Systems and methods for adaptive process control using a target kinematics profile in welding together multiple polymeric workpieces

Patent metadata

Field	Value
Publication number	US-9550323-B2
Application number	US-201414476310-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 6, 2013
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

An ultrasonic welding system, for welding together two workpieces wherein at least one of the workpieces includes a polymeric composite, comprising an energy applicator positioned along an action axis so that, in operation, ultrasonic vibrations transmitted from the energy applicator during a welding routine, are transmitted to the workpieces generally at and/or adjacent the axis. The system also includes a primary, course-control, actuator positioned along action axis so that a first load, output by the primary actuator, acts along the system action axis. The system further comprises a secondary, fine-control, actuator positioned along the system action axis so that a second load output, by the secondary actuator, acts along the axis. And the system comprises a controller for providing first command signals and second command signals to the primary actuator and second actuator to control them to effect loads on the workpieces, during the welding routine and along the axis.

First claim

What is claimed:

1. An ultrasonic welding system, for welding together two workpieces, comprising:
an energy applicator positioned along a system action axis so that, in operation, ultrasonic vibrations transmitted from the energy applicator during a welding routine are transmitted to the workpieces generally at and/or adjacent the system action axis;
a primary, course-control, actuator positioned along the system action axis so that a first, course-type, load output by the primary, course-control, actuator acts along the system action axis;
a secondary, fine-control, actuator positioned along the system action axis so that a second, fine-type, load output by the secondary, fine-control, actuator acts along the system action axis; and
a controller:
in operative communication with the primary, course-control, actuator and with the secondary, fine-control, actuator;
comprising data including an energy-applicator kinematic profile having target kinematic data points in association with time or output energy for the welding routine; and
configured to generate, based on the energy-applicator kinematic profile, a primary, course-type, command signal and a secondary, fine-type, command signal to control the primary, course-control, actuator and the secondary, fine-control, actuator, respectively, to effect loads on the workpieces along the system action axis during the welding routine.

2. The ultrasonic welding system of claim 1 , wherein the controller includes a processor and a computer-readable memory comprising the data and computer-executable instructions.

3. The ultrasonic welding system of claim 2 , wherein the instructions, when executed by the processor, cause the processor to perform operations comprising performing a first iteration of closed-loop, adaptive weld applicator control.

4. The ultrasonic welding system of claim 3 , wherein the first iteration of the closed-loop, adaptive weld applicator control comprises:
a. sending the primary, course-type, command signal to the primary, course-control, actuator to cause the primary, course-control, actuator to effect, along the system action axis, a next target energy-applicator movement characteristic, of the target kinematic data points; and
b. receiving, from a measurement device, feedback indicating an actual movement characteristic of the energy applicator.

5. The ultrasonic welding system of claim 4 , wherein the first iteration of the closed-loop, adaptive weld applicator control further comprises:
c. determining, based on the feedback during the welding routine, an error between the actual movement characteristic of the energy applicator and a corresponding target energy-applicator movement.

6. The ultrasonic welding system of claim 5 , wherein the first iteration of the closed-loop, adaptive weld applicator control further comprises:
d. generating, based on the error, a secondary, fine-type, command configured to cause the secondary, fine-control, actuator to actuate, along the system action axis to correct energy-applicator movement toward minimizing the error.

7. The ultrasonic welding system of claim 6 , wherein the first iteration of the closed-loop, adaptive weld applicator control further comprises:
e. sending the secondary, fine-type, command to the secondary, fine-control, actuator for execution by the secondary, fine-control, actuator to correct energy-applicator movement by providing fine-level load adjustment along the system action axis toward minimizing the error.

8. The ultrasonic welding system of claim 7 , wherein the operations further comprise repeating, the operations a.-e., in connection with next iterations during the welding routine in order to maintain energy-applicator movement as close as possible to the energy-applicator kinematic profile during the welding routine.

9. The ultrasonic welding system of claim 1 , further comprising an amplifier positioned between the secondary, fine-control, actuator and the energy applicator, for amplifying output load of the secondary, fine-control, actuator.

10. The ultrasonic welding system of claim 1 , wherein the primary, course-control, actuator includes an actuator selected from a group consisting of:
a pneumatic actuator; and
a hydraulic actuator.

11. The ultrasonic welding system of claim 1 , wherein the secondary, fine-control, actuator includes a servo motor.

12. The ultrasonic welding system of claim 11 , wherein the servo motor includes, or is connected to, a measurement device.

13. The ultrasonic welding system of claim 12 , wherein the measurement device includes an encoder or a potentiometer.

14. The ultrasonic welding system of claim 12 , wherein the measurement device includes a linear variable differential transformer.

15. The ultrasonic welding system of claim 5 , wherein:
the next target energy-applicator movement is a next target energy-applicator position;
the actual movement characteristic of the energy applicator is an actual position of the energy applicator; and
the corresponding target energy-applicator movement is a corresponding target energy-applicator position.

16. The ultrasonic welding system of claim 5 , wherein:
the next target energy-applicator movement is a next target energy-applicator movement;
the actual movement characteristic of the energy applicator is an actual displacement of the energy applicator; and
the corresponding target energy-applicator movement is a corresponding target energy-applicator displacement.

17. The ultrasonic welding system of claim 1 , wherein each movement characteristic includes velocity of the energy applicator or acceleration of the energy applicator.

18. The ultrasonic welding system of claim 1 , wherein a first material of a first workpiece of the workpieces and a second material of a second workpiece of the workpieces are dissimilar.

19. An ultrasonic welding system, for welding together two workpieces, comprising:
a primary, course-control, actuator positioned along a system action axis so that a first, course-type, load, output by the primary, course-control, actuator, acts along the system action axis;
a secondary, fine-control, actuator positioned along the system action axis so that a second, fine-type, load, output by the secondary, fine-control, actuator, acts along the system action axis; and
a controller:
comprising data including an energy-applicator kinematic profile comprising target kinematic data points in association with time or output energy of a welding routine;
configured to generate, based on the energy-applicator kinematic profile, a primary, course-type command signal and a secondary, fine-type command signal to control the primary, course-control, actuator and the secondary, fine-control, actuator, respectively; and
configured to perform operations comprising performing a first iteration of closed-loop, adaptive weld applicator control comprising (a) sending the primary, course-type, command signal to the primary, course-control, actuator to cause the primary, course-control, actuator to effect, along a system action axis, a next target energy-applicator movement characteristic, of the target kinematic data points, (b) receiving, from a measurement device, feedback indicating an actual movement characteristic of an energy applicator, (c) determining, based on the feedback during the welding routine, an error between the actual movement characteristic of the energy applicator and a corresponding target energy-applicator movement (d) generating, based on the error, a secondary, fine-type, command

Assignees

• Wang Pei-Chung
• Abell Jeffrey A
• Spicer John Patrick
• Gm Global Tech Operations Llc

Inventors

• Wang Pei-Chung
• Abell Jeffrey A
• Spicer John Patrick

Classifications

• B29C66/73116

  of different melting point, i.e. the melting point of one of the parts to be joined being different from the melting point of the other part · CPC title

• B29C66/9672

  involving special data inputs, e.g. involving barcodes, RFID tags · CPC title

• B29K2101/12

  Thermoplastic materials · CPC title

• B29C66/92921

  in specific relation to time, e.g. pressure-time diagrams · CPC title

• B29C66/9674

  involving special data outputs, e.g. special data display means (B29C66/8748 takes precedence) · CPC title