US 12,460,816 B2
Optical feedback control mechanism for solid reactant strand positioning
Clayton Geipel, Washington, DC (US); and Brian Fisher, Crofton, MD (US)
Assigned to The Government of the United States of America, as represented by the Secretary of the Navy, Arlington, VA (US)
Filed by The Government of the United States of America, as represented by the Secretary of the Navy, Arlington, VA (US)
Filed on May 9, 2023, as Appl. No. 18/144,992.
Claims priority of provisional application 63/340,889, filed on May 11, 2022.
Prior Publication US 2023/0366542 A1, Nov. 16, 2023
Int. Cl. F23N 1/00 (2006.01); F23K 3/00 (2006.01); G01N 33/22 (2006.01); G05D 3/12 (2006.01)
CPC F23N 1/002 (2013.01) [F23K 3/00 (2013.01); G01N 33/222 (2013.01); G05D 3/125 (2013.01); F23K 2203/202 (2013.01); F23N 2239/02 (2020.01)] 8 Claims
OG exemplary drawing
 
1. An active method of controlling the position of a burning surface of a solid fuel strand, comprising:
placing a solid fuel strand into a housing;
advancing the solid fuel strand through the housing using a screw attached to a motor that is controlled by a computer;
directing a beam of light from a diode laser that skims a desired fuel strand surface position, wherein the light transmitted by the diode laser is collected by a photodiode; and
using a digital control loop to control the solid fuel strand position, wherein the digital control loop sends commands to the motor to adjust velocity based on the light collected by the photodiode, and wherein solid fuel strand position data is saved as a function of time allowing for direct calculation of regression rate as a function of time.