A parametric CNC machining method and system for timber structure component joints

Abstract

This invention relates to the field of CNC machining technology for building timber structure components, specifically to a parametric CNC machining method and system for timber structure component nodes. The method involves dividing the timber structure component into multiple typical component nodes based on the node connection method; setting a reference point for each typical component node and extracting machining parameters; inputting the machining parameters into a PLC controller and converting them into I / O variables; pre-setting a VE variable array corresponding to each typical component node and writing the I / O variables into the VE variable array; calling the MAIN main program through a computer numerical control system to read the VE variable array; jumping to the corresponding node subroutine based on the typical component node in the VE variable array, assigning the VE variable array values ​​to local machining parameters, and generating machining instructions through CNC program processing; and controlling the machining equipment to perform machining according to the machining instructions. The method proposed in this invention effectively improves the production efficiency and accuracy of timber structure component machining, and reduces the production costs for enterprises.

Description

Technical Field

[0001] This invention relates to the field of CNC machining technology for structural components, specifically to a parametric CNC machining method and system for nodes of wooden structural components. Background Technology

[0002] With the continuous development of modern building structure theory and technology, people are constantly exploring how to achieve efficient construction of green buildings without affecting the economic practicality of the buildings themselves. Among them, modern glued laminated timber structures make more rational use of timber. Timber structural components can be processed in the factory and transported to the installation site, which greatly reduces the amount of construction work. This not only improves the design accuracy, but also meets the future trend of industrialization and modular production in the construction industry. The timber structure building manufacturing industry is developing towards mechanization, digitalization and intelligence.

[0003] Currently, CNC machining centers for woodworking are widely used in panel furniture manufacturing enterprises in China. The main processing steps include common woodworking processes such as board cutting, sawing, milling, and drilling. The processing of wooden structural building components is similar; sawing creates the external outline, some grooves, and ends of the components; milling creates tenons, mortises, and other joint connections; and drilling creates bolt holes and other structures. Common CNC machining centers used in wooden structural buildings can be broadly categorized according to the objects they process: CNC machining centers for wooden structural components, CNC machining centers for wooden frames, and CNC machining centers for composite walls. There are three main types of machining centers. CNC machining centers have strong comprehensive processing capabilities, enabling workpieces to complete multiple processing steps such as milling, drilling, and sawing in a single setup. They offer high processing accuracy and efficiency. However, large-scale timber structure processing in China mostly relies on imported equipment. While imported CNC machining centers are powerful, they are also much more expensive, resulting in excessively high processing and construction costs for timber structures, which most small and medium-sized timber structure enterprises cannot afford. Furthermore, they require highly skilled technicians, and operators need to have proficient skills and a certain level of professional expertise to perform the processing operations.

[0004] In addition, most timber structure manufacturers currently have outdated equipment, resulting in unstable production quality and a lack of automated equipment. Some processes are still manually operated, leading to slightly insufficient processing accuracy. Domestically produced CNC machine tools capable of parametric modular machining of timber structures are rare in the market, and research and development on CNC machining of timber structure building components are also very limited. Furthermore, due to the special nature of timber products, most timber structure components do not have a fixed and uniform standard size like metal parts. The size and type of each different building and each different component will vary depending on the design and structure. Therefore, in the actual design, verification, and machining process of timber structure building components, the timber building components and the required metal connectors are designed according to the actual situation. However, in the actual CNC machining center programming process, if the geometry of each component is programmed and output one by one according to different building components, not only will the program be lengthy and the data numerous, but it will also be prone to errors, resulting in low efficiency, high cost, and excessively high professional and technical requirements for operators, making it difficult to operate in practice. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a parametric CNC machining method for timber structure component nodes. This method divides the timber structure component into multiple typical component nodes based on the node connection method; sets a reference point for each typical component node and extracts machining parameters; inputs the machining parameters into a PLC controller and converts them into I / O variables; presets a VE variable array corresponding to each typical component node and writes the I / O variables into the VE variable array; the computer numerical control system calls the MAIN main program to read the VE variable array; based on the typical component node corresponding to the VE variable array, it jumps to the corresponding node subroutine, assigns the VE variable array values ​​to local machining parameters, and generates machining instructions through CNC program processing; and controls the machining equipment to perform machining according to the machining instructions. The method proposed in this invention effectively improves the efficiency and accuracy of timber processing production and reduces the production costs of enterprises.

[0006] This invention adopts the following technical solution: a parametric CNC machining method for nodes of wooden structural components, comprising: Based on the node connection method of the timber structure components, the timber structure components are divided into several typical component nodes; Each typical component node is assigned a reference point, and the machining parameters corresponding to each typical component node are extracted based on the reference point. The processing parameters corresponding to each typical component node are input into the PLC controller, and the PLC controller converts the processing parameters corresponding to each typical component node into IO variables. A VE variable array corresponding to each typical component node is preset, and the IO variable is written into the VE variable array of the corresponding typical component node; The computer digital control system calls the MAIN main program to read the VE variable array corresponding to each typical component node; The MAIN main program jumps to the corresponding node subroutine according to the typical component node corresponding to the VE variable array, and assigns the VE variable array corresponding to each typical component node to the local processing parameter through the corresponding node subroutine. The local machining parameters are processed by a CNC program to generate machining instructions, and the machining equipment is controlled to process the wooden structural components according to the machining instructions.

[0007] Furthermore, the timber structural components are divided into several typical component nodes, including: Obtain the load transfer path of key connection points in timber structural components; the key connection points include: beam-column connection points, beam-beam connection points, and column-foundation connection points; Based on the load transfer path, the timber structure components are divided into three types of basic component nodes, including: mortise and tenon joints, steel plate pin joints, and bracket joints. Typical component nodes are obtained based on the morphological characteristics of three types of basic component nodes; The mortise and tenon joints include: straight tenon joints, straight tenon mortise joints, I-beam joints, and lap joints. The steel plate pin type node includes: end steel plate pin connection node, non-end steel plate pin connection node, oblique end straight hole connection node and oblique end oblique hole connection node; The bracket-type node includes: a bracket-type connection node.

[0008] Furthermore, based on the reference point of each typical component node, the processing parameters corresponding to each typical component node are extracted, including: The processing parameters include shape parameters and position parameters; Each typical component node is assigned a reference point, and the machining parameters corresponding to each typical component node are extracted based on the geometric constraints of each part in each typical component node.

[0009] Furthermore, the processing parameters corresponding to each typical component node are input into the PLC controller, which then converts these parameters into I / O variables, including: The processing parameters corresponding to each typical component node are converted into binary data and sent to the PLC controller via the ADS protocol. The PLC controller writes the binary data corresponding to each typical component node into the pre-allocated IO variable address space in parallel.

[0010] Furthermore, a VE variable array corresponding to each typical component node is preset, and the IO variable is written into the VE variable array corresponding to the typical component node, including: The PLC controller pre-sets an array of VE variables corresponding to each typical component node; The IO variables are written to the VE variable array under the corresponding typical component node using the DMA engine.

[0011] Furthermore, the MAIN main program jumps to the corresponding node subroutine based on the typical component node corresponding to the VE variable array, and assigns the VE variable array corresponding to each typical component node to the local processing parameters through the corresponding node subroutine, including: In the MAIN main program, a node subroutine is established for each typical component node, and a node identifier mapping table is generated for each typical component node. The node subroutine corresponding to the VE variable array in the MAIN main program is determined based on the node identifier mapping table corresponding to each typical component node. The VE variable array is sent to the corresponding node subroutine via a program jump instruction; The node subroutine sequentially reads the elements in the VE variable array and assigns them as local processing parameters.

[0012] The present invention further proposes a parametric CNC machining system for timber structure component nodes to execute any of the above-mentioned parametric CNC machining methods for timber structure component nodes. The system includes: a parameter extraction module, a human-machine interaction module, a PLC control module, and a CNC module. The parameter extraction module is used to divide the wooden structure components into multiple typical component nodes according to the node connection method of the wooden structure components; set the reference point for each typical component node, and extract the processing parameters corresponding to each typical component node according to the reference point of each typical component node. The human-computer interaction module includes a typical component node selection unit, a processing parameter setting unit, and a 3D display unit for timber structure components. Specifically: the typical component node selection unit displays various typical component node types and provides option boxes for the user to select the typical component node to be processed; the processing parameter setting unit is used to input the processing parameters extracted by the parameter extraction module; and the 3D display unit for timber structure components displays the 3D model of the typical component node to be processed selected in the typical component node selection unit. The PLC control module is used to establish the IO variables corresponding to each typical component node. It reads the processing parameters input by the human-machine interaction module in real time through the ADS protocol and writes the corresponding IO variables according to the typical component node corresponding to the processing parameters. After writing the IO variables into the VE variable array of the corresponding typical component node, it maps them to the FPGA fixed register. The CNC module is used to call the MAIN main program CNC program through the computer digital control system to read the VE variables in the FPGA fixed register, and jump to the corresponding node subroutine according to the typical component node corresponding to the VE variable array. The corresponding node subroutine assigns the VE variable array corresponding to each typical component node to the local machining parameters; executes the CNC program to process the local machining parameters to generate machining instructions, and controls the machining equipment to process the wooden structure components according to the machining instructions.

[0013] The beneficial effects of this invention are as follows: This invention modularizes and parameterizes the processing of similar components and node connection methods, thereby extracting the processing parameters of component nodes and parametrically designing the size and position of component nodes. It transforms the traditional geometric design and processing process of component processing into a mathematical problem of component size and structural relationships, effectively reducing the writing of subsequent CNC machining programs, reducing program error rates, optimizing the CNC programming process, lowering the operational threshold of CNC machining, and enhancing the scientific nature of the design and processing process. Furthermore, based on parameterization, it establishes CNC machining programs for component nodes, creating a channel for parameters to be transmitted from the human-machine interface to the CNC machine tool. After the processing parameters are input into the human-machine interface, they are transmitted to the CNC program via the programmable logic controller (PLC), which calls the pre-written CNC machining program to instruct the machine tool to start processing. This lowers the operational threshold of CNC machining tools, allowing ordinary workers to operate the machining after simple training. In actual processing, only the node type needs to be called and the corresponding parameters input; no manual intervention is required, and processing can be completed in one feeding. This effectively improves production efficiency and accuracy, reduces enterprise production costs, achieves high-efficiency and high-precision processing, and improves the automation level of wood processing machinery. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic flowchart of a parametric CNC machining method for a wooden structure component node according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a parametric CNC machining system for a wooden structure component node according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the reference point setting of a straight tenon joint node according to an embodiment of the present invention; Figure 4This is a schematic diagram showing the reference point setting of a straight tenon and mortise joint component node according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the reference point setting for an I-shaped connection node according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the reference point setting for an overlapping connection node according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the orientation of the steel plate groove in an end steel plate pin connection node according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the reference point setting for an end steel plate pin connection node according to an embodiment of the present invention; Figure 9 This is a schematic diagram illustrating the reference point setting of a non-end steel plate pin connection node according to an embodiment of the present invention; Figure 10 This is a schematic diagram illustrating the reference point setting of a beveled end straight hole connection node according to an embodiment of the present invention; Figure 11 This is a schematic diagram illustrating the reference point setting of a beveled end beveled hole connection node according to an embodiment of the present invention; Figure 12 This is a schematic diagram of the reference point setting for a bracket-type connection node according to an embodiment of the present invention; Figure 13 This is a schematic diagram of the transmission route of processing parameters from the front end to the back end according to an embodiment of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] A schematic flowchart of a parametric CNC machining method for timber structure component nodes according to an embodiment of the present invention is shown below. Figure 1 As shown, it includes: Based on the node connection method of the timber structure components, the timber structure components are divided into several typical component nodes; Processing parameters are usually classified according to their structure, that is, the dimensional information of which part of the component they represent. In timber structure building components, they are mainly classified into several categories, such as the component's own parameters, tenon and mortise parameters, steel plate pin parameters, and bolt hole parameters. In different structures, the required processing parameters are mostly the same, with only a few differences. That is, it is sufficient to ensure that the extracted dimensional parameters can outline the characteristics of typical component nodes. Therefore, in this embodiment of the invention, the various parts of the timber structure component are first divided according to the node connection method of the timber structure component, thereby extracting multiple typical component nodes to facilitate the acquisition of processing parameters.

[0018] In one specific embodiment of the present invention, the load transfer path of key connection points in the timber structure components is first obtained; the key connection points include: beam-column connection points, beam-beam connection points, and column-foundation connection points; based on the load transfer path, the timber structure components are divided into three types of basic component nodes, including: mortise and tenon joints, steel plate pin joints, and bracket joints; based on the morphological characteristics of the three types of basic component nodes, typical component nodes are obtained, specifically including: Mortise and tenon joints: straight tenon joints, straight tenon and mortise joints, I-beam joints, and lap joints; Steel plate pin type joints: end steel plate pin connection joint, non-end steel plate pin connection joint, beveled end straight hole connection joint and beveled end beveled hole connection joint; Supported node: Supported connection node.

[0019] Each typical component node is assigned a reference point, and the machining parameters corresponding to each typical component node are extracted based on the reference point. Typical component nodes have a lot of dimensional information, and there are multiple choices for dimensional information. Taking a tenon component as an example, the distance from the tenon to the right side of the component and the distance from the tenon to the left side of the component can both indicate the left and right positions of the tenon component. However, we cannot arbitrarily choose a dimensional information that can clearly define the position. We need to set a reference point for the component based on the writing habits of the component machining code and the reference point of the machine tool. The dimensional information represented by the extracted machining parameters must be based on the reference point. We need to set the dimensional information that can clearly define the shape and position of the machining part from the reference point as the machining parameters of the component. That is, the extraction of machining parameters needs to consider the position of the reference point and set the machining parameters from the reference point. Therefore, we need to set a reference point for each typical component node separately, and extract the corresponding machining parameters for each typical component node according to the geometric constraint relationship of each part in each typical component node. Among them, the machining parameters include shape parameters and position parameters.

[0020] In a specific embodiment of the present invention, the specific method for obtaining the processing parameters corresponding to each typical component node is given as follows: The processing parameters extracted from the straight tenon component node include shape parameters and position parameters. The processing technology of the straight tenon component node mainly includes milling and drilling. The milling cutter mills out the tenon shape, and the drill bit drills out the bolt holes required for the component. In this embodiment of the invention, based on the shape of the straight tenon component node, its reference point needs to be set as a corner point of the tenon shoulder end face before extracting the processing parameters, such as... Figure 3 As shown in the figure, the red dots represent the reference points of the components. Further, the shape parameters of the straight tenon component nodes are first defined. These parameters mainly include two parts: the inherent shape parameters and the processing shape parameters. The inherent shape parameters include the cross-sectional width and height. The processing shape parameters include the tenon length, groove depth, groove height, and the number and diameter of bolt holes. The positional parameters include the tenon positioning parameters and the bolt hole positioning parameters. The tenon positioning parameters are the bottom edge distance and right edge distance. The bolt hole positioning parameters include the hole row spacing, hole column spacing, and the distance from the center of the positioning hole to the reference point, including the left edge distance and bottom edge distance. Thus, a total of 13 processing parameters are extracted from the straight tenon component nodes.

[0021] In most cases, the tenon is located in the center of the cross-section. The tenon width and tenon thickness are parameters that can be calculated. Tenon width = cross-section width - 2 × right side distance, and tenon thickness = cross-section height - 2 × bottom distance. The case where the tenon is not located in the center of the cross-section can be considered a very special case, an extreme case that is not commonly used, and is not considered in this embodiment of the invention. In this case, the tenon width and thickness cannot be set as processing parameters to avoid redundant parameters.

[0022] Bolt holes on the tenon are all through holes by default, meaning the hole depth equals the tenon width. There will be no more than three bolt holes for this type of tenon component, and the arrangement of the bolt holes will vary depending on their values. The bolt hole position parameters, right distance and bottom distance, are the distances between the nearest hole to the reference point and the reference point. For machining and installation purposes, the tenon and mortise joints are generally chamfered. The chamfer radius for straight tenon components is the milling cutter radius.

[0023] In addition to straight tenon joints, mortise and tenon structures should also include matching straight tenon groove joints. The parameters of these straight tenon groove joints are identical to those of the straight tenon joints. In actual machining, when inputting the machining parameters of the straight tenon joints into the CNC system, the parameters of the straight tenon groove joints that are related to the straight tenon joints should be consistent with the values ​​of the tenon joints to ensure a complete mortise and tenon connection. The parameter setting approach for straight tenon groove joints is the same as that for straight tenon joints, considering both shape and position parameters. The reference point is set at the upper right corner of the front view, such as... Figure 4As shown, the specific processing parameters include: component cross-section width, cross-section height, mortise depth, groove depth, groove height, mortise top distance, right distance, number of bolt holes, hole diameter, hole row spacing, hole column spacing, hole left distance, and hole top distance. Among these, the component cross-section width, cross-section height, mortise top distance, and right distance are different from the parameters of the straight tenon component node. The remaining parameters should be the same as the input values ​​of the matching straight tenon component node. The right distance is defined based on the reference point in the top view being in the lower right corner, and the hole left distance and hole top distance are defined based on the reference point in the right view being in the upper left corner.

[0024] The machining parameters for I-beam connectors are also divided into shape parameters and position parameters. The reference point settings for I-beam connectors are as follows: Figure 5 As shown, the specific processing parameters include: cross-sectional width and height, mortise and tenon width and height, and bolt hole shape and position parameters. Position parameters include the top edge distance of the mortise and the bolt hole spacing, as well as the top edge distance and left edge distance of the bolt holes. Based on the outline and structural characteristics of the I-shaped component, the mortise and tenon at both ends of the component are through, so the mortise depth is equal to the cross-sectional height. According to the cross-sectional dimensions of the component, the number of bolt holes in the component generally does not exceed 3, and the bolt holes are arranged linearly. The depth of the bolt holes is equal to the cross-sectional width SW-2 × mortise and tenon width.

[0025] The machining parameters extracted from the lap joint connection node are basically the same as those for the straight tenon and mortise joint component node. Specific reference point settings are as follows: Figure 6 As shown, the specific processing parameters include: cross-sectional width and height, top and bottom heights and overlap lengths of the milled end of the lap joint node. By determining the top and bottom heights and overlap lengths of the lap joint node, the angle of the lap slope and the shape and height of the lap joint can be determined. The processing parameters for extracting bolt holes from the component include the number of bolt holes, hole diameter, hole spacing, and left side distance of the hole.

[0026] The characteristic of end plate pin connection nodes is that the plate pin is inserted at the end of the component. The pin can be inserted into the plate groove in both the width and height directions of the component's cross-section. Based on the characteristics of plate pin metal connectors, the direction of the plate groove and the plane of the bolt hole are related, such as... Figure 7 As shown, if a component has a steel plate groove in direction A, the bolt holes are located on elevation A; if a component has a steel plate groove in direction B, the bolt holes are located on elevation B. A schematic diagram illustrating the setting of the reference points is shown below. Figure 8 As shown, if the setting is in the upper right corner of facade A, then the extraction and setting of processing parameters will be based on this.

[0027] For the end plate pin connection node itself, the parameters involved include the component cross-sectional width SW and the component cross-sectional height SH. The end face of the end plate pin connection node is provided with holes to accommodate the nuts on the connected components, so as to ensure a tight connection between the components. Therefore, the diameter of the holes on the end face of the component is generally large and the depth is shallow. At the same time, the end plate pin connection node is mainly divided into two directions, A and B. The processing parameters for the steel plate groove and bolt holes in both directions are the same. In this embodiment of the invention, the processing parameter extraction settings for the bolt holes in the steel plate groove in direction A are taken as an example. Direction B can be the same as direction A. The steel plate groove is generally located at the center of the width or height direction of the component cross-section by default. Therefore, the position parameters of the steel plate groove do not need to be input by the user. The main parameters include the width and depth of the steel plate groove. The processing parameters involved in the bolt holes on the A side include six parameters: number of holes, hole diameter, hole row spacing, hole column spacing, right side distance, and bottom side distance.

[0028] The parameter settings for non-end plate pin connection nodes and end plate pin connection nodes are similar, the main difference being the location of the plate groove. For non-end plate pins, the plate groove is located on the facade of the component, while the bolt holes are located on the adjacent facade. The reference point for extracting the machining parameters of the non-end plate groove is as follows: Figure 9 As indicated by the red marker, the extraction of processing parameters for non-end steel plate pin connection nodes mainly considers two aspects: the main processing of the steel plate groove and the bolt holes. The specific processing parameters include two shape parameters: the width and depth of the steel plate groove, and the right side distance of the steel plate groove position parameter. The processing parameters involved in the bolt holes include six parameters: the number of holes, the hole diameter, the hole row spacing, the hole column spacing, the right side distance, and the bottom distance. It should also be noted that the position parameter names are set according to the positional relationship between the processing part and the reference point in the view direction of the parameter.

[0029] The beveled-end straight-hole connection node still uses a plate pin connection. Compared to end plate pin connections and non-end plate pin connections, this type of component node has a certain angle at the end, which can meet the design and processing requirements of beams or rafters in most timber structures. The reference points for setting the component's processing parameters are as follows: Figure 10 As shown, the processing parameters are first set based on the reference point, including the component's cross-sectional width, cross-sectional height, and angle of the beveled end. The remaining parameters are set with reference to the processing parameters of the non-end steel plate pin connection node, including the shape parameters: steel plate groove width and steel plate groove depth. If the steel plate groove is at the component end, it is assumed to be located at the center of the width direction of the end, with a length equal to the height of the component cross-section cap; therefore, the position and length parameters of the steel plate groove are not considered. The bolt hole processing parameters include six parameters: number of holes, hole diameter, hole row spacing, hole column spacing, right side distance, and bottom distance.

[0030] The beveled end and beveled hole connection node has a certain angle at its end, which can meet the design and processing requirements of beams or rafters in most timber structures. The reference points for setting the processing parameters of the component are as follows: Figure 11 As shown, the processing parameters set according to the reference point include: cross-sectional width, component cross-sectional height, and angle of the inclined end. The remaining parameters refer to the processing parameters of the non-end steel plate pin connection node, including the shape parameters of the steel plate groove width and the steel plate groove depth. If the component steel plate groove is at the end of the component, it is assumed that the steel plate groove is located at the center position of the width direction of the end, and the length is the same as the height of the component cross-section cover. Therefore, the position and length parameters of the steel plate groove are not considered. The processing parameters of the bolt holes include six parameters: number of holes, hole diameter, hole row spacing, hole column spacing, right side distance, and bottom side distance.

[0031] Bracket-type connection nodes are commonly used in timber structures. However, the manufacturing process of this type of connection node is relatively simple, consisting only of bolt holes that connect to the metal connector bracket. The extracted machining parameters are consistent with those of bolt holes in other types of components, including the shape and position parameters of the bolt holes. Specific parameter classifications and reference points are as follows: Figure 12 As shown, the parametric design changes only manifest in the number and arrangement of bolt holes, and the specific shape of the components does not change. The bolt hole arrangement of each component in the steel plate pin node is the same, so the embodiments of the present invention will not be described in detail.

[0032] It should be noted that the parameterization of a component involves changes caused by different parameter values. In this component node, these changes are manifested as changes in the dimensions of the lap joint and the bolt holes. However, the shape of the component does not change accordingly. Therefore, no special explanation is given for the parameter changes of the component.

[0033] The processing parameters corresponding to each typical component node are input into the PLC controller, and the PLC controller converts the processing parameters corresponding to each typical component node into IO variables. In this embodiment of the invention, the processing parameters corresponding to each typical component node are first converted into binary data, and the binary data is sent to the PLC controller via the ADS protocol. The PLC controller writes the binary data corresponding to each typical component node into the pre-allocated IO variable address space in parallel, thereby realizing the conversion of processing parameters into IO variables.

[0034] A VE variable array corresponding to each typical component node is preset, and the IO variable is written into the VE variable array of the corresponding typical component node; In this embodiment of the invention, by pre-setting the VE variable array corresponding to each typical component node in the PLC controller, the DMA engine can be used to write the IO variables into the VE variable array under the corresponding typical component node.

[0035] The MAIN main program jumps to the corresponding node subroutine according to the typical component node corresponding to the VE variable array, and assigns the VE variable array corresponding to each typical component node to the local processing parameter through the corresponding node subroutine. In this embodiment of the invention, the computer digital control system calls the MAIN main program to read the VE variable array corresponding to each typical component node; a node subroutine corresponding to each typical component node is established in the MAIN main program, and a node identifier mapping table corresponding to each typical component node is generated; the node subroutine corresponding to the VE variable array in the MAIN main program is determined according to the node identifier mapping table corresponding to each typical component node; the VE variable array is sent to the corresponding node subroutine through a program jump instruction; the node subroutine sequentially reads the elements in the VE variable array and assigns them as local processing parameters.

[0036] The local machining parameters are processed by a CNC program to generate machining instructions, and the machining equipment is controlled to process the wooden structural components according to the machining instructions.

[0037] In a specific embodiment of the present invention: The process of inputting the machining parameters corresponding to each typical component node into the PLC controller is achieved through a human-machine interface (HMI). After the user inputs the corresponding machining parameters through the HMI, the parameters are downloaded from the front end of the HMI to the PLC, and then from the PLC to the NC machining program code. Finally, the machining parameter values ​​are transferred from the display interface to the machine tool. In the parametric design and CNC machining of wooden structural components, the transmission of machining parameters is a crucial part. The transmission route of machining parameters from the front end to the back end is as follows: Figure 13 As shown, it specifically includes: The CNC machining operation of timber structure components begins with the user inputting the specific values ​​of the component's machining parameters into the human-machine interface. The parameter values ​​are then transmitted through the interaction between parameter variables defined in the PLC. In this embodiment of the invention, the machining parameters of typical component nodes are defined as relevant variables and set as CNC parameters, which correspond to the IO variables in the PLC controller. These parameters are used to store the machining parameters, including the corresponding shape parameters and position parameters, input into the human-machine interface. That is, after inputting the machining parameters into the human-machine interface, clicking the parameter download button will send the machining parameters to the PLC controller and convert them into IO variables.

[0038] After the machining parameters are transmitted through the human-machine interface, the data in the CNC program can be exchanged with the external PLC controller through the VE variable array. By using the VE variable array, functions such as condition judgment or execution of motion trajectory in the CNC program can be realized. For example, if the workpiece height is 500 in the machining parameters input in the human-machine interface, it can be represented as VE.NC_01_INF0 as 500 in the VE variable array. Similarly, other machining parameters are also transmitted to the VE variable array in this way.

[0039] In this embodiment of the invention, when presetting the VE variable array corresponding to each typical component node, the VE variable array is configured by setting the name, type, and access method of the VE variable array in the channel configuration file of the CNC program, thereby generating a variable area in the form of an array. For example, when converting the channel configuration file to Channel 1, the VE variable array for interaction with the PLC is set in the "VE Var" tab of the Channel 1 parameter settings. Among them, "NC_01_INF0" stores the machining parameters of the straight tenon component node, and "NC_02_INF0" is the machining parameters of the straight tenon groove component node.

[0040] After writing the machining parameters into the VE variable array, the pre-written NC code is called in the CNC program, which defines the machining parameters to enable interaction between the VE variable data and the local machining parameters defined in the CNC program. In this embodiment of the invention, since the parametric design of the timber structure component library includes various different component node types, and the machining procedures and programs for each type of component are different, if a set of NC code is written for each type of component and then combined into a complete NC code, the entire program would be too large, adding many judgments and making the program more complex. Moreover, if additions or modifications are needed later, the entire NC code would have to be modified. Therefore, in order to facilitate the later parametric design of the component library, this embodiment of the invention... Additions or modifications are made to reduce instruction judgments and prevent program errors or lag. The same settings and processing procedures for components of the same type are extracted and compiled into a MAIN function file. The parameter changes for each wooden structure component are each written as a separate complete subroutine, serving as the activation subroutine under the MAIN function. Selecting different wooden structure component types and inputting different parameter values ​​activates different subroutines, instructing the machine tool to complete the processing. In actual processing, after the processing parameters interact with the VE variable array, the CNC program is called to run the MAIN function. Based on the input parameter values, the corresponding sub-processing program is activated. After activation, instructions are issued to control the machine tool to complete the actual processing based on the assigned local processing parameter values.

[0041] A parametric CNC machining system for timber structure component nodes according to an embodiment of the present invention is shown in the schematic diagram below. Figure 2 As shown, it includes: a parameter extraction module, a human-machine interaction module, a PLC control module, and a numerical control module; The parameter extraction module is used to divide the wooden structure components into multiple typical component nodes according to the node connection method of the wooden structure components; set the reference point for each typical component node, and extract the processing parameters corresponding to each typical component node according to the reference point of each typical component node. The human-computer interaction module includes a typical component node selection unit, a processing parameter setting unit, and a 3D display unit for timber structure components. Specifically: the typical component node selection unit displays various typical component node types and provides option boxes for selecting the typical component node to be processed; the processing parameter setting unit is used to input the processing parameters extracted by the parameter extraction module; and the 3D display unit for timber structure components displays the 3D model of the typical component node to be processed selected in the typical component node selection unit. The PLC control module is used to establish the IO variables corresponding to each typical component node. It reads the processing parameters input by the human-machine interaction module in real time through the ADS protocol and writes the corresponding IO variables according to the typical component node corresponding to the processing parameters. After writing the IO variables into the VE variable array of the corresponding typical component node, it maps them to the FPGA fixed register. The CNC module is used to call the MAIN main program CNC program through the computer digital control system to read the VE variables in the FPGA fixed register, and jump to the corresponding node subroutine according to the typical component node corresponding to the VE variable array. The corresponding node subroutine assigns the VE variable array corresponding to each typical component node to the local machining parameters; executes the CNC program to process the local machining parameters to generate machining instructions, and controls the machining equipment to process the wooden structure components according to the machining instructions.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A parametric CNC machining method for nodes of timber structure components, characterized in that, include: Based on the node connection method of the timber structure components, the timber structure components are divided into several typical component nodes; Each typical component node is assigned a reference point, and the corresponding machining parameters are extracted based on the reference point of each typical component node. The processing parameters corresponding to each typical component node are input into the PLC controller, and the PLC controller converts the processing parameters corresponding to each typical component node into IO variables. A VE variable array corresponding to each typical component node is preset, and the IO variable is written into the VE variable array of the corresponding typical component node; The computer digital control system calls the MAIN main program to read the VE variable array corresponding to each typical component node; The MAIN main program jumps to the corresponding node subroutine according to the typical component node corresponding to the VE variable array, and assigns the VE variable array corresponding to each typical component node to the local processing parameter through the corresponding node subroutine. The local machining parameters are processed by a CNC program to generate machining instructions, and the machining equipment is controlled to process the wooden structural components according to the machining instructions.

2. The parametric CNC machining method for timber structure component nodes according to claim 1, characterized in that: The timber structure components are divided into several typical component nodes, including: Obtain the load transfer path of key connection points in timber structural components; the key connection points include: beam-column connection points, beam-beam connection points, and column-foundation connection points; Based on the load transfer path, the timber structure components are divided into three types of basic component nodes, including: mortise and tenon joints, steel plate pin joints, and bracket joints. Typical component nodes are obtained based on the morphological characteristics of three types of basic component nodes; The mortise and tenon joints include: straight tenon joints, straight tenon groove joints, I-beam joints, and lap joints. The steel plate pin type node includes: end steel plate pin connection node, non-end steel plate pin connection node, oblique end straight hole connection node and oblique end oblique hole connection node; The bracket-type node includes: a bracket-type connection node.

3. The parametric CNC machining method for timber structure component nodes according to claim 1, characterized in that: Based on the reference point of each typical component node, the machining parameters corresponding to each typical component node are extracted, including: The processing parameters include shape parameters and position parameters; Each typical component node is assigned a reference point, and the machining parameters corresponding to each typical component node are extracted based on the geometric constraints of each part in each typical component node.

4. The parametric CNC machining method for timber structure component nodes according to claim 1, characterized in that: The processing parameters corresponding to each typical component node are input into the PLC controller, which then converts these parameters into I / O variables, including: The processing parameters corresponding to each typical component node are converted into binary data and sent to the PLC controller via the ADS protocol. The PLC controller writes the binary data corresponding to each typical component node into the pre-allocated IO variable address space in parallel.

5. The parametric CNC machining method for timber structure component nodes according to claim 1, characterized in that: A pre-defined VE variable array is established for each typical component node. The IO variables are then written into the VE variable array corresponding to the typical component node, including: The PLC controller pre-sets an array of VE variables corresponding to each typical component node; The IO variables are written to the VE variable array under the corresponding typical component node using the DMA engine.

6. The parametric CNC machining method for a timber structure component node according to claim 1, characterized in that: The MAIN main program jumps to the corresponding node subroutine based on the typical component node corresponding to the VE variable array. The corresponding node subroutine then assigns the VE variable array corresponding to each typical component node to local processing parameters, including: In the MAIN main program, a node subroutine is established for each typical component node, and a node identifier mapping table is generated for each typical component node. The node subroutine corresponding to the VE variable array in the MAIN main program is determined based on the node identifier mapping table corresponding to each typical component node. The VE variable array is sent to the corresponding node subroutine via a program jump instruction; The node subroutine sequentially reads the elements in the VE variable array and assigns them as local processing parameters.

7. A parametric CNC machining system for timber structure component nodes, comprising performing a parametric CNC machining method for timber structure component nodes as described in any one of claims 1-6, characterized in that, include: Parameter extraction module, human-machine interaction module, PLC control module, and CNC module; The parameter extraction module is used to divide the wooden structure components into multiple typical component nodes according to the node connection method of the wooden structure components; Each typical component node is assigned a reference point, and the corresponding machining parameters are extracted based on the reference point of each typical component node. The human-computer interaction module includes a typical component node selection unit, a processing parameter setting unit, and a three-dimensional display unit for wooden structure components. The typical component node selection unit is used to display various typical component node types and provide option boxes for users to select typical component nodes to be processed. The processing parameter setting unit is used to input the processing parameters extracted by the parameter extraction module; the three-dimensional display unit of the wooden structure component is used to display the three-dimensional model of the typical component node to be processed selected in the typical component node selection unit. The PLC control module is used to establish the IO variables corresponding to each typical component node. It reads the processing parameters input by the human-machine interaction module in real time through the ADS protocol and writes the corresponding IO variables according to the typical component node corresponding to the processing parameters. After writing the IO variables into the VE variable array of the corresponding typical component node, it maps them to the FPGA fixed register. The CNC module is used to call the MAIN main program CNC program through the computer digital control system to read the VE variables in the FPGA fixed register, and jump to the corresponding node subroutine according to the typical component node corresponding to the VE variable array. The corresponding node subroutine assigns the VE variable array corresponding to each typical component node to the local machining parameters; executes the CNC program to process the local machining parameters to generate machining instructions, and controls the machining equipment to process the wooden structure components according to the machining instructions.

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