SYSTEM AND METHOD FOR MONITORING MACHINE HEALTH

• US 20060089742A1
• Filed: 08/02/2005
• Published: 04/27/2006
• Est. Priority Date: 10/25/2004
• Status: Active Grant

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Jalluri, Chandra, Magadi, Prashanth, Kaufman, Ingrid
• Granted Patent: US 7,571,022 B2
• Time in Patent Office: Days
• US Class Current: 700/159
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition

Abstract

A method for monitoring health of a machine tool includes operating the machine tool outside an operation cycle to effect movement of a portion of the machine tool. Data from signals output from a sensor and from a controller attached to the machine tool are used to define at least one movement-specific data profile for the movement of the portion of the machine tool. An algorithm is then applied to at least a portion of the at least one movement-specific data profile to generate at least one movement-specific data point. This facilitates generation of at least one movement-specific trend line, which can be used to analysis the health of the machine tool.

Claims

1. A method for monitoring health of a machine tool operable to perform at least one operation cycle including at least one machining operation on a workpiece, the machine tool including a spindle configured to hold a cutting tool and a first slide operable to effect a linear movement of a portion of the machine tool, the machine tool having at least one sensor operatively connected thereto for sensing a machine operation parameter, and a controller configured to output data related to operation of the machine tool, the method comprising:

operating the machine tool outside an operation cycle to effect movement of a portion of the machine tool;

processing data from signals output from the at least one sensor and from the controller to define at least one movement-specific data profile for the movement of the portion of the machine tool; and

applying an algorithm to at least a portion of the at least one movement-specific data profile to generate at least one movement-specific data point, thereby facilitating generation of at least one movement-specific trend line.

2. The method of claim 1, wherein operating the machine tool includes loading a cutting tool in the spindle, and operating the spindle in a first manner, including accelerating the spindle until it reaches a first spindle speed, operating the spindle at the first spindle speed for a first predetermined time, and decelerating the spindle, and

wherein the at least one movement-specific data profile includes a first spindle data profile having an acceleration portion, a steady speed portion, and a deceleration portion corresponding to the respective movements of the spindle as it is operated in the first manner.

3. The method of claim 2, wherein the algorithm is applied to the entire first spindle data profile to generate a single movement-specific data point.

4. The method of claim 2, wherein the algorithm is separately applied to the acceleration portion, the steady speed portion, and the deceleration portion of the first spindle data profile to generate three corresponding movement-specific data points, thereby facilitating generation of three corresponding movement-specific trend lines.

5. The method of claim 2, wherein operating the machine tool further includes, operating the spindle in a second manner, including accelerating the spindle until it reaches a second spindle speed, operating the spindle at the second spindle speed for a second predetermined time, and decelerating the spindle, and

wherein the at least one movement-specific data profile includes a second spindle data profile having an acceleration portion, a steady speed portion, and a deceleration portion corresponding to the respective movements of the spindle as it is operated in the second manner.

6. The method of claim 1, wherein operating the machine tool includes operating the first slide, and

wherein the at least one movement-specific data profile includes a first slide data profile.

7. The method of claim 6, the machine tool further including second and third slides, each of the slides being operable to effect a linear movement of a portion of the machine tool in a direction different from the direction of movement effected by the other slides, wherein operating the machine tool further includes operating the second and third slides separately, and operating the three slides simultaneously, and

wherein the at least one movement-specific data profile further includes second and third slide data profiles and a combination slide data profile.

8. The method of claim 7, wherein the algorithm is applied to the first, second, third and combination slide data profiles to generate four corresponding movement-specific data points, thereby facilitating generation of four corresponding movement-specific trend lines.

9. A method for monitoring health of a machine tool operable to perform at least one operation cycle including at least one machining operation on a workpiece, the machine tool including a spindle configured to hold a cutting tool and a first slide operable to effect a linear movement of a portion of the machine tool, the machine tool having at least one sensor operatively connected thereto for sensing a machine operation parameter, and a controller configured to output data related to operation of the machine tool, the method comprising:

sensing a machine operation parameter for the machine tool while the machine tool is operating outside an operation cycle, the operation of the machine tool including movement of at least a portion of the machine tool;

storing data related to the sensed parameter;

associating the data from the sensor with the data from the controller, thereby defining at least one movement-specific data profile for the movement of the portion of the machine tool;

applying an algorithm to at least a portion of the at least one movement-specific data profile to generate at least one movement-specific data point; and

storing the at least one movement-specific data point, thereby facilitating subsequent retrieval.

10. The method of claim 9, wherein the operation of the machine tool includes operating the spindle according to three spindle operating profiles, each of the spindle operating profiles including accelerating the spindle, operating the spindle at a corresponding predetermined speed for a predetermined amount of time, and decelerating the spindle, each of the corresponding predetermined speeds being different for each of the three spindle operating profiles, and

wherein the at least one movement-specific data profile includes at least one spindle data profile for each of the spindle operating profiles, and

wherein the algorithm is separately applied to each of the spindle data profiles to generate corresponding movement-specific data points for each of the spindle data profiles.

11. The method of claim 10, the machine tool further including second and third slides, each of the slides being operable to effect a linear movement of a portion of the machine tool in a direction different from the direction of movement effected by the other slides, wherein the operation of the machine tool further includes operating the first, second and third slides separately, and operating the three slides simultaneously, and

wherein the at least one movement-specific data profile includes at least one slide data profile for each of the slides, and

wherein the algorithm is separately applied to each of the slide data profiles to generate corresponding movement-specific data points for each of the slide data profiles.

12. The method of claim 11, further comprising:

retrieving at least some of the movement-specific data points; and

plotting at least some of the retrieved movement-specific data points to create at least one movement-specific trend line.

13. The method of claim 12, further comprising applying another algorithm to the at least one movement-specific trend line to indicate an alarm condition to an operator of the machine tool.

14. The method of claim 9, wherein sensing a machine operation parameter for the machine tool includes sensing at least one of vibrations, current, temperature, torque or speed for the machine tool.

15. A system for monitoring health of a machine tool operable to perform at least one operation cycle including at least one machining operation on a workpiece, the machine tool including a spindle configured to hold a cutting tool and a first slide operable to effect a linear movement of a portion of the machine tool, the system comprising:

a sensor operatively connected to the machine tool for sensing a machine operation parameter and for outputting signals related to the sensed parameter;

a control system including at least one controller, the control system being configured to control operation of the machine tool according to at least one predetermined program which effects movement of at least a portion of the machine tool outside an operation cycle, the control system being operatively connected to the machine tool and further configured to output signals related to operation of the machine tool;

a processor operatively associated with the sensor and the control system, and configured to associate data from the signals output from the sensor and from the control system to define movement-specific data profiles, the processor being further configured to apply an algorithm to at least some of the movement-specific data profiles to generate at least one movement-specific data point; and

a memory operatively associated with the sensor, the control system, and the processor, and configured to store information including the at least one movement-specific data point, thereby facilitating subsequent retrieval of the stored information.

16. The system of claim 15, wherein the predetermined program is configured to operate the machine tool to load a cutting tool in the spindle, and operate the spindle in a first manner, including accelerating the spindle until it reaches a first spindle speed, operating the spindle at the first spindle speed for a first predetermined time, and decelerating the spindle, and

wherein the movement-specific data profiles include a first spindle data profile having an acceleration portion, a steady speed portion, and a deceleration portion corresponding to the respective movements of the spindle as it is operated in the first manner.

17. The system of claim 16, wherein the predetermined program is further configured to operate the spindle in a second manner, including accelerating the spindle until it reaches a second spindle speed, operating the spindle at the second spindle speed for a second predetermined time, and decelerating the spindle, and

wherein the movement-specific data profiles include a second spindle data profile having an acceleration portion, a steady speed portion, and a deceleration portion corresponding to the respective movements of the spindle as it is operated in the second manner.

18. The system of claim 15, wherein the predetermined program is configured to operate the machine tool to operate the first slide, and wherein the movement-specific data profiles include a first slide data profile.

19. The system of claim 18, the machine tool further including second and third slides, each of the slides being operable to effect a linear movement of a portion of the machine tool in a direction different from the direction of movement effected by the other slides, wherein the predetermined program is further configured to operate the second and third slides separately, and operate the three slides simultaneously, and

wherein the movement-specific data profiles include second and third slide data profiles and a combination slide data profile.

20. The system of claim 15, wherein the machine operation parameter is at least one of vibrations, current, temperature, torque or speed for the machine tool.

21. The system of claim 15, further comprising an output device in communication with the processor, and configured to retrieve the at least one movement-specific data point from the memory, thereby facilitating generation of a corresponding movement-specific trend line.