at the corresponding position in the corresponding sensor coordinate system; linearly fitting the profile feature data of the corresponding gauge block according to each profile XY axis data, respectively, and calculating the local coordinate system XY axis transformation matrix of each laser sensor based on the fitted profile feature data.

[0089] In an embodiment, the local coordinate system Z axis calibration method comprises: obtaining profile Z axis data of the gauge with Z axis direction cross section gradient variation placed on the rotary table collected by each laser sensor at the corresponding height; and calculating the Z axis transformation matrix of each laser sensor based on each profile Z axis data and the cross section profile data of the gauge with Z axis direction cross section gradient variation.

[0090] In an embodiment, the measurement device global coordinate system rotation calibration method comprises: obtaining the corresponding profile data collected by a laser sensor when the rotary table remains stationary and the gauge is moved to multiple Y axis positions along the Y axis direction by moving the first motion mechanism; and calculating the rotation conversion matrix based on the included angle data of the connecting line of the same vertex of the gauge block and the Y axis obtained by linearly fitting the profile data.

[0091] In one embodiment, the global coordinate system translation calibration method of the measuring device includes: acquiring contour data collected by a laser sensor when the first motion mechanism remains stationary and the measuring tool, which does not have a cross-sectional gradient change in the Z-axis direction, is rotated to multiple rotation angle positions by rotating the turntable; and calculating the corresponding translation transformation matrix based on the center position of the contour fitted by the center of the same measuring tool contour obtained by linear fitting of each contour data.

[0092] In one embodiment, the gauge block includes a feeler gauge and a cube gauge block.

[0093] like Figure 5 This is a schematic diagram of the structure of the complex surface contour calculation terminal 50 based on multi-laser sensor calibration in an embodiment of the present invention.

[0094] The complex surface contour calculation terminal 50 based on multi-laser sensor calibration includes: a memory 51 and a processor 52. The memory 51 is used to store computer programs; the processor 52 runs the computer programs to implement, for example... Figure 1 The method for calculating complex surface contours based on multi-laser sensor calibration is described above.

[0095] Optionally, the number of memories 51 can be one or more, and the number of processors 52 can be one or more. Figure 5 Each example is taken as an instance.

[0096] Optionally, the processor 52 in the complex surface contour calculation terminal 50 based on multi-laser sensor calibration will perform calculations according to the following... Figure 1 The steps described involve loading one or more instructions corresponding to the process of an application into memory 51, and having the processor 52 run the application stored in the first memory 51, thereby achieving the following: Figure 1 The various functions in the complex surface contour calculation method based on multi-laser sensor calibration.

[0097] Optionally, the memory 51 can include, but is not limited to, a high-speed random access memory, a nonvolatile memory, for example, one or more disk storage devices, a flash memory device, or other nonvolatile solid-state storage device; the processor 52 can include, but is not limited to, a central processing unit (CPU), a network processor (NP), etc.; and can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component.

[0098] Optionally, the processor 52 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; and can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component.

[0099] The application also provides a computer readable storage medium, which stores a computer program, and the computer program realizes the complex curved surface profile calculation method based on multi-laser sensor calibration as shown in the method when running. Figure 1 The computer readable storage medium can include, but is not limited to, a floppy disk, an optical disk, a CD-ROM (compact disk-read only memory), a magneto-optical disk, a ROM (read only memory), a RAM (random access memory), an EPROM (erasable programmable read only memory), an EEPROM (electrically erasable programmable read only memory), a magnetic card or an optical card, a flash memory, or other types of media / machine readable media suitable for storing machine executable instructions. The computer readable storage medium can be a product not connected to a computer device, or a component connected to a computer device.

[0100] In summary, the complex curved surface profile calculation method, system and terminal based on multi-laser sensor calibration of the present application, the present application obtains the profile data of the complex curved surface to be measured collected by each laser sensor respectively; based on the local sensor coordinate system conversion relationship of each laser sensor obtained by the multi-laser sensor calibration method, each profile data is converted from the corresponding sensor coordinate system to the local sensor coordinate system, and then based on the measurement device global coordinate system conversion relationship obtained by the multi-laser sensor calibration method, the local sensor coordinate profile data is converted from the local sensor coordinate system to the measurement device global coordinate system, and the measurement device global coordinate system profile data of each laser sensor obtained is spliced to obtain the corresponding complex curved surface profile. The present application realizes the calibration of the multi-laser sensor coordinate system and the global coordinate system, realizes online real-time calibration, ensures that the calibration can be quickly and accurately completed before each measurement, and greatly improves the accuracy of profile measurement. Therefore, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.

[0101] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought of the present application should be covered by the claims of the present application.

Claims

1. A method for calculating a complex curved surface profile based on multi-laser sensor calibration, characterized in that, The application is applied to a complex curved surface profile measuring device, the device comprises: a rotary table for driving a complex curved surface to be measured to rotate around the Z axis in a system coordinate system; a first motion mechanism for driving the rotary table fixed thereon to move along the Y axis direction in the system coordinate system; at least three laser sensors covering a visual angle range, the laser surfaces of which are perpendicular to the Z axis, for collecting profile data of the complex curved surface to be measured; a second motion mechanism for driving the laser collecting system fixed thereon to move along the Z axis direction, and the method comprises: acquiring profile data of the complex curved surface to be measured collected by each laser sensor respectively; based on the local sensor coordinate system conversion relationship of each laser sensor obtained through a multi-laser sensor calibration method, converting the profile data of the complex curved surface to be measured collected by each laser sensor from the corresponding sensor coordinate system to a local sensor coordinate system respectively, and obtaining local sensor coordinate profile data corresponding to each laser sensor; based on the global coordinate system conversion relationship of the measuring device obtained through the multi-laser sensor calibration method, converting the local sensor coordinate profile data corresponding to each laser sensor from the local sensor coordinate system to the global coordinate system of the measuring device, and obtaining global coordinate system profile data of the measuring device corresponding to each laser sensor; stitching the global coordinate system profile data of the measuring device of each laser sensor to obtain the corresponding complex curved surface profile.

2. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 1, wherein, The multi-laser sensor calibration method comprises: a local coordinate system XY axis calibration method, a local coordinate system Z axis calibration method, a global coordinate system rotation calibration method of the measuring device, and a global coordinate system translation calibration method of the measuring device; the local coordinate system XY axis calibration method is used to obtain the local coordinate system XY axis conversion relationship, so as to convert the XY axis data of the profile data of the complex curved surface to be measured collected by each laser sensor in the local sensor coordinate system; the local coordinate system Z axis calibration method is used to obtain the local coordinate system Z axis conversion matrix, so as to convert the Z axis data of the profile data of the complex curved surface to be measured collected by each laser sensor in the local sensor coordinate system; the global coordinate system rotation calibration method of the measuring device is used to obtain the global coordinate system rotation conversion relationship of the measuring device, so as to convert the global coordinate system profile data of the measuring device corresponding to each laser sensor in the global coordinate system of the measuring device; the global coordinate system translation calibration method of the measuring device is used to obtain the global coordinate system translation conversion relationship of the measuring device, so as to convert the global coordinate system profile data of the measuring device corresponding to each laser sensor in the global coordinate system of the measuring device.

3. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 2, wherein, the local coordinate system XY axis calibration method is used to obtain the local coordinate system XY axis conversion relationship based on the profile data of the gauge collected by each sensor for calibration; the local coordinate system Z axis calibration method is used to obtain the local coordinate system Z axis conversion matrix based on the profile data of the gauge with a cross-section gradient change in the Z axis direction collected by each sensor for calibration; The measurement device global coordinate system rotation calibration method is used for obtaining the measurement device global coordinate system rotation conversion relationship based on profile data of a gauge block collected by a sensor at multiple Y-axis positions for calibration; The measurement device global coordinate system translation calibration method is used for obtaining the measurement device global coordinate system translation conversion relationship based on profile data of a gauge collected by a sensor at multiple rotation angle positions for calibration.

4. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 3, wherein, The local coordinate system XY-axis calibration method comprises: Obtaining profile XY-axis data of the gauge block at different angles on the rotary table collected by the laser sensors; wherein the profile XY-axis data of the gauge block at different angles is collected by using at least two adjacent laser sensors to collect XY-axis data of the gauge block placed at the same position in the corresponding sensor coordinate system; Linearly fitting profile feature data of the corresponding gauge block according to each profile XY-axis data, and calculating a local coordinate system XY-axis transformation matrix of each laser sensor based on the fitted profile feature data.

5. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 3, wherein, The local coordinate system Z-axis calibration method comprises: Obtaining profile Z-axis data of the gauge with Z-axis direction cross-section gradient change collected by each laser sensor at a corresponding height; Calculating a Z-axis transformation matrix of each laser sensor based on the profile Z-axis data and the cross-section profile data of the gauge with Z-axis direction cross-section gradient change. The measurement device global coordinate system rotation calibration method comprises:

6. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 3, wherein, Obtaining profile data corresponding to the case where the rotary table remains stationary and the gauge moves to multiple Y-axis positions along the Y-axis direction by moving the first motion mechanism; Calculating a rotation conversion matrix based on the included angle data of the connecting line of the same vertex of the gauge block and the Y-axis obtained by linearly fitting the profile data. The measurement device global coordinate system translation calibration method comprises:

7. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 3, wherein, Obtaining profile data corresponding to the case where the first motion mechanism remains stationary and the gauge with no Z-axis direction cross-section gradient change rotates to multiple rotation angle positions by rotating the rotary table; Calculating a corresponding translation conversion matrix based on the center position of the profile fitted by the profile center of the same gauge obtained by linearly fitting each profile data. The gauge block comprises a plug gauge and a cube gauge.

8. The complex curved surface profile calculation method based on multi-laser sensor calibration according to claim 3, wherein, The device is applied to a complex curved surface profile measurement device, and comprises a rotary table for rotating a complex curved surface to be measured about the Z-axis in a system coordinate system, a first motion mechanism for moving the rotary table fixed thereon along the Y-axis in the system coordinate system, at least three laser sensors covering a visual angle range and having laser surfaces perpendicular to the Z-axis for collecting profile data of the complex curved surface to be measured, and a second motion mechanism for moving a laser collecting system fixed thereon along the Z-axis, wherein the system comprises:

9. A complex curved surface profile calculation system based on multi-laser sensor calibration, characterized by, A profile data acquisition module for acquiring profile data of the complex curved surface to be measured collected by each laser sensor respectively. ​ A local coordinate system conversion module is connected to the profile data acquisition module, and is configured to convert the profile data of the complex curved surface collected by each laser sensor from a corresponding sensor coordinate system to a local sensor coordinate system based on a local sensor coordinate system conversion relationship corresponding to each laser sensor obtained through multi-laser sensor calibration, and obtain local sensor coordinate profile data corresponding to each laser sensor. A measurement device global coordinate profile module is connected to the local coordinate system conversion module, and is configured to convert the local sensor coordinate profile data corresponding to each laser sensor from the local sensor coordinate system to a measurement device global coordinate system based on a measurement device global coordinate system conversion relationship obtained through multi-laser sensor calibration, and obtain measurement device global coordinate system profile data corresponding to each laser sensor. A profile splicing module is connected to the measurement device global coordinate profile module, and is configured to splice the measurement device global coordinate system profile data of each laser sensor to obtain corresponding complex curved surface profile data.

10. A complex curved surface profile calculation terminal based on multi-laser sensor calibration, characterized by, The computer program comprises: a memory for storing a computer program; a processor for executing the multi-laser sensor calibration-based complex curved surface profile calculation method according to any one of claims 1 to 8.

Images