Method and system for machining workpieces

Abstract

There is provided a method of treating a workpiece, comprising the steps of: treating a workpiece by pretreatment; generating a virtual workpiece model as a representation of the workpiece after and / or during the preprocessing; and planning or adapting post-processing of the workpiece using the virtual workpiece model. Also described herein is a system configured to perform the above method, including a data source, a data transmitter, and a data processing system.

Description

Technical Field

[0001] The present invention generally relates to a method of processing a workpiece and a system configured to perform the method of processing a workpiece so that the workpiece is processed in a multi-step adaptive machining process. Background Art

[0002] Workpiece machining often requires adaptive measures to account for differences or deviations between the actual and planned geometry of a semi-finished product, which may also be related to the geometry of the initial product. In particular, in multi-step machining processes, such as those implemented in tool manufacturing or in the serial production of cast, forged, or printed components, such deviations are common. Since any subsequent process steps are typically based on the actual geometry of the semi-finished product, such deviations can have negative consequences.

[0003] While it is possible to inspect the semi-finished product stage using precision measuring equipment such as coordinate measuring machines (CMMs), such measurements typically need to be performed outside the machine tool, may not fully cover the machined surface, and / or often require additional measuring time. This is often inefficient and slows down the entire machining process because it typically requires disassembly of at least one part, or because it is often practically impossible to traverse the free-form surface. Today, safety margins can be selected and trim cuts performed, which can lead to inefficiencies in the workpiece manufacturing process.

[0004] In some cases, advanced a priori simulations that consider multiple dimensions of process and equipment can be used to avoid rework at any step. However, such a priori simulations may not be applicable when the initial workpiece geometry is unknown. Therefore, when deviations between the actual and planned semi-finished product geometry are detected, additional comprehensive measurement of at least one part may be necessary to provide corrective measures.

[0005] In CN102865847A, a spline curve compensation method for measuring contour deviation based on path units is used to apply numerical control machining. In DE60222026T2, the Standard for Exchange of Product Models - Numerical Controllers (STEP-NC) is used to overcome the shortcomings of conventional NC with a closed structure.

[0006] Further prior art can be found, for example, in DE 11 2015 004 939 B4, which generally relates to a method for optimizing the productivity of a CNC machine process, and WO 2016 / 067492 A1, which generally relates to a computer-implemented method for part analysis of workpieces machined by at least one CNC machine.

[0007] In view of the above, there is a need for improvements in the machining of workpieces. SUMMARY

[0008] The present invention is set out in the independent claims. Preferred embodiments of the invention are set out in the dependent claims.

[0009] According to an aspect of the invention, there is provided a method of processing a workpiece, comprising the steps of: processing the workpiece by a pre-processing; generating a virtual workpiece model as a representation / characterization of the (actual) workpiece; and using the virtual workpiece model for planning a post-processing of the workpiece. In certain examples, the virtual workpiece is generated during the machining, e.g. delayed by 5ms or 10ms after the pre-processing is completed, and / or can be generated more than a second / minute / hour / day (or more) after the pre-processing is completed.

[0010] By using the virtual workpiece model in the process planning of one or more post-processing steps, the machining process can be shortened and the quality of the produced workpiece can be improved, wherein the virtual workpiece model can be generated from machine internal data (which can be control data / process data for controlling the machine tool, such as but not limited to force / vibration / temperature data, as will be further outlined below). The workpiece model can be provided with real-world imperfections and can better provide the basis for path planning and / or can enable a better interfacing of multiple (e.g. two) machining steps.

[0011] In several or any of the examples outlined throughout the present disclosure, the virtual workpiece model can be specific to the processing of a particular workpiece, in particular since the virtual workpiece model can be generated from machine internal data.

[0012] In certain examples, the virtual workpiece model can be related to the geometry of the workpiece. Additionally or alternatively, the virtual workpiece model can refer to one or more other parameters of the workpiece / process for producing the workpiece, wherein the one or more other parameters can be positionally resolved / time resolved. In certain examples, the one or more parameters can be or relate to force (e.g. force experienced by the machine tool when a cutting tool of the machining process cuts in), acceleration (e.g. acceleration of the machine tool at the center point of the tool), temperature (e.g. temperature of machine tool components / workpiece during the machining process), vibration (e.g. vibration of machine tool components / workpiece during the machining process), and other parameters related to the machining process, such as a bending of the processed workpiece / mathematical calculation of a drill hole / cut of the machine tool that penetrates the processed workpiece.

[0013] In view of the above, in certain examples, a virtual workpiece can be defined as a geometric construct describing a virtual representation of the workpiece shape in the workpiece coordinate system at any time of the manufacturing process (in certain examples, including surface description of different orders / more than one high order surface geometry error). In certain examples, the definition of the virtual workpiece can alternatively or additionally include a broader definition to include one or more of metadata, (arbitrary) sensor data, one or more process parameters and one or more of sensor data measured on the part surface at any time of the manufacturing process.

[0014] The virtual workpiece can be based on a trajectory used in the machining process, wherein the trajectory can be or include a list of numerical control (NC) / programmable logic controller (PLC) / sensor data (topics) in time domain with synchronized time stamps.

[0015] In any one or more (or all) examples outlined throughout this disclosure, post processing can be defined as a second (e.g. intermediate / final) process occurring after pre processing, whereby pre processing can be defined as a first (e.g. initial) process occurring before post processing. Thus generally, pre processing can be a first process and post processing can be a second process, with the first process occurring before the second process.

[0016] In certain examples of the method, pre processing / post processing is performed using one or more numerical control (NC) code blocks.

[0017] In certain examples of the method, at least one of pre processing and post processing is planned by computer-based path planning. Herein, in certain examples, the computer-based path planning can be related to path planning of a machine tool. Path planning can be considered in the process planning of post processing. Path planning can be performed for one or both of pre processing and post processing. In certain examples, path planning can be performed by a computer-aided manufacturing (CAM) algorithm.

[0018] In certain examples of the method, pre processing and post processing are performed using at least one machine tool, the number of which is equal to or less than the number of process steps to process the workpiece using pre processing and post processing.

[0019] In certain examples of the method, the virtual workpiece model is generated using (actual) data from a controller of the machine tool / integrated sensors in the machine tool. In certain examples, the (actual) data can be related to machine internal data outlined throughout this disclosure.

[0020] In certain examples of the method, the virtual workpiece model is generated quasi-parallel to / after pre processing. In certain examples, quasi-parallel means a delay of less than 50 ms, preferably less than 10 ms. This can enable efficient production of the workpiece.

[0021] In certain examples of the method, the virtual workpiece model is generated by considering one or more displacement amounts of one or more physical components (of the workpiece) caused by the force loop. In certain examples, the physical components can be the cutting tool / clamping / fixing device. Additionally or alternatively, in certain examples, when determining the one or more displacement amounts, the stiffness of one or more correction tables / one or more machines / parts can be considered. Additionally or alternatively, the workpiece itself can be deformed due to machining forces / clamping forces.

[0022] In certain examples of the method, the virtual workpiece model is generated by considering a compensation algorithm (of the virtual workpiece model) running on the machine tool or the NC controller. In certain examples, the compensation algorithm can be related to kinematic / thermal compensation of geometric errors, which can be considered during the generation of the virtual workpiece.

[0023] In certain examples of the method, the generation of the virtual workpiece model is done with a local geometric resolution that is smaller than the part-specific local geometric dimensions and tolerances (GDT). Here, the resolution can be smaller than the features subsequently measured on the virtual workpiece model.

[0024] In certain examples of the method, after the pre-processing, one or more (specific) areas of the virtual workpiece model are enriched / modified using precision measurements in the micrometer or sub-micrometer range, in particular measurements by coordinate measuring machines / using in-machine touch / optical measurements, and the measured point clouds. For calibration purposes, a complete model of the surface of the virtual workpiece model can be obtained.

[0025] In certain examples of the method, the calibration of the process model as a function of one or more boundary conditions is carried out in parallel to the pre-processing. The process model can include one or more of a force model, a tool material (model), and a workpiece model. The tool- material model can here relate to the cutting tool (e.g. geometry, material) - workpiece material model. The tool material model (cutting tool - workpiece material model) can be a model based on one or more parameters for solving a force calculation equation (e.g. Kienzle formula), which depends on one or more parameters, which can depend on one or more of tool geometry, tool wear, lubrication, tool material, and workpiece material (in particular related to local properties of the workpiece / global properties throughout the workpiece). The force calculation equation can additionally or alternatively be influenced / defined by one or both of thermal conditions and melting conditions around each cutting edge by a specific spindle speed, cutting tool - workpiece engagement, or feed speed. Additionally or alternatively, the one or more parameters can be or relate to the stiffness / deformability of the tool / workpiece, respectively.

[0026] In certain examples, the calibration of the process model can include an initial generation of the process model / a subsequent adaptation of the process model. In certain examples, the initial model (e.g. Kienzle model) can be subsequently calibrated / adapted.

[0027] Throughout this disclosure, the tool-material model can be a cutting tool (e.g. geometry / material, etc.) - workpiece material model.

[0028] In certain examples, the model can be an empirical model.

[0029] Based on the tool-material model (cutting tool - workpiece material model), the amount of cutting can be calculated, whereby the cutting forces that arise when machining the workpiece with a machine tool or spindle integrated force sensor or force measurement platform on the worktable can be determined using a physical simulation (tool-workpiece engagement calculation driven by trajectory data). In the physical simulation, the cutting conditions (e.g. ae (radial cut depth), ap (axial cut depth) / force direction / force value) are calculated. The engagement simulation is based on bool, dexel or voxel operations.

[0030] More than one tool-material model (cutting tool - workpiece material model) can be stored in a database and can be used for more than one subsequent process step / for subsequent parts to be manufactured.

[0031] In certain examples, the calibrated process model (tool-material - workpiece material model) is used for the planning of the post-processing.

[0032] In certain examples of the method, the calibration of the tool-material model (tool-material - workpiece material model) is carried out in parallel with the post-processing. This enables post-calibration of the model.

[0033] In certain examples of the method, the planning of the post-processing is carried out using an initial workpiece geometry based on a virtual workpiece model. In certain examples, the virtual workpiece model can be used as the initial geometry without any further workpiece geometry information being required to define the initial workpiece geometry. In certain examples, the data for the planning of the post-processing can be sent from (or obtained by) the machine tool on which the pre-processing is carried out. In certain examples, the planning of the post-processing is carried out after the pre-processing and the generation of the virtual workpiece model.

[0034] In certain examples of the method, at the planning of the post-processing, more than one process parameter (such as feed rate and rotational speed, for example, not just the path) is adjusted based on high order topographical deviations on the virtual workpiece model. Such high order topographical deviations can relate to, for example, one or more of waviness, roughness and other high order surface features.

[0035] In certain examples of the method, one or more supplemental sensor signals, in particular acceleration data, are added to the virtual workpiece model in a position dependent (geometrically related) manner. Additionally or alternatively, one or more signals from the controller of the machine tool / from one or more external sensors (in certain examples, these sensors can be non-critical to the machining process) can be added to the virtual workpiece model. The supplemental information can be used to adjust one or more process parameters, such as but not limited to feed rate / rotational speed (of the machine tool).

[0036] In certain examples of the method, the planning of the post-processing is done by a simulation of the ideal geometry obtained as initial workpiece geometry in the planning of the pre-processing. Here, in certain examples, in a first step, the planning can be a CAM planning based on the ideal final geometry of the workpiece. In certain examples, the method further comprises a step of planning a path for the post-processing. The path planning for the post-processing can be done before / during / after the pre-processing.

[0037] In certain examples of the method, one or more initial calculated paths for the post-processing are adjusted based on additional input generated from the virtual workpiece model. In certain examples, the additional input can be a deviation, and one or more other parameters (such as surface roughness / one or more higher order parameters) can be used additionally or as an alternative to the deviation. Additionally or alternatively, in certain examples, such adjustment can be based on a (internet) cloud service.

[0038] In certain examples of the method, the virtual workpiece model is used to generate one or more parametric NC (numerical control) code variables / pose dependent offset tables that depend on the geometry deviation / displacement of the tool center point. The offset tables can additionally or alternatively depend on the spatial positioning. The offset tables throughout this disclosure can provide one or more dimensional offset information, in particular for 3-axis or 5-axis machining. As another example of the method, the virtual workpiece model is used to modify the initially created NC code for the post-processing within a path adaptation engine. A conversion of the initial NC code into a specific machine tool dialect (referred to as NC interpreter) can be included for both the post-processing before the path modification and the post-processing after the modification.

[0039] The one or more offset tables can be stored in a database (e.g. together with one or more tool material models (cutting tool - workpiece material models)) and can be used for subsequent parts to be manufactured.

[0040] The adaptation of the machine tool path can not be limited to the method of offset tables, but can also employ other methods of modifying the machining path based on a micrometer.

[0041] In certain examples of the method, the path adjustment is conducted by a controller of the machine tool (for processing the workpiece) in order to generate more than one final path in the NC device / machine tool. This adjustment can be conducted in parallel to the machining process (quasi-parallel). By actual data adjustment or target data adjustment, the final path can be generated in the NC or on the machine.

[0042] In certain examples of the method, more than one target path of the post-processing is adjusted locally / in the cloud. In certain examples, no update in the NC can be provided.

[0043] In certain examples of the method, the path adjustment amount is less than a preset threshold, wherein the preset threshold is based on more than one process parameter for processing the workpiece (during pre-processing / post-processing) / based on a tool geometry of a tool for processing the workpiece (during pre-processing / post-processing). In certain examples of the method, the path adjustment amount is a displacement amount of a single path, which is less than an overlap amount of adjacent cutting contours. In certain examples, additional (e.g. all) paths can be added.

[0044] In certain examples of the method, the preset threshold is less than half of a tool diameter. This enables a finer division when adjusting more than one path. In general, the preset threshold can be set in accordance with a kinematic roughness expected to occur / measured during processing the workpiece.

[0045] In certain examples of the method, more than one path is adjusted by adding a single path segment.

[0046] In certain examples of the method, the planning of the post-processing comprises determining a virtual tool (tool) - workpiece engagement (e.g. in preparation for force determination) and calculating a displacement of a tool center point. Here, a measured virtual path can be used. In certain examples, a usual (also initial) calculated / adapted path can be used for simulation. In certain examples, this simulation can be a virtual (e.g. iterative) process optimization before the post-processing step.

[0047] In certain examples of the method, the planning is conducted using a tool- material model (tool material - workpiece material model) established / calibrated in the pre-processing.

[0048] In certain examples of the method, a virtual NC controller, in particular comprising more than one offset table, NC internal corrections / compensations, is used to calculate an expected actual path in connection with a priori simulation of the virtual workpiece model. In particular comprising NC internal corrections / compensations, it is generally possible to interpret more than one offset table and to contribute to a better prediction of the result.

[0049] In certain examples of the method, the target path (of the tool) is iteratively (in particular virtually) generated taking into account the displacement of the tool center point. As less actual steps are required in the method, the costs for preparing the workpiece are further reduced.

[0050] In any of the examples outlined herein, the path adaptation is not limited to open loop control. Based on fast real-time data measurements, tool-workpiece engagement calculations, force calculations, tool center point (TCP) deflection calculations, compensation definitions, a priori TCP deflection simulations and NC, path adaptation can also be performed for path and process parameters in closed loop control. In certain examples of the method, the above steps are triggered in parallel or after a machining sequence (segmentation of the process or roughing / fine machining) or continuously during the segments of a single path.

[0051] In certain examples of the method, the post-processing is performed by an electro-discharge machining machine. Spark erosion machining can be planned here for the post-processing including a specific process plan. In certain examples, knowledge about the actual electrode geometry of the electro-discharge machining machine as a virtual workpiece model helps to optimize the precise results achieved by the electro-discharge machining machine.

[0052] In certain examples of the method, the post-processing is performed by an electro-chemical machining. In certain examples, knowledge about the actual cathode geometry of the electro-chemical machining machine as a virtual workpiece model helps to optimize the precise results achieved by the electro-chemical machining machine.

[0053] In certain examples, the method further comprises a step of micron / sub-micron precision part measurement processing after the pre-processing and using the corresponding measurement point cloud to correct the virtual workpiece model coordinate system with respect to a reference point, in particular with respect to a virtual workpiece coordinate system clamped to the electrode (EDM) / cathode (ECM) zero-point positioning.

[0054] According to another aspect of the present disclosure, a system is provided configured to perform the method according to any one or more of the examples outlined throughout the present disclosure. The system comprises a data source, a data transmitter and a data processing system.

[0055] In certain examples of the system, the data source is a machine tool with a high (i.e. above a threshold value) sampling rate data interface for transmitting / reading machine internal data.

[0056] In certain examples of the system, the data is provided by a data interface providing PLC data at a frequency of less than 2 kHz and / or servo data at a frequency of between 100 Hz and 20 kHz and / or rotor shaft deformation data at a frequency of between 2 kHz and 40 kHz.

[0057] In certain examples of the system, the data comprises one or more of: current supplied to the motor, signals from rotary encoders / linear scales, displacement of the spindle, one or more tool tables, one or more compensation tables and one or more NC blocks. These data can be read from the machine tool.

[0058] In certain examples of the system, the data is obtained from sensors for measuring rotor shaft deformation between / forward of the bearing pairs. Additionally or alternatively, the data can relate to one or more turning / lathing processes.

[0059] In certain examples of the system, the data source is a machine internal job manager / (e.g. high level) cell controller / manufacturing execution system.

[0060] In certain examples, the system is configured to provide one or more images from one or more pre-processed jobs information / context information / workpieces.

[0061] In certain examples of the system, the data source, the data transmitter and the data processing system for generating a virtual workpiece model, comprising a software unit for material removal simulation and a software unit for determining deformation, are equipped with a software unit for computer aided path planning (e.g. CAM), in particular a machine tool comprising a built-in edge PC. Thus, the system can be provided within or on the machine tool (i.e. coupled with the machine tool). This can be particularly advantageous, as the system integrated in the machine tool can enable real-time application of embodiments of the method outlined throughout this disclosure. Computing and implementing the system on the machine tool can also enable a self-standing / self-sufficient system. BRIEF DESCRIPTION OF DRAWINGS

[0062] These and other aspects of the present invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0063] Figure 1 A schematic diagram showing a sequence of steps according to some embodiments of the disclosure;

[0064] Figure 2 A schematic diagram showing a sequence of steps according to some embodiments of the disclosure;

[0065] Figure 3 A schematic diagram showing a sequence of steps according to some embodiments of the disclosure;

[0066] Figure 4 A schematic diagram showing a sequence of steps according to some embodiments of the disclosure;

[0067] Figures 5a to 5c A cross-sectional side view of a cutting schematic when processing a workpiece;

[0068] Figure 6 schematic diagram showing a sequence of steps according to some embodiments of the present disclosure;

[0069] Figure 7 schematic diagram showing a sequence of steps according to some embodiments of the present disclosure;

[0070] Figure 8 schematic diagram showing a sequence of steps according to some embodiments of the present disclosure;

[0071] Figure 9 schematic diagram showing a sequence of steps according to some embodiments of the present disclosure;

[0072] Figure 10 schematic diagram showing a refinement of a virtual workpiece model coordinate system according to some embodiments of the present disclosure;

[0073] Figure 11 schematic diagram showing a system setup according to some embodiments of the present disclosure;

[0074] Figure 12 flowchart of a method according to some embodiments of the present disclosure; and

[0075] Figure 13 schematic block diagram of a system according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0076] According to embodiments generally outlined throughout the present disclosure, a machining step can be adapted to a planned geometry faster by using a virtual workpiece model generated from machine internal data according to a pre-processing step.

[0077] Herein, machine internal data can relate to e.g. positions passed by the machine / forces acting on one or more motors of the machine. Generally, machine internal data can refer to data used for controlling the machine. In some examples, machine internal data can not take into account data obtained from subsequent measurements.

[0078] Machine internal data can relate to data originating from a current machining process. In some examples, machine internal data can relate to one or more of forces, accelerations, temperatures, vibrations and other parameters related to the machining process, e.g. a bending of the workpiece to be produced (e.g. a resolution of less than 50 pm) / a bending of the machine (cutting) tool / a drilling of the machine penetrating the workpiece to be produced / a mathematical calculation of a cut. Data can be obtained in the (current) machining process. Data can originate from a controller used for controlling the machine / a sensor not (at least not directly) connected to the controller.

[0079] In some examples, machine internal data can be mapped to a positional resolution of below 1 micrometer (e.g. 1 picometer). Additionally or alternatively, machine internal data can be time resolved.

[0080] According to examples outlined throughout the present disclosure, for example, safety cuts or additional corrective cuts including using a CMM for actual measurement can be eliminated, thereby significantly reducing the cost of producing a workpiece. Furthermore, quality improvement of the workpiece to be produced can be achieved. After the initial machining step, the actual geometry in the case of a blank geometry fluctuation / unknown (e.g. casting or additive manufacturing) can be learned. Furthermore, the actual geometry at the semi-finished stage can be better learned, thereby saving / eliminating safety cuts and achieving higher tolerance accuracy after post-processing (e.g. DM).

[0081] Figure 1 A schematic diagram of a sequence of steps 100 according to some embodiments of the present disclosure is shown.

[0082] In some examples, the sequence 100 can be used for batch machining of castings, forgings or additively manufactured parts.

[0083] In the sequence 100, one or more pose-dependent offset tables can be generated as numerical control input for a step (i.e. one or more or all steps) of processing the workpiece.

[0084] In the present example, the initial (ideal) geometry is provided to a path generation kernel (Computer Aided Manufacturing (CAM)) and post-processor at step 101, where the initial geometry_2, …, n corresponds to the target geometry_2-1, …, n-1.

[0085] In the present example, the path generation kernel (Computer Aided Manufacturing (CAM)) and post-processor are used at step 102 to output data / program NC_1 (“Numerical Control_1”) for controlling a machine tool that manufactures the workpiece.

[0086] In some examples, the post-processor can process the path planning results after they are generated. This can include (1) adding one or more process parameters / spindle stops / runs, etc. to the path data (CAM can only calculate the path in a 3D environment); (2) describing the path as a list of vectors (e.g. movement commands); (3) generating NC code in a machine tool specific dialect (e.g. M and G codes vary for specific machine tools / machine tool suppliers / NC suppliers).

[0087] In the present example, the data NC_1 is provided to a pre-processing 104, which can be a roughing process when preparing the workpiece. In the pre-processing, in the present example, (computer) numerical control (NC) machining is used in the manufacturing process, where preprogrammed computer software can be used to control the movement of the machine tool.

[0088] In the present example, in the pre-processing 104, the raw part (with (potential) oversize / size fluctuations) is processed in the pre-processing.

[0089] In the present example, the NC output data NC Trajectory_1 used in the pre-processing, which can be or include a list containing a plurality of numerical control (NC) / programmable logic controller (PLC) / sensor data (topics) with synchronized time stamps in the time domain.

[0090] When the rough part has been prepared, adaptive process correction (APC) based on the virtual workpiece model is performed in the Edge-NC system. In the present example, in the APC processing, in step 106, a machine (cutting tool) - workpiece engagement simulation (CWES) with (optional force calculation and) deformation calculation is performed based on the measured machine trajectory data (in the present example based on NC Trajectory_1). In step 108, the virtual workpiece model (virtual workpiece model_1) generated from step 106 is provided for the calculation of local geometric deviations. In the present example, data regarding the target geometry configuration (target geometry configuration_1) is provided from the path generation kernel (computer aided manufacturing (CAM)) and post-processor to the calculation of local geometric deviations in step 108.

[0091] The local deviations calculated in step 108 are then provided in the present example to a pose dependent offset table generator 110, in which one or more offset tables are generated, and these offset tables are provided to the numerical control (NC) for the post-processing (in the present example semi-finishing process), in which the one or more offset tables are used in step 112. In the present example, the numerical control data NC_2 is provided from the path generation kernel (computer aided manufacturing (CAM)) and post-processor to the NC for the post-processing (semi-finishing).

[0092] In the present example, the data NC Trajectory_n-1 is output by the NC of the post-processing (semi-finishing) to a further adaptive process correction (APC) 114, which can implement steps corresponding to the steps described in steps 106 to 112. In the present example, data regarding the target geometry configuration of the workpiece for the n-th process step (target geometry configuration_n) is provided from the path generation kernel (computer aided manufacturing (CAM)) and post-processor to the APC 114.

[0093] An offset table_n-1 is provided from the APC 114 to the numerical control (NC) at step 116, after which the post-processing (in this example, the n-th step, i.e. the finishing process) is performed at the numerical control (NC) to obtain the final processed workpiece from the semi-finished part. In this example, data NC_n is provided from the path generation kernel (computer aided manufacturing (CAM)) and post-processor to the NC for the post-processing performed at step 116.

[0094] It can be seen that a pose-dependent offset table generator is used in the manufacturing sequence to generate an adaptation based on the virtual geometry of the workpiece and the position deviations. The offset table can be used as an input for manufacturing the workpiece based on a previous (ideal) planning.

[0095] In this example, all steps of the workpiece manufacturing process are planned from the start based on the ideal geometry. In this example, n CAM steps are performed simultaneously when planning the workpiece manufacturing process.

[0096] Figure 1 The illustrated sequence is particularly suitable for castings, which can involve (relatively cheap) components / parts that can be manufactured relatively fast / with a higher frequency compared to other sequences outlined throughout this disclosure.

[0097] The more than one offset table generated by the pose-dependent offset table generator is based on the difference between the ideal workpiece and the virtual workpiece. Parameters that can be considered in the comparison of the ideal / virtual workpiece relate to one or more of the geometry of the workpiece, the temperature of the workpiece, the vibrations of the workpiece, the bending of the workpiece, etc. In certain examples, the offsets provided in the offset table can be positionally / time resolved.

[0098] It is noted here that throughout this disclosure, whenever a plurality of offset tables is mentioned, a single offset table can be used / generated instead of a plurality of offset tables in the illustrated embodiments.

[0099] Figure 2 A schematic diagram of a step sequence 200 according to part of the embodiments of the disclosure is shown.

[0100] The sequence 200 generally corresponds to the sequence 100 as Figure 1 However, in the sequence 200, a prior simulation with a virtual NC kernel is performed at step 211. For the prior simulation, one or more model parameters (e.g. an empirical force model) are input from the machine tool (cutting tool)-workpiece engagement simulation. Furthermore, in this example, the pose-dependent offset table generator is configured to output an offset table_1, which is used as an input for the prior simulation. Furthermore, in this example, data NC_2 is provided from the path generation kernel and post-processor as an input for the prior simulation. With the prior simulation, an offset table_1b is generated and provided as an input to the numerical control for the post-processing (semi-finishing) at step 112.

[0101] It can be seen that the a priori simulation is part of the adaptive process correction based on the virtual workpiece model. With the a priori simulation, the difference between the nominal profile of the workpiece after processing and the manufactured profile of the workpiece can be reduced compared to a process implemented in the sequence Figure 1

[0102] Figure 3 A schematic diagram of a sequence of steps 300 according to some embodiments of the present disclosure is shown. In the sequence 300, more than one variable is generated for the parameterized NC code for different steps of processing the workpiece.

[0103] The sequence 300 generally corresponds to the sequence 100 as shown in Figure 1 However, in the sequence 300, a variable generator is used in step 310 instead of the pose-dependent offset table generator to generate more than one variable_1 from the local deviations obtained when calculating the local geometric deviations (i.e. the deviations between the virtual workpiece model and the ideal geometric configuration), which are input into the numerical control for post-processing (semi-finishing). When generating the variables, the parameterized NC_2 data is input into the variable generator. Furthermore, the data parameterized NC_2 is also input into the numerical control for post-processing (semi-finishing). The data parameterized NC_2 can comprise, for example, more than one variable which enables path modification for specific features of the workpiece. In the present example, the data is input into the variable generator 310 so that the variable generator 310 knows which parameter or parameters to optimize and in which way (i.e. based on which parameters to modify the path) to reach the target geometric configuration by post-processing. In some examples, the more than one parameters can be found by a fitting algorithm.

[0104] The above applies equally to the APC 114 from which the variable_n-1 is generated and input (together with the data parameterized NC_n) into the numerical control for post-processing (the n-th step of finishing the workpiece).

[0105] Figure 4 A schematic diagram of a sequence of steps 400 according to some embodiments of the present disclosure is shown.

[0106] The sequence 400 generally corresponds to the sequence 100, 200 or 300. However, in the sequence 400, in step 410, a path adaptation kernel and a post-processor are used to generate the NC code as input into the numerical control for post-processing (in the present example semi-finishing and the corresponding n-th process step for finishing the workpiece) instead of the pose-dependent offset table / variable generator used in the sequence 300. Either only path_1 or NC_1 can be input. In the case of NC_1, an integrated NC interpreter can be required in some examples.

[0107] ​In any one or more of the embodiments outlined throughout the present disclosure, for the edge of the workpiece, no new movement can be calculated, but rather only a correction / adaption in the machining process can be provided.

[0108] Further, the offset table / variable calculated for the preceding part in the batch can be applied at pre-processing to minimize the out-of-tolerance for the first operation.

[0109] Figures 5a to 5c A cross-sectional side view of a cutting schematic is shown when processing a workpiece.

[0110] In Figures 5a to 5c a schematic of a cutting tool 502 and a schematic of a cutting tool 504 that can be used to machine / cut a workpiece are shown. Here, the cutting tool 502 can be used for a roughing process and / or the cutting tool 504 can be used for a semi-finishing process / fine finishing process. It should be understood that in Figures 5a to 5c examples, the same cutting tool can be used for different cutting processes.

[0111] In Figure 5a the post-processing is performed without taking into account the intermediate part geometry (virtual workpiece model) after the roughing process.

[0112] In this example, a blank piece 505 of a workpiece is first cut by a cutting tool 502. As shown, the manufactured profile 506 after roughing deviates from the nominal profile 508 after roughing, resulting in a local error in pre-processing (as indicated by the upper arrow in Figure 5a ).

[0113] After the roughing process, the workpiece is cut by a cutting tool 504. As shown, the manufactured profile 510 after finishing deviates from the nominal profile 512 after finishing (i.e., the target part geometry), resulting in a local error in post-processing (as indicated by the lower arrow in Figure 5a ).

[0114] In Figure 5b the post-processing is performed taking into account the intermediate part geometry (virtual workpiece model) after the roughing process.

[0115] In this example, a blank piece 505 of a workpiece is first cut by a cutting tool 502. As shown, the manufactured profile 506 after roughing deviates from the nominal profile 508 after roughing, resulting in a local error in pre-processing (as indicated by the upper arrow in Figure 5b ).

[0116] After the roughing process, the workpiece is cut by a cutting tool 504. As shown, the manufactured profile 510 after finishing deviates from the nominal profile 512 after finishing (i.e., the target part geometry), resulting in a local error in post-processing (as indicated by the lower arrow inFigure 5b However, compared to the process shown in Figure 5a the local error in the post-processing of the process shown in Figure 5b is less.

[0117] In Figure 5c , the intermediate part geometry after the roughing process (virtual workpiece model) is considered when performing the post-processing and a priori simulation is used when planning the post-processing.

[0118] In this example, the workpiece's blank 505 is first machined by a cutting tool 502. As shown, the manufactured profile 506 after roughing deviates from the nominal profile 508 after roughing, resulting in a local error in the pre-processing (as indicated by the upper arrow in Figure 5c ).

[0119] After the roughing process, the workpiece is machined by a cutting tool 504. As shown, the manufactured profile 510 after finishing does not (or hardly) deviate from the nominal profile 512 after finishing (i.e. the target part geometry), resulting in no (or very little) local error in the post-processing. Thus, the process shown in Figure 5c can avoid the local error in the post-processing shown in Figure 5b (and Figure 5a ).

[0120] In some examples, a workpiece's blank is processed by a first cut. Based on a path calculated originally to achieve a nominal (ideal) geometry, a specific profile (the "is contour") is obtained. This specific profile is different from the intended due to physical effects not considered in the original path planning. While there is initially an unknown excess in the processed workpiece, a tool center point displacement is then determined from the machine internal (actual) data, referred to as a virtual workpiece model with a predicted acquired contour. This enables determination of the deviation between the nominal profile and the predicted acquired profile, so that the excess can be determined.

[0121] In other words, this deviation is added to the machine (cutting tool)-workpiece engagement in the post-processing. In a second cut, the amount of excess is known, which enables calculation of a tool center point displacement for compensation, so that the "is contour" is aligned with the finished part. In some examples, only a single iteration can be required when applying the excess information in the planning / execution of the second cut. However, there can still be some residual excess after the second cut.

[0122] Figure 6 A schematic diagram showing a sequence of steps 600 according to some embodiments of the disclosure is shown. Typically, process data from a previous manufacturing step (especially a virtual workpiece geometry) is used for CAM planning of an actual manufacturing step.

[0123] In this example, at step 601 , the initial (ideal) geometry_1 and the target geometry_1 are input to the path generation kernel (CAM) and the post-processor.

[0124] The virtual workpiece model obtained by the machine tool (cutter)-workpiece interface simulation 106 is provided to a second path generation kernel (CAM) and post-processor 602. The cutter-workpiece interface simulation together with the path generation kernel (CAM) and post-processor 602 is used for CAM planning based on process data (integrated CAM), which can be executed n times up to and including the nth finishing process (post-processing).

[0125] Figure 7 A schematic diagram illustrating a step sequence 700 according to some embodiments of the present disclosure is shown.

[0126] Sequence 700 generally corresponds to Figure 6 The sequence 600 is shown. However, in the sequence 700, a priori simulation 702 using virtual NC is used in the CAM planning based on the process data. Using a priori simulation, the uncertainty of the properties of the processed workpiece, in particular the geometric configuration, can be reduced (or even avoided). In some examples, a (newly) parameterized physical process simulation (e.g., capable of measuring machining forces / tool ​​deflections) is used.

[0127] One or more model parameters (eg, an empirical force model) may be provided from a machine (cutting tool)-workpiece interface simulation to the a priori simulation using the virtual NC 702 .

[0128] In this example, the a priori simulation exchanges data NC_2 with the path generation kernel (CAM) and the post-processor 602. The downward arrow (arrow 701a) represents the NC_2 generated above (note that NC_2 will (slightly) change with each iteration of the a priori simulation / virtual optimization and can be referred to as NC_2*). The upward arrow (arrow 701b) is the geometric offset information after virtual machining during post-processing, which can be taken into account in the next path generation above. It may depend on the position / pose and can be relative or absolute. If the offset during virtual machining is within the predefined tolerance range, it can send a command to use NC_2* upward.

[0129] The data NC_2b is then output by the path generation kernel (CAM) and post-processor 602 as input to the numerical control 112 used in post-processing. The integrated CAM can be used n times until the finished workpiece is obtained.

[0130] Figure 8 FIG2 is a schematic diagram showing a step sequence 800 according to some embodiments of the present disclosure. In this example, the step sequence 800 is applied to the machining of an electro-discharge machining (EDM) electrode.

[0131] In this example, the initial (ideal) geometry_1 and the target geometry_1 are input to the path generation kernel (CAM) and post-processor. The path generation kernel (CAM) and post-processor 802 output data / program NC_1 to the numerical control 804 used in the pre-process, in this example, the pre-process is the electrode machining process. The blank is processed in the pre-process.

[0132] The data NC trajectory_1 is output by the numerical control 804 and provided to the machine (cutting tool)-workpiece engagement simulation (CWES) with (optional force and) deformation calculation based on the measured machine trajectory data 806. The NC trajectory_1 can be or include a list comprising several numerical control (NC) / programmable logic controller (PLC) / sensor data (topics) with synchronized time stamps in the time domain.

[0133] From the machine (cutting tool)-workpiece engagement simulation (CWES), a virtual workpiece model of the electrode is obtained and input (along with the target geometry_2) to the process planning 810 for the EDM.

[0134] When the post-process is performed, the data NC_2 is output from the process planning 810 EDM and input to the numerical control 812, in this example, the post-process is the EDM machining of the electrode.

[0135] Figure 9 A schematic diagram showing a sequence of steps 900 according to some embodiments of the disclosure is shown. In this example, the virtual workpiece model can be refined by (in-machine tactile) probing / based on one or more measurements performed with a coordinate measuring machine (CMM).

[0136] In this example, the initial (ideal) geometry_1 and the target geometry_1 are provided to the process planning. The process is then planned in step 902 (which can be the same as 802 in sequence 800). The data NC_1 is provided as input to the numerical control used to control the pre-process in step 904. The blank is processed in the pre-process.

[0137] The NC trajectory_1 is output by the numerical control system and used as input to the machine (cutting tool)-workpiece engagement simulation (CWES) in step 906, in which (optional force and) deformation calculation is performed based on the measured machine trajectory data. Based on the machine (cutting tool)-workpiece engagement simulation, a virtual workpiece model is generated and provided (along with the target geometry_2) to the process planning step 908.

[0138] Further, in this example, step 904 includes in-machine metrology, which is used to generate point cloud measurement data that is provided as input to the process planning of step 908 along with the virtual workpiece model. Further, in this example, an external CMM 907 is provided to generate point cloud measurement data that is input to the process planning 908. It should be appreciated that in some examples, only machine metrology (i.e., no external CMM) or only an external CMM (i.e., no in-machine metrology) can be used.

[0139] From the process planning of step 908, data NC_2 is output and provided to the numerical control 910 for performing post-processing of the rough part in this example.

[0140] Figure 10 A refinement of the virtual workpiece model coordinate system is shown in accordance with some embodiments of the present disclosure.

[0141] The actual workpiece 1002 and the virtual workpiece model 1004 (shown here based only on the geometric representation of the virtual workpiece model) are shown in the schematic. The zero point 1006 of the virtual workpiece model is shown to be located at the center of the virtual workpiece model 1004. Further, the zero point 1008 of the zero point positioning chuck (ZPC) system is also depicted.

[0142] If a fully virtual process chain is used in parallel with a physical process chain, in the real world, progressive errors due to misalignment between the virtual world and the real world can be corrected. Effects of looseness in the clamping device can be compensated.

[0143] Figure 11 A schematic of a system setup 1100 is shown in accordance with some embodiments of the present disclosure.

[0144] In this example, the system setup 1100 includes an edge PC 1102 that includes a virtual workpiece generator 1104 and a CAM 1106. Different deployment options for the path planning or adaptation engine are shown (1106, 1108, 1112).

[0145] The edge PC 1102 is an additional computing unit within the machine tool that enables high intensity computation without interfering with critical NC operations. It also enables quasi-process parallel computation. It can host any one or more of the algorithms outlined throughout this disclosure. In this example, the edge PC 1102 is coupled to the cloud in a secure manner, in which path planning and / or path adaptation is performed by the path planning / adaptation engine 1108.

[0146] Further, in this example, the edge PC 1102 is coupled to a locally arranged cell controller 1110, i.e. on-site arrangement of cell-specific metadata of the workpiece processing job. Such metadata can be part ID / tool data / NC data / workpiece material data. Further, in this example, the CAM 1112 is arranged locally and coupled to the edge PC 1102.

[0147] In this example, the edge PC 1102 is further coupled to a computer numerical control (CNC) / programmable logic controller (PLC) 1114. Reference sign 1116 denotes the dynamics from the cutting tool to the workpiece, where the force loop acts on the machining. It is noted that the force loop is not part of the machine tool. A spindle integrated force sensor 1118 is arranged to measure the acting force during machining.

[0148] Figure 12 A flowchart of a method 1200 according to some embodiments of the present disclosure is shown.

[0149] In this example, the method 1200 of processing a workpiece comprises, at step S1202, processing the workpiece by pre-processing.

[0150] At step S1204, a virtual workpiece model is generated as a representative / characterization of the (actual) workpiece after / during pre-processing.

[0151] At step S1206, the virtual workpiece model is used to plan post-processing of the workpiece.

[0152] The method 1200 of processing a workpiece can be implemented in any one or more of the embodiments outlined throughout the present disclosure, in particular in any one or more of the above sequences 100, 200, 300, 400, 600, 700, 800, and 900.

[0153] Figure 13 A schematic block diagram of a system 1300 according to some embodiments of the present disclosure is shown.

[0154] In this example, the system 1300 comprises a data source 1302, a data transmitter 1304, and a data processing system 1306. The system 1300 is configured to perform a method according to any one or more of the embodiments outlined throughout the present disclosure, in particular in / above the above sequences 100, 200, 300, 400, 600, 700, 800, and 900.

[0155] In certain examples, the data source 1302 is a machine tool having a data interface for high-frequency sending / reading of machine-internal data. Here, the machine-internal data can relate to, for example, the position passed through by the machine tool, the current / force acting on one or more motors of the machine tool. Generally, the machine-internal data can refer to data used for controlling the machine tool. In certain examples, data obtained subsequently to the measurement can not be taken into account for the machine-internal data.

[0156] The machine-internal data can relate to data originating from the current machining process. In certain examples, the machine-internal data can relate to one or more of the following: force, acceleration, temperature, vibration, and other parameters related to the machining process, for example the bending of the workpiece to be produced (for example resolution less than 50 pm) / the mathematical calculation of the drilling / cutting penetration of the machine tool into the workpiece to be produced. The data can be obtained in the (current) machining process. The data can originate from a controller / sensor used for controlling the machine tool, which can not be (at least not directly) connected to the controller.

[0157] In certain examples, the data source 1302, the data sender 1304, and the data processing system 1306 (for generating the virtual workpiece model) comprise a software unit for material removal simulation and a software unit for determining the deformation, which are equipped with a software unit for computer-aided path planning, in particular a machine tool comprising a built-in edge PC. Any two or all of the above-mentioned software units can be integrated into a single software unit.

[0158] It should be noted that the path planning as used throughout the present disclosure can not be limited to the understanding of being realized only by computer-aided manufacturing. For example, one or more offset tables regarding target position data / actual position data can be included.

[0159] The examples outlined throughout the present disclosure can be applied in manufacturing, in particular mass production, and / or mold technology in finishing of castings, and / or printed / forged products, for example but not limited to automotive, agricultural, medical, aerospace, semiconductor, and other fields. The examples outlined throughout the present disclosure can include all machining processes, for example but not limited to milling, turning, grinding, and other machining processes in pre- / post-processing steps.

[0160] The machine-internal data outlined throughout the present disclosure can additionally or alternatively relate to or include one or more of the following: deformation of the tool, deformation of the workpiece, static / dynamic load of the machine tool, and compensation of the machine tool and tool geometry related to volume / thermal effects.

[0161] In some embodiments outlined throughout the present disclosure, methods for adapting path positions at a machine tool can be taken. All methods can start after a virtual workpiece and deviation analysis from a target profile are generated. Any variable for adaptation can be based on the deviation between the virtual workpiece and the target profile. Edge kernel based path adaptation enables path adaptation under predefined boundary conditions (to reduce the risk of collision or machine tool damage, etc.). Here, the number or direction of paths does not fundamentally change.

[0162] The following examples are also included in the present disclosure and can be incorporated in embodiments in whole or in part:

[0163] 1. A method of processing a workpiece, comprising the steps of:

[0164] processing the workpiece by pre-processing;

[0165] generating a virtual workpiece model as a representation of the workpiece after and / or during pre-processing; and

[0166] planning post-processing of the workpiece using the virtual workpiece model.

[0167] 2. The method according to clause 1, wherein pre-processing and / or post-processing is performed using more than one NC code block.

[0168] 3. The method according to clause 1 or 2, wherein at least one of the pre-processing and post-processing is planned by computer-based path planning.

[0169] 4. The method according to any of the preceding clauses, wherein the pre-processing and the post-processing are performed using at least one machine tool, the number of machine tools being equal to or less than the number of process steps used to process the workpiece with the pre-processing and the post-processing.

[0170] 5. The method according to clause 4, wherein the virtual workpiece model is generated using data from a controller of a machine tool and / or from integrated sensors in a machine tool.

[0171] 6. The method according to any of the preceding clauses, wherein the virtual workpiece model is generated quasi-parallel to the pre-processing and / or after the pre-processing.

[0172] 7. The method according to clause 6, wherein quasi-parallel means a delay of less than 50 ms, preferably less than 10 ms.

[0173] 8. The method according to any of the preceding clauses, wherein the virtual workpiece model is generated by considering more than one displacement amount of more than one physical component, wherein the more than one displacement amount is caused by more than one machining force acting along a force loop.

[0174] 9. The method according to any of the preceding clauses, wherein the virtual workpiece model is generated by considering more than one compensation algorithm running on the machine and / or NC controller.

[0175] 10. The method according to any of the preceding clauses, wherein the generation of the virtual workpiece model is done with a local geometric resolution that is smaller than the part-specific local geometric dimensions and tolerances (GDT).

[0176] 11. The method according to any of the preceding clauses, wherein after the pre-processing, more than one region of the virtual workpiece model is refined and / or corrected using micron / sub-micron precision measurements, in particular by means of coordinate measuring machines and / or in-machine touch and / or optical measurements, and / or point clouds of measurements.

[0177] 12. The method according to any of the preceding clauses, wherein the calibration of the process model as a function of more than one boundary condition is done in parallel to the pre-processing.

[0178] 13. The method according to clause 12, wherein the calibrated process model is used for planning the post-processing.

[0179] 14. The method according to any of the preceding clauses, wherein the calibration of the tool-material model is done in parallel to the post-processing.

[0180] 15. The method according to any of the preceding clauses, wherein the planning of the post-processing is done using an initial workpiece geometry based on the virtual workpiece model.

[0181] 16. The method according to any of the preceding clauses, wherein the planning of the post-processing is done after the pre-processing and the generation of the virtual workpiece model.

[0182] 17. The method according to any of the preceding clauses, wherein during the planning of the post-processing, more than one process parameter is adjusted according to high-order topographical deviations on the virtual workpiece model.

[0183] 18. The method according to any of the preceding clauses, wherein more than one supplemental sensor signal, in particular acceleration data, is added to the virtual workpiece model in a position-dependent manner.

[0184] 19. The method according to any of the preceding clauses, wherein the planning of the post-processing is done by using the ideal geometry obtained in the planning of the pre-processing as an initial workpiece geometry.

[0185] 20. The method according to any of the preceding clauses, further comprising the step of post-processing planning one or more paths.

[0186] 21. The method according to any of the preceding clauses, wherein one or more initial computed paths of the post-processing are adjusted based on additional input generated from the virtual workpiece model.

[0187] 22. The method according to any of the preceding clauses, wherein one or more variables of a pose dependent offset table and / or parameterized NC code dependent on a tool center point’s geometric deviation and / or displacement are generated using the virtual workpiece model.

[0188] 23. The method according to clause 21 or clause 22 as dependent on clause 21, wherein the path adjustment is performed by a controller of the machine tool in order to generate one or more final paths in the NC device and / or the machine tool.

[0189] 24. The method according to clause 21, or clause 22 as dependent on clause 21, or clause 23, wherein the adjustment of the one or more target paths of the post-processing is performed locally and / or in the cloud.

[0190] 25. The method according to clause 21, or clause 22 as dependent on clause 21, or clause 23 or 24, wherein the amount of path adjustment is less than a predetermined threshold, wherein the predetermined threshold is based on one or more process parameters for processing the workpiece and / or based on a tool geometry of a tool for processing the workpiece.

[0191] 26. The method according to clause 25, wherein the threshold is less than half of a tool diameter of the tool.

[0192] 27. The method according to any of clause 21, or clause 22 as dependent on clause 21, or any of clauses 23 to 26, wherein the one or more paths are adjusted by adding a single path segment.

[0193] 28. The method according to any of the preceding clauses, wherein the post-processing planning comprises determining a virtual tool-workpiece engagement and calculating a displacement of a tool center point.

[0194] 29. The method according to clause 28, wherein the planning is performed using a tool- material model established and / or calibrated in a pre-processing.

[0195] 30. The method according to clause 28 or 29, wherein a virtual NC controller, in particular comprising one or more offset tables, in particular NC internal corrections / compensations, is used to calculate an expected actual path in relation to a priori simulation of the virtual workpiece model.

[0196] 31. The method according to any one of clauses 28 to 30, wherein the target path is iteratively generated taking into account displacement of the tool center point.

[0197] 32. The method according to any one of the preceding clauses, wherein the post processing is performed by an electro-discharge machining machine.

[0198] 33. The method according to any one of the preceding clauses, wherein the post processing is performed by an electro-chemical machining machine.

[0199] 34. The method according to any one of the preceding clauses, further comprising the step of performing a micron / sub-micron precision part measurement process after the pre-processing and using the corresponding measurement point cloud to correct the virtual workpiece coordinate system with respect to a reference point, in particular to position a clamped virtual workpiece coordinate system with respect to an electrode (EDM) or cathode (ECM) zero point.

[0200] 35. A system configured to perform the method of any one of the preceding clauses, comprising a data source, a data transmitter and a data processing system.

[0201] 36. The system according to clause 35, wherein the data source is a machine tool having a data interface for transmitting and reading machine internal data.

[0202] 37. The system according to clause 36, wherein the data is provided by the data interface providing PLC data at a frequency of less than 2 kHz and / or servo data at a frequency of between 100 Hz and 20 kHz and / or rotor shaft deformation at a frequency of between 2 kHz and 40 kHz.

[0203] 38. The system according to clause 36 or 37, wherein the data comprises one or more of: current supplied to a motor, one or more signals from rotary and / or linear encoders, displacement of the tool center point, one or more tool tables, one or more compensation tables and / or NC blocks.

[0204] 39. The system according to any one of clauses 35 to 38, wherein the data is obtained from sensors located in front of and / or between bearing pairs for measuring rotor shaft deformation.

[0205] 40. The system according to any one of clauses 35 to 39, wherein the data source is a machine internal job manager and / or cell controller and / or manufacturing execution system.

[0206] 41. The system according to clause 40, wherein the system is configured to provide job information and / or context information from one or more pre-processes and / or corresponding one or more images of the workpiece.

[0207] 42. The system according to any one of clauses 35 to 41, wherein the data source, the data transmitter and the data processing system for generating the virtual workpiece model comprise a software unit for material removal simulation equipped with a software unit for computer-aided path planning and a software unit for determining a deformation, in particular a machine tool comprising a built-in edge PC.

[0208] It goes without saying that many other effective alternatives will be immediately apparent to those skilled in the art. It is understood that the application is not limited to the embodiments described, but also includes modifications which will be apparent to those skilled in the art and which fall within the scope of the appended claims.

Claims

1. A method of processing a workpiece, comprising the steps of: processing the workpiece by a pre-process; generating a virtual workpiece model as a representation of the workpiece after and / or during the pre-process; and planning a post-process of the workpiece using the virtual workpiece model.

2. The method according to claim 1, wherein the pre-process and / or the post-process is performed using more than one NC code block. At least one of the pre-process and the post-process is planned by computer-based path planning.

3. The method of claim 1, wherein, The pre-process and the post-process are performed using at least one machine tool, the number of machine tools being equal to or less than the number of process steps used for processing the workpiece with the pre-process and the post-process.

4. The method of claim 1, wherein, The virtual workpiece model is generated using data from a controller of a machine tool and / or from integrated sensors in a machine tool.

5. The method of claim 4, wherein, The virtual workpiece model is generated quasi-parallel to the pre-process and / or after the pre-process.

6. The method of claim 1, wherein, Quasi-parallel means a delay of less than 50 ms, preferably less than 10 ms.

7. The method of claim 6, wherein, The virtual workpiece model is generated by considering more than one displacement amount of more than one physical component, wherein the more than one displacement amount is caused by more than one machining force acting along a force loop.

8. The method according to claim 1, wherein The virtual workpiece model is generated by considering more than one compensation algorithm running on a machine and / or a NC controller.

9. The method of claim 1, wherein, The generation of the virtual workpiece model is performed with a local geometric resolution that is smaller than the local geometric dimensions and tolerances (GDT) of the part.

10. The method of claim 1, wherein, After the pre-process, one or more regions of the virtual workpiece model are refined and / or corrected using micron / sub-micron precision measurements, in particular by means of a coordinate measuring machine and / or in-machine touch and / or optical measurements, and / or a point cloud of measurements.

11. The method of claim 1, wherein, Calibration of a process model as a function of one or more boundary conditions is performed in parallel to the pre-process.

12. The method of claim 1, wherein, The post-process is planned using the calibrated process model.

13. The method of claim 12, wherein, Calibration of a tool-material model is performed in parallel to the post-process.

14. The method of claim 1, wherein, The planning of the post-process is performed using an initial workpiece geometry based on the virtual workpiece model.

15. The method of claim 1, wherein, The planning of the post-process is performed after the pre-process and the generation of the virtual workpiece model.

16. The method according to claim 15, wherein During the planning of the post-process, one or more process parameters are adjusted according to high-order topographical deviations on the virtual workpiece model.

17. The method of claim 1, wherein, One or more supplemental sensor signals, in particular acceleration data, are added to the virtual workpiece model in a position-dependent manner.

18. The method of claim 1, wherein, The planning of the post-process is performed by using an ideal geometry obtained in the planning of the pre-process as an initial workpiece geometry.

19. The method of claim 1, wherein, 20. The method according to claim 19, further comprising the step of planning one or more paths of the post-process. One or more initial calculated paths of the post-process are adjusted based on additional inputs generated from the virtual workpiece model.

21. The method of claim 1, wherein, One or more variables of a pose-dependent offset table and / or parameterized NC code depending on a geometric deviation and / or displacement of a tool center point are generated using the virtual workpiece model.

22. The method according to claim 21, wherein The path adjustment is performed by a controller of a machine tool in order to generate one or more final paths in a NC device and / or a machine tool.

23. The method of claim 21, wherein, ​ 24. The method of claim 21, wherein, Adjusting one or more target paths of a post-processing locally and / or in the cloud.

25. The method of claim 21, wherein, The path adjustment amount is less than a predetermined threshold, wherein the predetermined threshold is based on one or more process parameters for processing the workpiece and / or based on a tool geometry of a tool for processing the workpiece.

26. The method of claim 25, wherein, The threshold is less than half of a tool diameter of the tool.

27. The method of claim 21, wherein, Adjusting the one or more paths by adding a single path segment.

28. The method of claim 1, wherein, The planning of the post-processing comprises determining a virtual tool-workpiece engagement and calculating a displacement of a tool center point.

29. The method of claim 28, wherein, The planning uses a tool-material model established and / or calibrated in a pre-processing.

30. The method of claim 28, wherein A virtual NC controller, in particular comprising one or more offset tables, in particular NC internal corrections / compensations, is used to calculate an expected actual path in relation to a priori simulation of a virtual workpiece model.

31. The method of claim 28, wherein, The target path is generated iteratively taking into account a displacement of a tool center point.

32. The method of claim 1, wherein, The post-processing is performed by an electro discharge machining machine.

33. The method of claim 1, wherein, The post-processing is performed by an electro chemical machining machine.

34. The method according to claim 1, further comprising the step of performing a micron / sub-micron precision part measurement process after the pre-processing and using the corresponding measurement point cloud to correct a virtual workpiece coordinate system with respect to a reference point, in particular a virtual workpiece coordinate system clamped with respect to an electrode (EDM) or cathode (ECM) zero point positioning.

35. A system configured to perform the method according to claim 1, comprising a data source, a data transmitter and a data processing system.

36. The system of claim 35, wherein, The data source is a machine tool with a data interface for transmitting and reading machine internal data.

37. The system of claim 36, wherein, The data is provided by the data interface, which provides PLC data at a frequency of less than 2 kHz and / or servo data at a frequency of between 100 Hz and 20 kHz and / or rotor shaft deformation at a frequency of between 2 kHz and 40 kHz.

38. The system of claim 36, wherein, The data comprises one or more of the following: current supplied to a motor, one or more signals from rotary and / or linear encoders, displacement of a tool center point, one or more tool tables, one or more compensation tables and / or NC blocks.

39. The system of claim 35, wherein, The data is obtained from sensors for measuring rotor shaft deformation located in front of and / or between bearing pairs.

40. The system of claim 35, wherein, The data source is a machine internal job manager and / or cell controller and / or manufacturing execution system.

41. The system of claim 40, wherein, The system is configured to provide job information and / or context information from one or more pre-processings and / or corresponding one or more images of the workpiece.

42. The system of claim 35, wherein, The data source, the data transmitter and the data processing system for generating the virtual workpiece model comprise a software unit for material removal simulation equipped with a software unit for computer aided path planning and a software unit for determining deformation, in particular a machine tool comprising a built-in edge PC.

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