Additive and subtractive collaborative concrete 3D printing method and apparatus

Abstract

The application provides an additive-subtractive collaborative concrete 3D printing method and device, which comprises the following steps: constructing a three-dimensional topological optimization model of a concrete component to be printed, planning an additive path based on the three-dimensional topological optimization model and printing; detecting an image of a target printing layer based on a pre-constructed defect detection model; when it is determined that the target printing layer has defects, determining printing parameters of a next layer of the target printing layer at the target defects based on defect parameters of the target defects; when the printing of the concrete component to be printed is completed, performing three-dimensional scanning on the printed component; and when it is determined that the printed component has contour errors, performing subtractive processing on the printed component based on defect parameters of the contour errors. The application can improve the printing quality and precision of the concrete printed component.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of structure optimization and additive and subtractive technology, and particularly relates to a method and device for additive and subtractive collaborative concrete 3D printing. BACKGROUND

[0002] Concrete 3D printing technology is an additive manufacturing technology that does not require a template. Through the rational arrangement of concrete materials, a three-dimensional design structure can be flexibly constructed in a layer-by-layer accumulation manner. In recent years, it has been widely used in the construction industry due to its automation, freedom and rapidity.

[0003] Concrete 3D printing can complete the related construction using software modeling data, and can construct a large number of complex structures in a short time, greatly reducing the construction time of related components. In addition, the concrete 3D printing technology can integrate the model to be printed and eliminate the construction process of unnecessary components.

[0004] However, due to the difficulty in effectively controlling the rheological properties of the concrete material and the coordination of the printing process, it is difficult to avoid the formation of hole defects due to interruptions or voids during the printing process. In addition, the profile error of the excess material formed by the adhesion of the material leads to many defects in the formed structure, and the forming quality is difficult to meet the designer's requirements. SUMMARY

[0005] The embodiment of the present application provides a method and device for additive and subtractive collaborative concrete 3D printing to solve the problem that many defects appear in the printed components after forming.

[0006] In a first aspect, the embodiment of the present application provides a method for additive and subtractive collaborative concrete 3D printing, comprising:

[0007] constructing a three-dimensional topological optimization model of a concrete component to be printed, planning an additive path based on the three-dimensional topological optimization model, and printing;

[0008] detecting the image of the target printing layer based on a pre-constructed defect detection model; wherein the target printing layer is the layer just printed by the 3D printing system and does not include the last layer;

[0009] when it is determined that the target printing layer has defects, determining the printing parameters of the next layer of the target printing layer at the target defect based on the defect parameters of the target defect; wherein the target defect is any defect existing in the target printing layer, and the defect is a hole existing in the target printing layer;

[0010] when the concrete component to be printed is completed, performing three-dimensional scanning on the printed component;

[0011] When it is determined that the printed component has a contour error, the printed component is subjected to subtractive processing based on a defect parameter of the contour error; wherein the contour error at least includes an excess material defect.

[0012] In a possible implementation, a three-dimensional topology optimization model of the concrete component to be printed is constructed, comprising:

[0013] Based on the three-dimensional structure of the concrete component to be printed, a design domain of the concrete component to be printed is determined, and the design domain is discretized into a plurality of finite element units;

[0014] Taking the element density and the printing angle vector of each finite element unit as design variables, taking the minimization of the structural strain energy as the objective function, and taking the amount of concrete material as the constraint condition, the optimal element density and the optimal printing angle vector of each finite element unit are determined;

[0015] Based on the optimal element density and the optimal printing angle vector of each finite element unit, a three-dimensional topology optimization model of the concrete component to be printed is constructed.

[0016] In a possible implementation, based on the defect parameter of the target defect, the printing parameters of the next layer of the target printing layer at the target defect are determined, comprising:

[0017] Based on the coordinates of the center of the envelope circle of the two-dimensional slice of the target printing layer and the diameter, and the coordinates of the center of the envelope circle of the image of the target printing layer and the diameter, the two-dimensional slice of the target printing layer and the image of the target printing layer are subjected to coordinate transformation to determine the relative coordinates of the two-dimensional slice of the target printing layer and the image of the target printing layer;

[0018] Based on the relative coordinates of the two-dimensional slice of the target printing layer and the image of the target printing layer, the position of the target defect on the two-dimensional slice of the target printing layer is determined;

[0019] Based on the identification of the detection result of the image of the target printing layer by the defect detection model, the volume of the target defect is determined; wherein when the defect detection model detects that there is a defect on the image of the target printing layer, the defect is identified by a regular pattern;

[0020] Based on the position of the target defect on the two-dimensional slice of the target printing layer and the volume of the target defect, the printing parameters of the next layer of the target printing layer at the target defect are determined.

[0021] In a possible implementation, the printing parameters of the next layer of the target printing layer at the target defect are determined, comprising:

[0022] Based on the flow pressure curve of the extrusion flow under different pumping pressures, the fitting coefficient of the 3D printing system is fitted and determined;

[0023] determine a pumping pressure, a print layer height, and a print speed of the 3D printing system at a target defect of a next print layer of the target print layer based on a volume of the target defect and fitting coefficients;

[0024] ;

[0025] wherein V is the volume of the target defect, h is the print layer height of the next layer at the target defect, P is the pumping pressure of the next layer at the target defect, f is the print speed of the next layer at the target defect, a and b are fitting coefficients, and d is the diameter of the print nozzle.

[0026] In a possible implementation, when it is determined that the printed component has the contour error, before the subtractive processing of the printed component based on the defect parameters of the contour error, the method comprises:

[0027] aligning a coordinate system of a three-dimensional point cloud model of the printed component and a three-dimensional CAD model of the printed component based on the three-dimensional point cloud model obtained by scanning the printed component by a three-dimensional laser scanner, the three-dimensional CAD model of the printed component at the time of construction, and an ICP algorithm.

[0028] determining whether the printed component has the contour error based on the three-dimensional point cloud model after the coordinate alignment processing and the three-dimensional CAD model after the coordinate alignment processing.

[0029] In a possible implementation, when it is determined that the printed component has the contour error, the subtractive processing of the printed component based on the defect parameters of the contour error comprises:

[0030] when a size on the three-dimensional point cloud model after the coordinate alignment processing is greater than a size on the three-dimensional CAD model after the coordinate alignment processing, it is determined that the printed component has the excess material defect;

[0031] determining a defect size error value and a position of a first target defect based on a size and a position of the contour error on the three-dimensional point cloud model after the coordinate alignment processing and a size and a position of the contour error on the three-dimensional CAD model after the coordinate alignment processing; wherein the first target defect is any one of the excess material defects;

[0032] subtractively processing the excess material defects existing in the printed component based on the defect size error values and the positions of all the excess material defects.

[0033] In a possible implementation, the contour error further comprises a surface roughness defect.

[0034] When it is determined that the printed component has the contour error, the subtractive processing of the printed component based on the defect parameters of the contour error further comprises:

[0035] determine that the printed component exists a surface roughness defect when the roughness of the three-dimensional point cloud model is greater than the preset roughness;

[0036] determine the position of the second target defect and the roughness error of the second target defect of the printed component based on the roughness of the three-dimensional point cloud model and the preset roughness;

[0037] determine the polishing parameters of the subtractive head of the 3D printing system at the second target defect based on the roughness error of the second target defect and the surface hardness of the concrete, so as to perform subtractive processing on the surface roughness defect existing in the printed component.

[0038] In a possible implementation, the polishing parameters include a grinding head radius, a grinding head rotation speed, and a grinding head feed speed.

[0039] The calculation method of the grinding head radius r, the grinding head rotation speed n, and the grinding head feed speed v is as follows:

[0040] ;

[0041] wherein q1, q2, and q3 are grinding parameters corresponding to different materials and different processes, H is the surface hardness of the concrete, is the roughness error, and k and n are operation coefficients.

[0042] In a second aspect, an embodiment of the present application provides a 3D printing device for additive and subtractive materials for concrete, comprising:

[0043] a construction model module, configured to construct a three-dimensional topology optimization model of a concrete component to be printed, and plan an additive path and perform printing based on the three-dimensional topology optimization model;

[0044] an image detection module, configured to detect an image of a target printing layer based on a pre-constructed defect detection model; wherein the target printing layer is a layer just printed by the 3D printing system and does not include the last layer;

[0045] a defect repair module, configured to, when it is determined that the target printing layer exists a defect, determine printing parameters of a next layer of the target printing layer at the target defect based on defect parameters of the target defect; wherein the target defect is any defect existing in the target printing layer, and the defect is a hole existing in the target printing layer;

[0046] a three-dimensional scanning module, configured to perform three-dimensional scanning on the printed component after the concrete component to be printed is printed;

[0047] a subtractive processing module, configured to, when it is determined that the printed component exists a contour error, perform subtractive processing on the printed component based on defect parameters of the contour error; wherein the contour error at least includes an excess material defect.

[0048] In a possible implementation, the model building module is configured to determine a design domain of the to-be-printed concrete component based on a three-dimensional structure of the to-be-printed concrete component, and discretize the design domain into a plurality of finite element units;

[0049] The model building module is configured to determine an optimal unit density and an optimal printing angle vector of each finite element unit, taking the unit density and the printing angle vector of each finite element unit as design variables, taking minimization of structural strain energy as an objective function, and taking a concrete material usage as a constraint condition;

[0050] The model building module is configured to build a three-dimensional topology optimization model of the to-be-printed concrete component based on the optimal unit density and the optimal printing angle vector of each finite element unit.

[0051] In a possible implementation, the defect repairing module is configured to perform coordinate transformation on a two-dimensional slice of a target printing layer and an image of the target printing layer, and determine relative coordinates of the two-dimensional slice of the target printing layer and the image of the target printing layer, based on coordinates of a center of a bounding circle of the two-dimensional slice of the target printing layer and a diameter of the center, and coordinates of a center of a bounding circle of the image of the target printing layer and a diameter of the center.

[0052] The defect repairing module is configured to determine a position of a target defect on the two-dimensional slice of the target printing layer, based on the relative coordinates of the two-dimensional slice of the target printing layer and the image of the target printing layer.

[0053] The defect repairing module is configured to determine a volume of the target defect, based on an identifier of a detection result of the image of the target printing layer by the defect detection model; when the defect detection model detects that there is a defect on the image of the target printing layer, the defect is identified by a rule pattern.

[0054] The defect repairing module is configured to determine a printing parameter of a next layer of the target printing layer at the target defect, based on the position of the target defect on the two-dimensional slice of the target printing layer and the volume of the target defect.

[0055] In a possible implementation, the defect repairing module is configured to determine fitting coefficients of a 3D printing system by fitting, based on a flow-pressure curve of extrusion flow under different pumping pressures.

[0056] The defect repairing module is configured to determine a pumping pressure, a printing layer height, and a printing speed of the 3D printing system at the target defect of the next printing layer of the target printing layer, based on the volume of the target defect and the fitting coefficients.

[0057] ;

[0058] wherein V is the volume of the target defect, h is the printing layer height of the next layer at the target defect, P is the pumping pressure of the next layer at the target defect, f is the printing speed of the next layer at the target defect, a and b are the fitting coefficients, and d is a diameter of a printing nozzle.

[0059] In a possible implementation, the subtractive processing module is configured to perform coordinate system alignment processing on the three-dimensional point cloud model of the printed component and the three-dimensional CAD model of the printed component based on the three-dimensional point cloud model obtained by scanning the printed component with the three-dimensional laser scanner, the three-dimensional CAD model of the printed component at the time of construction, and an ICP algorithm.

[0060] Based on the three-dimensional point cloud model after the coordinate alignment processing and the three-dimensional CAD model after the coordinate alignment processing, it is determined whether the printed component has a contour error.

[0061] In a possible implementation, the subtractive processing module is configured to determine that the printed component has a redundant material defect when the size on the three-dimensional point cloud model after the coordinate alignment processing is greater than the size on the three-dimensional CAD model after the coordinate alignment processing.

[0062] Based on the size and position of the contour error on the three-dimensional point cloud model after the coordinate alignment processing and the size and position of the contour error on the three-dimensional CAD model after the coordinate alignment processing, the defect size error value and the position of the first target defect are determined; wherein the first target defect is any one of the redundant material defects.

[0063] Based on the defect size error values and positions of all the redundant material defects, the subtractive processing is performed on the redundant material defects existing in the printed component.

[0064] In a possible implementation, the contour error further includes a surface roughness defect.

[0065] The subtractive processing module is configured to determine that the printed component has a surface roughness defect when the roughness of the three-dimensional point cloud model is greater than a preset roughness.

[0066] Based on the roughness of the three-dimensional point cloud model and the preset roughness, the position of the second target defect and the roughness error of the second target defect are determined.

[0067] Based on the roughness error of the second target defect and the surface hardness of the concrete, the polishing parameters of the subtractive head of the 3D printing system at the second target defect are determined to perform subtractive processing on the surface roughness defect existing in the printed component.

[0068] In a possible implementation, the polishing parameters include a grinding head radius, a grinding head rotation speed, and a grinding head feed speed.

[0069] The calculation method of the grinding head radius r, the grinding head rotation speed n, and the grinding head feed speed v is as follows:

[0070] ;

[0071] wherein q1, q2, q3 are grinding parameters corresponding to different materials and different processes respectively, and H is the surface hardness of the concrete, is the roughness error, and k and n are operation coefficients.

[0072] In a third aspect, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method according to the first aspect or any possible implementation manner of the first aspect when executing the computer program.

[0073] In a fourth aspect, a computer readable storage medium is provided, which stores a computer program, and the computer program implements the steps of the method according to the first aspect or any possible implementation manner of the first aspect when executed by a processor.

[0074] The embodiment of the present application provides a kind of additive-subtractive collaborative concrete 3D printing method and equipment, first, the three-dimensional topological optimization model of the concrete component to be printed is constructed, additive path is planned based on the three-dimensional topological optimization model and printing is carried out.Then, the image of target printing layer is detected based on the pre-constructed defect detection model.Next, when determining that target printing layer exists defect, the printing parameter of the next layer of target printing layer at target defect is determined based on the defect parameter of target defect.Then, after the concrete component to be printed is printed, the printed component is scanned three-dimensionally.Finally, when determining that printed component exists contour error, the printed component is subtractively processed based on the defect parameter of contour error.

[0075] By using defect detection model to detect hole defect of just printed target printing layer, and when detecting that target printing layer exists hole defect, the filling repair of target printing layer defect is realized by changing the printing parameter of the next layer of target printing layer at target defect, so that hole defect does not appear in printed component.In addition, after the concrete component to be printed is printed, its contour is scanned three-dimensionally, and when determining that there is contour error on its contour through scanning result, it is subtractively processed, to ensure that the contour is the same as the contour when designing.Through the repair of hole defect in additive process and the subtractive processing of redundant contour in subtractive process, the quality of printed component meets the design requirements. BRIEF DESCRIPTION OF DRAWINGS

[0076] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0077] Figure 1 is the implementation flowchart of the additive and subtractive material collaborative concrete 3D printing method provided by the embodiment of the present application.

[0078] Figure 2 is the defect detection model identification schematic diagram provided by the embodiment of the present application.

[0079] Figure 3 is the structural schematic diagram of the multifunctional subtractive head provided by the embodiment of the present application.

[0080] Figure 4 is the structural schematic diagram of the additive and subtractive material collaborative concrete 3D printing device provided by the embodiment of the present application.

[0081] Figure 5 is the schematic diagram of the electronic device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0082] In the following description, specific details are set forth in order to provide a thorough understanding of the embodiments of the present application. However, persons skilled in the art should understand that the present application can also be implemented in other embodiments without these specific details. In other cases, 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 details.

[0083] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be described by specific embodiments in combination with the drawings.

[0084] 3D printing is an additive manufacturing technology developed in recent years without the need for a template. Through reasonable arrangement of concrete materials, flexible construction of three-dimensional design structures can be realized.

[0085] However, for concrete 3D printing, due to the difficulty in effectively controlling the coordination of the rheological properties of the concrete material and the printing process, defects such as interruption, void, and adhesion of multiple materials are difficult to avoid during the printing process, resulting in difficulty in meeting the design requirements of the molding quality. At the same time, for large-scale prefabricated structures, although a larger-diameter printing nozzle can ensure efficiency, the molding precision is poor. Using a smaller-diameter nozzle improves the molding precision, but the construction efficiency is low. Therefore, for concrete 3D printing, the quality control and molding precision optimization of the additive molding process are the focus of current research.

[0086] To solve the problems in the prior art, the embodiments of the present application provide an additive and subtractive collaborative concrete 3D printing method and equipment. First, the additive and subtractive collaborative concrete 3D printing method provided by the embodiments of the present application will be introduced. It should be noted that the 3D printing system in the present application includes an additive mechanical arm and a subtractive mechanical arm.

[0087] Referring to Figure 1 which shows the implementation flowchart of the additive and subtractive collaborative concrete 3D printing method provided by the embodiments of the present application, and the details are as follows:

[0088] Step S110, a three-dimensional topological optimization model of a to-be-printed concrete component is constructed, and an additive path is planned and printed based on the three-dimensional topological optimization model.

[0089] In some embodiments, in order to improve the structural performance of the to-be-printed concrete component by improving the anisotropy of the 3D printing concrete printing path, the printing angle is introduced as a design variable, and the collaborative optimization of the structural performance and the path is realized. The specific implementation steps are as follows:

[0090] Step S1110, based on the three-dimensional structure of the to-be-printed concrete component, the design domain of the to-be-printed concrete component is determined, and the design domain is discretized into a plurality of finite element units.

[0091] Step S1120, taking the element density and the printing angle vector of each finite element unit as design variables, taking the minimization of the structural strain energy as the objective function, and taking the concrete material usage as the constraint condition, the optimal element density and the optimal printing angle vector of each finite element unit are determined.

[0092] Step S1130, based on the optimal element density and the optimal printing angle vector of each finite element unit, a three-dimensional topological optimization model of the to-be-printed concrete component is constructed.

[0093] By taking the structural strain energy as the objective function to improve the structural stiffness, the concrete material consumption as the constraint condition to realize the lightweight of the structure, and the unit density and printing angle vector as the design variable, the mechanical anisotropy characteristics of 3D printed concrete are fully utilized, the structural performance can be further improved, so that the construction advantages of 3D printed concrete can be effectively exerted.

[0094] For example, the formula of the three-dimensional topology optimization model is as follows:

[0095]

[0096]

[0097] wherein, p and θ are the unit density and the printing angle vector respectively, n is the number of units for discretizing the design domain; C is the structural strain energy, and the smaller the value is, the greater the structural stiffness is, p e and v e are the finite element units e corresponding to the unit density and the unit volume, K and U are the overall stiffness matrix and the node displacement vector respectively, V and V 0 are the material volume after optimization and the total volume of the initial design domain respectively, f is the specified volume fraction, p min is the minimum allowable unit density.

[0098] Anisotropy is mainly reflected in the calculation of the rotated elastic matrix D e used for finite element analysis, specifically as follows:

[0099] ;

[0100] wherein, θ is the printing angle vector, T is the rotation matrix, D 0 is the initial elastic matrix before rotation.

[0101] In the additive process, by topologically optimizing the three-dimensional model of the concrete component to be printed, the accuracy of the additive manufacturing process can be improved.

[0102] Step S120, detecting the image of the target printing layer based on the pre-constructed defect detection model.

[0103] The target printing layer is a layer just printed by the 3D printing system and does not include the last layer.

[0104] After the target printing layer is printed, a high-speed camera or a laser scanner in the 3D printing system can obtain an image of the target printing layer. In order to improve the accuracy of detection, before the image of the target printing layer is detected by using a pre-constructed defect detection model, the image needs to be pre-processed, including denoising processing, contrast enhancement, image registration and the like. After the image is pre-processed, the processed image can be input into the pre-constructed defect detection model to detect whether the image has a hole defect.

[0105] The pre-constructed defect detection model is obtained by training a neural network model or other types of models using images containing hole defects, and the hole defects on the images containing hole defects are all labeled, and the accuracy of the model is tested before use to meet the accuracy requirements.

[0106] After being detected by the pre-constructed defect detection model, if the image has a hole defect, the hole defect will be identified from a regular image.

[0107] Here, a defect detection model is briefly introduced, which is a concrete 3D printing defect recognition model based on DeeplabV3+ semantic recognition model. The construction steps of the model are as follows:

[0108] First, a concrete 3D printing defect training set is constructed, including various images of concrete 3D printing that can be collected, and the defects in the images are labeled by using Labelme software.

[0109] Then, the DeeplabV3+ model is constructed, and the learning rate lr is set to 0.001, the weight decay is set to 0.0001, and the loss function is set to cross-entropy loss function.

[0110] Next, the training set, the validation set and the test set are randomly set according to 7:1:2, and the constructed DeeplabV3+ model is trained.

[0111] Finally, the actual printing video image is input into the constructed defect detection model as a parameter to obtain real-time hole defect position information.

[0112] Figure 2 A schematic view of the hole defect identified after being detected by the pre-constructed defect detection model provided by the present application.

[0113] Step S130, when it is determined that the target print layer has a defect, determining, based on a defect parameter of the target defect, a print parameter of a next layer of the target print layer at the target defect.

[0114] The target defect is any defect present in the target print layer, and the defect is a hole present in the target print layer.

[0115] When a defect of a hole is detected, the position and volume of the defect need to be determined in order to repair it.

[0116] In some embodiments, the position and volume of the defect can be determined by the following steps in order to determine the print parameter of the next layer of the target print layer at the target defect. The specific steps are as follows:

[0117] Step S1301, based on the coordinates of the center of the envelope circle of the two-dimensional slice of the target print layer and the diameter, and the coordinates of the center of the envelope circle of the image of the target print layer and the diameter, performing coordinate transformation on the two-dimensional slice of the target print layer and the image of the target print layer to determine the relative coordinates of the two-dimensional slice of the target print layer and the image of the target print layer.

[0118] The two-dimensional slice is to convert a three-dimensional topology optimization model into an STL format file, and to slice the STL format file.

[0119] The image of the target print layer is an image processed by binaryzation, and the defect is white and the rest is black. The image processed by binaryzation has an outline of the target print layer and an outline of the hole defect.

[0120] The coordinates of the center of the envelope circle of the two-dimensional slice of the target print layer and the diameter are and ; the coordinates of the center of the envelope circle of the image of the target print layer and the diameter are and After coordinate transformation of the two images, the relative coordinates of the two-dimensional slice of the target print layer and the image of the target print layer are obtained:

[0121] , ;

[0122] wherein and are the relative coordinates of the two-dimensional slice of the target print layer and the image of the target print layer relative to the center.

[0123] Step S1302, based on the relative coordinates of the two-dimensional slice of the target print layer and the image of the target print layer, determining the position of the target defect on the two-dimensional slice of the target print layer.

[0124] Step S1303, based on the identification of the detection result of the image of the target print layer by the defect detection model, determine the volume of the target defect.

[0125] Step S1304, based on the position of the target defect on the two-dimensional slice of the target print layer and the volume of the target defect, determine the printing parameter of the next layer of the target print layer at the target defect.

[0126] In this embodiment, the position of the target defect on the two-dimensional slice of the target print layer and the volume of the target defect can be determined based on the above steps S1301-S1304 to determine the printing parameter of the next layer of the target print layer at the target defect.

[0127] In some embodiments, since the volume of each target defect is different, in order to ensure that each defect can be repaired, different printing parameters need to be set for different defects. The setting steps of the printing parameter are as follows:

[0128] Step S13041, based on the flow pressure curve of the extrusion flow under different pumping pressures, determine the fitting coefficient of the 3D printing system.

[0129] Firstly, the flow pressure curve is obtained by testing the extrusion flow under different pumping pressures, and then the fitting coefficient of the 3D printing system is determined based on the least square method.

[0130] Step S13042, based on the volume of the target defect and the fitting coefficient, determine the pumping pressure, the print layer height and the printing speed of the 3D printing system at the target defect of the next print layer of the target print layer.

[0131] The specific calculation formula is:

[0132] ;

[0133] Wherein, V is the volume of the target defect, h is the print layer height of the next layer at the target defect, P is the pumping pressure of the next layer at the target defect, f is the printing speed of the next layer at the target defect, a and b are fitting coefficients, and d is the diameter of the printing nozzle.

[0134] By setting different printing parameters for different hole defects, the remaining printing parameters without defects are still the same as the original printing parameters, so that the next layer of the target print layer can be printed, and the defects in the target print layer can be repaired.

[0135] When the last layer is printed and the printing of the last layer is completed, the image of the last layer will not be detected for defects. Instead, contour detection needs to be performed on the entire printed component.

[0136] By detecting the image of each target printing layer in the additive process, when it is detected that there is a hole defect, the printing parameters of the target defect of the next printing layer of the target printing layer are adjusted to repair the target defect, thereby reducing the hole defects in the additive process and improving the printing quality of the component.

[0137] Step S140, after the printing of the concrete component to be printed is completed, the printed component is scanned in three dimensions.

[0138] A high-precision three-dimensional point cloud model of the printed component can be extracted in real time by using a line laser scanner, i.e., its geometric contour. In order to determine whether there is an error in the three-dimensional point cloud model, the coordinate system of the three-dimensional point cloud model and the three-dimensional CAD model of the printed component at the time of construction needs to be aligned to determine whether there is a contour error. The three-dimensional CAD model here is a three-dimensional topology optimization model of the concrete component to be printed.

[0139] In some embodiments, the alignment of the coordinate system of the three-dimensional point cloud model and the three-dimensional CAD model of the printed component at the time of construction can be achieved by the ICP algorithm, and the specific steps are as follows:

[0140] Step S1401, based on the three-dimensional point cloud model obtained by scanning the printed component by the three-dimensional laser scanner, the three-dimensional CAD model of the printed component at the time of construction, and the ICP algorithm, the three-dimensional point cloud model of the printed component and the three-dimensional CAD model are processed in the coordinate system.

[0141] The process of coordinate system alignment is to unify two or more three-dimensional models under different angles and different reference coordinate systems through certain rotation and translation transformation, so as to obtain the complete information of the object and perform a series of visualization operations on the object.

[0142] The ICP algorithm is essentially a least squares-based optimal matching algorithm, which repeatedly finds corresponding points and optimal rigid body transformation until a certain convergence criterion is met, and the iteration is terminated.

[0143] Step S1402, based on the three-dimensional point cloud model after the coordinate alignment processing and the three-dimensional CAD model after the coordinate alignment processing, it is determined whether the printed component has a contour error.

[0144] The contour error here at least includes the excess material defect, and the distance between the corresponding points of the three-dimensional point cloud model after the coordinate alignment processing and the three-dimensional CAD model after the coordinate alignment processing can determine whether the printed component has a contour error.

[0145] In addition, the contour error can also include a roughness error, that is, the roughness of the printed component can be obtained by analyzing the three-dimensional point cloud model. When designing the component, the roughness of the component is required to meet the requirements. By comparing the roughness of the printed component with the preset roughness of the three-dimensional CAD model of the printed component during construction, it can also be determined whether the printed component has a roughness error, which is also a contour error.

[0146] By three-dimensional laser scanning of the printed component, and by the scanned three-dimensional point cloud model and the three-dimensional CAD model of the printed component during construction, it can be determined whether there is a contour error.

[0147] It should be noted that, in the additive stage, that is, after the printed concrete component is printed, only the printed component is scanned, and the scanning does not include hole defect detection, but only detects the excess material defects and roughness of the contour surface.

[0148] Step S150, when it is determined that the printed component has a contour error, the printed component is subjected to subtractive processing based on the defect parameters of the contour error.

[0149] In some embodiments, the contour error can be an excess material defect. First, when the size on the three-dimensional point cloud model after coordinate alignment processing is greater than the size on the three-dimensional CAD model after coordinate alignment processing, it can be determined that the printed component has an excess material defect. Then, based on the size and position of the contour error on the three-dimensional point cloud model after coordinate alignment processing, and the size and position of the contour error on the three-dimensional CAD model after coordinate alignment processing, the defect size error value and position of the first target defect are determined. Wherein, the first target defect is any one of the excess material defects. Finally, after determining the defect size error value and position of all excess material defects, the excess material on the printed component can be removed.

[0150] In this embodiment, a subtractive needle assembly is arranged on the subtractive mechanical arm of the 3D printing system. The subtractive needle assembly can include a control motor, a shaft coupling, a subtractive needle clamp and a subtractive needle. Different diameters and lengths of subtractive needles can be replaced according to different application scenarios. When it is determined that there is an excess material defect and the defect size error value and position of all excess material defects are determined, the subtractive needle can be used to remove the excess material on the printed component. During the subtractive process, the three-dimensional laser scanner can extract the three-dimensional point cloud model in real time during the subtractive process, and monitor the subtractive process in real time.

[0151] In some embodiments, since the printed component needs to meet the different precision requirements of the component surface flatness under different working conditions, the contour error also includes a surface roughness defect, and the roughness of the printed component needs to be detected after printing.

[0152] Firstly, when the roughness of the three-dimensional point cloud model of the printed component is greater than the preset roughness, it is determined that the printed component has surface roughness defects. After determining that there are surface roughness defects, then, based on the roughness of the three-dimensional point cloud model and the preset roughness, the position of the printed component where the second target defect exists and the roughness error of the second target defect are determined. Wherein, the second target defect is any one of the surface roughness defects. Finally, through the roughness error of the second target defect and the surface hardness of the concrete, the polishing parameters of the subtractive head of the 3D printing system at the second target defect are determined to perform subtractive processing on the surface roughness defects existing in the printed component.

[0153] In this embodiment, the polishing assembly and the polishing assembly are also provided on the subtractive mechanical arm of the 3D printing system, the polishing assembly includes a coarse grinding head assembly and a fine grinding head assembly. The coarse grinding head assembly includes a control motor, a shaft coupling, a subtractive needle clamp and a tungsten carbide metal grinding head, wherein the type of the cutting edge of the tungsten carbide metal grinding head can be replaced according to the application scenario. The fine grinding piece assembly includes a control motor, a shaft coupling, a subtractive needle clamp and a diamond grinding piece, wherein the mesh number of the diamond grinding piece can also be replaced according to the application scenario. The polishing disc assembly includes a control motor, a shaft coupling, a subtractive needle clamp and a water polishing piece, wherein the arc and mesh number of the water polishing piece can also be replaced according to the application scenario.

[0154] Since the roughness of the surface of the printed component is not completely the same, different subtractive methods need to be selected according to different roughness, that is, coarse grinding, fine grinding, fine grinding or polishing process is selected according to the roughness to achieve the surface flatness required by the design.

[0155] In order to improve the efficiency and flexibility of processing, the subtractive needle assembly, the coarse grinding head assembly, the fine grinding head assembly and the polishing assembly can be integrated on the multifunctional subtractive head. As shown in Figure 3 The multifunctional subtractive head includes a mounting base 9 fixed with a subtractive mechanical arm end connector through a bolt hole 10. The driving part 8 is built-in with a driving motor for connecting and driving the rotary table 6 and the rotary table 7. The lower part of the rotary table 6 is respectively fixed with the subtractive needle assembly 4, the coarse grinding head assembly 3, the fine grinding piece assembly 1, the polishing disc assembly 2 and the control hub 5. Among them, the control hub 5 is a control hub integrating scanning, image processing and coded feedback.

[0156] In some embodiments, in order to improve the processing efficiency and processing quality, the rotating speed and feed speed of the assembly can be adjusted to improve the processing efficiency and quality.

[0157] In the case of considering the radius of the grinding head, the rotating speed of the grinding head, the feed speed and the material hardness, the control formula of the grinding force and the roughness of the surface is as follows:

[0158] ;

[0159] wherein F represents the size of the grinding force; q 1、 q 2、 q 3 are grinding parameters related to specific materials and processes, which can be determined by experiments or experience, and different materials and processes can have different values; r is the radius of the grinding head; n is the grinding head speed; v is the grinding head feed speed; and H is the surface hardness of the concrete.

[0160] In addition, during the grinding of the concrete component, there is a certain relationship between the grinding force and the surface roughness of the component. The greater the grinding force, the smaller the surface roughness of the component, and the relationship between the grinding force and the roughness is:

[0161] ;

[0162] The above two formulas are integrated to obtain the relationship between the roughness and the grinding head radius, the grinding head speed, the feed speed, and the material hardness, and the formula is as follows:

[0163] ;

[0164] wherein q1, q2, and q3 are grinding parameters corresponding to different materials and different processes, respectively, H is the surface hardness of the concrete, is the roughness error, and k and n are operation coefficients.

[0165] After determining the roughness error and the position of each surface roughness defect, the corresponding subtractive coefficient can be determined using the above formula according to the roughness error, so as to not only improve the speed of grinding and printing the completed component, but also improve the grinding quality, so that the surface meets the design requirements.

[0166] By scanning the completed component in three dimensions, when it is determined that there are excess material defects and / or surface roughness defects on the contour surface, the detected contour error is processed by the subtractive assembly on the subtractive mechanical arm. Thus, the error requirements of the designer on the geometric size precision of the 3D printed concrete prefabricated component are met, and the surface precision and yield of the printed component are improved.

[0167] The application realizes the design and construction integrated processing of components from modeling to final completion of subtractive, not only improves the processing efficiency of 3D printing concrete prefabricated components, but also detects the image of each printing layer in the additive processing process, and the last printing layer is not included, when it is determined that there is a hole defect in the image, the hole defect is repaired by controlling the printing parameters of the next layer, and the processing quality of the prefabricated component is improved. In addition, after the prefabricated component is printed, the profile is scanned three-dimensionally, and when it is detected that there is a profile error, the profile is processed subtractively to polish the profile surface, so that the profile meets the requirements of surface precision and dimensional precision of the design. Through one coordinate positioning, the whole process of additive and subtractive processing can be realized, and the error caused by the change of coordinate system can be avoided. In the additive processing process, only each layer of printing layer except the last layer is detected for hole defect. In the subtractive processing process, only the excess material defect and surface roughness defect existing on the profile surface are detected, and the hole defect is not detected.

[0168] The concrete 3D printing method provided by the application first constructs a three-dimensional topological optimization model of a to-be-printed concrete component, plans an additive path based on the three-dimensional topological optimization model, and performs printing. Then, the image of the target printing layer is detected based on a pre-constructed defect detection model. Next, when it is determined that the target printing layer has a defect, the printing parameters of the next layer of the target printing layer at the target defect are determined based on the defect parameters of the target defect. Then, when the to-be-printed concrete component is printed, the printed component is scanned three-dimensionally. Finally, when it is determined that the printed component has a profile error, the printed component is processed subtractively based on the defect parameters of the profile error.

[0169] By using the defect detection model to capture the target printing layer that is just printed in real time, when it is determined that the target printing layer has a hole defect, the printing parameters of the next layer of the target printing layer at the defect are determined based on the geometric parameters of the captured hole defect. When the to-be-printed concrete component is printed, the printed component is scanned three-dimensionally, three-dimensional point cloud data is obtained, and point cloud data at geometric feature points of the printed model is extracted, which is compared with a topological optimization digital model, the geometric positive and negative errors of the actual printed forming model and the digital model are quantified, and the positive and negative errors are processed subtractively.

[0170] It should be understood that the size of the serial number of each step in the above-mentioned embodiments does not mean the order of execution, the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the application.

[0171] Based on the additive and subtractive collaborative concrete 3D printing method provided in the above embodiments, correspondingly, the present application also provides a specific implementation mode of an additive and subtractive collaborative concrete 3D printing device applied to the additive and subtractive collaborative concrete 3D printing method. Please refer to the following embodiments.

[0172] As shown in Figure 4 , an additive and subtractive collaborative concrete 3D printing device 300 is provided, comprising:

[0173] A construction model module 410 is configured to construct a three-dimensional topological optimization model of a concrete component to be printed, and plan an additive path and perform printing based on the three-dimensional topological optimization model;

[0174] An image detection module 420 is configured to detect an image of a target printing layer based on a pre-constructed defect detection model; wherein the target printing layer is a layer just printed by the 3D printing system and does not include the last layer;

[0175] A defect repair module 430 is configured to, when it is determined that the target printing layer has a defect, determine the printing parameters of the next layer of the target printing layer at the target defect based on the defect parameters of the target defect; wherein the target defect is any defect existing in the target printing layer;

[0176] A three-dimensional scanning module 440 is configured to perform three-dimensional scanning on the printed component when the concrete component to be printed is completed;

[0177] A subtractive processing module 450 is configured to, when it is determined that the printed component has a contour error, perform subtractive processing on the printed component based on the defect parameters of the contour error; wherein the contour error at least includes an excess material defect.

[0178] In one possible implementation, the construction model module 410 is configured to determine a design domain of the concrete component to be printed based on the three-dimensional structure of the concrete component to be printed, and discretize the design domain into a plurality of finite element units;

[0179] The unit density and the printing angle vector of each finite element unit are taken as design variables, the minimization of the structural strain energy is taken as the objective function, and the concrete material usage is taken as the constraint condition, so as to determine the optimal unit density and the optimal printing angle vector of each finite element unit;

[0180] Based on the optimal unit density and the optimal printing angle vector of each finite element unit, the three-dimensional topological optimization model of the concrete component to be printed is constructed.

[0181] In a possible implementation, the defect repairing module 430 is configured to perform coordinate transformation on the two-dimensional slice of the target print layer and the image of the target print layer based on the coordinates of the center of the envelope circle of the two-dimensional slice of the target print layer and the diameter of the envelope circle, and the coordinates of the center of the envelope circle of the image of the target print layer and the diameter of the envelope circle, and determine relative coordinates of the two-dimensional slice of the target print layer and the image of the target print layer.

[0182] The position of the target defect on the two-dimensional slice of the target print layer is determined based on the relative coordinates of the two-dimensional slice of the target print layer and the image of the target print layer.

[0183] The volume of the target defect is determined based on the identification of the detection result of the image of the target print layer by the defect detection model. When the defect detection model detects that there is a defect on the image of the target print layer, the defect is identified by a regular pattern.

[0184] The printing parameters of the next layer of the target print layer at the target defect are determined based on the position of the target defect on the two-dimensional slice of the target print layer and the volume of the target defect.

[0185] In a possible implementation, the defect repairing module 430 is configured to determine the fitting coefficients of the 3D printing system based on the flow-pressure curve of the extrusion flow under different pumping pressures.

[0186] The pumping pressure, the print layer height, and the printing speed of the 3D printing system at the target defect of the next print layer of the target print layer are determined based on the volume of the target defect and the fitting coefficients.

[0187] ;

[0188] wherein V is the volume of the target defect, h is the print layer height of the next layer at the target defect, P is the pumping pressure of the next layer at the target defect, f is the printing speed of the next layer at the target defect, a and b are the fitting coefficients, and d is the diameter of the printing nozzle.

[0189] In a possible implementation, the subtractive processing module 450 is configured to perform coordinate system alignment processing on the three-dimensional point cloud model of the printed component and the three-dimensional CAD model of the printed component based on the three-dimensional point cloud model obtained by scanning the printed component by the three-dimensional laser scanner, the three-dimensional CAD model of the printed component at the time of construction, and the ICP algorithm.

[0190] Whether the printed component has a contour error is determined based on the three-dimensional point cloud model after the coordinate alignment processing and the three-dimensional CAD model after the coordinate alignment processing.

[0191] In a possible implementation, the subtractive processing module 450 is configured to determine that the printed component has the excess material defect when the size of the coordinate-aligned three-dimensional point cloud model is greater than the size of the coordinate-aligned three-dimensional CAD model.

[0192] Based on the size and position of the contour error on the coordinate-aligned three-dimensional point cloud model and the size and position of the contour error on the coordinate-aligned three-dimensional CAD model, the defect size error value and the position of the first target defect are determined, wherein the first target defect is any one of the excess material defects.

[0193] Based on the defect size error values and the positions of all the excess material defects, the subtractive processing is performed on the excess material defects in the printed component.

[0194] In a possible implementation, the contour error further includes a surface roughness defect.

[0195] The subtractive processing module 450 is configured to determine that the printed component has the surface roughness defect when the roughness of the three-dimensional point cloud model is greater than the preset roughness.

[0196] Based on the roughness of the three-dimensional point cloud model and the preset roughness, the position of the second target defect and the roughness error of the second target defect in the printed component are determined.

[0197] Based on the roughness error of the second target defect and the surface hardness of the concrete, the polishing parameters of the subtractive head of the 3D printing system at the second target defect are determined, so as to perform the subtractive processing on the surface roughness defect in the printed component.

[0198] In a possible implementation, the polishing parameters include the radius of the grinding head, the rotating speed of the grinding head, and the feeding speed of the grinding head.

[0199] The calculation method of the radius r of the grinding head, the rotating speed n of the grinding head, and the feeding speed v of the grinding head is as follows:

[0200] ;

[0201] wherein q1, q2, and q3 are grinding parameters corresponding to different materials and different processes, H is the surface hardness of the concrete, R is the roughness error, k and n are operation coefficients.

[0202] During polishing, different mesh numbers of grinding wheels can be replaced in real time according to the roughness. During coarse grinding, a grinding wheel matched with the corrugated surface of the 3D component is used. During fine grinding, a grinding wheel matched with the particle size of quartz sand is used. During polishing, a polishing disc matched with the fineness of cement is used.

[0203] ​In addition, a polishing paste mainly composed of stearic acid, fatty acid, aluminum oxide, micron-level ultra-fine quartz sand and nano-level glue powder can be used, through the synergistic effect of organic and inorganic materials, filling the material surface gap and smoothness, and at the same time improving the material surface hardness.

[0204] Figure 5 is a schematic diagram of an electronic device provided by an embodiment of the application. Figure 5 As shown, the electronic device 5 of this embodiment includes a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. The processor 50 implements the steps in each of the additive and subtractive material collaborative concrete 3D printing method embodiments described above when executing the computer program 52, such as steps 110-150 shown in Figure 1 Alternatively, the processor 50 implements the functions of each module in each of the device embodiments described above when executing the computer program 52, such as the functions of modules 410-450 shown in Figure 4 .

[0205] For example, the computer program 52 can be divided into one or more modules, which are stored in the memory 51 and executed by the processor 50 to complete the application. The one or more modules can be a series of computer program instruction segments that can complete a specific function, which are used to describe the execution process of the computer program 52 in the electronic device 5. For example, the computer program 52 can be divided into modules 410-450 shown in Figure 4 .

[0206] The electronic device 5 can include, but is not limited to, a processor 50, a memory 51. Those skilled in the art can understand that Figure 5 The electronic device 5 is only an example and does not constitute a limitation on the electronic device 5, and can include more or fewer components than shown, or combine certain components, or different components, for example, the electronic device can also include an input / output device, a network access device, a bus, etc.

[0207] The processor 50 can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0208] The memory 51 can be an internal storage unit of the electronic device 5, such as a hard disk or a memory of the electronic device 5. The memory 51 can also be an external storage device of the electronic device 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 51 can also include both the internal storage unit and the external storage device of the electronic device 5. The memory 51 is used to store the computer program and other programs and data required by the electronic device. The memory 51 can also be used to temporarily store data that has been output or will be output.

[0209] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to complete all or part of the above described functions. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit, and the integrated unit can be realized in the form of hardware or in the form of software. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the present application. The specific working process of the units and modules in the above system can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0210] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can refer to the relevant description of other embodiments.

[0211] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0212] In the embodiments provided by the present application, it should be understood that the disclosed apparatus / equipment and method can be implemented in other ways. For example, the apparatus / equipment embodiments described above are merely schematic. The division of the modules or units is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or communication connection between the units can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or in other forms.

[0213] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place, or distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0214] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0215] The integrated module / unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of each additive and subtractive material collaborative concrete 3D printing method embodiment described above can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0216] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method of additive-subtractive synergic concrete 3D printing, characterized in that, The method comprises the following steps: constructing a three-dimensional topological optimization model of a to-be-printed concrete component, planning an additive path and printing based on the three-dimensional topological optimization model; detecting the image of the target printing layer based on the pre-constructed defect detection model; wherein the target printing layer is the layer just printed by the 3D printing system and does not include the last layer; when it is determined that the target printing layer has defects, determining the printing parameters of the next layer of the target printing layer at the target defect based on the defect parameters of the target defect; wherein the target defect is any defect existing in the target printing layer, and the defect is a hole existing in the target printing layer; after the to-be-printed concrete component is printed, performing three-dimensional scanning on the printed component; performing coordinate system alignment processing on the three-dimensional point cloud model of the printed component and the three-dimensional CAD model based on the three-dimensional laser scanner, the three-dimensional point cloud model obtained by scanning the printed component, the three-dimensional CAD model of the printed component at the time of construction, and the ICP algorithm; determining whether the printed component has contour errors based on the three-dimensional point cloud model after coordinate alignment processing and the three-dimensional CAD model after coordinate alignment processing; when it is determined that the printed component has contour errors, performing subtractive processing on the printed component based on the defect parameters of the contour errors; wherein the contour errors at least include excess material defects and surface roughness defects; when it is determined that the printed component has the contour errors, performing subtractive processing on the printed component based on the defect parameters of the contour errors, further comprising: when the roughness of the three-dimensional point cloud model is greater than the preset roughness, it is determined that the printed component has a surface roughness defect; based on the roughness of the three-dimensional point cloud model and the preset roughness, determining the position of the second target defect and the roughness error of the second target defect in the printed component; wherein the second target defect is any one of the surface roughness defects; based on the roughness error of the second target defect and the surface hardness of the concrete, determining the polishing parameters of the subtractive head of the 3D printing system at the second target defect to perform subtractive processing on the surface roughness defects existing in the printed component; the polishing parameters include the radius of the grinding head, the rotating speed of the grinding head, and the feed speed of the grinding head; the calculation method of the radius of the grinding head r, the rotating speed of the grinding head n1, and the feed speed of the grinding head v is: Wherein, q1, q2, q3 are grinding parameters corresponding to different materials and different processes respectively, H is the surface hardness of concrete, R a is the roughness error, k and n2 are operation coefficients.

2. The AM-CMMC 3D printing method according to claim 1, wherein, the method for constructing a three-dimensional topological optimization model of a to-be-printed concrete component comprises the following steps: based on the three-dimensional structure of the to-be-printed concrete component, determining the design domain of the to-be-printed concrete component, and discretizing the design domain into a plurality of finite element units; taking the unit density and the printing angle vector of each finite element unit as design variables, taking the minimization of the structural strain energy as the objective function, and taking the concrete material usage as the constraint condition, determining the optimal unit density and the optimal printing angle vector of each finite element unit; constructing a three-dimensional topology optimization model of the concrete component to be printed based on the optimal element density and the optimal printing angle vector of each finite element unit.

3. The AM-CMM concrete 3D printing method of claim 1, wherein, The printing parameter of the next layer of the target printing layer at the target defect is determined based on the defect parameter of the target defect. The relative coordinates of the two-dimensional slice of the target printing layer and the image of the target printing layer are determined by coordinate transformation based on the coordinates and diameter of the center of the envelope circle of the two-dimensional slice of the target printing layer and the coordinates and diameter of the center of the envelope circle of the image of the target printing layer. The position of the target defect on the two-dimensional slice of the target printing layer is determined based on the relative coordinates of the two-dimensional slice of the target printing layer and the image of the target printing layer. The volume of the target defect is determined based on the identification of the detection result of the image of the target printing layer by the defect detection model; wherein when the defect detection model detects that there is a defect on the image of the target printing layer, the defect is identified by a regular pattern. The printing parameter of the next layer of the target printing layer at the target defect is determined based on the position of the target defect on the two-dimensional slice of the target printing layer and the volume of the target defect.

4. The AM-CMM concrete 3D printing method of claim 1, wherein, When it is determined that the printed component has the contour error, the printed component is subtractively processed based on the defect parameter of the contour error, including: When the size on the three-dimensional point cloud model after coordinate alignment processing is greater than the size on the three-dimensional CAD model after coordinate alignment processing, it is determined that the printed component has a redundant material defect. The defect size error value and position of the first target defect are determined based on the size and position of the contour error on the three-dimensional point cloud model after coordinate alignment processing and the size and position of the contour error on the three-dimensional CAD model after coordinate alignment processing; wherein the first target defect is any one of the redundant material defects. All redundant material defects in the printed component are subtractively processed based on the defect size error value and position of all redundant material defects.

5. An electronic device, comprising: The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 4.

6. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 5. The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 4.

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