CN111022883B

CN111022883B - Three-dimensional acquisition device capable of moving horizontally

Info

Publication number: CN111022883B
Application number: CN201911276042.7A
Authority: CN
Inventors: 左忠斌; 左达宇
Original assignee: Tianmu Aishi Beijing Technology Co Ltd
Current assignee: Tianmu Aishi Beijing Technology Co Ltd
Priority date: 2019-12-12
Filing date: 2019-12-12
Publication date: 2020-11-17
Anticipated expiration: 2039-12-12
Also published as: CN111022883A

Abstract

The invention provides a three-dimensional acquisition device capable of moving horizontally, which comprises a horizontal rail and an acquisition frame, wherein the acquisition frame is movably connected with the horizontal rail; the collecting frame comprises a stand column and a cross beam, and an image collecting device is arranged on the collecting frame; the image acquisition device is connected with the acquisition frame. The gantry support structure is firstly proposed, and three-dimensional information of a large object can be acquired. The gantry support can be detached and stretched, can adapt to objects with different sizes, and is convenient to disassemble and assemble.

Description

Three-dimensional acquisition device capable of moving horizontally

Technical Field

The invention relates to the technical field of object measurement, in particular to the technical field of 3D acquisition and length and other geometric dimension measurement of a target object by utilizing an image.

Background

At present, when 3D collection is carried out on a large object, laser scanning is generally used, but the laser scanning needs to specially calibrate the object, a plurality of calibration points are arranged on the object, and the calibration process is complicated. For example, when scanning the vehicle shell, the laser scanner is used to depend on the calibration accuracy, so that the whole calibration operation needs to last for one or two days, and the operation efficiency is extremely low. And are not suitable for outdoor operations subject to weather changes. Whereas conventional devices for 3D acquisition using image photographing are generally only suitable for photographing small objects. Corresponding exploration is also carried out in order to photograph large objects. For example, in the Digital Emily project of the university of California, a spherical bracket is adopted, and hundreds of cameras are fixed at different positions and different angles on the bracket, so that 3D acquisition and modeling of a human body are realized. However, even with such devices, only human-sized object 3D information can be acquired and can only be used indoors. Meanwhile, the use of a large number of cameras causes great difficulty in installation and debugging of the whole device, and the device is very expensive. Moreover, current acquisition devices are all designed for a single size and cannot work once the size of an object changes greatly.

Meanwhile, in order to take the synthetic speed and effect into consideration, the camera position is defined by using an empirical formula comprising a rotation angle, a target object size and an object distance, and the camera position is found in practical application: unless a precise angle measuring device is provided, the user is insensitive to the angle and is difficult to accurately determine the angle; the size of the target is difficult to accurately determine, and particularly, the target needs to be frequently replaced in certain application occasions, each measurement brings a large amount of extra workload, and professional equipment is needed to accurately measure irregular targets. The measured error causes the camera position setting error, thereby influencing the acquisition and synthesis speed and effect; accuracy and speed need to be further improved. .

Therefore, there is a great need in the art for a device capable of rapidly and accurately acquiring 3D information of large objects such as vehicles, which is convenient to use and low in cost, and particularly can be adapted to objects of different sizes.

Disclosure of Invention

In view of the above, the present invention has been developed to provide an acquisition apparatus that overcomes, or at least partially solves, the above-mentioned problems.

The invention provides a three-dimensional acquisition device capable of moving horizontally, which comprises a horizontal rail and an acquisition frame, wherein the acquisition frame is movably connected with the horizontal rail;

the collecting frame comprises a stand column and a cross beam, and an image collecting device is arranged on the collecting frame;

the image acquisition device is connected with the acquisition frame;

the position of the image acquisition device satisfies the following conditions:

μ＜0·482

wherein L is the linear distance between the optical centers of the two adjacent image acquisition positions; f is the focal length of the image acquisition device; d is the rectangular length of a photosensitive element (CCD) of the image acquisition device; m is the distance from the photosensitive element of the image acquisition device to the surface of the target object along the optical axis; μ is an empirical coefficient.

Optionally, the upright post comprises multiple sections, and is combined or telescopic.

Optionally, the cross beam comprises multiple sections, and is combined or telescopic.

Optionally, the image acquisition device is connected with the acquisition frame through a linear movement device.

Optionally, the image acquisition device is connected with the acquisition frame through a rotating device.

Optionally, one or more image capturing devices are disposed on each section of the column.

Optionally, one or more image capturing devices are disposed on each section of the beam.

Optionally, the image acquisition device is a camera or a video camera.

Optionally, two adjacent upright columns or cross beams are provided with locking devices.

Optionally, a horizontal moving device is arranged below the horizontal rail.

Invention and technical effects

1. The gantry support structure is firstly proposed, and three-dimensional information of a large object can be acquired.

2. The gantry support can be detached and stretched, can adapt to objects with different sizes, and is convenient to disassemble and assemble.

3. The camera can move and rotate on the gantry support, three-dimensional information of the object is acquired from different angles, and the gantry support can move horizontally on the track, so that excessive use of the camera is avoided.

4. Whole equipment can remove, makes things convenient for outdoor use.

5. By optimizing the camera position, the speed and effect of 3D synthesis are considered.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic perspective view of a three-dimensional acquisition device capable of moving horizontally according to an embodiment of the present invention;

the correspondence of the components to the reference numerals in the drawings is as follows:

the device comprises a horizontal rail 1, a collecting frame 2, a vertical column 3, a cross beam 4, a translation device 5, an image collecting device 6 and a rotating device 7.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Device structure

To solve the above technical problem, an embodiment of the present invention provides a three-dimensional acquisition device capable of moving horizontally. As shown in fig. 1, the method specifically includes: horizontal track 1 and collection frame 2.

The collecting frame is of a gantry type and comprises a stand column 3 and a cross beam 4. The upright post is formed by combining a plurality of sections, and the sections can be mutually disassembled and assembled and can stretch out and draw back. And a locking screw is arranged between two adjacent sections. After the positions of two adjacent upright columns reach the preset positions, the locking screws are fastened, so that the positions of the two upright columns are relatively fixed. The beam is also formed by combining a plurality of sections, and the sections can be mutually disassembled and assembled and can stretch out and draw back. And a locking screw is arranged between two adjacent sections. After the positions of two adjacent sections of cross beams reach the preset positions, fastening the locking screws to enable the positions of the two sections of cross beams to be relatively fixed. The locking screw can be in a screw thread fastening type or a bolt type.

Every section stand is provided with along vertical direction's translation device 5, for example adopts the linear lead screw slip table of following model:

the model is as follows: FSL80

Effective stroke of the sliding table is 100 mm-1500 mm

Using motor 60 step motor

Screw rod specification G1610

The positioning precision is 0.05mm

The image acquisition device 6 can be directly mounted on the sliding table, the lens is aligned with the target object and vertically moves along with the sliding table according to control, and therefore images of the target object are acquired from different positions. This can reduce the number of image capture devices required in the vertical direction, replacing multiple cameras with movement at different times.

Each section of upright post is provided with a rotating device 7, for example, an electric rotating table with the following types is adopted:

the product model is as follows: HT03RA100

Stroke: 360 degree

The transmission mode is as follows: worm gear

Resolution ratio: 0.01 degree

Maximum speed: 25 DEG/s

Positioning accuracy: 0.005 degree

The electric rotating platform is of a pitching type, namely the table top is arranged on the upright post 3 in parallel with the vertical direction. The image acquisition device 6 can be directly arranged on the electric rotating platform and rotates along with the rotating platform in a pitching way according to the control, so that the images of the target object can be acquired from different directions. This reduces the number of image acquisition devices 6 required in the vertical direction, replacing multiple cameras by rotation at different times.

For better effect, the image acquisition device 6 can be installed on an electric rotary table, the lens is aligned with the target object, the electric rotary table is installed on a screw rod sliding table, and the screw rod sliding table is installed on the upright post 3. Thereby realize that lead screw slip table drives the translation of electric rotary table along vertical direction, electric rotary table drives 6 every single move rotations of image acquisition device. Therefore, the image acquisition device can be adjusted in two dimensions in the vertical direction and the pitching direction, and the acquired object information is more comprehensive.

Similarly, each section of the cross beam 4 is provided with a translation device 5 along the horizontal direction of the cross beam, and the FSL80 linear type screw rod sliding table can also be adopted. The image acquisition device 6 can be directly arranged on the sliding table, the lens is aligned with the target object, and the lens moves horizontally along the direction of the beam 4 along with the sliding table according to control, so that the image of the target object is acquired from different positions. This can reduce the number of image capture device demands in the horizontal direction, replacing multiple cameras with movement at different times.

Each beam is provided with a rotation device 7, for example an HT03RA100 electric rotary table. The electric rotating platform has a left-right swinging direction, and the swinging direction is along a direction parallel to the cross beam 4, namely the table top is parallel to the vertical direction and is arranged on the cross beam 4 in parallel to the cross beam direction. The image acquisition device 6 can be directly installed on the electric rotating platform and rotates left and right along with the rotating platform according to control, so that images of the target object are acquired from different directions. This can reduce the number of image acquisition devices 6 required in the horizontal direction, replacing multiple cameras by rotation at different times.

For better effect, can install image acquisition device 6 on electronic revolving stage, electronic revolving stage installs on the lead screw slip table, and the lead screw slip table is installed on crossbeam 4. Thereby realize that lead screw slip table drives the translation of electric rotating table along 4 horizontal directions of crossbeam, and electric rotating table drives image acquisition device 6 and rotates about. Thus, the image acquisition device 6 can be two-dimensionally adjusted in the horizontal direction and the horizontal pitch direction, and the object information can be acquired more comprehensively.

It can be understood that a plurality of cameras can be arranged on each section of the upright column 3 or the cross beam 4, for example, on the basis of the scheme, a plurality of cameras can be arranged side by side through the assembly, and the assembly is fixed on the electric rotary table or the lead screw sliding table, so that the information acquisition efficiency can be improved.

The image acquisition device 6 may be an industrial camera, a general camera, a video camera, or the like. For example, Sony DSC-HX400, Haokangwei DS2CD3T56WD, and the like can be used.

And a light source mounting rod which is vertical to the upright column is arranged on each upright column 3, a group of light sources are respectively arranged at two ends of each light source mounting rod, and the irradiation range of each group of light sources is larger than the field range of the corresponding camera. Therefore, the two groups of light sources on each light source mounting rod respectively irradiate the target object from different angles in the approximate horizontal direction, and the light sources on the upper and lower adjacent light source mounting rods respectively irradiate the target object from different angles in the approximate vertical direction, so that the shadow problem generated by a single light source is avoided.

And a light source mounting rod which is vertical to the upright column in the horizontal direction is arranged on each beam 4, a group of light sources are respectively arranged at two ends of each light source mounting rod, and the irradiation range of each group of light sources is larger than the field range of the corresponding camera. Thus, the two groups of light sources on each light source mounting rod respectively irradiate the target object from the front direction and the rear direction, and the light sources on the left and right adjacent light source mounting rods respectively irradiate the target object from the left direction and the right direction, so that the shadow problem generated by a single light source is avoided.

In particular, a plurality of groups of light sources are arranged on the cross beam 4 and the upright post 3, so that the target object is illuminated from different spatial angles, and the shadow problem is avoided to the greatest extent. Preferably, the light source may also be mounted on the translation means 5 and/or the rotation means 7, so as to adjust the irradiation range of the light source.

The light source is an LED lamp, but an intelligent light source can also be arranged, for example, different light source brightness, on-off and the like can be selected according to requirements. The light source is used for illuminating the target object, and the situation that the acquisition effect and accuracy are influenced by the excessive dark ambient light is prevented. But also prevent the light source from being too bright, resulting in loss of texture information of the object.

Gather frame 2 and horizontal track 1 and be connected, gather frame 2 and can follow the horizontal direction translation on horizontal track 1, like this to longer target, can gather the information of different positions around the target respectively through removing the frame to can synthesize complete three-dimensional information, avoid using too much camera in the horizontal direction.

The device may further comprise a processor, also referred to as a processing unit, for synthesizing a 3D model of the object according to the plurality of images acquired by the image acquisition device and according to a 3D synthesis algorithm, to obtain 3D information of the object.

Image acquisition device position optimization

When 3D acquisition is carried out, the direction of the optical axis of the image acquisition device at different acquisition positions does not change relative to the target object, and is generally approximately vertical to the surface of the target object, and at the moment, the positions of two adjacent image acquisition devices or two adjacent acquisition positions of the image acquisition devices meet the following conditions:

μ＜0·482

When the two positions are along the length direction of the photosensitive element of the image acquisition device, d is a rectangle; when the two positions are along the width direction of the photosensitive element of the image acquisition device, d is in a rectangular width.

When the image acquisition device is at any one of the two positions, the distance from the photosensitive element to the surface of the target object along the optical axis is taken as M.

As mentioned above, L should be a straight-line distance between the optical centers of the two image capturing devices, but since the optical center position of the image capturing device is not easily determined in some cases, the center of the photosensitive element of the image capturing device, the geometric center of the image capturing device, the axial center of the connection between the image capturing device and the pan/tilt head (or platform, support), and the center of the proximal or distal surface of the lens may be used in some cases instead, and the error caused by the displacement is found to be within an acceptable range through experiments, and therefore the above range is also within the protection scope of the present invention.

Experiments were conducted using the apparatus of the present invention, and the following experimental results were obtained.

From the above experimental results and a lot of experimental experience, it can be concluded that the value of μ should satisfy μ <0.482, and at this time, it is already possible to synthesize a part of the 3D model, and although some parts cannot be automatically synthesized, it is acceptable in the case of low requirements, and the part that cannot be synthesized can be compensated manually or by replacing the algorithm. Particularly, when the value satisfies μ <0.353, the balance between the synthesis effect and the synthesis time can be optimally taken into consideration; mu <0.213 can be chosen for better synthesis, where the synthesis time increases but the synthesis quality is better. When μ is 0.5151, it cannot be synthesized. It should be noted that the above ranges are only preferred embodiments and should not be construed as limiting the scope of protection.

The above data are obtained by experiments for verifying the conditions of the formula, and do not limit the invention. Without these data, the objectivity of the formula is not affected. Those skilled in the art can adjust the equipment parameters and the step details as required to perform experiments, and obtain other data which also meet the formula conditions.

The adjacent acquisition positions refer to two adjacent positions on a movement track where acquisition actions occur when the image acquisition device moves relative to a target object. This is generally easily understood for the image acquisition device movements. However, when the target object moves to cause relative movement between the two, the movement of the target object should be converted into the movement of the target object, which is still, and the image capturing device moves according to the relativity of the movement. And then measuring two adjacent positions of the image acquisition device in the converted movement track.

The target object, and the object all represent objects for which three-dimensional information is to be acquired. The object may be a solid object or a plurality of object components. For example, a vehicle, a large sculpture, etc. The three-dimensional information of the target object comprises a three-dimensional image, a three-dimensional point cloud, a three-dimensional grid, a local three-dimensional feature, a three-dimensional size and all parameters with the three-dimensional feature of the target object. Three-dimensional in the present invention means having XYZ three-direction information, particularly depth information, and is essentially different from only two-dimensional plane information. It is also fundamentally different from some definitions, which are called three-dimensional, panoramic, holographic, three-dimensional, but actually comprise only two-dimensional information, in particular not depth information.

The capture area in the present invention refers to a range in which an image capture device (e.g., a camera) can capture an image. The image acquisition device can be a CCD, a CMOS, a camera, a video camera, an industrial camera, a monitor, a camera, a mobile phone, a tablet, a notebook, a mobile terminal, a wearable device, intelligent glasses, an intelligent watch, an intelligent bracelet and all devices with image acquisition functions.

The three-dimensional information of the multiple regions of the target object obtained in the above embodiment can be used for comparison. It can be understood that the comparison can also be used for identifying fixed properties such as antiques, artworks and the like, namely, three-dimensional information of a plurality of areas of the antiques and the artworks is firstly acquired as standard data, and when identification is needed, the three-dimensional information of the plurality of areas is acquired again and compared with the standard data to identify authenticity. The three-dimensional information of the plurality of regions of the target object obtained in the above embodiment can be used for designing, producing and manufacturing a kit for the target object. For example, three-dimensional data of the oral cavity and the teeth of a human body are obtained, and a more proper denture can be designed and manufactured for the human body. The three-dimensional information of the target object obtained in the above embodiments can also be used for measuring the geometric dimension and the outline of the target object.

In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

The various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It will be appreciated by those skilled in the art that a microprocessor or Digital Signal Processor (DSP) may be used in practice to implement some or all of the functionality of some or all of the components in an apparatus in accordance with embodiments of the present invention. The present invention may also be embodied as apparatus or device programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present invention may be stored on computer-readable media or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.

Claims

1. The utility model provides a three-dimensional collection system that can horizontally move which characterized in that: the device comprises a horizontal rail and an acquisition frame, wherein the acquisition frame is movably connected with the horizontal rail;

the image acquisition device is connected with the acquisition frame;

μ＜0.482

wherein L is the linear distance between the optical centers of the two adjacent image acquisition positions; f is the focal length of the image acquisition device; d is the rectangular length of the photosensitive element of the image acquisition device; m is the distance from the photosensitive element of the image acquisition device to the surface of the target object along the optical axis; μ is an empirical coefficient.

2. The acquisition device as set forth in claim 1, wherein: the upright post comprises a plurality of sections and is combined.

3. The acquisition device as set forth in claim 1, wherein: the beam comprises a plurality of sections and is combined.

4. The acquisition device as set forth in claim 1, wherein: the image acquisition device is connected with the acquisition frame through the linear moving device.

5. The acquisition device as set forth in claim 1, wherein: the image acquisition device is connected with the acquisition frame through the rotating device.

6. The acquisition device as set forth in claim 2, wherein: one or more image acquisition devices are arranged on each section of upright post.

7. The acquisition device as set forth in claim 3, wherein: one or more image acquisition devices are arranged on each section of the cross beam.

8. The acquisition device as set forth in claim 1, wherein: the image acquisition device is a camera or a video camera.

9. The acquisition device as set forth in claim 2 or 3, wherein: two adjacent upright columns or cross beams are provided with locking devices.

10. The acquisition device as set forth in claim 1, wherein: and a horizontal moving device is arranged below the horizontal rail.