Computer-aided optimization of numerically controlled machining of a workpiece

Patent metadata

Field	Value
Publication number	US-11567470-B2
Application number	US-201917310300-A
Country	US
Kind code	B2
Filing date	Dec 17, 2019
Priority date	Jan 28, 2019
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

In order to be able to take into account machining configurations more flexibly, a method for optimizing numerically controlled machining of a workpiece includes ascertaining geometric interaction data. A relationship between a force to be expected and a configuration parameter of the machining is determined on the basis of the interaction data. The force is calculated during the machining on the basis of the relationship and a current value of the at least one configuration parameter. The machining is adapted depending on the calculated force.

First claim

The invention claimed is:

1. A method for computer-aided optimization of numerically controlled machining of a workpiece with a tool of a machine tool, the method comprising:
prior to commencement of the numerically controlled machining, determining interaction data that describe a geometric interaction of the tool with the workpiece in a section of a toolpath;
based on the interaction data, determining a relationship between a force to be expected during the numerically controlled machining and at least one machining configuration parameter;
calculating the force during the numerically controlled machining based on the relationship and a current value of the at least one configuration parameter during the numerically controlled machining; and
adjusting the numerically controlled machining as a function of the calculated force by correcting the toolpath as a function of one or more stiffness values of the machine tool.

2. The method of claim 1 , further comprising:
determining a chip thickness to be expected during the numerically controlled machining; and
determining the relationship based on the established chip thickness.

3. The method of claim 1 , wherein the interaction data are determined using a graphics processor.

4. The method of claim 1 , wherein the relationship is determined at least in part prior to the commencement of the numerically controlled machining.

5. The method of claim 1 , further comprising:
acquiring sensor data during the numerically controlled machining; and
adjusting the relationship or a model for calculating the force as a function of the sensor data.

6. The method of claim 5 , further comprising:
determining a deviation of an actual position of the tool from a target position commensurate with the corrected toolpath as a function of the sensor data; and
adjusting the relationship or the model as a function of the deviation.

7. The method of claim 1 , wherein the machine tool is embodied as a robot which is configured for guiding the tool for machining the workpiece.

8. The method of claim 1 , wherein the interaction data are independent of the at least one machining configuration parameter.

9. The method of claim 1 , wherein the interaction data are determined by intersecting of a simulated tool with a simulated workpiece.

10. The method of claim 9 , wherein the intersecting comprises a Boolean operation.

11. The method of claim 9 , wherein the interaction data are determined by identifying elements of the simulated workpiece that come into contact with or are cut by points of the simulated tool while the simulated tool is located in the section of the toolpath.

12. The method of claim 1 , wherein an actual value of the machining configuration parameter is specified immediately prior to the numerically controlled machining and after determination of the interaction data.

13. The method of claim 1 , wherein the at least one machining configuration parameter is changed during the numerically controlled machining.

14. The method of claim 1 , wherein the at least one configuration parameter is measured or read out from a memory during the numerically controlled machining, in order to calculate the force during the numerically controlled machining.

15. A control system for numerically controlled machining of a workpiece with a tool of a machine tool and for computer-aided optimization of the numerically controlled machining, the control system comprising:
a first electronic computing device configured to determine interaction data that describe a geometric interaction of the tool with the workpiece in a section of a toolpath, and a second electronic computing device,
wherein at least one of the first and second electronic computing devices is configured to determine a relationship between a force to be expected during the numerically controlled machining and at least one machining configuration parameter based on the interaction data; and
wherein the second electronic computing device is configured to calculate the force during the numerically controlled machining based on the relationship and a current value of the at least one configuration parameter during the numerically controlled machining: to adjust the numerically controlled machining as a function of the calculated force by correcting the toolpath as a function of one or more stiffness values of the machine tool.

16. The control system of claim 15 , wherein the second electronic computing device is configured to control the tool during the numerically controlled machining independently, without the first electronic computing device.

17. The control system of claim 15 , wherein the first electronic computing device comprises a graphics processor unit for determining the interaction data.

18. A machine tool for numerically controlled machining of a workpiece, comprising:
a tool for machining of the workpiece, and
a control system comprising
a first electronic computing device configured to determine interaction data that describe a geometric interaction of the tool with the workpiece in a section of a toolpath, and a second electronic computing device,
wherein at least one of the first and second electronic computing devices is configured to determine a relationship between a force to be expected during the numerically controlled machining and at least one machining configuration parameter based on the interaction data; and
wherein the second electronic computing device is configured to calculate the force during the numerically controlled machining based on the relationship and a current value of the at least one configuration parameter during the numerically controlled machining; to adjust the numerically controlled machining as a function of the calculated force by correcting the toolpath as a function of one or more stiffness values of the machine tool.

19. The machine tool of claim 18 , comprising
a computer-aided manufacturing system which comprises the first electronic computing device; and
a numerical controller which comprises the second electronic computing device.

20. A computer program stored on a non-transitory storage medium and comprising computer-readable commands which, when read into a memory of a computer system and executed by a processor of a control system for numerically controlled machining of a workpiece with a tool of a machine tool and for computer-aided optimization of the numerically controlled machining, causes the control system to:
prior to commencement of the numerically controlled machining, determine interaction data that describe a geometric interaction of the tool with the workpiece in a section of a toolpath;
based on the interaction data, determine a relationship between a force to be expected during the numerically controlled machining and at least one machining configuration parameter;
calculate the force during the numerically controlled machining based on the relationship and a current value of the at least one configuration parameter during the numerically controlled machining;
adjust the numerically controlled machining as a function of the calculated force by correcting the toolpath as a function of one or more stiffness values of the machine tool.

Assignees

• Siemens Ag

Inventors

• Hartmann Dirk
• Bitterolf David
• Köpken Hans-Georg
• Obst Birgit
• Schnös Florian Ulli Wolfgang
• Tauchmann Sven

Classifications

• G05B19/316 Primary

  with force or acceleration feedback only · CPC title

• G05B2219/35167

  Automatic toolpath generation and tool selection · CPC title

• Y02P90/02

  Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS] · CPC title

• B25J9/1633

  compliant, force, torque control, e.g. combined with position control · CPC title

• B25J9/163 Primary

  learning, adaptive, model based, rule based expert control · CPC title