Methods and systems for controlling and adjusting heat distribution over a part bed

• US 7,515,986 B2
• Filed: 04/20/2007
• Issued: 04/07/2009
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Huskamp, Christopher S.
• Primary Examiner(s): BARNES-BULLOCK, CRYSTAL JOY
• Application Number:
  US11/737,962
• Publication Number:
  US 20080262659A1
• Time in Patent Office: 718 Days
• Field of Search: 700/118, 700/119, 700/121, 700/207, 700/212, 700/299, 700/300, 219/121.61, 219/121.65, 219/405, 219/482, 219/483, 219/486, 250/492.1, 250/492.2, 264/40.1, 264/40.6, 264/128, 264/497, 374/130, 374/131, 399/69, 427 8- 10, 432/36
• US Class Current: 700/207
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: G05D 23/1919 characterised by the type of controller
• CPC Class Codes: G05D 23/27 with sensing element responsive to radiation

Abstract

Methods and systems for controlling and adjusting heat distribution over a part bed are disclosed. In one embodiment, a technique for providing a calibrated heat distribution over a part bed includes determining the temperature distribution within a part bed, generating a zone heat distribution for a plurality of heat zones from the temperature distribution, analyzing the zone heat distribution to create an adjustment command to calibrate a heater for providing a substantially consistent temperature distribution within the part bed, and adjusting the heater based on the adjustment command.

Claims

1. A method, comprising:

determining a temperature distribution within a part bed by capturing an infrared image of the part bed and analyzing the infrared image to infer the temperature distribution;

illuminating a powder within the part bed with a laser to transform the powder from a solid state to a liquid state simultaneous to the capturing the infrared image of the part bed;

generating a zone heat distribution for one or more heat zones from the temperature distribution;

analyzing the zone heat distribution to create an adjustment command to control at least one heater for providing a desired temperature distribution within the part bed; and

adjusting the at least one heater based on the adjustment command.

2. The method of claim 1, wherein the desired temperature distribution includes an approximately uniform temperature distribution within a predetermined temperature threshold of a target temperature.

3. The method of claim 1, wherein adjusting the at least one heater based on the adjustment command includes adjusting an orientation of the at least one heater.

4. The method of claim 3, wherein the temperature distribution in determined by an IR camera.

5. The method of claim 1, wherein

capturing an infrared image of the part bed includes capturing a two dimensional image of infrared radiant intensity emanating from the powder within the part bed, and

analyzing the zone heat distribution to create an adjustment command includes creating an adjustment signal that controllably adjusts at least one of outputs and locations of a plurality of heating elements to provide a desired two dimensional temperature distribution.

6. The method of claim 1, wherein the adjustment command is at least one of:

a command to reposition a heater;

a command to adjust an energy supply for a heater; and

a command to adjust a resistance for a heater circuit.

7. The method of claim 1, wherein generating a zone heat distribution includes averaging pixilated temperature distribution data to create the one or more heat zones.

8. One or more computer readable media comprising computer-executable instructions that, when executed by a computer, perform acts comprising:

measuring a temperature distribution of a part bed;

generating temperature zones from the temperature distribution; and

creating a heater adjustment command from the temperature zones to adjust at least one of a plurality of heaters to provide a desired temperature distribution over the part bed, wherein the heater adjustment command includes a command to adjust a position of the heater by at least one of rotating the heater about a mounting axis and moving the heater along a plane parallel to the heater bed.

9. One or more computer readable media as in claim 8, wherein generating temperature zones from the temperature distribution includes creating average temperatures for each temperature zone from pixilated data points in the temperature distribution.

10. One or more computer readable media as in claim 8, wherein measuring a temperature distribution of a part bed includes capturing an infrared image of the part bed, and analyzing the infrared image to infer the temperature distribution.

11. One or more computer readable media as in claim 10, wherein the acts further comprise, simultaneously with capturing an infrared image of the part bed, illuminating a powder within the part bed with a laser to transform the powder from a solid state to a liquid state.

12. One or more computer readable media as in claim 8, wherein measuring a temperature distribution of a part bed is performed by controlling an IR camera.

13. One or more computer readable media as in claim 8, wherein creating a heater adjustment command includes at least one of changing the resistance of a heater circuit and adjusting the plurality of heaters to obtain a target temperature for each temperature zone.

14. One or more computer readable media as in claim 8, wherein measuring a temperature distribution of a part bed and product formation in the part bed occur substantially simultaneously.

15. A system, comprising:

a thermal imaging device to generate temperature distribution data from material in a part bed; and

a processor to receive the temperature distribution data, convert the temperature distribution data into a zone temperature grid, create a heater control command based on the difference between a target temperature and the zone temperature grid, and transmit the heater control command to at least one heater element of a plurality of heater elements, wherein the processor includes a first module to convert the temperature distribution data into a zone temperature grid by averaging the temperatures of sub-zones within each zone of the zone temperature grid.

16. The system of claim 15, wherein the thermal imaging device is an IR camera.

17. The system of claim 15, wherein the heater element includes at least one of:

an actuator to reposition the heater;

a variable resistor; and

a power source.

18. The system of claim 15, wherein the processor further commands a laser to illuminate portions of the part bed to transform the powder from a solid state to a liquid state.

19. The system of claim 15, wherein the processor includes a second module to create a heater control command based on the target temperature and the zone temperature grid.

20. The system of claim 15, wherein the heater control command includes instructions to manually adjust at least one heater.