A STEP-NC online interpretation method for machining robots

Abstract

A STEP-NC online interpretation method for a processing robot, opening a STEP-NC file and performing text processing, checking basic syntax, and storing the file in an internal data format in units of lines; establishing a tree data structure according to the relationship between the internal entities of the file, and obtaining a complete mapping of STEP-NC data on the internal data; traversing the established data structure in a numbered order, and establishing a coordinate transformation matrix between a robot coordinate system, a clamping coordinate system, and a workpiece coordinate system; searching an executable structure entity list, and generating a tool motion trajectory in a feature coordinate system according to the order of the executable structure entities in the list and transforming it into a tool trajectory in a robot coordinate system; and finally outputting the processing robot motion trajectory according to the type of processing robot controller. The present invention reduces the workload of information conversion and programming during the working process of the processing robot, and effectively solves the problems of low work efficiency, inconvenient operation, and poor adaptability of STEP-NC file interpretation of the processing robot.

Description

Technical Field

[0001] The invention relates to the technical field of numerical control automation and industrial robots, and in particular to an online interpretation method of a STEP-NC file for a processing robot. Background Art

[0002] Industrial robots are gradually being used in cutting processing to supplement the shortcomings of traditional machine tools in on-site processing and large-scale parts processing. The programming and program interpretation of processing robots is one of the main steps to achieve automated processing, and it plays an important role in fully achieving processing goals and ensuring processing accuracy. In cutting processing, the shape, size and placement of the processed object often change, so the program needs to be modified at any time. At present, the most commonly used industrial robot programming methods are teaching programming and offline programming. Teaching programming is mainly suitable for application scenarios such as handling and loading and unloading that only require point control, while offline programming can be used for application scenarios such as welding and spraying that have certain requirements for the robot's motion trajectory. The characteristics of these two programming methods are that they basically do not need to be modified after programming once, and the program complexity cannot be too high, so there are obvious disadvantages when applied to processing robots. At the same time, these methods, like the G code in CNC machine tools, use motion instructions and auxiliary instructions arranged in execution order to represent the robot's trajectory and other auxiliary function switches, completely losing high-level data such as geometric information, process information and execution status information. This requires operators to make complex settings according to the working environment and part conditions every time they program, which increases the difficulty of programming.

[0003] The STEP-NC standard adopts an object-oriented data description method to fully describe the information of the processed object and the processing process information, and can be used as a carrier for closed-loop lossless transmission of data in the manufacturing system. By reading the STEP-NC file, the robot control system can accurately grasp the data such as the size, position and cutting amount of the part, and can complete the predetermined processing task without manually setting too many parameters. However, the existing robot controller does not support the interpretation of STEP-NC files, and there are few CAM platforms that can process STEP-NC files, so only part of the process information can be extracted offline, and then programming and other operations can be performed according to the traditional manual operation of CAM software. This working method not only does not improve the efficiency of processing robot programming, but also requires an additional information extraction operation due to the introduction of STEP-NC files, and does not preserve the integrity of the STEP-NC file information. Therefore, there is an urgent need for an online interpretation method of STEP-NC files for processing robots to reduce the workload of information conversion and programming in the manufacturing process.

[0004] Related patent documents: CN113961195A discloses a method for interpreting an industrial robot programming language, including the following steps: storing variable information in a variable file according to a custom format, parsing the variable information in the variable file and storing it in the form of a linked list; setting corresponding identifiers for process control instructions, statement-type instructions, instructions in an instruction set, operators, special symbols, and variables and saving them to an identifier file; inputting an edited program file, and interpreting the program code in the program file into a tag file based on the identifier file; performing syntax analysis on the tag file and the variable linked list, and prompting if there is a syntax error, otherwise executing the next step; performing semantic analysis on the program code line by line based on the tag file and the variable linked list, and finally generating an instruction structure, and sending the instruction structure to a shared memory, waiting for the controller to command the robot to move. CN108874394A provides a method and device for interpreting a robot user program. The interpretation method includes: receiving a user program; the user program includes a mutually independent user main program and a user background program; creating a mutually independent first state machine and a second state machine; the first state machine translates the user main program into a computer executable code; and the second state machine translates the user background program into a computer executable code.

[0005] The above technologies do not provide specific guidance on how to use the STEP-NC online interpretation method for processing robots to reduce the workload of information conversion and programming during the working process of the processing robots, and effectively solve the problems of low efficiency, inconvenient operation and poor adaptability of STEP-NC file interpretation of processing robots. Summary of the invention

[0006] The purpose of the present invention is to provide a STEP-NC online interpretation method for a processing robot, which can reduce the workload of information conversion and programming during the working process of the processing robot, and effectively solve the problems of low work efficiency, inconvenient operation and poor adaptability of STEP-NC file interpretation of the processing robot.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A STEP-NC online interpretation method for a processing robot (the STPE-NC standard targeted by the present invention is ISO 14649), wherein the technical solution is that the method comprises the following specific steps: Step (1): Open the STEP-NC file and perform text processing, check whether the basic syntax is correct, and then store it in an internal data format in units of lines. Step (2): Obtain the relationship between the internal entities of the STEP-NC file and establish the internal data mapping of the STEP-NC file. Step (3): Traverse the data structure mapped by the STEP-NC file in the order of numbers, search for installation and workpiece installation entities, and establish the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system. Step (4): Traverse the internal data structure mapped by the STEP-NC file in the order of numbers, search for the list of executable structure entities, generate the tool motion trajectory in the feature coordinate system in the order of the executable structure entities in the list, and then transform it into the tool trajectory in the robot coordinate system through the coordinate transformation matrix established in step (3). Step (5): Output the motion trajectory of the processing robot, and determine the output mode according to the type of processing robot controller.

[0009] In the above technical scheme, the preferred technical scheme may be that the internal data mapping of the STEP-NC file established in the step (2) is a tree data structure with the STEP-NC project as the root node, and the information of all STEP-NC entities is associated through C++ pointers to obtain a complete mapping of the STEP-NC data on the internal data, while checking whether the attributes of the STEP-NC entity are complete and whether the association relationship is correct.

[0010] The steps of obtaining the relationship between the internal entities of the STEP-NC file in the step (2) and establishing the internal data mapping of the STEP-NC file are as follows: Step (21): Determine whether the start and end identifiers of the STEP-NC file are complete and in the correct format, and determine whether the start and end identifiers of the file header and the file data part are complete and in the correct format. Step (22): Read the identifier of the auxiliary part and establish its internal data mapping, including the file start and end, the header start and end, and the data segment start and end identifiers. Step (23): Read the entity information such as file description, file name, file mode, and establish its internal data mapping. Step (24): Read the entity information such as attribute parameters, direction, Cartesian point, positive and negative value, milling cutter size, hole bottom, groove bottom, cavity bottom, and establish its internal data mapping. Step (25): Read the entity information such as oblique cut-in, milling technology, material, 2-axis 3D position, tolerance value, milling cutter body, bidirectional milling, unidirectional milling, and their relationship with other entities, and establish its internal data mapping. Step (26): Read entity information such as basic surface, linear path, linear profile, tool assembly, rectangular closed profile, U-shaped profile, general closed profile and their mutual relationship with other entities, and establish their internal data mapping. Step (27): Read entity information such as milling cutter, milling machine function and their mutual relationship with other entities, and establish their internal data mapping. Step (28): Read entity information such as workpiece, plane milling, drilling, side milling, end face and side composite milling and their mutual relationship with other entities, and establish their internal data mapping. Step (29): Read entity information such as workpiece installation, plane, circular hole, closed cavity, open cavity, groove and their mutual relationship with other entities, and establish their internal data mapping. Step (210): Read entity information such as installation, processing step and their mutual relationship with other entities, and establish their internal data mapping. Step (211): Read process plan entity information and its mutual relationship with other entities, and establish their internal data mapping. Step (212): Read the engineering entity information and its relationship with other entities, and establish its internal data mapping.

[0011] In the above technical scheme, a preferred technical scheme may be that the information required for step (3) to establish the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system is directly read from the STEP-NC file without manually setting the coordinate system parameters.

[0012] The steps of establishing the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system in step (3) are as follows: Step (31): Read the origin attribute position and direction of the installation (SETUP) entity, establish the clamping coordinate system, and calculate the homogeneous transformation matrix from the clamping coordinate system to the robot coordinate system Step (32): Read the origin attribute position and direction of the workpiece installation (WORKPIECE_SETUP) entity, establish the clamping coordinate system, and calculate the homogeneous transformation matrix from the workpiece coordinate system to the clamping coordinate system

[0013] In the above technical scheme, the preferred technical scheme may be that the step (4) generates the tool motion trajectory in the feature coordinate system according to the order of the executable structural entities in the list, and then the coordinate transformation matrix established in the step (3) is used to transform the tool trajectory in the robot coordinate system. The process is completed automatically, and there is no need to include a specific tool trajectory in the STEP-NC file.

[0014] The steps of generating the tool trajectory in the robot coordinate system in step (4) are as follows: Step (41): Traverse the internal data structure mapped by the STEP-NC file to obtain a list of executable structural entities. Step (42): Read the information of the executable structural entities in the order of the list, including entities such as processing operations, manufacturing features, processing technology, and milling machine functions. Step (43): Further read information such as tools, feature positions, safety planes, cutting amounts, etc. from the above entities, and calculate the homogeneous transformation matrix from the feature coordinate system to the workpiece coordinate system. Step (44): Calculate the homogeneous transformation matrix from the feature coordinate system to the robot coordinate system using the homogeneous transformation matrix obtained in step (31), step (32), and step (43) Step (45): Generate tool trajectories approaching the manufacturing feature, cutting into the manufacturing feature, cutting the manufacturing feature, cutting out the manufacturing feature, and leaving the manufacturing feature in the feature coordinate system. Step (46): Use the homogeneous transformation matrix obtained in step (44) to transform into the tool trajectory in the robot coordinate system.

[0015] Among the above technical solutions, the preferred technical solution may be that the specific method of determining the output mode in step (5) according to the type of processing robot controller is: if it is an open pure software architecture controller, then directly connect the software programming interface of the interpolation control module; if it is a closed architecture controller, then post-process it into a robot control program, and then input it into the robot controller through online transmission, storage medium import, manual input, etc.

[0016] The present invention has the following beneficial effects:

[0017] (1) The STEP-NC online interpretation method for a processing robot of the present invention is aimed at the control of a processing robot based on STEP-NC. First, the STEP-NC file is opened and text processing and basic syntax checking are performed, and the files are stored in an internal data format in units of lines. Then, according to the relationship between the internal entities of the STEP-NC file, a tree data structure with the STEP-NC project as the root node is established to obtain a complete mapping of the STEP-NC data on the internal data. The established data structure is traversed in the order of numbers to establish a coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system. The list of executable structure entities is searched, and the tool motion trajectory in the feature coordinate system is generated in the order of the executable structure entities in the list and transformed into the tool trajectory in the robot coordinate system. Finally, the processing robot motion trajectory is output according to the type of processing robot controller.

[0018] (2) The present invention adopts an online interpretation method for STEP-NC files, which eliminates the need to add offline STEP-NC information extraction operations, manually set various process parameters through CAM software, and compile robot control programs through teaching or other offline programming tools. This reduces the information conversion and programming workload during the working process of the processing robot, and effectively solves the problems of low work efficiency, inconvenient operation, and poor adaptability of STEP-NC file interpretation of the processing robot.

[0019] (3) When interpreting a STEP-NC file, the method constructed by the present invention establishes a complete mapping of STEP-NC data on internal data by reading and analyzing all entity information in the STEP-NC file, thereby maintaining the integrity of high-level information in the STEP-NC file and effectively solving the problem of data loss during the transmission of manufacturing information within the manufacturing system.

[0020] In summary, the present invention provides a STEP-NC online interpretation method for a processing robot, which uses a processing robot control system to read STEP-NC files, establishes a mapping of a STEP-NC engineering tree data structure using an internal data format, generates the motion trajectory of the processing robot in sequence according to an executable operation list, and automatically generates motion control instructions or establishes communication to directly drive the robot to move according to the communication interface form of the robot controller. This method can reduce the workload of information conversion and programming during the working process of the processing robot, and effectively solves the problems of low work efficiency, inconvenient operation and poor adaptability of STEP-NC file interpretation of the processing robot. This method has the advantages of high efficiency, simple operation and strong adaptability. According to experiments, compared with the existing technology, the work efficiency of STEP-NC file interpretation of the processing robot after adopting the present invention is increased by more than 15%, and the information integrity is high, reaching 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a flow chart of the STEP-NC online interpretation method for machining robots according to the present invention.

[0022] Figure 2 This is a diagram of the software module architecture of the present invention (in an embodiment).

[0023] Figure 3 Schematic diagram of the software operation interface of the present invention (in an embodiment).

[0024] Figure 4 It is a schematic diagram of processing parts in the present invention (in an embodiment).

[0025] Figure 5 It is a schematic diagram of the STEP-NC file of the present invention (in an embodiment).

[0026] Figure 6 This is a diagram of the internal data mapping structure of the present invention (in an embodiment).

[0027] Figure 7 Schematic diagram of feature milling processing strategy for manufacturing the present invention (in an embodiment).

[0028] Figure 8 Schematic diagram of generating tool trajectory and robot control program for the present invention (in an embodiment). DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments (including the accompanying drawings). Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example: Figure 1 As shown, Figure 1 The flow chart of the STEP-NC online interpretation method for machining robots of the present invention mainly includes the steps of opening files, checking basic syntax, establishing data mapping, establishing coordinate transformation matrix, reading executable structure entities, generating robot motion trajectory, interpolation and motion control or outputting robot control program, etc. Figure 2 This is a software module architecture diagram of an embodiment of the present invention. This embodiment is developed in the C++ language under the QT5.7.0 environment, and includes a human-machine interface module, a STEP-NC entity mapping module, a file interpretation module, a robot trajectory generation module, a post-processing module, a file editing module, an error checking module, a mathematical calculation module, and a kinematic calculation module. Figure 3The diagram is a schematic diagram of the software operation interface of the embodiment of the present invention. The left side is the STEP-NC file display and editing area, and the right side is the function button, tool information setting, and STEP-NC step information display area.

[0031] Step (1): Pass Figure 3 The human-machine interface module shown is open Figure 4 The machined parts shown correspond to Figure 5 The STEP-NC file shown in the figure is processed into text to check whether the basic syntax is correct, and then stored in the internal data format in lines.

[0032] The internal data format stored in lines is as follows:

[0033] Variable Types Variable Name illustrate int lineNo Entity Number std::string lineEntityName Entity Name std::vector <std::string> < / std::string> lineEntityAttrib Entity attribute list

[0034] Among them, the STEP-NC file is compiled using the ISO 14649 standard. The main work plan (WORKPLAN) includes two machining steps (MACHINING_WORKINGSTEP), which correspond to the two manufacturing features of the round hole (ROUND_HOLE) and the closed cavity (CLOSED_POCKET) located on the upper surface of the part, as well as the two machining operations of drilling (DRILLING) and end and side composite milling (BOTTOM_AND_SIDE_FINISH_MILLING).

[0035] Step (2): Obtain the relationship between the internal entities of the STEP-NC file and establish Figure 6 Internal data mapping of STEP-NC file is shown.

[0036] The internal data mapping of the STEP-NC file established in step (2) is a tree data structure with the STEP-NC project as the root node. The information of all STEP-NC entities is associated through C++ pointers to obtain a complete mapping of the STEP-NC data on the internal data. At the same time, it is checked whether the attributes of the STEP-NC entity are complete and whether the association relationship is correct.

[0037] Wherein, in step (2), each STEP-NC entity is mapped with a C++ class, and its member variables are all pointer types, pointing to the C++ class instance corresponding to the attribute of the entity or the C++ class instance corresponding to the data type.

[0038] Furthermore, the steps of obtaining the complete mapping of STEP-NC data on the internal data in step (2) are as follows:

[0039] Step (21): Determine whether the start and end identifiers of the STEP-NC file are complete and in the correct format, and determine whether the start and end identifiers of the file header and the file data part are complete and in the correct format.

[0040] Step (22): Read the auxiliary part identifier and establish its internal data mapping, including the file start and end, header start and end, data segment start and end identifiers. The established auxiliary part identifier internal data mapping is as follows:

[0041] Variable Types Variable Name illustrate fileStart* inputStart STEP-NC file start headerSection* inputHeader STEP-NC file header dataSection* inputData STEP-NC file data section fileEnd* inputEnd STEP-NC file ending

[0042] Step (23): Read the entity information such as file description, file name, file mode, etc., and establish its internal data mapping. The established file header internal data mapping is as follows:

[0043] Variable Types Variable Name illustrate headerStarter* headerStart Head start fileDescription* headerDescription Explanatory text fileName* headerName File name, author, etc. fileSchema* headerSchema File Mode endSection* sectionEnd Head end

[0044] Step (24): Read entity information such as attribute parameters, directions, Cartesian points, positive and negative values, milling cutter size, hole bottom, slot bottom, cavity bottom, etc., and establish its internal data mapping.

[0045] Step (25): Read entity information such as oblique cutting, milling technology, material, 2-axis 3D position, tolerance value, milling cutter body, bidirectional milling, unidirectional milling, and their relationship with other entities, and establish its internal data mapping.

[0046] Step (26): Read entity information such as basic surfaces, linear paths, linear contours, tool components, rectangular closed contours, U-shaped contours, general closed contours, and their relationships with other entities, and establish their internal data mapping.

[0047] Step (27): Read entity information such as milling cutter, milling machine functions and their relationships with other entities, and establish their internal data mapping.

[0048] Step (28): Read the entity information of the workpiece, plane milling, drilling, side milling, end face and side composite milling, and their relationship with other entities, and establish its internal data mapping.

[0049] Step (29): Read the entity information of workpiece installation, plane, circular hole, closed cavity, open cavity, groove and the like and their relationship with other entities, and establish its internal data mapping.

[0050] Step (210): Read entity information such as installation and processing steps and their relationships with other entities, and establish their internal data mapping.

[0051] Step (211): Read the process plan entity information and its relationship with other entities, and establish its internal data mapping.

[0052] Step (212): Read the engineering entity information and its relationship with other entities, and establish its internal data mapping.

[0053] Steps (24) to (212) establish the internal data mapping of the STEP-NC file data portion, as follows:

[0054] Variable Types Variable Name illustrate dataStarter* dataStart Data Department Starts std::list<instance*>* items All entities in the data part of the STEP-NC file endSection* sectionEnd End of Data Department

[0055] Among them, the pointer std::list<instance*> *items is the internal data mapping of all data department entities. The root node is the projet class instance, corresponding to the STEP-NC entity:

[0056] #1=PROJECT('EXECUTE EXAMPLE1',#2,(#4),$,$,$);

[0057] The main member variables are the workplan class instance pointer and the workpiece class instance pointer, which correspond to the STEP-NC entities respectively:

[0058] #2=WORKPLAN('MAIN WORKPLAN',(#11,#14),$,#8,$);

[0059] #4=WORKPIECE('SIMPLEWORKPIECE',#6,0.01,$,$,$,(#66,#67,#68,#69));

[0060] The main member variables of the workplan class instance are the executable structure class instance pointer list, including two machiningWorkingstep class instance pointers, corresponding to STEP-NC entities:

[0061] #11=MACHINING_WORKINGSTEP('WS DRILL HOLE1',#62,#17,#20,$);

[0062] #14=MACHINING_WORKINGSTEP('WS FINISH POCKET1',#62,#18,#23,$);

[0063] Step (3): traverse the data structure mapped by the STEP-NC file in the order of numbers, search for installation and workpiece installation entities, and establish the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system.

[0064] The information required for the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system established in step (3) is directly read from the STEP-NC file without manually setting the coordinate system parameters.

[0065] Furthermore, the steps of establishing the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system in step (3) are as follows:

[0066] Step (31): Read the origin attribute position and direction of the setup entity, establish the clamping coordinate system, and calculate the homogeneous transformation matrix from the clamping coordinate system to the robot coordinate system. The entities in the STEP-NC file are as follows:

[0067] #8=SETUP('SETUP1',#71,#62,(#9));

[0068] Step (32): Read the origin attribute position and direction of the workpiece installation (WORKPIECE_SETUP) entity, establish the clamping coordinate system, and calculate the homogeneous transformation matrix from the workpiece coordinate system to the clamping coordinate system The entities in the STEP-NC file are as follows:

[0069] #9=WORKPIECE_SETUP(#4,#74,$,$,());

[0070] Step (4): Traverse the internal data structure mapped by the STEP-NC file in numerical order, search the list of executable structure entities, generate the tool motion trajectory in the feature coordinate system according to the order of the executable structure entities in the list, and then transform it into the tool trajectory in the robot coordinate system through the coordinate transformation matrix established in step (3).

[0071] Among them, step (4) generates the tool motion trajectory in the feature coordinate system according to the order of the executable structural entities in the list, and then transforms it into the tool trajectory in the robot coordinate system through the coordinate transformation matrix established in step (3). The process is completed automatically and does not require the STEP-NC file to include a specific tool trajectory.

[0072] Furthermore, the steps of generating the tool trajectory in the robot coordinate system in step (4) are as follows:

[0073] Step (41): Traverse the internal data structure mapped by the STEP-NC file to obtain the list of executable structure entities. The specific entities in the STEP-NC file are as follows:

[0074] #11=MACHINING_WORKINGSTEP('WS DRILL HOLE1',#62,#17,#20,$);

[0075] #14=MACHINING_WORKINGSTEP('WS FINISH POCKET1',#62,#18,#23,$);

[0076] Step (42): Read the information of executable structure entities in the order of the list, including entities such as machining operations, manufacturing features, machining technologies, milling machine functions, etc. The key entities in the STEP-NC file are as follows:

[0077] #17=ROUND_HOLE('HOLE1 D=6MM',#4,(#20),#81,#64,#58,$,#26);

[0078] #18=CLOSED_POCKET('POCKET1',#4,(#23),#84,#65,(),$,#27,$,$,#28);

[0079] #20=DRILLING($,$,'DRILL HOLE1',10.0,$,#39,#45,#41,$,$,$,$,$,$);

[0080] #23=BOTTOM_AND_SIDE_FINISH_MILLING($,$,'FINISHPOCKET1',10.0,$,#39,#52,#41,$,$,$,$,2.0,6.0,$,$);

[0081] Step (43): Further read the information of tool, feature position, safety plane, cutting amount, etc. from the above entities, and calculate the homogeneous transformation matrix from the circular hole feature coordinate system to the workpiece coordinate system Homogeneous transformation matrix from closed cavity feature coordinate system to workpiece coordinate system

[0082] Step (44): Calculate the homogeneous transformation matrix from the circular hole feature coordinate system to the robot coordinate system using the homogeneous transformation matrix obtained in step (31), step (32), and step (43) Homogeneous transformation matrix from closed cavity feature coordinate system to robot coordinate system

[0083] Step (45): Generate tool trajectories approaching the manufacturing feature, cutting into the manufacturing feature, cutting the manufacturing feature, cutting out the manufacturing feature, and leaving the manufacturing feature in the feature coordinate system.

[0084] Among them, the circular hole feature tool path generation method:

[0085] ① Calculate the Z coordinate of the safety plane in the feature coordinate system and move along the Z axis to the safety plane;

[0086] ② Calculate the X and Y coordinates of the hole axis in the characteristic coordinate system, and fast forward to the top of this point in the XY plane;

[0087] ③ Calculate the Z coordinate of the retracting plane in the feature coordinate system and move along the Z axis to the retracting plane;

[0088] ④ Calculate the Z coordinate of the hole bottom in the characteristic coordinate system and move to the hole bottom along the Z axis;

[0089] ⑤ Move along the Z axis to the retract plane, and then move to the safety plane.

[0090] Among them, the closed cavity feature tool path generation method:

[0091] ① Calculate the Z coordinate of the safety plane in the feature coordinate system and move along the Z axis to the safety plane;

[0092] ② Calculate the number of passes according to the following formula;

[0093]

[0094] Where w is the cavity width;

[0095] d – tool diameter.

[0096] ③ Figure 7 To machine the tool path inside the cavity, calculate the first starting point and end point according to the cavity width and length, and fast forward to above the starting point in the XY plane;

[0097] ④ Calculate the Z coordinate of the retracting plane in the feature coordinate system and move along the Z axis to the retracting plane;

[0098] ⑤ Calculate the Z coordinate of the bottom surface of the cutting layer in the characteristic coordinate system, and move along the Z axis to the bottom surface of the cutting layer;

[0099] ⑥ Move to the first end point in the XY plane;

[0100] ⑦ Add i=d(1-x) to the Y coordinates of the first starting point and end point and swap their positions to get the second starting point and end point, and move to the second starting point in the XY plane;

[0101] ⑧ Move to the second end point in the XY plane;

[0102] ⑨ Repeat steps ⑥ to ⑧ until the cutting is completed and moves along the cavity contour in the XY plane for one circle;

[0103] ⑩ Move along the Z axis to the retract plane, and then move to the safety plane.

[0104] Step (46): Use the homogeneous transformation matrix obtained in step (44) to transform the tool trajectory in the robot coordinate system.

[0105] Step (5): Output the motion trajectory of the processing robot, and determine the output method according to the type of processing robot controller.

[0106] Furthermore, the specific method of determining the output mode according to the type of processing robot controller in step (5) is:

[0107] If it is an open pure software architecture controller, it is directly connected to the software programming interface of the interpolation control module; if it is a closed architecture controller, it is post-processed into a robot control program and then input into the robot controller through online transmission, storage medium import, manual input, etc.

[0108] The processing robot controller used in the embodiment of the present invention is a closed architecture. After the robot trajectory is generated, the robot control program is generated through the post-processing module. The specific process is as follows: Figure 8 shown.

[0109] In summary, the above embodiments of the present invention provide a STEP-NC online interpretation method for a processing robot, which uses a processing robot control system to read STEP-NC files, establishes a mapping of a STEP-NC engineering tree data structure using an internal data format, generates the motion trajectory of the processing robot in sequence according to an executable operation list, and automatically generates motion control instructions or establishes communication to directly drive the robot to move according to the communication interface form of the robot controller. This method can reduce the workload of information conversion and programming during the working process of the processing robot, and effectively solve the problems of low work efficiency, inconvenient operation and poor adaptability of STEP-NC file interpretation of the processing robot. This method has the advantages of high efficiency, simple operation and strong adaptability. According to experiments, compared with the existing technology, the work efficiency of STEP-NC file interpretation of the processing robot after adopting the present invention is improved by more than 15%, and the information integrity is high, reaching 100%.

Claims

1. A STEP-NC online interpretation method for a processing robot, characterized in that The method comprises the following specific steps: Step (1): Open the STEP-NC file and perform text processing to check whether the basic syntax is correct, and then store it in an internal data format in lines; Step (2): Obtain the relationship between the internal entities of the STEP-NC file and establish the internal data mapping of the STEP-NC file; Step (3): traverse the data structure mapped by the STEP-NC file in the order of numbers, search for installation and workpiece installation entities, and establish the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system; Step (4): traverse the internal data structure mapped by the STEP-NC file in the order of numbers, search the list of executable structure entities, generate the tool motion trajectory in the feature coordinate system according to the order of the executable structure entities in the list, and then transform it into the tool trajectory in the robot coordinate system through the coordinate transformation matrix established in step (3); Step (5): output the motion trajectory of the processing robot, and determine the output method according to the type of processing robot controller; The steps of establishing the coordinate transformation matrix between the robot coordinate system, the clamping coordinate system and the workpiece coordinate system in step (3) are as follows: Step (31): Read the origin attribute position and direction of the setup entity, establish the clamping coordinate system, and calculate the homogeneous transformation matrix from the clamping coordinate system to the robot coordinate system. Step (32): Read the origin attribute position and direction of the workpiece installation (WORKPIECE_SETUP) entity, establish the clamping coordinate system, and calculate the homogeneous transformation matrix from the workpiece coordinate system to the clamping coordinate system The steps of generating the tool trajectory in the robot coordinate system in step (4) are as follows: Step (41): traverse the internal data structure of the STEP-NC file mapping to obtain the executable structure entity list; Step (42): reading information of executable structural entities in a list order, including machining operations, manufacturing features, machining technologies, and milling machine functional entities; Step (43): Further read the tool, feature position, safety plane, and cutting amount information from the above entities, and calculate the homogeneous transformation matrix from the feature coordinate system to the workpiece coordinate system Step (44): Calculate the homogeneous transformation matrix from the feature coordinate system to the robot coordinate system using the homogeneous transformation matrix obtained in step (31), step (32), and step (43) Step (45): generating tool trajectories approaching the manufacturing feature, cutting into the manufacturing feature, cutting the manufacturing feature, cutting out the manufacturing feature, and leaving the manufacturing feature in the feature coordinate system; Step (46): Use the homogeneous transformation matrix obtained in step (44) to transform the tool trajectory in the robot coordinate system.

2. The STEP-NC online interpretation method for a processing robot according to claim 1, characterized in that: The internal data mapping of the STEP-NC file established in step (2) is a tree data structure with the STEP-NC project as the root node. The information of all STEP-NC entities is associated through C++ pointers to obtain a complete mapping of the STEP-NC data on the internal data. At the same time, it is checked whether the attributes of the STEP-NC entity are complete and whether the association relationship is correct.

3. The STEP-NC online interpretation method for a processing robot according to claim 1 or 2, characterized in that: The steps of obtaining the relationship between the internal entities of the STEP-NC file and establishing the internal data mapping of the STEP-NC file in step (2) are as follows: Step (21): determine whether the start and end identifiers of the STEP-NC file are complete and in the correct format, and determine whether the start and end identifiers of the file header and the file data part are complete and in the correct format; Step (22): read the identifier of the auxiliary part and establish its internal data mapping, including the file start and end, header start and end, data segment start and end identifiers; Step (23): read the file description, file name, file mode entity information, and establish its internal data mapping; Step (24): reading attribute parameters, directions, Cartesian points, positive and negative values, milling cutter size, hole bottom, slot bottom, and cavity bottom entity information, and establishing internal data mapping; Step (25): reading the entity information of the oblique line cutting, milling technology, material, 2-axis 3D position, tolerance value, milling cutter body, bidirectional milling, unidirectional milling and their relationship with other entities, and establishing its internal data mapping; Step (26): reading basic surface, linear path, linear profile, tool assembly, rectangular closed profile, U-shaped profile, general closed profile entity information and their relationship with other entities, and establishing internal data mapping; Step (27): reading the milling cutter and milling machine functional entity information and their relationship with other entities, and establishing their internal data mapping; Step (28): reading workpiece, plane milling, drilling, side milling, end face and side composite milling entity information and their relationship with other entities, and establishing its internal data mapping; Step (29): reading workpiece installation, plane, circular hole, closed cavity, open cavity, slot entity information and their relationship with other entities, and establishing its internal data mapping; Step (210): reading installation and processing step entity information and its relationship with other entities, and establishing its internal data mapping; Step (211): reading the process plan entity information and its relationship with other entities, and establishing its internal data mapping; Step (212): Read the engineering entity information and its relationship with other entities, and establish its internal data mapping.

4. The STEP-NC online interpretation method for a processing robot according to claim 1, characterized in that: The information required for establishing the coordinate transformation matrix among the robot coordinate system, the clamping coordinate system and the workpiece coordinate system in step (3) is directly read from the STEP-NC file without manually setting the coordinate system parameters.

5. The STEP-NC online interpretation method for a processing robot according to claim 1, characterized in that: The step (4) generates the tool motion trajectory in the feature coordinate system according to the order of the executable structural entities in the list, and then transforms it into the tool trajectory in the robot coordinate system through the coordinate transformation matrix established in step (3). The process is completed automatically and does not require the STEP-NC file to include a specific tool trajectory.

6. The STEP-NC online interpretation method for a processing robot according to claim 1, characterized in that: The specific method of determining the output mode according to the type of processing robot controller in step (5) is: If it is an open pure software architecture controller, it is directly connected to the software programming interface of the interpolation control module; if it is a closed architecture controller, it is post-processed into a robot control program, and then input into the robot controller through online transmission, storage medium import, or manual input.

Images