CN111623723B

CN111623723B - Detection device and detection method

Info

Publication number: CN111623723B
Application number: CN202010369780.2A
Authority: CN
Inventors: 陈鲁; 李青格乐; 江博闻; 吕肃; 张嵩
Original assignee: Shenzhen Zhongke Feice Technology Co Ltd
Current assignee: Shenzhen Zhongke Feice Technology Co Ltd
Priority date: 2020-05-06
Filing date: 2020-05-06
Publication date: 2022-09-27
Anticipated expiration: 2040-05-06
Also published as: CN111623723A

Abstract

The invention provides a detection device and a detection method. The detection device includes: the first detection module is used for collecting a first light beam reflected by a first sub-area on the surface of the object to be detected to form first signal light; the second detection module is used for collecting a second light beam reflected by a second sub-area on the surface of the object to be detected to form second signal light, and the central axis of the first light beam and the central axis of the second light beam form an included angle; and the processing module is used for acquiring the three-dimensional coordinates of the first sub-area on the surface of the object to be measured according to the collected first signal light and acquiring the three-dimensional coordinates of the second sub-area on the surface of the object to be measured according to the collected second signal light. The invention solves the technical problem that the appearance of diversified objects to be detected cannot be completely detected.

Description

Detection device and detection method

Technical Field

The invention relates to the technical field of detection, in particular to detection equipment and a detection method.

Background

With the continuous development of intelligent equipment, the appearance of the object to be detected is diversified, and the existing detection equipment cannot completely detect the appearance of the diversified object to be detected.

Disclosure of Invention

The invention aims to provide detection equipment and a detection method, which are used for solving the technical problem that the appearance of a large-radian object to be detected cannot be completely detected and improving the system stability.

The present invention provides a detection apparatus comprising: the first detection module is used for collecting a first light beam reflected by a first sub-area on the surface of the object to be detected to form first signal light; the second detection module is used for collecting a second light beam reflected by a second sub-area on the surface of the object to be detected to form second signal light, and the central axis of the first light beam and the central axis of the second light beam form an included angle; and the processing module is used for acquiring the three-dimensional coordinates of the first sub-area on the surface of the object to be measured according to the collected first signal light and acquiring the three-dimensional coordinates of the second sub-area on the surface of the object to be measured according to the collected second signal light.

Wherein the first detection module has a first angular range of extent, the first angular range of extent being an angular range of a direction of propagation of the first light beam; the second detection module has a second angular range of range, the second angular range of range being an angular range of a direction of propagation of the second light beam, the first angular range of range partially overlapping the second angular range of range.

Wherein the central ray of the first light beam and the central ray of the second light beam converge along the propagation direction.

Wherein the detection apparatus further comprises: the third detection module is used for collecting a third light beam reflected by a third sub-area on the surface of the object to be detected to form a third signal light, the central axis of the third light beam and the central axis of the first light beam form an included angle, and the central axis of the third light beam and the central axis of the second light beam form an included angle; the processing module is further used for acquiring a three-dimensional coordinate of a third sub-area on the surface of the object to be measured according to the collected third signal light.

Wherein the third detection module has a third triangulation range, the third triangulation range being an angular range of the direction of propagation of the third light beam; the first detection module has a first angular range of measurement and the second detection module has a second angular range of measurement; the third angular range partially overlaps the first angular range, or the third angular range partially overlaps the second angular range.

The central axis of the first light beam, the central axis of the second light beam and the central axis of the third light beam are positioned on the same plane.

The first light beam is used for intersecting a first line segment on the surface of the object to be measured, and the first line segment is perpendicular to a plane where the central axis of the first light beam and the central axis of the second light beam are located.

Wherein, check out test set still includes plummer and drive arrangement, the plummer is used for bearing the weight of the determinand, drive arrangement with the plummer, first detection module or the second is surveyed the module and is connected, drive arrangement includes: one or a combination of the translation driving device and the rotation driving device;

the rotation driving device is used for driving the bearing table to rotate around a rotating shaft, and the rotating shaft is parallel to the arrangement direction of the bearing table and the first detection module or the second detection module;

the translation driving device is used for enabling the bearing table to translate relative to the first detection module or the second detection module along a direction parallel to a translation plane, and the translation plane is perpendicular to the arrangement direction of the bearing table and the first detection module.

The first detection module comprises a first light-emitting device and a second light-emitting device, wherein the first light-emitting device is used for emitting first detection light to the object to be detected, and the first detection light is reflected by the object to be detected to form a first light beam; the first detection device is used for collecting the first light beam reflected by the first sub-area on the surface of the object to be detected to form the first signal light;

the second detection module comprises: the second light-emitting device is used for emitting second detection light to the object to be detected, and the second detection light is reflected by the object to be detected to form a second light beam; and the second detection device is used for collecting the second light beam reflected by the second sub-area on the surface of the object to be detected to form the second signal light.

The first detection light is used for forming a first light spot on the surface of an object to be detected, the second detection light beam is used for forming a second light spot on the surface of the object to be detected, and one or both of the first light spot and the second light spot are linear light spots; the extending direction of the line light spot is perpendicular to the central axis of the first light beam and perpendicular to the central axis of the second light beam.

Wherein one or both of the first detection module and the second detection module comprises a detector and a mirror;

the detector and the reflector are arranged at intervals, the reflector is used for reflecting the first signal light, and the detector is used for detecting the first signal light reflected by the reflector.

Wherein the mirror is configured to rotate relative to the detector to increase the first angular range.

The first detection module is spectral confocal equipment, white light interference equipment, confocal microscope equipment or differential phase shift interference equipment;

the second detection module is a spectrum confocal device, a white light interference device, a confocal microscope device or a differential phase shift interference device.

The invention provides a detection method for detecting an object to be detected, wherein a region to be detected of the object to be detected comprises a first sub-region and a second sub-region, and the detection step of the region to be detected comprises the following steps:

providing the above-mentioned detection device;

emitting light to the area to be measured of the object to be measured, wherein the light is reflected by the first sub-area to form a first light beam, and the light is reflected by the second sub-area to form a second light beam;

collecting the first light beam reflected by the first sub-area of the object to be detected through the first detection module to form first signal light,

collecting the second light beam reflected by the second sub-area of the object to be detected through the second detection module to form second signal light, wherein the central axis of the first light beam and the central axis of the second light beam form an included angle;

and acquiring the three-dimensional coordinate of the first sub-area of the surface of the object to be measured according to the first signal light and acquiring the three-dimensional coordinate of the second sub-area of the surface of the object to be measured according to the second signal light through the processing module.

The object to be tested comprises a middle part and an edge part surrounding the middle part, the edge part comprises a first arc surface facing the bending of the detection equipment, the middle part comprises a plane and a second arc surface facing the bending of the detection equipment, the second arc surface is arranged between the first arc surface and the plane, the first arc surface, the second arc surface and the plane are the same surface, the first sub-area comprises at least part of the first arc surface, and the second sub-area comprises at least part of the second arc surface and at least part of the plane.

Under the condition that the detection equipment further comprises a bearing table and a driving device, the number of the first sub-regions is multiple, and the number of the second sub-regions is multiple; the driving device comprises a translation driving device;

the detection method further comprises the following steps: enabling the object to be detected and the first detection module to relatively translate through a translation driving device, enabling the first light beam to scan the first sub-areas, and obtaining three-dimensional coordinates of the first sub-areas; and relatively translating the object to be detected and the second detection module through the translation driving device, so that the second light beam scans the plurality of second sub-areas, and the three-dimensional coordinates of the plurality of second sub-areas are obtained.

Under the condition that the detection equipment further comprises a bearing table and a driving device, the driving device comprises a rotary driving device;

the object to be detected comprises a plurality of areas to be detected, and the arrangement direction of the areas to be detected is perpendicular to the arrangement direction of the bearing table and the first detection module; the plurality of regions to be detected comprise a first region to be detected and a second region to be detected;

the detection method further comprises the following steps: respectively detecting the first regions to be detected through the steps of detecting the regions to be detected;

after the first region to be detected is detected, the object to be detected is rotated around the rotating shaft through the rotating driving device;

and after the object to be detected rotates around the rotating shaft, respectively detecting the second area to be detected through the detection step of the area to be detected.

Wherein the method further comprises: and performing three-dimensional reconstruction on the three-dimensional coordinates of the plurality of first sub-areas and the three-dimensional coordinates of the plurality of second sub-areas to obtain the surface topography of the area to be measured.

To sum up, among the technical scheme that this application provided, check out test set includes first detection module and second detection module, can acquire the three-dimensional coordinate of the first subregion in determinand surface and the three-dimensional coordinate of second subregion, and then acquires the surface morphology of determinand, and this has just increased detection range, and because the center pin of first light beam is the contained angle setting with the center pin of second light beam, even this makes the appearance of determinand diversified, the direction of the normal vector of the first subregion of determinand and second subregion is different, and the check out test set of this application still can detect out the diversified surface morphology of determinand. In addition, the plurality of detection modules are used for detecting the areas with different normal vectors, so that the movement of the object to be detected or the detection modules can be reduced, the stability of the system can be improved, the detection steps can be simplified, and the detection speed can be increased.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a detection apparatus provided in an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a first structure of a detection apparatus for detecting an object to be detected according to an embodiment of the present application.

Fig. 3 is a schematic view of optical path structures of a first detection module and a second detection module provided in the embodiment of the present application.

Fig. 4 is a schematic structural diagram of a first light beam and a second light beam provided in the present embodiment.

Fig. 5 is a schematic structural diagram of a second structure of the detection apparatus for detecting an object to be detected according to an embodiment of the present application.

Fig. 6 is a schematic structural diagram of a third structure for detecting an object to be detected by the detection apparatus according to the embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, fig. 1 is a schematic structural diagram of a detection apparatus according to the present invention. Fig. 2 shows a schematic diagram of the detection device for detecting the object 10.

As shown in fig. 2, the present invention provides a detection apparatus, which is used for detecting a three-dimensional coordinate of the surface of an object to be measured 10, and performing three-dimensional reconstruction according to the three-dimensional coordinate to obtain the surface topography of the object to be measured 10. The object 10 may be a mobile phone case or screen, a tablet computer case, a multimedia player screen, an e-book reader screen, a notebook computer case, or a wearable device screen, etc.

The embodiment shown in fig. 1 is described by taking the mobile phone case as the test object 10.

The surface of the test object 10 includes a plurality of test areas. The plurality of regions to be measured at least include a first region to be measured and a second region to be measured, the morphology of the first region to be measured may be the same as or different from that of the second region to be measured, and the first region to be measured and the second region to be measured may also be arranged in axial symmetry with respect to the central axis of the object to be measured 10. The first region to be detected is described as follows. The first region to be measured includes a plurality of sub-regions. The plurality of sub-regions includes at least a first sub-region and a second sub-region.

The detection device includes: the first detection module 20 is configured to collect a first light beam 50 reflected by a first sub-area on the surface of the object 10 to be measured to form a first signal light; the second detection module 30 is configured to collect a second light beam 60 reflected by a second sub-area on the surface of the object to be detected 10 to form a second signal light, and a central axis of the first light beam 50 and a central axis of the second light beam 60 form an included angle; and the processing module 40 is configured to obtain a three-dimensional coordinate of a first sub-region on the surface of the object 10 to be measured according to the collected first signal light, and obtain a three-dimensional coordinate of a second sub-region on the surface of the object 10 to be measured according to the collected second signal light.

The first detection module 20 includes a first light emitting device and a first detection device, the first light emitting device is configured to emit first detection light to the object to be detected 10, and the first detection light is reflected by the object to be detected 10 to form the first light beam 50; the first detection device is used for collecting the first light beam 50 reflected by the first sub-area on the surface of the object to be measured 10 to form the first signal light;

the second detection module 30 includes a second light emitting device and a second detection device, the second light emitting device is configured to emit second detection light to the object to be detected 10, and the second detection light is reflected by the object to be detected 10 to form the second light beam 60; the second detecting device is used for collecting the second light beam 60 reflected by the second sub-area on the surface of the object to be measured 10 to form the second signal light.

The first detection light is used for forming a first light spot on the surface of the object to be detected 10, the second detection light beam is used for forming a second light spot on the surface of the object to be detected 10, and one or both of the first light spot and the second light spot are linear light spots; the line spot extends perpendicular to the central axis of the first light beam 50 and perpendicular to the central axis of the second light beam 60. In this application, the first detection light is mainly scanned on the first sub-area, and the second detection light is mainly scanned on the second sub-area.

The linear light spots comprise continuous linear light spots or dot matrix light spots arranged along a straight line.

In another embodiment, one or both of the first and second spots are spot spots; alternatively, one or both of the first and second light spots are surface light spots.

The first sub-area is an area covered by the first light spot, and the second sub-area is an area covered by the second light spot.

The first light beam 50 is used to intersect with a first line segment on the surface of the object 10, and the first line segment is perpendicular to the plane where the central axis of the first light beam 50 and the central axis of the second light beam 60 are located. That is to say, the first light spot formed on the surface of the object 10 by the first detection light may be a line light spot, that is, the first detection light may be scanned on the object 10 to form a first line segment, and the first line segment-shaped line light spot is reflected by the object 10 to form the first light beam 50.

In one embodiment, the first light emitting device is different from the second light emitting device. In another embodiment, the first light emitting device and the second light emitting device may be the same light emitting device, that is, the first detection module 20 and the second detection module 30 share the same light emitting device.

The first light beam 50 is a portion of the first detection light reflected by the object to be measured 10 and collected by the first detection device to form the first signal light, and the second light beam 60 is a portion of the second detection light reflected by the object to be measured 10 and collected by the second detection device to form the second signal light.

It can be understood that after the processing module 40 obtains the three-dimensional coordinates of the first sub-region and the three-dimensional coordinates of the second sub-region, three-dimensional reconstruction may be performed according to the three-dimensional coordinates, and the surface topography of the first sub-region and the second sub-region of the region to be measured may be obtained, so that the surface topography of the object to be measured 10 may be obtained.

In one embodiment, the first detection module 20 may be one of a spectral confocal device, a white light interference device, a confocal microscope device, or a differential phase-shift interference device.

The second detection module 30 is a spectrum confocal device, a white light interference device, a confocal microscope device or a differential phase shift interference device.

Specifically, in this embodiment, the first detection module 20 is a spectrum confocal device; the second detection module 30 is a spectrum confocal apparatus.

The spectrum confocal device can detect the height of the region to be detected without moving the lens, so that the stability of the system can be further improved, the detection steps can be simplified, and the detection speed can be increased.

The spectrum confocal equipment is used for emitting detection light with different wavelengths to the object to be detected 10, and the detection light with different wavelengths is converged to different positions along an optical axis; the detection module collects light beams reflected by the object to be detected to form signal light and obtains light intensity of the signal light with different wavelengths. And the processing system acquires the three-dimensional coordinates of the area to be detected according to the light intensity of the signal light with different wavelengths. Therefore, the detection device can obtain the three-dimensional coordinates of the first sub-area and the three-dimensional coordinates of the second sub-area on the surface of the object 10 to be detected, and further obtain the surface topography of the object, so as to increase the detection range, and because the central axis of the first light beam 50 and the central axis of the second light beam 60 are arranged at an included angle, even if the topography of the object 10 is diversified, the topography of the first sub-area and the second sub-area of the object 10 to be detected is different, for example, the first sub-area is curved, or the second sub-area is curved, or both the first sub-area and the second sub-area are curved, the detection device of the present application can still detect the diversified surface topography of the object 10 to be detected. In addition, the plurality of detection modules detect regions with different normal vectors, so that the movement of the object to be measured 10 or the detection modules can be reduced, the stability of the system can be improved, the detection steps can be simplified, and the detection speed can be increased.

The first detection module 20 has a first angular range, which is the angular range of the propagation direction of the first light beam 50; second detection module 30 has a second angular range of degrees that is the angular range of the direction of propagation of second light beam 60, the first angular range partially overlapping the second angular range. Specifically, since the first angular range and the second angular range are partially overlapped, the light ray of the first light beam 50 and the light ray propagation direction of the second light beam 60 are at least partially crossed, so that the detection device has a larger continuous angular range, and a continuous curved surface of a normal vector in the angular range of the detection device can be detected.

The central ray 503 of the first light beam 50 converges with the central ray 603 of the second light beam 60 in the propagation direction.

When the normal direction of a point on the surface of the object 10 to be detected falls within the angle range of the propagation direction of the first light beam 50, the first detection module 20 can detect the point; when the normal direction of a point on the surface of the object 10 falls within the angle range of the propagation direction of the second light beam 60, the second detection module 30 can detect the point. The central ray 503 of the first light beam 50 converges with the central ray 603 of the second light beam 60 in the propagation direction, the detection device is advantageous for detecting the topography of the large arc concave surface.

Specifically, in this embodiment, the first sub-area is a concave arc area, or the second sub-area is at least partially a concave arc area, so that the central light ray 503 of the first light beam 50 and the central light ray 603 of the second light beam 60 converge along the propagation direction of the light rays. The central ray 503 of the first light beam 50 converges with the central ray 603 of the second light beam 60 in the propagation direction. The detection equipment can detect the shape of the large-radian concave surface.

In one embodiment, one or both of the first detection module 20 and the second detection module 30 includes a detector and a mirror.

Specifically, the first detection module 20 includes a detector 20a and a reflector 20b, the detector 20a and the reflector 20b are disposed at an interval, the reflector 20b is configured to reflect the first signal light, and the detector 20a is configured to detect the first signal light reflected by the reflector 20 b.

That is, the detector 20a is a first detecting means.

The mirror 20b changes the propagation direction of the first light beam, thereby enabling a change of the first angular range of the first detection module 20.

Specifically, in an embodiment, an included angle is formed between a central axis of the first light beam 50 reflected by the object to be measured 10 and a central axis of the second light beam 60, but after the reflection mirror 20b reflects the first light beam 50, a propagation direction of the first light beam 50 can be changed, so that the central axis of the light beam collected by the first detection device is parallel to the central axis of the second light beam 50, and thus the first detection device and the second detection device can be arranged in parallel, which is beneficial to reducing an installation space of the detection device, and further, the object to be measured is not easy to interfere with the detection device.

Mirror 20b is configured to rotate relative to detector 20a to increase the first angular range.

Specifically, in the present embodiment, the rotation axis of the reflecting mirror 20b is perpendicular to the plane where the central axis of the first detection light and the central axis of the second detection light before reaching the reflecting mirror 20b are located.

That is, if the arc-shaped bending degree of the first sub-area is larger, the included angle between the central axis of the first light beam 50 and the central axis of the second light beam is larger, the reflector 20b can rotate relative to the detector 20a, and the range of the first angular range of the first detection module 20 can be further expanded by rotating the reflector 20 b. Because the first light beam 50 is converged on the surface of the object to be measured 10, and the reflector 20b is arranged in the light path between the detection device and the object to be measured 10, the irradiation area of the first light beam 50 on the reflector 20b is small, and the volume of the reflector 20b is small, so that the first angular range is enlarged by adjusting the rotation angle of the reflector 20b, the adjustment flexibility can be improved, and the interference with the object to be measured 10 is not easy. The detection device in this embodiment can detect the object 10 to be detected with a large arc angle. The mirror 20b has a small volume, and its rotation does not easily interfere with the object 10. Changing the beam propagation direction by the mirror 20b can reduce the installation space of the inclined first detection module 20, reducing the volume of the first detection module 20.

The detection device further comprises a bearing table and a driving device, the bearing table is used for bearing the object to be detected 10, the driving device is connected with the bearing table, the first detection module 20 or the second detection module 30, and the driving device comprises: one or a combination of the translation driving device and the rotation driving device;

the rotation driving device is used for driving the plummer to rotate around a rotation shaft 1021, and the rotation shaft 1021 is parallel to the arrangement direction of the plummer and the first detection module 20 or the second detection module 30;

the translation driving device is used for translating the bearing platform relative to the first detection module 20 or the second detection module 30 along a direction parallel to a translation plane, and the translation plane is perpendicular to the arrangement direction of the bearing platform and the first detection module 20.

In one embodiment, the translation drive is configured to translate the stage in a first direction and a second direction parallel to the translation plane. Specifically, the first direction is perpendicular to the second direction.

For convenience of description, the present application defines two mutually perpendicular x-axis, y-axis and z-axis, the x-axis being parallel to the first direction and the y-axis being parallel to the second direction.

In one embodiment, the central axis of the second light beam 60 is perpendicular to the first direction and perpendicular to the second direction, i.e. the central axis of the second light beam 60 is parallel to the z-axis. In another embodiment, the central axes of the two beams 60 have an acute angle with the z-axis.

It is understood that the rotation axis 1021 may be the z-axis in fig. 2 or a direction parallel to the z-axis. In the present application, the rotation axis 1021 is the central axis of the object 10. The translation plane may be the xoy plane in fig. 2. In this embodiment, the driving device may drive the object 10 to rotate around the z-axis or the central axis of the object 10. Because the rotation axis 1021 is parallel to the arrangement direction of the loading platform and the first detection module 20 or the second detection module, the loading platform drives the object to be detected to rotate, and the interference with the first detection device and the second detection device is not easy.

In one embodiment, the rotation angle of the carrier table about the x-axis is fixed and the rotation angle of the carrier table about the y-axis is fixed. The bearing table does not rotate around the x axis, so that collision interference of the object to be detected 10 with the first detection module 20 and the second detection module 30 can be reduced; the bearing table does not rotate around the y axis, so that the collision interference of the object to be detected 10 with the first detection module 20 and the second detection module 30 can be reduced.

In another embodiment, the driving device may also drive the object 10 to be tested to turn around the x-axis, or drive the object 10 to be tested to turn around the y-axis.

The driving device may also drive the test object 10 to translate along the x-axis, or drive the test object 10 to translate along the y-axis, or in any direction within the xoy plane. After the detection device acquires the three-dimensional coordinates of a position and reconstructs the shape of the position, the driving device may drive the object to be detected to rotate around the rotation shaft 1021, or drive the object to be detected 10 to translate in the xoy plane, so as to acquire the coordinates of all positions of the object to be detected 10 and reconstruct the whole shape of the object to be detected 10. Therefore, the detection equipment can scan each part of the object 10 to be detected, and can detect the three-dimensional coordinates of each region of the object 10 to be detected, so as to obtain the appearance profile of the object 10 to be detected. In this application, the object to be measured 10 may be a 3D curved screen of a mobile phone or a 3D housing of the mobile phone, and the material of the curved screen or the housing may be glass.

The utility model provides a detection equipment has increased detection range's basis, can also detect the topography of the bending region on determinand 10 surface, the determinand 10 of this application can not carry out the low-angle upset around x axle or y axle or determinand 10 carries out the low-angle upset around x axle or y axle and can acquire the topography of the bending region on determinand 10 surface promptly, need not to carry out the high angle upset around x axle or around y axle to determinand 10, this error that has just solved the detection of determinand 10 bending region and need carry out the high angle upset and lead to is great, and the longer technical problem of check out time. Therefore, when the object to be measured 10 is not turned around the x axis or the y axis or the object to be measured 10 is turned around the x axis or the y axis by a small angle, the time for turning can be saved, the measuring time is short, and the measuring speed is high. And errors due to large angle flipping can be reduced. In this application, a small angle is understood to be 0-45 ° and a large angle is understood to be 45 ° or more. It can be understood that the detection of the first sub-region and the detection of the second sub-region by the detection device may be performed simultaneously, that is, the detection device may detect the topography of the first sub-region and the topography of the second sub-region simultaneously in one detection process, thereby saving detection time. Of course, the detection device may also perform the detection of the first sub-region first and then perform the detection of the second sub-region, or perform the detection of the second sub-region first and then perform the detection of the first sub-region. The curvature of the first sub-region may be arcuate. The curvature of the second sub-area may be an arc curvature. The detection apparatus further comprises: a third detection module 80 (as shown in fig. 6), where the third detection module 80 is configured to collect a third light beam reflected by a third sub-area on the surface of the object 10 to be detected to form a third signal light, a central axis of the third light beam forms an included angle with a central axis of the first light beam 50, and a central axis of the third light beam forms an included angle with a central axis of the second light beam 60; the processing module 40 is further configured to acquire a three-dimensional coordinate of a third sub-area on the surface of the object 10 according to the collected third signal light. In a specific embodiment, the first detection module 20 and the third detection module 80 are respectively disposed at two sides of the second detection module 30, the first sub-area and the third sub-area are respectively disposed at two sides of the second sub-area, and the first sub-area is connected or not connected to the second sub-area; the second sub-region may or may not be connected to the third sub-region.

The third light beam is a portion of the light beam reflected by the object to be measured 10, which is collected by the third detection module 80 to form the third signal light.

The detection device comprises a bottom plate 70, and the first detection module 20, the second detection module 30, the processing module 40 and the third detection module 80 are all mounted on the bottom plate 70.

Therefore, the detection device of the present application can also obtain the three-dimensional coordinates of the third sub-area on the surface of the object 10 to be detected, and further obtain the surface topography of the object to be detected, which further increases the detection range, and because the central axis of the third light beam and the central axis of the first light beam 50 are arranged at an included angle, and the central axis of the third light beam and the central axis of the second light beam 60 are arranged at an included angle, even if the topography of the object 10 is diversified, the first sub-area, the second sub-area and the third sub-area of the object 10 have different topographies, for example, the first sub-area is curved, the second sub-area is curved, or the third sub-area is curved, or at least two of the first sub-area, the second sub-area and the third sub-area are curved, the detection device of the present application can still detect the surface topography of the object 10 to be detected. The utility model provides a check out test set is ascending on the basis that has increased detection range, can also detect the appearance of the more radian scope on determinand 10 surface, the determinand 10 of this application can not carry out the small-angle upset around x axle or y axle or determinand 10 can acquire the appearance of the arc region on determinand 10 surface around x axle or y axle promptly, need not to carry out the large-angle upset around x axle or around y axle to determinand 10, this error that has just solved the detection of determinand 10 bending region and need carry out the large-angle upset and lead to is great, and the longer technical problem of check out time. Therefore, when the object to be measured 10 is not turned around the x axis or the y axis or is turned around the x axis or the y axis by a small angle, the time for turning can be saved, the measurement time is short, and the measurement speed is high; and errors due to large angle flipping can be reduced. It will be appreciated that the detection device may detect one of the first, second and third sub-regions at a time, or two, or three simultaneously. The curvature of the first sub-region may be arcuate. The curvature of the second sub-area may be an arc curvature. The curvature of the third sub-region may be arcuate.

The third detection module 80 has a third angular range of travel, which is the angular range of the direction of propagation of the third beam; the first detection module 20 has a first angular range of measurement, and the second detection module 30 has a second angular range of measurement; the third angular range partially overlaps the first angular range or the third angular range partially overlaps the second angular range.

Specifically, since the third angular measurement range partially overlaps the first angular measurement range, or the third angular measurement range partially overlaps the second angular measurement range, the light of the third light beam 50 at least partially intersects the light propagation direction of the second light beam 60, or the light of the third light beam 50 at least partially intersects the light propagation direction of the first light beam 50, so that the detection device has a larger continuous angular measurement range, and a continuous curved surface of a normal vector within the angular measurement range of the detection device can be detected.

In one embodiment, the central axis of the first beam 50, the central axis of the second beam 60, and the central axis of the third beam are in the same plane. Specifically, the plane on which the central axis of the first light beam 50, the central axis of the second light beam 60, and the central axis of the third light beam are located may be a detection plane. Therefore, the detection equipment can detect the crossed position of the object to be detected 10 and the detection surface at one time, the detection range is large, and all the appearances of the object to be detected can be detected only by translating the object to be detected 10 and rotating around the rotating shaft 1021 or overturning around the x axis or the y axis at a small angle subsequently. This avoids errors caused by large angular turns of the test object 10.

In this application, the detection device does not contact the object to be detected 10, that is, the first detection module 20 and the second detection module 30, the third detection module 80 and the object to be detected 10 do not contact each other, which also avoids the risk of scratching the object to be detected 10 by the contact detection device. Moreover, because the object to be detected 10 of the present application does not turn around the x axis or around the y axis, or the turning angle is small, the first detection module 20 and the second detection module 30 are not easy to contact with the object to be detected 10, and this can also reduce the risk of scratching the object to be detected 10 by the detection equipment.

Three specific embodiments are described below.

In the first embodiment, the detection apparatus includes a first detection module 20 and a second detection module 30.

As shown in fig. 2, the object to be measured 10 is located on the plane of xoy, the second detection module 30 is installed vertically, and the first detection module 20 is installed obliquely.

The object 10 to be tested comprises a middle part 102 and an edge part 101 surrounding the middle part 102, wherein the edge part 101 comprises a first arc surface 101a bending towards the detection equipment, the middle part 102 comprises a plane 102b and a second arc surface 102a bending towards the detection equipment, the second arc surface 102a is arranged between the first arc surface 101a and the plane 102b, and the first arc surface 101a, the second arc surface 102a and the plane 102b are the same surface. The detection device is configured to detect three-dimensional coordinates of each position point of the first arc surface 101a, the second arc surface 102a, and the plane 102b, and further reconstruct a surface topography of the object 10. The first region to be measured includes a first arc surface 101a, a second arc surface 102a, and a partial plane 102 b. It is understood that the first sub-area comprises at least part of the first arc 101a and the second sub-area comprises at least part of the second arc 102a and at least part of the plane 102 b.

Thus, when the first detection module 20 is installed obliquely, an included angle is formed between the central light of the first detection light and the z-axis, and the first detection light can reach the first cambered surface 101a, so that the three-dimensional coordinates of the first cambered surface 101a can be obtained, and the shape of the first cambered surface 101a can be obtained. The second detection module 30 is vertically installed, the central light of the second detection light is parallel or substantially parallel to the z-axis, and the second detection light can reach the second arc surface 102a, so that the three-dimensional coordinate of the second arc surface 102a can be obtained, and the shape of the second arc surface 102a can be obtained.

Referring to fig. 3, the first light beam 50 has a first included angle range a, and the second light beam 60 has a second included angle range B. Specifically, the first light beam 50 includes a first inner boundary light ray 501 close to the second detection module 30, a first outer boundary light ray 502 far away from the second detection module 30, and a first central light ray 503 located between the first inner boundary light ray 501 and the first outer boundary light ray 502, an included angle between the first inner boundary light ray 501 and the first outer boundary light ray 502 forms a first included angle range a, the second light ray 60 includes a second outer boundary light ray 602 close to the first detection module 20, a second inner boundary light ray 601 far away from the first detection module 20, and a second central light ray 603 located between the second inner boundary light ray 601 and the second outer boundary light ray 602, an included angle between the second inner boundary light ray 601 and the second outer boundary light ray 602 forms a second included angle range B, the first inner boundary light ray 501 reaches an end of the first detection module 20 close to the second detection module 30, the first outer boundary light ray 502 reaches an end of the first detection module 20 far away from the second detection module 30, the second inner boundary light ray 601 reaches an end of the second detection module 30 close to the first detection module 20, and the second outer boundary light ray 602 reaches an end of the second detection module 30 far from the first detection module 20. It is understood that the first light beam 50 is from the first detecting light reflected by the first arc 101a, and the second light beam 60 is from the second detecting light reflected by the second arc 102a or the plane 102 b.

Therefore, the detecting apparatus of this embodiment can obtain the feature of the first arc surface 101a, the feature of the second arc surface 102a, and the feature of the plane 102b of the object 10. After the detection device detects the first region to be detected, the second detection region is detected to complete the detection of all regions to be detected on the surface of the object 10 to be detected.

Referring to fig. 4, in an embodiment, the first detecting module 20 is installed obliquely, the angle between the first central ray 503 of the first light beam 50 and the x-axis in the horizontal direction is 20 °, and the angle between the first central ray 503 of the first light beam 50 and the z-axis is 70 °. The second detection module 30 is vertically installed, an included angle between a second central ray of the second light beam 60 and the x axis in the horizontal direction is 90 °, the second central ray of the second light beam 60 is perpendicular to the plane 102b of the middle portion 102 of the object to be measured 10, the second central ray of the second light beam 60 is parallel to the z axis, and the object to be measured 10 is placed on the xoy plane 102 b. The position and direction of the object to be measured 10 and the detection device in the present application are based on those in fig. 2. The first included angle range a of the first light beam 50 is 50 degrees, the included angle between the first inner boundary light beam 501 and the first central light beam 503 is 25 degrees, and the included angle between the first outer boundary light beam 502 and the first central light beam 503 is 25 degrees, so that the included angle between the first inner boundary light beam 501 and the x axis (horizontal direction) is 45 degrees, and the included angle between the first outer boundary light beam 502 and the x axis (horizontal direction) is 5 degrees. The second included angle range B of the second light ray 60 is 90 degrees, the included angle between the second inner boundary light ray 601 and the second central light ray 603 is 45 degrees, and the included angle between the second outer boundary light ray 602 and the second central light ray 603 is 45 degrees, so that the included angle between the second inner boundary light ray 601 and the z-axis (vertical direction) is 45 degrees, and the included angle between the second outer boundary light ray 602 and the z-axis (vertical direction) is 45 degrees. Therefore, when the first inner boundary light ray 501 and the second outer boundary light ray 602 are coincident, the angle between the first outer boundary light ray 502 and the second central light ray 603 can reach 95 degrees. The angle range that the light of the detection device can detect can reach 95 degrees on the arc surfaces (the first arc surface 101a and the second arc surface 102a) and 45 degrees on the plane 102 b. Therefore, the detection equipment can realize the shape detection of the object to be detected 10 in a large angle.

It will be appreciated that if there are two edge portions 101. Two edge portions 101 are connected to both sides of the middle portion 102, respectively. The object 10 is symmetrical about the central axis 1021. In the detecting process, after the first detecting module 20 detects the feature profile of the first arc surface 101a of one edge portion 101, and the second detecting module 30 detects the features of one second arc surface 102a of the middle portion 102 and the portion plane 102b connected to the second arc surface 102a, the driving device may drive the object 10 to rotate around the central axis 1021, the first detecting module 20 may detect the feature profile of the first arc surface 101a of another edge portion 101, and the second detecting module 30 may detect the features of another second arc surface 102a and the portion plane 102b connected to the second arc surface 102 a. Then, the driving device can drive the object 10 to move (translate) along the x-axis or the y-axis, and the second detection module 30 can complete the detection of the topography of the remaining plane 102b of the object 10. That is, after the detection device detects the first region to be detected, the detection device detects the second region to be detected, so as to complete the detection of all regions to be detected on the surface of the object 10 to be detected.

Therefore, even if the number of the edge portions 101 is two, the object 10 to be tested only needs to be rotated along the central shaft 1021, and the object 10 to be tested does not need to be turned around the x axis or the y axis by a large angle, so that the technical problems that the error is large and the detection time is long due to the large-angle turning of the object 10 to be tested are solved.

In the second embodiment, the detection apparatus includes a first detection module 20 and a second detection module 30.

As shown in fig. 5, the object to be measured 10 is located on a plane 102b where xoy is located, the second detection module 30 is installed obliquely, and the first detection module 20 is installed obliquely.

Unlike the first embodiment, the second detecting module 30 is installed obliquely, and the central ray of the second detecting light forms an angle with the z-axis, so that the first detecting light can reach the first arc surface 101a, and the second detecting light can reach the second arc surface 102a more easily. Therefore, even if the arc angle of the object 10 becomes larger, the detection equipment can still detect the appearance of the object 10.

In a third embodiment, the detection apparatus includes a first detection module 20, a second detection module 30, and a third detection module 80.

As shown in fig. 6, the object to be measured 10 is located on a plane 102b where xoy is located, the second detection module 30 is vertically installed, the first detection module 20 is obliquely installed, the third detection module 80 is obliquely installed, and the inclination direction of the third detection module 80 is different from the inclination direction of the first detection module 20. Optionally, the tilt direction of the third detection module 80 is symmetrical to the tilt direction of the first detection module 20 with respect to the second detection module 30.

Different from the first embodiment, the region to be measured includes a first region to be measured and a second region to be measured. The detection device is augmented with a third detection module 80. The number of the edge portions 101 is two, the two edge portions 101 are connected to two sides of the middle portion 102, and the first detection module 20 and the second detection module 30 are used together to obtain the feature of the first region to be detected. The second detection module 30 and the third detection module 80 are used together to obtain the topography of the second region under test. The first detecting module 20 is configured to obtain a shape of the first arc surface 101a of the first region to be detected, and the third detecting module 80 is configured to obtain a shape of the first arc surface 101a of the second region to be detected. The second detection module 30 is used for acquiring the topography of the second arc surface 102a and the plane 102 b. In this embodiment, the two first cambered surfaces 101a can be detected without rotating the object to be measured 10 around the z axis, and in this embodiment, the shape of the second cambered surface 102a connected to each first cambered surface 101a and the shape of the plane 102b connected between the two second cambered surfaces 102a can be detected only by driving the object to be measured 10 to move along the x axis and the y axis. The embodiment only needs to translate, does not need to rotate completely, and is high in measurement precision and short in measurement time. The shape of the object to be detected 10 can be obtained without overturning the object to be detected 10 around an x axis or a y axis, and the object to be detected 10 does not need to rotate around a z axis, so that the technical problems of large error and long detection time caused by overturning and rotating the object to be detected 10 are solved.

The invention also provides a detection method for detecting the region to be detected of the object to be detected 10, wherein the region to be detected of the object to be detected 10 comprises a first sub region and a second sub region. The object 10 to be tested comprises a middle part 102 and an edge part 101 surrounding the middle part 102, the edge part 101 comprises a first arc surface 101a bending towards the detection equipment, the middle part 102 comprises a plane 102b and a second arc surface 102a bending towards the detection equipment, the second arc surface 102a is arranged between the first arc surface 101a and the plane 102b, the first arc surface 101a, the second arc surface 102a and the plane 102b are the same surface, the first sub-area comprises at least part of the first arc surface 101a, and the second sub-area comprises at least part of the second arc surface 102a and at least part of the plane 102 b.

The detection step of the area to be detected comprises the following steps:

s1, providing the above detecting device.

S2, emitting a light beam to the region to be measured of the object 10, the light beam being reflected by the first sub-region to form a first light beam 50, and the light beam being reflected by the second sub-region to form a second light beam 60. It is understood that the light emitting device emits the first detecting light to the first sub-area, and emits the second detecting light to the second sub-area, the first sub-area reflects the first detecting light to form the first light beam 50, and the second sub-area reflects the second detecting light to form the second light beam 60.

S3, the first light beam 50 reflected by the first sub-area of the object 10 is collected by the first detection module 20 to form a first signal light.

S4, the second detection module 30 collects the second light beam 60 reflected by the second sub-area of the object 10 to be detected to form a second signal light, wherein the central axis of the first light beam 50 forms an included angle with the central axis of the second light beam 60.

S5, the processing module 40 obtains the three-dimensional coordinates of the first sub-region on the surface of the object 10 according to the first signal light, and obtains the three-dimensional coordinates of the second sub-region on the surface of the object 10 according to the second signal light. The shape of the object to be measured 10 can be reconstructed through the three-dimensional coordinates.

Therefore, the detection method of the present application can obtain the three-dimensional coordinates of the first sub-area and the three-dimensional coordinates of the second sub-area on the surface of the object to be detected 10, and further obtain the surface topography of the object to be detected, which increases the detection range, and because the central axis of the first light beam 50 and the central axis of the second light beam 60 form an included angle, even if the topography of the object to be detected 10 is diversified, the topography of the first sub-area and the second sub-area of the object to be detected 10 is different, for example, the first sub-area is curved, or the second sub-area is curved, or both the first sub-area and the second sub-area are curved, the detection device of the present application can still detect the diversified surface topography of the object to be detected 10. The detection method can also detect the shape of the bending area on the surface of the object to be detected 10 on the basis of increasing the detection range, namely, the object to be detected 10 can not turn around the x axis or the y axis or the object to be detected 10 can turn around the x axis or the y axis at a small angle to obtain the shape of the bending area on the surface of the object to be detected 10, and the object to be detected 10 does not need to turn around the x axis or the y axis at a large angle, so that the technical problems that the error caused by the fact that the large-angle turning is needed to be carried out in the detection of the bending area of the object to be detected 10 is large and the detection time is long are solved. Therefore, when the object to be measured 10 is not turned around the x axis or the y axis or the object to be measured 10 is turned around the x axis or the y axis by a small angle, the time for turning can be saved, the measuring time is short, and the measuring speed is high. And errors due to large angle flipping can be reduced.

When the first light spot is a line light spot or a plane light spot, the first sub-area is a line or a plane, the first sub-area consists of a plurality of points, and the three-dimensional coordinates of the first sub-area comprise three-dimensional coordinates of the plurality of points; when the second light spot is a line light spot or a plane light spot, the second sub-area is a line or a plane, the second sub-area is composed of a plurality of points, and the three-dimensional coordinates of the second sub-area comprise three-dimensional coordinates of the plurality of points.

In a specific embodiment, the number of the first sub-regions is multiple, and the number of the second sub-regions is multiple; under the condition that the detection device further comprises a bearing table and a driving device, the driving device comprises a translation driving device.

The detection method further comprises the following steps: the object to be detected 10 and the first detection module are relatively translated through the translation driving device, so that the first light beam 50 scans a plurality of first sub-areas, and three-dimensional coordinates of the plurality of first sub-areas are obtained; the object to be measured 10 and the second probe module are relatively translated by the translation driving device, so that the second light beam 60 scans the plurality of second sub-regions, and the three-dimensional coordinates of the plurality of second sub-regions are obtained.

Therefore, the detection method can acquire the three-dimensional coordinates of the plurality of first sub-areas and the three-dimensional coordinates of the plurality of second sub-areas, can reconstruct the plurality of three-dimensional coordinates, can acquire the surface topography of the plurality of first sub-areas and the surface topography of the plurality of second sub-areas, and further acquire all the topography of the area to be detected. In addition, the embodiment only needs to translate the object to be measured 10, so that the measurement precision is high and the measurement time is short. When the object 10 to be detected does not need to rotate or turn around the z axis, the technical problems that the error is large and the detection time is long due to the turning and the rotation of the object 10 to be detected are solved.

In a specific embodiment, the detection device further comprises a bearing table and a driving device, wherein the driving device comprises a rotary driving device; the object to be detected 10 comprises a plurality of areas to be detected, and the arrangement direction of the areas to be detected is perpendicular to the arrangement direction of the bearing platform and the first detection module 20; the plurality of regions to be measured include a first region to be measured and a second region to be measured. It is understood that the first region to be measured and the second region to be measured are axisymmetric about the rotation axis 1021.

The detection method further comprises the following steps: respectively detecting the first regions to be detected through the detection steps of the regions to be detected;

after detecting the first region to be detected, the object to be detected 10 is rotated around the rotation axis 1021 by the rotation driving device;

after the object 10 is rotated around the rotation axis 1021, the second regions to be detected are detected by the region-to-be-detected detecting step, respectively.

That is to say, after the detecting device of the present application obtains the shape of the first region to be detected, the detecting device can also obtain the shape of the second region to be detected by rotating the region to be detected, and further obtain the shape of the whole object to be detected 10.

The embodiment only needs to rotate the object to be measured 10, has high measurement precision and short measurement time, and solves the technical problems of large error and long detection time caused by the overturning of the object to be measured 10.

Of course, if the surface of the object 10 is large, the object 10 may be translated and the object 10 may also be rotated, so as to detect all surface features of the object 10.

The technical features of the above embodiments may be arbitrarily combined, and for the sake of brief description, all possible combinations of the technical features in the above embodiments are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A detection apparatus, comprising: the first detection module is used for collecting a first light beam reflected by a first sub-area on the surface of the object to be detected to form first signal light; the second detection module is used for collecting a second light beam reflected by a second sub-area on the surface of the object to be detected to form a second signal light, the central axis of the first light beam and the central axis of the second light beam form an included angle, the first detection module is provided with a first angular distance range, and the first angular distance range is the angular range of the propagation direction of the first light beam; the second detection module has a second angular range, the second angular range is an angular range of the propagation direction of the second light beam, the first angular range and the second angular range partially overlap, and the central ray of the first light beam and the central ray of the second light beam converge along the propagation direction; the processing module is used for acquiring the three-dimensional coordinates of a first sub-area on the surface of the object to be measured according to the collected first signal light, wherein the first sub-area is in a concave arc shape, and acquiring the three-dimensional coordinates of a second sub-area on the surface of the object to be measured according to the collected second signal light; the first detection module comprises a reflecting mirror used for reflecting the first signal light, and the reflecting mirror changes the propagation direction of the first light beam so as to change the first angular range of the first detection module and reduce the installation space for inclining the first detection module.

2. The detection apparatus according to claim 1, characterized in that the detection apparatus further comprises: the third detection module is used for collecting a third light beam reflected by a third sub-area on the surface of the object to be detected to form a third signal light, the central axis of the third light beam and the central axis of the first light beam form an included angle, and the central axis of the third light beam and the central axis of the second light beam form an included angle; the processing module is further used for acquiring a three-dimensional coordinate of a third sub-area on the surface of the object to be measured according to the collected third signal light.

3. The detection apparatus of claim 2, wherein the third detection module has a third angular range of travel, the third angular range of travel being an angular range of a direction of propagation of the third beam of light; the first detection module has a first angular range of measurement and the second detection module has a second angular range of measurement; the third angular range partially overlaps the first angular range, or the third angular range partially overlaps the second angular range.

4. The apparatus of claim 2, wherein the central axis of the first light beam, the central axis of the second light beam, and the central axis of the third light beam are located in a same plane.

5. The apparatus according to claim 1, wherein the first light beam is configured to intersect a first line segment on the surface of the object, and the first line segment is perpendicular to a plane in which the first light beam central axis and the second light beam central axis are located.

6. The detecting apparatus according to claim 1, further comprising a carrying stage and a driving device, wherein the carrying stage is used for carrying the object to be detected, the driving device is connected to the carrying stage, the first detecting module or the second detecting module, and the driving device comprises: one or a combination of the translation driving device and the rotation driving device;

7. The detection apparatus according to claim 1, wherein the first detection module includes a first light emitting device for emitting a first detection light to the object to be detected, and the first detection light is reflected by the object to be detected to form the first light beam; the first detection device is used for collecting the first light beam reflected by the first sub-area on the surface of the object to be detected to form the first signal light;

8. The detection apparatus according to claim 7, wherein the first detection light is used to form a first light spot on the surface of the object, the second detection light is used to form a second light spot on the surface of the object, and one or both of the first light spot and the second light spot are linear light spots; the extending direction of the line light spot is perpendicular to the central axis of the first light beam and perpendicular to the central axis of the second light beam.

9. The detection apparatus of claim 1, wherein one or both of the first detection module and the second detection module comprises a detector;

the detector is arranged at an interval with the reflector and is used for detecting the first signal light reflected by the reflector.

10. The apparatus of claim 9, wherein the mirror is configured to rotate relative to the detector to increase the first range of angular travel.

11. The detection apparatus according to claim 1, wherein the first detection module is a spectral confocal apparatus, a white light interference apparatus, a confocal microscope apparatus, or a differential phase shift interference apparatus;

12. A detection method is used for detecting an object to be detected, and is characterized in that a region to be detected of the object to be detected comprises a first sub-region and a second sub-region, and the detection step of the region to be detected comprises the following steps:

providing a detection device according to any one of claims 1 to 11;

13. The detecting method according to claim 12, wherein the object includes a middle portion and an edge portion surrounding the middle portion, the edge portion includes a first arc surface bending toward the detecting device, the middle portion includes a plane and a second arc surface bending toward the detecting device, the second arc surface is disposed between the first arc surface and the plane, the first arc surface, the second arc surface and the plane are the same surface, and the first sub-region includes at least part of the first arc surface, and the second sub-region includes at least part of the second arc surface and at least part of the plane.

14. The inspection method according to claim 12, wherein, in a case where the inspection apparatus further includes a stage and a driving device, the number of the first sub-regions is plural, and the number of the second sub-regions is plural; the driving device comprises a translation driving device;

15. The inspection method of claim 12, wherein the inspection apparatus further comprises a stage and a driving device, wherein the driving device comprises a rotary driving device;

after the first area to be detected is detected, the object to be detected is rotated around a rotating shaft through the rotating driving device;

16. The detection method according to claim 12, further comprising: and performing three-dimensional reconstruction on the three-dimensional coordinates of the plurality of first sub-areas and the three-dimensional coordinates of the plurality of second sub-areas to obtain the surface topography of the area to be measured.