GRINDING AND POLISHING SIMULATION METHOD AND SYSTEM AND GRINDING AND POLISHING PROCESS TRANSFERRING METHOD
20210331287 · 2021-10-28
Assignee
Inventors
- Yuan-Chieh LO (Taichung City, TW)
- Yu-Hsun WANG (Taichung City, TW)
- Pei-Chun LIN (Taipei City, TW)
- Chih-Hsuan Shih (Xihu Township, TW)
- Shu Huang (Zhudong Township, TW)
Cpc classification
G05B17/00
PHYSICS
International classification
Abstract
A grinding and polishing simulation method, a grinding and polishing simulation system and a grinding and polishing process transferring method. The grinding and polishing simulation method includes the following steps. A sensing information of a grinding and polishing apparatus when grinding or polishing a workpiece is obtained. A plurality of model parameters is identified according to the sensing information. At least one quality parameter is calculated according to a machining path, a plurality of process parameters and the plurality of model parameters.
Claims
1. A grinding and polishing simulation system, comprising: a sensing unit configured to obtain a sensing information of a grinding and polishing apparatus when grinding or polishing a workpiece; an identification unit configured to identify a plurality of model parameters according to the sensing information; and a simulation unit configured to calculate at least one quality parameter according to a machining path, a plurality of process parameters and the plurality of model parameters.
2. The grinding and polishing simulation system according to claim 1, further comprising: a machining path generation unit configured to generate the machining path according to the workpiece.
3. The grinding and polishing simulation system according to claim 1, wherein the identification unit defines a region, receives the sensing information of a plurality of touch points in the region, on which the workpiece is guided by a robot to move relative to the grinding and polishing apparatus, from the sensing unit, receives the at least one quality parameter from the simulation unit, and calculates an error between the sensing information and the at least one quality parameter, and obtains the plurality of model parameters corresponding to the at least one quality parameter when the error is lower than a threshold value to identify the plurality of model parameters.
4. The grinding and polishing simulation system according to claim 1, wherein the simulation unit creates a grinding and polishing apparatus physical model according to the grinding and polishing apparatus, creates a workpiece physical model according to the workpiece, and inputs the machining path, the plurality of process parameters and the plurality of model parameters to the grinding and polishing apparatus physical model and the workpiece physical model to calculate the at least one quality parameter.
5. The grinding and polishing simulation system according to claim 1, wherein the process parameters comprise grinding and polishing touch points, sand belt number, workpiece speed, sand belt/polisher speed, feed depth, workpiece material, or original surface quality of the workpiece.
6. The grinding and polishing simulation system according to claim 1, wherein the model parameters comprise geometric parameter, sand belt tension, deformation correction parameter, or wear correction parameter of the grinding and polishing apparatus and the workpiece.
7. The grinding and polishing simulation system according to claim 1, wherein the at least one quality parameter comprises normal/tangential force distribution, material removal rate, surface roughness, or coverage.
8. The grinding and polishing simulation system according to claim 1, wherein the sensing information comprises six-axis force information, geometric variation, surface roughness, or surface state of the workpiece.
9. The grinding and polishing simulation system according to claim 1, further comprising: an external sensing unit configured to obtain the plurality of model parameters from the grinding and polishing apparatus and the workpiece.
10. A grinding and polishing simulation method, comprising: obtaining a sensing information of a grinding and polishing apparatus when grinding or polishing a workpiece; identifying a plurality of model parameters according to the sensing information; and calculating at least one quality parameter according to a machining path, a plurality of process parameters and the plurality of model parameters.
11. The grinding and polishing simulation method according to claim 10, further comprising: generating the machining path according to the workpiece.
12. The grinding and polishing simulation method according to claim 10, wherein identifying the plurality of model parameters according to the sensing information comprises: defining a region; receiving the sensing information of a plurality of touch points in the region, on which the workpiece is guided by a robot to move relative to the grinding and polishing apparatus; receiving the at least one quality parameter, and calculating an error between the sensing information and the at least one quality parameter; and when the error is lower than a threshold value, obtaining the model parameters corresponding to the at least one quality parameter to identify the plurality of model parameters.
13. The grinding and polishing simulation method according to claim 10, wherein calculating the at least one quality parameter according to the machining path, the process parameters and the model parameters comprises: creating a grinding and polishing apparatus physical model according to the grinding and polishing apparatus; creating a workpiece physical model according to the workpiece; and inputting the machining path, the process parameters and the model parameters to the grinding and polishing apparatus physical model and the workpiece physical model to calculate the at least one quality parameter.
14. The grinding and polishing simulation method according to claim 10, wherein the process parameters comprise grinding and polishing touch points, sand belt number, workpiece speed, sand belt/polisher speed, feed depth, workpiece material, or original surface quality of the workpiece.
15. The grinding and polishing simulation method according to claim 10, wherein the model parameters comprise geometric parameter, sand belt tension, deformation correction parameter, or wear correction parameter of the grinding and polishing apparatus and the workpiece
16. The grinding and polishing simulation method according to claim 10, wherein the at least one quality parameter comprises normal/tangential force distribution, material removal rate, surface roughness, or coverage.
17. The grinding and polishing simulation method according to claim 10, wherein the sensing information comprises six-axis force information, geometric variation, surface roughness, or surface state of the workpiece.
18. The grinding and polishing simulation method according to claim 10, further comprising: obtaining the model parameters from the grinding and polishing apparatus and the workpiece.
19. A grinding and polishing process transferring method, comprising: creating a first simulated environment corresponding to a first real environment, wherein the first real environment comprises a first grinding and polishing apparatus and a first robot, and the first simulated environment comprises a first grinding and polishing apparatus physical model and a first workpiece physical model; obtaining a first sensing information of the first grinding and polishing apparatus and the first robot when grinding or polishing a first workpiece; identifying a plurality of first model parameters according to the first sensing information; inputting a first machining path, a plurality of first process parameters and the plurality of first model parameters to the first grinding and polishing apparatus physical model and the first workpiece physical model to calculate at least one first quality parameter; creating a second simulated environment corresponding to a second real environment, wherein the second real environment comprises a second grinding and polishing apparatus and a second robot, and the second simulated environment comprises a second grinding and polishing apparatus physical model and a second workpiece physical model; obtaining a first calibration information associated with the first grinding and polishing apparatus and the first robot, obtaining a second calibration information associated with the second grinding and polishing apparatus and the second robot, and calibrating the first simulated environment and the second simulated environment according to the first calibration information and the second calibration information respectively; analyzing the first simulated environment and the second simulated environment to obtain a difference information; and inputting at least one part of the first machining path, the plurality of first process parameters and the plurality of first model parameters to the second grinding and polishing apparatus physical model and the second workpiece physical model according to the difference information to simulate the operation of grinding or polishing a second workpiece by the second grinding and polishing apparatus and the second robot and to calculate at least one second quality parameter.
20. The grinding and polishing process transferring method according to claim 19, wherein the first calibration information comprises position calibration of the first robot and the first grinding and polishing apparatus, size calibration of the gripper unit of the first robot, variation correction of the first workpiece, or additional rotation axis calibration of the first grinding and polishing apparatus; the second calibration information comprises position calibration of the second robot and the second grinding and polishing apparatus, size calibration of the gripper unit of the second robot, variation correction of the second workpiece, or additional rotation axis calibration of the second grinding and polishing apparatus.
21. The grinding and polishing process transferring method according to claim 19, wherein inputting at least one part of the first machining path, the plurality of first process parameters and the plurality of first model parameters to the second grinding and polishing apparatus physical model and the second workpiece physical model according to the difference information comprises: when the first workpiece and the second workpiece are the same, and a configuration of the first robot and the first grinding and polishing apparatus and a configuration of the second robot and the second grinding and polishing apparatus are also the same, inputting the first machining path, the first process parameter and the first model parameter to the second grinding and polishing apparatus physical model and the second workpiece physical model.
22. The grinding and polishing process transferring method according to claim 19, wherein inputting at least one part of the first machining path, the plurality of first process parameters and the plurality of first model parameters to the second grinding and polishing apparatus physical model and the second workpiece physical model according to the difference information comprises: when the first workpiece and the second workpiece are the same, but a configuration of the first robot and the first grinding and polishing apparatus and a configuration of the second robot and the second grinding and polishing apparatus are different, identifying a plurality of second model parameters, and inputting the first machining path, the plurality of first process parameters and the plurality of second model parameters to the second grinding and polishing apparatus physical model and the second workpiece physical model.
23. The grinding and polishing process transferring method according to claim 19, wherein inputting at least one part of the first machining path, the plurality of first process parameters and the plurality of first model parameters to the second grinding and polishing apparatus physical model and the second workpiece physical model according to the difference information comprises: when the first workpiece and the second workpiece are different, and a configuration of the first robot and the first grinding and polishing apparatus and a configuration of the second robot and the second grinding and polishing apparatus are also different, identifying a plurality of second model parameters, comparing the first workpiece with the second workpiece to obtain an identical part between the first workpiece and the second workpiece, and inputting the first machining path corresponding to the identical part, the first process parameter corresponding to the identical part, and the second model parameters to the second grinding and polishing apparatus physical model and the second workpiece physical model.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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[0019] In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
DETAILED DESCRIPTION
[0020] Referring to
[0021] Refer to
[0022] In step S120, a plurality of model parameters MP is identified by the identification unit 120 according to the sensing information SI. Referring to
[0023] In step S121, a region R is defined by the identification unit 120. Referring to
[0024] In step S122, the sensing information SI of a plurality of touch points TP in the region R, on which the workpiece 400 is guided by the robot 300 to move relative to the grinding and polishing apparatus 200, is received from the sensing unit 110 by the identification unit 120. Furthermore, the sensing unit 110 obtains the sensing information SI of each of the touch points TP, and the identification unit 120 receives the sensing information SI.
[0025] In step S123, the predictive value of a quality parameter is calculated by the identification unit 120 according to the set value of the model parameter corresponding to the quality parameter. The identification unit 120 needs to calculate the predictive value of the quality parameter according to a pre-arbitrarily set value of a model parameter. The set value of the model parameter is such as the set value of the geometric parameter, the set value of the sand belt tension, the set value of the deformation correction parameter, or the set value of the wear correction parameter of the grinding and polishing apparatus 200 and the workpiece 400. The predictive value of the quality parameter is such as the predictive value of the normal/tangential force distribution, the predictive value of the material removal rate, the predictive value of the surface roughness, or the predictive value of the coverage. Since the predictive value of the quality parameter and the set value of the model parameter are associated with each other, the predictive value of a quality parameter can be calculated according to the set value of the model parameter corresponding to the quality parameter.
[0026] In step S124, whether the error between the predictive value of the quality parameter and the real sensing information SI is lower than a threshold value is calculated by the identification unit 120. If yes, the method proceeds to step S127; otherwise, the method proceeds to step S125. Firstly, the identification unit 120 analyzes the quality parameter corresponding to the real sensing information SI. For example, the identification unit 120 analyzes the normal/tangential force distribution corresponding to the six-axis force information, analyzes the material removal rate corresponding to the workpiece geometric variation, and analyzes the coverage corresponding to the surface state of the workpiece. Then, the identification unit 120 calculates whether the error between the predictive value of the quality parameter and the quality parameter corresponding to the real sensing information SI is lower than a threshold value, For example, the identification unit 120 calculates whether the root mean square error (RMSE), the mean square error (MSE), the mean absolute error (MAE), the mean absolute percentage error (MAPE) or the symmetric mean absolute percentage error (SMAPE) between the predictive value of the quality parameter and the real sensing information SI of the quality parameter is lower than a threshold value, wherein the setting of the threshold value depends on the situations.
[0027] If the error between the predictive value of the quality parameter and the real sensing information SI is lower than the threshold value, this implies that the set value of the model parameter of step S123 is suitable. Then, the method proceeds to step S127, the set value of the model parameter is defined as the model parameter MP finally adopted by the identification unit 120, and the method proceeds to step S130.
[0028] If the error between the predictive value of the quality parameter and the real sensing information SI is not lower than the threshold value, this implies that the set value of the model parameter of step S123 is not suitable, and the method proceeds to step S125.
[0029] In step S125, whether the count of updating the set value of the model parameter is greater than a predetermined count is determined by the identification unit 120, wherein the setting of the predetermined count depends on the situations. If yes, this implies that the error between the predictive value of the quality parameter and the real sensing information SI is not lower than the threshold value within the predetermined count, and the method returns to step S122 to obtain another sensing information SI and perform subsequent steps; otherwise, this implies that the count of updating the set value of the model parameter is still within the predetermined count, and the method proceeds to step S126.
[0030] In step S126, the set value of the model parameter is updated by the identification unit 120. For example, the identification unit 120 updates the set value of the geometric parameter, the set value of the sand belt tension, the set value of the deformation correction parameter, or the set value of the wear correction parameter of the grinding and polishing apparatus 200 and the workpiece 400. Then, the method returns to step S123, the updated predictive value of the quality parameter is calculated by the identification unit 120 according to the updated set value of the model parameter corresponding to the quality parameter. Then, the method proceeds to step S124, whether the error between the updated predictive value of the quality parameter and the real sensing information SI is lower than a threshold value is calculated by the identification unit 120. That is, steps S123 to S126 form a recursive process which will be repeated until the error between the predictive value of the quality parameter and the real sensing information SI calculated according to the set value of the model parameter is lower than the threshold value (step S124), or until the count of updating the set value of the model parameter is greater than the predetermined count (step S125).
[0031] In step S125, when the identification unit 120 determines that the count of updating the set value of the model parameter is greater than the predetermined count, this implies that the initial set value of the model parameter is not selected properly, therefore the set value of the model parameter will not converge regardless how many times the set value of the model parameter has been updated (that is, despite that the count of repeating steps S123 to S126 is over the predetermined count, the error is still not lower than the threshold value). Under such circumstance, the method needs to return to step S122 of obtaining the sensing information SI to select an initial set value and start the next recursive process of error comparison.
[0032] Refer to
[0033] Referring to
[0034] In step S131, a grinding and polishing apparatus physical model is created by the simulation unit 130 according to the grinding and polishing apparatus 200. In step S132, a workpiece physical model is created by the simulation unit 130 according to the workpiece 400. It should be noted that step S131 and step S132 can be performed concurrently or consecutively. As indicated in
[0055] Then, the method proceeds to step S133, the machining path PT, the process parameters PP and model parameters MP are inputted to the grinding and polishing apparatus physical model 210 and the workpiece physical model 410 by the simulation unit 130 to calculate at least one quality parameter QP. Let the quality parameter QP be the normal/tangential force distribution. The two-dimensional normal/tangential force distribution F.sub.2D and the three-dimensional normal/tangential force distribution F.sub.3D can be obtained according to formula 1 and formula 2 respectively:
F.sub.2D=f(T,r,L.sub.m0,δ,R.sub.1,R.sub.2,L) (formula 1)
F.sub.3D=∫.sup.w.sub.0F.sub.2D(y)×dy (formula 2)
Wherein, T represents a sand belt tension (model parameter MP), δ represents a grinding depth (machining path PT).
[0056] Let the quality parameter QP be the material removal rate γ.sub.ij. The material removal rate γ.sub.ij can be obtained according to formula 3:
[0057] Wherein C.sub.A represents a fixed calibration parameter (model parameters MP), K.sub.A represents a parameter relevant to the workpiece material and the sand belt number (model parameter MP), K.sub.t represents a wear correction parameter (model parameter MP), V.sub.b represents a sand belt/polisher speed (process parameter PP), V.sub.w represent a workpiece speed (process parameter PP), α, β, γ represent calibration factors (model parameters MP).
[0058] Although the above descriptions are exemplified by the normal/tangential force distribution and the material removal rate, the present disclosure is not limited thereto.
[0059] Through the grinding and polishing simulation method and system of the present disclosure, model parameters can be identified immediately and at least one quality parameter can be calculated during the grinding and polishing process. Thus, the present disclosure can adjust various device parameters without using a large amount of labor and time.
[0060] Refer to
[0061] In step S210, a first simulated environment EV1 corresponding to a first real environment is created, wherein the first real environment includes a first grinding and polishing apparatus 2001 and a first the robot 3001, and the first simulated environment EV1 includes a first grinding and polishing apparatus physical model GMD1 and a first workpiece physical model WMD1.
[0062] In step S220, the grinding and polishing simulation method is performed in the first simulated environment EV1. The grinding and polishing simulation method of the present step is similar to the grinding and polishing simulation method of
[0063] In step S230, a second simulated environment EV2 corresponding to a second real environment is created, wherein the second real environment includes a second grinding and polishing apparatus 2002 and a second robot 3002, and the second simulated environment EV2 includes a second grinding and polishing apparatus physical model GMD2 and a second workpiece physical model WMD2.
[0064] In step S240, the first simulated environment EV1 and the second simulated environment EV2 are calibrated. Firstly, a first calibration information associated with the first grinding and polishing apparatus 2001 and the first the robot 3001 is obtained, a second calibration information associated with the second grinding and polishing apparatus 2002 and the second robot 3002 is obtained, and the first simulated environment EV1 and the second simulated environment EV2 are calibrated according to the first calibration information and the second calibration information respectively. The first calibration information is, for example, a position calibration of the first the robot 3001 and the first grinding and polishing apparatus 2001, a size calibration of the gripper unit of the first the robot 3001, a variation correction of the first workpiece 4001, or additional rotation axis calibration of the first grinding and polishing apparatus 2001. The second calibration information is, for example, a position calibration of the second robot 3002 and the second grinding and polishing apparatus 2002, a size calibration of the gripper unit of the second robot 3002, a variation correction of the second workpiece 4002, or additional rotation axis calibration of the second grinding and polishing apparatus 2002.
[0065] In step S250, the first simulated environment EV1 and the second simulated environment EV2 are analyzed to obtain a difference information. The difference information is, for example, the geometric difference between the geometry of the first workpiece 4001 and the geometry of the second workpiece 4002 or the configuration difference between the configuration of the first the robot 3001 and the first grinding and polishing apparatus 2001 and the configuration of the second robot 3002 and the second grinding and polishing apparatus 2002.
[0066] In step S260, the grinding and polishing process is transferred to the second simulated environment EV2 from the first simulated environment EV1 according to the difference information. Furthermore, at least one part of the first machining path, the first process parameters and the first model parameters are inputted to the second grinding and polishing apparatus physical model GMD2 and the second workpiece physical model WMD2 according to the difference information to simulate the operation of grinding or polishing the second workpiece 4002 by the second grinding and polishing apparatus 2002 and the second robot 3002 and to calculate at least one second quality parameter. In the present step, the first machining path is such as the workpiece machining path or the robot machining path. Furthermore, there is a correspondence relation between the workpiece machining path and the robot machining path, and the workpiece machining path can be transferred to a corresponding robot machining path according to the type of the robot. Detailed descriptions of the difference information are disclosed below.
[0067] When the difference information is that the first workpiece 4001 and the second workpiece 4002 are the same, and the configuration of the first the robot 3001 and the first grinding and polishing apparatus 2001 and the configuration of the second robot 3002 and the second grinding and polishing apparatus 2002 are also the same, the first machining path, the first process parameters and the first model parameters are inputted to the second grinding and polishing apparatus physical model GMD2 and the second workpiece physical model WMD2 to simulate the operation of grinding or polishing the second workpiece 4002 by the second grinding and polishing apparatus 2002 and the second robot 3002 and to calculate at least one second quality parameter.
[0068] When the difference information is that the first workpiece 4002 and the second workpiece 4002 are the same, but the configuration of the first the robot 3001 and the first grinding and polishing apparatus 2001 and the configuration of the second robot 3002 and the second grinding and polishing apparatus 2002 are different, a plurality of second model parameters is identified in the second simulated environment EV2, and the first machining path, the first process parameters and the second model parameters are inputted to the second grinding and polishing apparatus physical model GMD2 and the second workpiece physical model WMD2 to simulate the operation of grinding or polishing the second workpiece 4002 by the second grinding and polishing apparatus 2002 and the second robot 3002 and to calculate at least one second quality parameter.
[0069] When the difference information is that the first workpiece 4001 and the second workpiece 4002 are different, and the configuration of the first the robot 3001 and the first grinding and polishing apparatus 2001 and the configuration of the second robot 3002 and the second grinding and polishing apparatus 2002 are also different, a plurality of second model parameters is identified in the second simulated environment EV2, the first workpiece 4001 is compared with the second workpiece 4002 to obtain an identical part between the first workpiece 4001 and the second workpiece 4002, and the first machining path corresponding to the identical part, the first process parameter corresponding to the identical part, and the second model parameters are inputted to the second grinding and polishing apparatus physical model GMD2 and the second workpiece physical model WMD2 to simulate the operation of grinding or polishing the second workpiece 4002 by the second grinding and polishing apparatus 2002 and the second robot 3002 and to calculate at least one second quality parameter. Detailed description of the identical part between the first workpiece 4001 and the second workpiece 4002 are disclosed below.
[0070] Referring to
[0071] Thus, through the grinding and polishing process transferring method of the present disclosure, the grinding and polishing process can be transferred between different production lines according to the commonality and difference information between different production lines.
[0072] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.