阅读说明：本技术 一种3d打印机喷嘴位置自动校准方法和装置 (Automatic calibration method and device for nozzle position of 3D printer ) 是由 刘锬 韩成超 于 2020-06-19 设计创作，主要内容包括：本发明属于打印机技术领域,提供了一种3D打印机喷嘴位置自动校准方法和装置,其方法包括：至少从一个校准方向获取基准喷嘴图像和至少一个待校准喷嘴图像；通过图像处理所述基准喷嘴图像和至少一个所述待校准图像,识别所述基准喷准的校准点坐标和所述待校准喷嘴的校准点坐标；基于所述基准喷准的校准点坐标和所述待校准喷嘴的校准点坐标,在所述校准方向自动校准至少一个所述待校准喷嘴的位置。本发明实现了全自动化、成本低、精度高的自动校准3D打印机喷嘴位置。(The invention belongs to the technical field of printers, and provides a method and a device for automatically calibrating the position of a nozzle of a 3D printer, wherein the method comprises the following steps: acquiring a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction; processing the image of the reference nozzle and at least one image to be calibrated through images, and identifying the coordinates of a calibration point of the reference spray nozzle and the coordinates of a calibration point of the nozzle to be calibrated; and automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the calibration point coordinates of the reference spray calibration and the calibration point coordinates of the nozzle to be calibrated. The invention realizes the automatic calibration of the nozzle position of the 3D printer, and has the advantages of full automation, low cost and high precision.)

1. A3D printer nozzle position automatic calibration method is characterized by comprising the following steps:

acquiring a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction;

processing the image of the reference nozzle and at least one image to be calibrated through images, and identifying the coordinates of a calibration point of the reference spray nozzle and the coordinates of a calibration point of the nozzle to be calibrated;

and automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the calibration point coordinates of the reference spray calibration and the calibration point coordinates of the nozzle to be calibrated.

2. The automatic calibration method for nozzle position of 3D printer according to claim 1, wherein said at least obtaining a reference nozzle image and at least one nozzle image to be calibrated from one calibration direction comprises the steps of:

respectively acquiring a reference nozzle image positioned at a calibration position and at least one to-be-calibrated nozzle image positioned at the calibration position from XY directions; the calibration position is a position where the calibration point coordinates of the nozzle can be obtained;

or;

and respectively acquiring the reference nozzle image at the calibration position and at least one to-be-calibrated nozzle image at the calibration position from the Z direction.

3. The automatic calibration method for the nozzle position of the 3D printer according to claim 2, wherein said acquiring the reference nozzle image located at the calibration position and the at least one nozzle image to be calibrated located at the calibration position from the XY direction respectively comprises the steps of:

when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the XY direction;

and moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the XY direction.

4. The automatic calibration method for the nozzle position of the 3D printer according to claim 2, wherein said acquiring the reference nozzle image located at the calibration position and the at least one nozzle image to be calibrated located at the calibration position from the XY direction respectively comprises the steps of:

when the reference nozzle and at least one nozzle to be calibrated are independent nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the XY direction;

and moving at least one nozzle to be calibrated to the calibration position, and acquiring at least one nozzle image to be calibrated from the XY direction.

5. The method for automatically calibrating the nozzle position of a 3D printer according to claim 2, wherein the step of respectively acquiring the reference nozzle image at the calibration position and at least one nozzle image to be calibrated at the calibration position from the Z direction comprises the steps of:

when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the Z direction;

and moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the Z direction.

6. The method for automatically calibrating the nozzle position of a 3D printer according to claim 2, wherein the step of respectively acquiring the reference nozzle image at the calibration position and at least one nozzle image to be calibrated at the calibration position from the Z direction comprises the steps of:

when the reference nozzle and at least one nozzle to be calibrated are independent nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the Z direction;

and moving at least one nozzle to be calibrated to the calibration position, and acquiring at least one nozzle image to be calibrated from the Z direction.

7. The method for automatically calibrating the nozzle position of a 3D printer according to claim 1, wherein before said acquiring the reference nozzle image and the at least one nozzle image to be calibrated from at least one calibration direction, further comprises the steps of:

the reference nozzles are selected, including the nozzles that are most mechanically positionally stable among the printer nozzles or the nozzles that are fixedly selected.

8. The automatic calibration method for the nozzle position of the 3D printer according to any one of claims 1 to 7, wherein the step of identifying the calibration point coordinates of the reference nozzle and the calibration point coordinates of the nozzle to be calibrated by image processing the reference nozzle image and at least one image to be calibrated comprises the steps of:

processing the image of the reference nozzle and at least one image to be calibrated through images to obtain the outline of the reference nozzle and the outline of the nozzle to be calibrated;

and identifying the outline of the reference nozzle and the outline of the nozzle to be calibrated through images, and acquiring the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

9. The automatic calibration method for the nozzle position of the 3D printer according to claim 8, wherein the position of at least one nozzle to be calibrated is automatically calibrated in the calibration direction based on the coordinates of the calibration point of the reference spray and the coordinates of the calibration point of the nozzle to be calibrated, comprising the steps of:

calculating a position deviation value between the coordinates of the calibration point of the reference spray accuracy and the coordinates of the calibration point of the nozzle to be calibrated based on the coordinates of the calibration point of the reference spray accuracy and the coordinates of the calibration point of the nozzle to be calibrated;

and automatically calibrating the position of at least one nozzle to be calibrated according to the position deviation value.

10. The utility model provides a 3D printer nozzle position automatic calibration device which characterized in that includes:

the shooting module is used for acquiring a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction;

a coordinate acquisition module: the calibration point coordinates of the reference spray nozzle and the calibration point coordinates of the nozzle to be calibrated are identified by processing the reference nozzle image and at least one image to be calibrated through images;

an automatic calibration module: and the calibration device is used for automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

Technical Field

The invention relates to the technical field of printers, in particular to a method and a device for automatically calibrating the position of a nozzle of a 3D printer.

Background

The three-dimensional printing technology (3D printing technology) is a rapid forming technology based on droplet jet forming, wherein single-layer printing forming is similar to an ink jet printing process, namely under the excitation of a digital signal, liquid materials in a working cavity of a printing head form droplets instantly or by jet flow, and the droplets are ejected from a nozzle at a certain frequency speed and are ejected to a specified position to be stacked layer by layer to form a three-dimensional solid part. Due to the physical deviation of a mechanical mechanism of the 3D printer, lines printed by different nozzles often have certain position deviation after different nozzles are switched to be current movable nozzles. This deviation includes a coordinate deviation in the XY horizontal direction and a distance deviation between the Z-direction nozzle and the stage. For this situation, a 3D printer nozzle position calibration method occurs, and the existing 3D printer nozzle position calibration method generally includes three types: lines or patterns of different nozzles are drawn respectively, and then the nozzle positions are calibrated by comparing the printed lines or patterns. Or the position of the nozzle is judged according to the electric signal generated when the position sensor is collided by different nozzles touching the position sensor, and the position of the nozzle is calibrated by comparing the positions.

The first method requires human intervention and is not fully automated. The second method can be completely automated, but requires a high sensor and touches the nozzle edge, which can cause errors due to the distance from the nozzle edge to the nozzle. Therefore, the prior art has the problems of complex operation, high cost and low precision.

Disclosure of Invention

The invention aims to provide a method and a device for automatically calibrating the position of a 3D printer nozzle, which realize automatic calibration of the position of the printer nozzle with full automation, low cost and high precision.

The technical scheme provided by the invention is as follows:

the invention provides a 3D printer nozzle position automatic calibration method, which comprises the following steps:

at least one reference nozzle image and at least one nozzle image to be calibrated are acquired from at least one calibration direction.

And processing the image of the reference nozzle and at least one image to be calibrated through images, and identifying the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

And automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the calibration point coordinates of the reference spray calibration and the calibration point coordinates of the nozzle to be calibrated.

Further preferably, the acquiring at least one reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction includes the steps of:

respectively acquiring a reference nozzle image positioned at a calibration position and at least one to-be-calibrated nozzle image positioned at the calibration position from XY directions; the calibration position is a position where the calibration point coordinates of the nozzle can be obtained; or; and respectively acquiring the reference nozzle image at the calibration position and at least one to-be-calibrated nozzle image at the calibration position from the Z direction.

Further preferably, the acquiring a reference nozzle image located at a calibration position and at least one nozzle image to be calibrated located at the calibration position from the XY direction, respectively, includes the steps of:

and when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the XY direction.

And moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the XY direction.

Further preferably, the acquiring a reference nozzle image located at a calibration position and at least one nozzle image to be calibrated located at the calibration position from the XY direction, respectively, includes the steps of:

when the reference nozzle and at least one of the nozzles to be calibrated are independent nozzles, the reference nozzle is moved to the calibration position, and the reference nozzle image is acquired from the XY direction.

And moving at least one nozzle to be calibrated to the calibration position, and acquiring at least one nozzle image to be calibrated from the XY direction.

Further preferably, the acquiring the reference nozzle image located at the calibration position and the at least one nozzle-to-be-calibrated image located at the calibration position from the Z direction respectively includes:

and when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the Z direction.

And moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the Z direction.

Further preferably, the acquiring the reference nozzle image located at the calibration position and the at least one nozzle-to-be-calibrated image located at the calibration position from the Z direction respectively includes:

and when the reference nozzle and at least one nozzle to be calibrated are independent nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the Z direction.

And moving at least one nozzle to be calibrated to the calibration position, and acquiring at least one nozzle image to be calibrated from the Z direction.

Further preferably, before the acquiring the reference nozzle image and the at least one nozzle image to be calibrated from at least one calibration direction, the method further comprises the following steps:

the reference nozzles are selected, including the nozzles that are most mechanically positionally stable among the printer nozzles or the nozzles that are fixedly selected.

Further preferably, the identifying the calibration point coordinates of the reference nozzle and the calibration point coordinates of the nozzle to be calibrated by image processing the reference nozzle image and at least one of the images to be calibrated includes the steps of:

and processing the image of the reference nozzle and at least one image to be calibrated through images to obtain the outline of the reference nozzle and the outline of the nozzle to be calibrated.

And identifying the outline of the reference nozzle and the outline of the nozzle to be calibrated through images, and acquiring the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

Further preferably, the automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the calibration point coordinates of the reference spray header and the calibration point coordinates of the nozzle to be calibrated includes the steps of:

and calculating a position deviation value between the coordinate of the calibration point of the reference spray accuracy and the coordinate of the calibration point of the nozzle to be calibrated based on the coordinate of the calibration point of the reference spray accuracy and the coordinate of the calibration point of the nozzle to be calibrated.

And automatically calibrating the position of at least one nozzle to be calibrated according to the position deviation value.

The invention also provides an automatic calibration device for the nozzle position of the 3D printer, which comprises:

and the photographing module is used for acquiring a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction.

A coordinate acquisition module: and the calibration point coordinates of the reference spray nozzle and the calibration point coordinates of the nozzle to be calibrated are identified by image processing of the reference nozzle image and at least one image to be calibrated.

An automatic calibration module: and the calibration device is used for automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

The invention provides a method and a device for automatically calibrating the position of a nozzle of a 3D printer, which at least have the following beneficial effects:

1) the invention obtains images of a reference nozzle and a nozzle to be calibrated from a plurality of calibration directions, and automatically calibrates the nozzle to be calibrated through image recognition and processing and a series of algorithms. The automatic calibration of the position of the printer nozzle is realized, and the automatic calibration has the advantages of full automation, low cost and high precision.

2) The invention carries out subsequent calibration by photographing the reference nozzle and the nozzle to be calibrated. In the traditional method, calibration needs to be carried out by touching the position sensor through different nozzles, so that the cost of the calibration device is reduced.

3) The invention obtains the coordinates of the calibration points of the reference nozzle and the nozzle to be calibrated at the calibration position through image recognition and processing, and further calculates the position deviation of the nozzle to be calibrated and calibrates the position deviation. The conventional method for calibrating the position sensor by touching the sensor has high requirements on the position sensor, and the edge of the nozzle touches the edge of the nozzle, so that certain errors are generated due to the fact that the edge of the nozzle has a certain distance to the nozzle. The invention can not generate errors and can realize automatic calibration with extremely high precision.

4) The automatic calibration method and device for the nozzle position of the 3D printer, provided by the invention, can calibrate the nozzle to be calibrated through a series of automatic algorithms and devices without human participation.

Drawings

The above features, technical features, advantages and implementations of a method and apparatus for automatic calibration of nozzle positions in a 3D printer will be further described in the following detailed description of preferred embodiments in a clearly understandable manner with reference to the accompanying drawings.

FIG. 1 is a flow chart of one embodiment of a method for automatic calibration of nozzle positions for a 3D printer in accordance with the present invention;

FIG. 2 is a flow chart of another embodiment of a method for automatic calibration of nozzle positions in a 3D printer according to the present invention;

FIG. 3 is a flow chart of another embodiment of a method for automatic calibration of nozzle positions in a 3D printer according to the present invention;

FIG. 4 is a flow chart of yet another embodiment of a method for automatic calibration of nozzle positions for a 3D printer according to the present invention;

FIG. 5 is a schematic illustration of a reference nozzle image in XY of the present invention with an integrated dual nozzle;

FIG. 6 is a schematic diagram of an image of a nozzle to be calibrated in the XY direction of the integrated dual nozzle in accordance with the present invention;

FIG. 7 is a schematic view showing a positional deviation value in XY directions of the integrated dual nozzle in the present invention;

FIG. 8 is a schematic diagram of the offset values of the multiple image positions in the Z direction for the integrated dual nozzle of the present invention;

FIG. 9 is a schematic diagram of a Z-direction single image offset for the integrated dual nozzle system of the present invention;

FIG. 10 is an XY-directional reference nozzle image in the present invention;

FIG. 11 is an image of a nozzle to be calibrated in the XY direction in the present invention;

FIG. 12 is a schematic view of the profile of an XY-oriented reference nozzle in accordance with the present invention;

FIG. 13 is a schematic view of the profile of the nozzle to be calibrated in the XY direction in the present invention;

FIG. 14 is a schematic illustration of the coordinates of the center hole of the nozzle to be calibrated in the present invention;

FIG. 15 is a schematic structural diagram of an embodiment of an automatic calibration device for the nozzle position of a 3D printer according to the present invention;

FIG. 16 is a schematic diagram of center hole coordinates of a bottom view direction image of a reference nozzle in XY directions for an individual dual or multi-nozzle in accordance with the present invention;

FIG. 17 is a front view of a reference nozzle in the Z direction of the present invention with a single dual or multiple nozzle;

FIG. 18 is a schematic diagram of the center hole coordinates of a bottom view direction image of an individual dual or multi-nozzle to be calibrated in XY directions in accordance with the present invention;

FIG. 19 is a schematic view of a front view of a nozzle to be calibrated in the Z direction for an independent dual or multi-nozzle in accordance with the present invention;

FIG. 20 is a schematic view showing a positional deviation value in XY directions of the individual double nozzles or the multiple nozzles in the present invention;

FIG. 21 is a schematic view showing a deviation of the position of the independent dual nozzles or multi nozzles in the Z direction according to the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

In addition, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

In an embodiment of the present invention, as shown in fig. 1, a method for automatically calibrating a nozzle position of a 3D printer includes:

s110 acquires at least a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction.

Specifically, the calibration direction may include a calibration direction selected according to a calibration requirement, and the calibration direction may further include a calibration direction selected according to a device from which the image is acquired.

For example, when acquiring the reference nozzle image from one calibration direction, at least one nozzle image to be calibrated may be acquired, respectively. When the reference nozzle image is acquired from another calibration direction, at least one nozzle image to be calibrated may also be acquired, respectively.

S120, the reference nozzle image and at least one image to be calibrated are processed through images, and the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated are identified.

In particular, the image processing method may include an algorithm for processing the contour of the image obtained from the image; the method related to image processing may specifically include: graying (if a color picture), binarization, smoothing, denoising, edge detection, etc. The edge detection algorithm may specifically include Roberts, Sobel, Prewitt, Laplacian, Log/Marr, Canny, Kirsch, nevita operators, and other algorithms suitable for edge detection. In practical application, algorithm combination can be carried out according to needs.

Specifically, the position of the calibration point can be automatically found by the image recognition algorithm involved in recognizing the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated, and the coordinates of the calibration point can be automatically calculated by software through pixel matching.

S130, automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the calibration point coordinates of the reference spray calibration and the calibration point coordinates of the nozzle to be calibrated.

Specifically, through the obtained coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated, the position deviation value between the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated can be automatically calculated through software, so that the position calibration is performed.

For example, after obtaining the position deviation value between the reference nozzle and the nozzle to be calibrated, in the actual operation process, the printer software will compensate the position deviation value to the motion coordinate of the nozzle to be calibrated during printing to realize the position calibration.

In another embodiment of the present invention, as shown in fig. 2, a method for automatically calibrating a nozzle position of a 3D printer includes:

s210 selects the reference nozzles including a nozzle which is mechanically most stably positioned among nozzles of the printer or a fixedly selected nozzle.

Specifically, in the integrated or independent dual/multi-nozzle, the reference nozzle is generally the leftmost nozzle for the integrated nozzle, and the left nozzle is selected as the reference nozzle because other nozzles may be switched up and down and the position is unstable. Or selecting the nozzle with the most stable mechanical position as the reference nozzle. For the independent nozzle, the reference nozzle may be any one of the nozzles, and the left nozzle or the most stable nozzle is generally selected as the reference nozzle. In short, the calibration method of the dual/multi-nozzle specifically comprises the steps of: firstly, taking a picture of a reference nozzle (generally, a left nozzle), then switching other nozzles, namely, nozzles to be calibrated to working positions to take a picture, and finally, carrying out position calibration on the nozzles to be calibrated relative to the reference nozzle. And a plurality of nozzles to be calibrated only need to be switched to working positions one by one and photographed, and then the positions are analyzed and identified by images, and the deviation is automatically calibrated.

S220 acquires at least a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction.

Specifically, the calibration direction may include a calibration direction selected according to a calibration requirement, and the calibration direction may further include a calibration direction selected according to a device from which the image is acquired.

For example, when acquiring the reference nozzle image from one calibration direction, at least one nozzle image to be calibrated may be acquired, respectively. When the reference nozzle image is acquired from another calibration direction, at least one nozzle image to be calibrated may also be acquired, respectively.

S230, the reference nozzle image and at least one image to be calibrated are processed through images, and the outline of the reference nozzle and the outline of the nozzle to be calibrated are obtained.

Specifically, when the contour of the reference nozzle and the contour of the nozzle to be calibrated are obtained through the image processing algorithm, the image processing algorithm judges according to a threshold value set in a program, whether the obtained contour is a clear contour or not is judged through a software execution algorithm, and when the contour is the clear contour, the process of obtaining the contour of the reference nozzle and the contour of the nozzle to be calibrated is achieved.

S240, identifying the outline of the reference nozzle and the outline of the nozzle to be calibrated through the image, and acquiring the coordinate of the calibration point of the reference spray nozzle and the coordinate of the calibration point of the nozzle to be calibrated.

Furthermore, the position of the calibration point, which may include the center of the spray, is automatically found by the image recognition algorithm, and the coordinates of the calibration point are automatically calculated by the software by pixel matching. Illustratively, the nozzle center hole coordinates of the right nozzle as shown in fig. 14, fig. 14 shows the nozzle center hole coordinates: x is 1255.44, Y is 1118.79, and the radius R is 19.1025.

S250, calculating a position deviation value between the coordinate of the calibration point of the reference spray accuracy and the coordinate of the calibration point of the nozzle to be calibrated based on the coordinate of the calibration point of the reference spray accuracy and the coordinate of the calibration point of the nozzle to be calibrated.

And S260, automatically calibrating the position of at least one nozzle to be calibrated according to the position deviation value.

Specifically, through the obtained coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated, the position deviation value between the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated can be automatically calculated through software, so that the position calibration is performed.

For example, after obtaining the position deviation value between the reference nozzle and the nozzle to be calibrated, in the actual operation process, the printer software will compensate the position deviation value to the motion coordinate of the nozzle to be calibrated during printing to realize the position calibration.

In another embodiment of the present invention, as shown in fig. 3, a method for automatically calibrating a nozzle position of a 3D printer includes:

s310 selects the reference nozzles including a nozzle which is mechanically most stably positioned among nozzles of the printer or a fixedly selected nozzle.

Specifically, in the integrated or independent dual/multi-nozzle, the reference nozzle is generally the leftmost nozzle, and since the right nozzle is moved up and down and the position is unstable, the left nozzle is selected as the reference nozzle. Or selecting the nozzle with the most stable mechanical position as the reference nozzle.

S320, respectively acquiring a reference nozzle image at a calibration position and at least one to-be-calibrated nozzle image at the calibration position from the XY direction; the calibration position is a position at which the calibration point coordinates of the nozzle can be acquired.

Illustratively, as shown in FIGS. 10-11, FIG. 10 is an image of the reference nozzle taken from the XY direction, and FIG. 11 is an image of the nozzle to be calibrated taken from the XY direction.

Specifically, the calibration position may include a position where all pixels of the nozzle can be acquired, and the calibration position may also include a position where the center of the nozzle can be acquired.

The method comprises the following steps of respectively acquiring a reference nozzle image located at a calibration position and at least one nozzle image to be calibrated located at the calibration position from the XY direction, and specifically comprises the following steps:

and when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the XY direction.

And moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the XY direction.

For example, as shown in fig. 5 to 7, the two nozzles of the integrated dual nozzle are processed together, so that both nozzles can be photographed when a picture is taken. When the left nozzle, i.e., the reference nozzle in fig. 5, moves to X100, Y100 and then to X200, Y200, the right nozzle also performs the same operation, and the paths along which the two nozzles move are completely identical, and when the two nozzles print like one nozzle, it is described that the positions of the two nozzles are not misaligned. Theoretically, the two nozzles are not offset, but actually, the two nozzles are offset due to mechanical differences. For example, when two nozzles have been aligned and one of the nozzles is replaced with a new one, the outer diameter of the base of the new nozzle is 0.01mm larger due to mechanical deviation. The path followed by the new nozzle is then offset from the original nozzle. I.e. the actual positions of the two nozzles that move to the same coordinate when in operation are not coincident. Therefore, the two nozzles need to be recalibrated after replacement to compensate for the deviation of the two nozzles. The calibration is to make the actual positions of the coordinates of the two nozzles coincide completely.

In an actual application scene, a special mechanism is used for controlling the nozzles, meanwhile, the whole integrated double-nozzle moves to the left, and the right nozzle moves to the position of the original left nozzle. As shown in fig. 5, the two nozzles of the integrated dual nozzle are processed together, so that both nozzles are photographed when taking a picture. When the reference nozzle in fig. 5 is moved to the calibration position, the reference nozzle is photographed to acquire the reference nozzle image; as shown in fig. 6, when the nozzle to be calibrated moves to the calibration position, the nozzle to be calibrated is photographed, and an image of the nozzle to be calibrated is acquired; as shown in fig. 7, when the reference nozzle image and the nozzle image to be calibrated are subjected to image processing, fig. 7 shows the positional deviation value of the nozzle to be calibrated with respect to the reference nozzle.

Alternatively, the right nozzle may be rotated, for example, by rotating the integrated dual nozzle so that the left nozzle faces the print area.

Optionally, the acquiring a reference nozzle image located at a calibration position and at least one nozzle image to be calibrated located at the calibration position from the XY direction respectively includes:

when the reference nozzle and at least one of the nozzles to be calibrated are independent nozzles, the reference nozzle is moved to the calibration position, and the reference nozzle image is acquired from the XY direction.

And moving at least one nozzle to be calibrated to the calibration position, and acquiring at least one nozzle image to be calibrated from the XY direction.

Specifically, the reference nozzle is moved to the calibration position, and the reference nozzle image, for example, X100, Y100, is acquired. And then moving the nozzle to be calibrated to the calibration position to acquire the image of the nozzle to be calibrated. I.e. each time a shot is taken of a different nozzle to the working position (calibration position) and the two positions are compared.

S330, the image of the reference nozzle and at least one image to be calibrated are processed through images, and the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated are identified.

In particular, the image processing method may include an algorithm for processing the contour of the image obtained from the image; the method related to image processing may specifically include: graying (if a color picture), binarization, smoothing, denoising, edge detection, etc. The edge detection algorithm may specifically include Roberts, Sobel, Prewitt, Laplacian, Log/Marr, Canny, Kirsch, nevita operators, and other algorithms suitable for edge detection. In practical application, algorithm combination can be carried out according to needs.

Specifically, the position of the calibration point can be automatically found by the image recognition algorithm involved in recognizing the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated, and the coordinates of the calibration point can be automatically calculated by software through pixel matching.

Further preferably, the identifying the calibration point coordinates of the reference nozzle and the calibration point coordinates of the nozzle to be calibrated by image processing the reference nozzle image and at least one of the images to be calibrated includes the steps of:

and processing the image of the reference nozzle and at least one image to be calibrated through images to obtain the outline of the reference nozzle and the outline of the nozzle to be calibrated.

And identifying the outline of the reference nozzle and the outline of the nozzle to be calibrated through images, and acquiring the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

Specifically, when the contour of the reference nozzle and the contour of the nozzle to be calibrated are obtained through the image processing algorithm, the image processing algorithm judges according to a threshold value set in a program, whether the obtained contour is a clear contour or not is judged through a software execution algorithm, and when the contour is the clear contour, the process of obtaining the contour of the reference nozzle and the contour of the nozzle to be calibrated is achieved.

Illustratively, as shown in FIGS. 10-14, FIG. 10 is an image of the reference nozzle taken from the XY direction, and FIG. 11 is an image of the nozzle to be calibrated taken from the XY direction. Fig. 12 is a profile of the reference nozzle obtained by image-processing the reference nozzle image obtained from the XY direction, and fig. 13 is a profile of the nozzle to be calibrated obtained by image-processing the nozzle image to be calibrated obtained from the XY direction.

Furthermore, the position of the calibration point, which may include the center of the spray, is automatically found by the image recognition algorithm, and the coordinates of the calibration point are automatically calculated by the software by pixel matching. Illustratively, the nozzle center hole coordinates of the right nozzle as shown in fig. 14, fig. 14 shows the nozzle center hole coordinates: x is 1255.44, Y is 1118.79, and the radius R is 19.1025.

S340, automatically calibrating the position of at least one nozzle to be calibrated in the XY direction based on the calibration point coordinates of the reference spray nozzle and the calibration point coordinates of the nozzle to be calibrated.

Further preferably, the automatically calibrating the position of at least one nozzle to be calibrated in the XY direction based on the calibration point coordinates of the reference spray point and the calibration point coordinates of the nozzle to be calibrated includes the steps of:

and calculating a position deviation value between the coordinate of the calibration point of the reference spray accuracy and the coordinate of the calibration point of the nozzle to be calibrated based on the coordinate of the calibration point of the reference spray accuracy and the coordinate of the calibration point of the nozzle to be calibrated.

And automatically calibrating the position of at least one nozzle to be calibrated according to the position deviation value.

Specifically, through the obtained coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated, the position deviation value between the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated can be automatically calculated through software, so that the position calibration is performed.

For example, after obtaining the position deviation value between the reference nozzle and the nozzle to be calibrated, in the actual operation process, the printer software will compensate the position deviation value to the motion coordinate of the nozzle to be calibrated during printing to realize the position calibration. For example: the G code originally cut from the slice shows that what the right nozzle, i.e. the nozzle to be calibrated, is going to be G1: the path of X100 and Y100. However, in the calibration, it is found that the X direction of the right nozzle is deviated from 0.05, the Y direction is deviated from-0.05, and the X, Y coordinates compensate the deviation when the printing is actually performed, so that the right nozzle actually moves to G0: x99.95 and Y100.05, the deviation can be compensated.

In another embodiment of the present invention, as shown in fig. 4, a method for automatically calibrating a nozzle position of a 3D printer includes:

s410 selects the reference nozzles including a nozzle which is mechanically most stably positioned among nozzles of the printer or a fixedly selected nozzle.

Specifically, in the integrated or independent dual/multi-nozzle, the reference nozzle is generally the leftmost nozzle, and since the right nozzle is moved up and down and the position is unstable, the left nozzle is selected as the reference nozzle. Or selecting the nozzle with the most stable mechanical position as the reference nozzle.

S420 acquires the reference nozzle image located at the calibration position and at least one nozzle image to be calibrated located at the calibration position from the Z direction, respectively.

Optionally, the acquiring the reference nozzle image located at the calibration position and the at least one nozzle image to be calibrated located at the calibration position from the Z direction respectively includes:

and when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the Z direction.

And moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the Z direction.

Specifically, the reference nozzle is moved to the calibration position, and the reference nozzle image is acquired from the Z direction. And then moving the nozzle to be calibrated to the calibration position, and acquiring an image of the nozzle to be calibrated from the Z direction. I.e. each time a shot is taken of a different nozzle to the working position (calibration position) and the two positions are compared. Because the integrated double-nozzle is formed by integrating two nozzles, the aim of switching the current working nozzle is fulfilled by adjusting the up-down position of one nozzle.

Alternatively, the nozzle may be rotated, for example, the left nozzle, i.e., the reference nozzle, faces the printing area, and the integrated dual nozzle is rotated to change the right nozzle, i.e., the nozzle to be calibrated, faces the printing area.

Specifically, as shown in fig. 8, Δ Z in fig. 8 is a positional deviation in the Z direction between the reference nozzle and the nozzle to be calibrated.

As shown in fig. 9, optionally, the acquiring the reference nozzle image located at the calibration position and the at least one nozzle image to be calibrated located at the calibration position from the Z direction respectively further includes:

when the reference nozzle and the nozzle to be calibrated are integrated double nozzles, the reference nozzle is a fixed nozzle, and the nozzle to be calibrated moves up and down as a movable nozzle.

When the nozzle to be calibrated is below as a movable nozzle, acquiring the image simultaneously containing the reference nozzle and the nozzle to be calibrated.

Specifically, the position of the reference nozzle is known, that is, the reference nozzle image is stored, and when the nozzle to be calibrated is in the calibration position as the movable nozzle, the image including both the reference nozzle and the nozzle to be calibrated is acquired.

Specifically, the left and right nozzles of the integrated dual-nozzle printer are fixed together, the left nozzle of the partially integrated dual-nozzle printer is stationary in the Z direction, and the right nozzle moves up and down. Thus, only one photograph is required to recognize the deviation between the right nozzle and the left nozzle in the Z direction.

According to the above embodiment, as shown in fig. 16 to 21, the acquiring the reference nozzle image located at the calibration position and the at least one nozzle image to be calibrated located at the calibration position from the Z direction in this embodiment includes:

and when the reference nozzle and at least one nozzle to be calibrated are independent nozzles, moving the reference nozzle to the calibration position, and acquiring the reference nozzle image from the Z direction.

And moving at least one nozzle to be calibrated to the calibration position, and acquiring at least one nozzle image to be calibrated from the Z direction.

Specifically, the at least one nozzle to be calibrated is an independent nozzle comprising an independent double nozzle and a multi-nozzle, and when the nozzle to be calibrated and the reference nozzle are independent double nozzles or multi-nozzles, the nozzle to be calibrated can be calibrated from the XY direction and/or the Z direction.

For example, the calibrating at least one nozzle to be calibrated with respect to the XY direction may include: moving the reference nozzle to the calibration position, the reference nozzle image is acquired, for example, X100, Y100, as shown in fig. 16. Then, the nozzle to be calibrated is moved to the calibration position, and an image of the nozzle to be calibrated is acquired, as shown in fig. 18. That is, different nozzles are photographed to the operating positions (calibration positions), respectively, and then the two positions are compared to obtain the position difference between the reference nozzle and the nozzle to be calibrated in the XY direction, as shown in fig. 20.

For example, the calibrating at least one nozzle to be calibrated from the Z direction may include: the reference nozzle is moved to the calibration position, and an image of the reference nozzle in the Z direction is acquired, as shown in fig. 17. Then, the nozzle to be calibrated is moved to the calibration position, and an image of the nozzle to be calibrated is acquired, as shown in fig. 19. That is, different nozzles are photographed to operating positions (calibration positions), and the two positions are compared to obtain the position difference between the reference nozzle and the nozzle to be calibrated in the Z direction, as shown in fig. 21.

And S430, identifying the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated by image processing of the image of the reference nozzle and at least one image to be calibrated.

Specifically, the contour of the reference nozzle and the contour of the nozzle to be calibrated are obtained by image processing of the reference nozzle image and at least one image to be calibrated.

And identifying the outline of the reference nozzle and the outline of the nozzle to be calibrated through images, and acquiring the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

Specifically, when the contour of the reference nozzle and the contour of the nozzle to be calibrated are obtained through the image processing algorithm, the image processing algorithm judges according to a threshold value set in a program, whether the obtained contour is a clear contour or not is judged through a software execution algorithm, and when the contour is the clear contour, the process of obtaining the contour of the reference nozzle and the contour of the nozzle to be calibrated is achieved.

S440 automatically calibrating a position of at least one nozzle to be calibrated in the Z direction based on the calibration point coordinates of the reference spray level and the calibration point coordinates of the nozzle to be calibrated.

Specifically, based on the coordinates of the calibration point of the reference spray accuracy and the coordinates of the calibration point of the nozzle to be calibrated, a position deviation value between the coordinates of the calibration point of the reference spray accuracy and the coordinates of the calibration point of the nozzle to be calibrated is calculated.

And automatically calibrating the position of at least one nozzle to be calibrated according to the position deviation value.

Specifically, through the obtained coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated, the position deviation value between the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated can be automatically calculated through software, so that the position calibration is performed.

As shown in fig. 15, the present invention also provides an automatic calibration apparatus for a nozzle position of a 3D printer, comprising:

the photographing module 201 is configured to obtain a reference nozzle image and at least one nozzle image to be calibrated from at least one calibration direction.

The coordinate acquisition module 202: and the calibration point coordinates of the reference spray nozzle and the calibration point coordinates of the nozzle to be calibrated are identified by image processing of the reference nozzle image and at least one image to be calibrated.

The auto-calibration module 203: and the calibration device is used for automatically calibrating the position of at least one nozzle to be calibrated in the calibration direction based on the coordinates of the calibration point of the reference spray nozzle and the coordinates of the calibration point of the nozzle to be calibrated.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of program modules is illustrated, and in practical applications, the above-described distribution of functions may be performed by different program modules, that is, the internal structure of the apparatus may be divided into different program units or modules to perform all or part of the above-described functions. Each program module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one processing unit, and the integrated unit may be implemented in a form of hardware, or may be implemented in a form of software program unit. In addition, the specific names of the program modules are only used for distinguishing the program modules from one another, and are not used for limiting the protection scope of the application.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or recited in detail in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described embodiments of the apparatus/method are merely exemplary, and it is exemplary that the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, and it is exemplary that a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.