KR102080506B1 - 3D optical scanner - Google Patents

Abstract

The present invention relates to a scanner device for measuring and modeling the shape of a dimensional object. More specifically, the present invention uses an optical method without using a laser method with a low scanning speed and a low accuracy, but is stable to changes in external light. In addition, a technical field of an optical 3D scanner that can be used for education because of high measurement accuracy and low manufacturing cost is disclosed.
In addition, the present invention is to shape the three-dimensional information on the target object by irradiating light into the point data, and to reduce the manufacturing cost by miniaturizing the respective sensor module, camera, etc., and to move the light source to irradiate Therefore, the effect of measuring objects of various sizes and the effect of adjusting the irradiation range of the light source, and the effect of measuring only the desired range by the user, and the center line mark with the light source to easily check the center of the light source, Easily matched effects can be achieved.

Description

Optical 3D Scanner {3D optical scanner}

The present invention relates to a scanner device for measuring and modeling the shape of a three-dimensional object, and in more detail, using an optical method without using a laser method with a low scanning speed and low precision, It is a technical field of an optical 3D scanner which is stable, has high measurement accuracy, and has low manufacturing cost and can be used for education.

In general, three-dimensional shape measurement of free-formed objects is widely applied in various fields such as inspection of various workpieces, CAD / CAM, medical care, and solid modeling.

One of the three-dimensional shape measurement technology has been used to measure the entire curved shape by measuring a point on the surface by using a contact three-dimensional measuring device, this contact three-dimensional shape measurement method has been used I have an excessive problem.

Recently, the optical method has been used to solve the shortcomings of the contact type 3D measuring device and increase the measuring efficiency.

As such, a device for measuring a three-dimensional shape of an object by using an optical method is commonly referred to as a "3D scanner".

The three-dimensional scanner is composed of an image acquisition unit consisting of a lens and a camera and a pattern light projection unit for projecting pattern light. The image acquisition unit and pattern light projection unit are fixed mechanically so that the user cannot arbitrarily adjust them. The lens of the image acquisition unit is also fixed so that the user cannot adjust it.

However, in a conventional camera taking a picture, it is necessary to adjust the lens mounted on the camera before pressing the shutter to focus the lens so that a sharp image can be obtained even before the three-dimensional shape is measured in the three-dimensional scanner. Should be adjusted.

However, as described above, the 3D scanner is fixed so that a user cannot adjust the lens, so the distance between the measurement object and the 3D scanner should be adjusted to focus.

In other words, when the measurement object is located in a poorly focused position, it is difficult to obtain a clear image and thus the reliability of the 3D shape measurement is poor. Therefore, the measurement object must be moved to find an optimal position.

The focus position setting method of a conventional measurement system using a 3D scanner includes an image acquisition unit consisting of a lens and a camera, and a pattern light projection unit projecting pattern light onto a surface of a measurement object.

In general, since the 3D scanner has its own optimal focus position, it is necessary to find the optimal focus position determined according to the specification of the 3D scanner by using a tape measure or the like, and then place the measurement object there.

The method of locating the measurement object at the optimum focus position of the scanner using a tape measure, etc., is inefficient because the user has to prepare a tape measure every time the user uses the 3D scanner.

Another embodiment of a focal position setting method of a measurement system using a conventional 3D scanner includes an image acquisition unit consisting of a lens and a camera, a pattern light projection unit projecting pattern light onto a surface of a measurement object, and a point light source on the surface of the measurement object. And a point light source generator.

According to another embodiment of the present invention, separate point light source generators are installed on both sides of the image acquisition unit of the 3D scanner to generate point light, respectively, and the position where the two point light sources overlap with each other while moving the object forward or backward is set to an optimal position. do.

That is, two point lights do not overlap when the measurement object is too far from the focus position and when the measurement object is too close to the focus position.

In this case, when the measurement object is moved forward or backward, the distance between two point light sources irradiated to the measurement object is changed. When moving the measurement object with reference to this, two point lights overlap and appear as one point light. When the object is positioned, a clear image can be obtained.

This three-dimensional scanner equipped with two point sources provides convenience for users to easily find the optimal location. However, two separate point sources need to be arranged, making the device bulky and costly. There is a problem that spending is inevitable.

In addition, the three-dimensional scanner as described above is expensive, but there is no low-cost product is excellent in the precision for supply to the education site, low-cost product development is urgently required.

Republic of Korea Patent No. 162439 Republic of Korea Patent No. 0910937

The present invention has been made to solve the problems according to the prior art described above, the conventional three-dimensional scanner is difficult to position the object to be measured at the optimum focus position of the scanner, when the object is too far or close to the focus position, It is difficult to measure only the part that the user wants while measuring forward or backward, and there is a problem that there is no low-cost equipment that can be used for education. The main object of the present invention is to provide an optical 3D scanner that can be shaped, and can move a light source to be irradiated, easily align the center of the object with the center of the light source, and at a low cost.

The present invention, to achieve the desired object as described above, the object is seated on the top, the turntable for rotating the object left and right, the sensor module for irradiating the light source to the object, and the object to which the light source is irradiated by the sensor module It comprises a measuring unit having a CCD camera and a control unit for receiving the image data of the object measured by the measuring unit to form the point data, the measuring unit is characterized in that for moving the light source irradiated from the sensor module The sensor module provides an optical 3D scanner, characterized in that the range of the light source to be irradiated is adjustable.

In addition, the sensor module of the present invention is characterized in that for irradiating the center line marks indicating the center of the light source to be irradiated with the light source.

Optical 3D scanner according to the present invention as described above is to form a three-dimensional information on the target object by irradiating light into the point data, and to reduce the manufacturing cost by miniaturizing the respective sensor module, camera, etc. and Since the light source is moved, it is possible to measure objects of various sizes, adjust the irradiation range of the light source, and measure the center of the light source so that the user can easily check the center of the light source. By irradiating together, the effect of easily matching the object and the light source can be obtained.

1 is a photograph showing an optical 3D scanner according to a preferred embodiment of the present invention.
Figure 2 is a photograph showing a measuring unit according to a preferred embodiment of the present invention.
3 is a photograph showing an optical 3D scanner according to a preferred embodiment of the present invention.
Figure 4 is a photograph of the dental correction measured by the preferred embodiment of the present invention.
5 is a view schematically showing a principle of operation according to a preferred embodiment of the present invention and a data table.

The present invention relates to a scanner device for measuring and modeling the shape of a three-dimensional object, and in more detail, using an optical method without using a laser method with a low scanning speed and low precision, It is a technical field of an optical 3D scanner which is stable, has high measurement accuracy, and has low manufacturing cost and can be used for education.

That is, the present invention is not only low-cost manufacturing cost, but also high-performance, high-precision measurement so that it can be used for educational purposes.

In addition, the present invention is characterized by improving the measurement accuracy by applying the Sub-Pixel Accuracy Technique.

The configuration for achieving the present invention as described above is the object 10 is seated on the top, the turntable 20 for rotating the object 10 left and right; and the sensor module 32 for irradiating a light source to the object 10 And a measuring unit 30 including a CCD camera 34 for capturing the object 10 irradiated with a light source by the sensor module 32; and the measured object 30 measured by the measuring unit 30. And a control unit 40 configured to receive image data and convert the light source irradiated from the sensor module 32 into the sensor module 32. ) Is characterized in that the adjustable range of the light source to be irradiated.

In addition, the sensor module 32 of the present invention is characterized in that for irradiating the center line mark indicating the center of the light source to be irradiated with the light source.

Turntable 20, which is a major component to achieve the present invention,

As the object 10 is seated on the top, and rotates the object 10 left and right, in order to three-dimensionally measure the object 10 by rotating the object 10 seated on the top of the sensor module to be described in detail later ( 32) characterized in that the light source irradiated from the object 10 can be evenly reflected.

In addition, it is preferable that the turntable 20 of the present invention be manufactured in a small size in consideration of a relatively small size in view of the characteristics of the object 10 used for education to be manufactured for education, and to the controller 40 to be described in detail later. By controlling with the measuring unit 30 it is possible to measure the object 10 efficiently.

In addition, when the turntable 20 of the present invention completes the measurement of one side of the object 10 in the measuring unit 30, the control unit 40 is rotated to measure the adjacent portion of the one side. .

Measuring unit 30 is a major component to achieve the present invention

A sensor module 32 for irradiating a light source to the object 10 and a CCD camera 34 for photographing the object 10 irradiated with the light source by the sensor module 32, the sensor module 32. After irradiating the light source to the object in the image is taken by using the CCD camera 34, the object 10 irradiated with the light source, it is possible to obtain the image data, accordingly, the controller 40 to obtain the coordinates of the object 10 It becomes possible. The method of obtaining the coordinates of the object 10 by using a light source uses a conventionally known triangulation, and a detailed description thereof will be omitted.

In addition, the measuring unit 30 of the present invention is characterized by moving the light source irradiated from the sensor module 32, as shown in Figure 3, of the support frame (not shown) for supporting the measuring unit 30 The measurement unit 30 itself is rotated about the center, thereby moving the light source irradiated from the sensor module 32 to realize the effect of matching the center of the object 10 and the light source.

At this time, the measuring unit 30, as mentioned above, the measuring unit 30 itself may be rotated to move the light source, so that the sensor module 32 is rotated left and right and up and down on the measuring unit 30. It may be installed.

In addition, the measurement unit 30 of the present invention is controlled by the control unit 40 to move the light source, it is possible to precisely rotate, and also precisely controlled by the control unit 40 even when the sensor module 32 is rotated Being will be self-evident.

In addition, it will be apparent that the sensor module 32 is manufactured to be small for educational use, and may be installed to be inserted into the measuring unit 30 or to protrude.

In connection with the above, the sensor module 32 is characterized in that it is possible to adjust the range of the light source to be irradiated, which is if the user wants to model only a portion of the object 10, for example, the nose of the pig pig It is characterized in that the range of the light source can be adjusted so that only a portion of the light source shines, and by adjusting the range of the light source, the user can selectively select a portion of the object 10, that is, a model of ROL (Region of Interest). The effect can be obtained.

At this time, it will be apparent that the range control of the light source irradiated from the sensor module 32 is precisely controlled by the control unit 40, and can control the aperture range or the size of the light irradiated in general. Any technique can be used.

In addition, the sensor module 32 is characterized in that to irradiate the center line mark (not shown) indicating the center of the light source to be irradiated with the light source, which realizes the effect that can effectively measure the object 10 do.

In general, when using the optical method for 3D modeling, the first condition to be performed is to match the center of the light source to be irradiated with the object 10. The present invention provides a centerline together with the light source irradiated to the sensor module 32. By irradiating the mark with the light source, the center of the object 10 and the light source can be easily matched, which is suitable for education.

The center line mark may be irradiated in the form of a cross so that the center of the cross may indicate the center of the light source, and the display method may be irradiated by changing the color of the light source, and may prevent a part of the light source from being irradiated. It may be displayed using. That is, the centerline mark may be displayed by any method conventionally used by the judgment of those skilled in the art.

In connection with the above, the light source irradiated from the sensor module 32 uses an LED beam projector, preferably Grayscale, and the grayscale is in the gradual step range of gray from white to black. As a measure of the difference in brightness, there are 10 levels of brightness, which can be set by the controller 40 according to the judgment of those skilled in the art.

In addition, the CCD camera 34 is a camera generally used in a three-dimensional scanner in the prior art, it can be operated for educational purposes, it is preferable to use a small and inexpensive, detailed description thereof will be omitted.

The controller 40, which is a main component for achieving the present invention,

Receiving the image data of the target object 10 measured by the measuring unit 30 to form a point data, including an operating program and a PC capable of operating the operating program, using a turntable (using an operating program) 20 and the sensor module 32 and the CCD camera 34 of the measurement unit 30, and characterized in that the image data measured by the CCD camera 34 is received.

That is, the controller 40 of the present invention receives the image data, forms the point data, and checks the x, y, and z charges of the object 10, thereby allowing the object 10 to be modeled.

Looking at the process of scanning a three-dimensional measurement object according to a preferred embodiment of the present invention.

1. The measurement object 10 is seated on the turntable 20 and then the control unit 40 controls the turntable 20 and the measurement unit 30 to illuminate the light source irradiated from the sensor module 32 of the object 10. Center

At this time, the CCD camera is calibrated, and the calibration is to find the relative position (external variable), focal length and lens distortion coefficient (internal variable) of the camera from the reference coordinate system.

In the camera calibration method as described above, first, an object having a shape (for example, a correction panel in which round points are regularly placed on a flat plate) is photographed with a camera, and a reference coordinate system is created on the object.

In addition, it finds out how the three-dimensional shape of the object appears on the two-dimensional image, generates several equations, and solves the equations to obtain external and internal variables. These parameters are later used to generate three-dimensional point data.

2. When the camera calibration as described above is completed, a series of patterns are irradiated to the measurement object using the sensor module 32.

In this case, since the LED projector is considerably expensive and bulky, it is preferable to use a compact and inexpensive manufacturing cost, and a series of patterns can be irradiated using a printed pattern film.

That is, when the sensor module 32 receiving a predetermined control signal from the controller 40 moves the pattern film on which a series of patterns are printed from left to right or vice versa at a predetermined time interval, The light from the provided light source passes through the optical lens provided at the front and rear sides of the pattern film to sequentially irradiate each pattern of the pattern film.

Therefore, the present invention automatically recognizes the correspondence by projecting the pattern of the structured light on the object 10. In the present invention, gray scale is used.

In addition, each pattern fills the computer's screen tightly, and projecting these patterns over a number of lines creates a line with different histories by combining a series of different images formed by the pattern. You will be able to make it.

For example, if the value of a point or pixel on a binary image is listed from pattern 1 to pattern 8, for example, 01001011, this is called a history, and no other line can have the same value. will be.

The projected image of the last pattern binarizes it and finds an edge where the black and white lines cross in the image transversely, which appears as a number of vertical lines, which are directly related to the three-dimensional data calculation algorithm. Will be the data.

When the gray scale floating on the computer monitor by the LED projector or the gray pattern printed film is irradiated to the measurement object 10 as described above, the CCD camera 34 captures the state of the irradiated measurement object 10. The received image is input to the controller 40. This process is repeated for the number of patterns projected.

That is, if the pattern is nine, the above process is repeated nine times, and since nine pattern images are photographed through each CCD camera 34, the pattern image input to the controller 40 is used. It consists of nine image data.

Therefore, the controller 40 implements three-dimensional point data using nine pattern image information input from the CCD camera 34.

3. The 3D point data implementation using the pattern image information is performed by the controller 40. A line having the same history is sampled among the lines corresponding to the last pattern projected on each image, and the line is sampled. The algorithm for obtaining three-dimensional points for is as follows.

In other words, a straight line connecting an arbitrary point on one line of image 1 with the center of the lens appears as an outer polar line projected on the image 2, connecting the intersection of the outer line with the line of the image 2 and the center of the lens. You get a straight line. If you find the point where the two straight lines meet, the point becomes three-dimensional coordinates.

The above has been described with reference to a preferred embodiment of the present invention, but is not limited to the above embodiments, the person having ordinary skill in the art to which the present invention pertains through the above embodiments without departing from the gist of the present invention Can be implemented in a variety of changes.

10: object
20: turntable
30: measuring unit
32: sensor module
34: CCD camera
40: control unit

Claims (2)

A turntable 20 mounted on an upper portion of the object 10 and rotating the object 10 left and right; and
Measuring unit 30 having a sensor module 32 for irradiating a light source to the object 10 and a CCD camera 34 for capturing the object 10 irradiated with a light source by the sensor module 32 ;Wow
And a controller 40 configured to receive the image data of the object 10 measured by the measuring unit 30 and form the point data.
The measuring unit 30 is made of moving the light source irradiated from the sensor module 32,
The sensor module 32 is made to be possible to adjust the range of the light source to be irradiated,
The measuring unit 30
The measuring unit 30 itself is configured to rotate around the center of the supporting frame as an axis,
The sensor module 32 is
Consisting of an LED beam projector with grayscale
The sensor module 32 is
An optical 3D scanner characterized by irradiating a centerline mark indicating the center of the light source to be irradiated with the light source.
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