# US 2014/0207274 A1 · Effort modulation for process control of friction stir operations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0207274 A1 - Document ID: US20140207274A1 - Status: Published application - Kind: A1 - Application number: 13/853,798 - Filed: 2013-03-29 - Published: 2014-07-24 - Earliest claimed: 2012-03-30 - Assignees: Brigham Young University - Inventors: Kenneth Alec Ross; Carl D. Sorensen - Web page: https://patentgrep.com/patent/US20140207274A1 ## CPC - B23K 20/1235: {with temperature control during joining} - B23K 20/125: {Rotary tool drive mechanism} - G05B 19/188: {characterised by special applications and not provided for in the relevant subclasses, (e.g. making dies, filament winding)} - G05B 2219/49077: Control of feed and spindle, cutting speed - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A system and method for making adjustments to output effort from a spindle driver using a multi-stage nested control loop of an active controller to provide constant power to a friction stir zone during a friction stir operation. Providing constant power facilitates temperature control within the friction stir zone and thereby improves the result of the operation such as a weld. ## Claims ### Claim 1 A method for using an active controller to control the temperature of a friction stir zone, said method comprising: providing an active controller for controlling operation of a friction stir tool; and controlling power provided by the friction stir tool to a friction stir zone using the active controller to control a temperature of the friction stir zone, wherein the power provided to the friction stir zone is controlled by making adjustments to an output effort of a spindle driver that is used to drive the friction stir tool. ### Claim 2 (depends on 1) The method as defined in claim 1, wherein controlling the power provided to the friction stir zone further comprises using the active controller to maintain a desired power input level. ### Claim 3 (depends on 2) The method as defined in claim 2, wherein using the active controller to maintain the power input level to a friction stir zone further comprises implementing a multi-stage nested control loop. ### Claim 4 (depends on 3) The method as defined in claim 3, wherein implementing the multi-stage nested control loop further comprises: 1) implementing an inner control loop to thereby maintain the desired power input level through control of the output effort of the spindle driver; and 2) implementing an outer control loop that adjusts the power provided to thereby maintain a desired temperature for the friction stir zone. ### Claim 5 (depends on 4) The method as defined in claim 4, wherein controlling the output effort of the spindle driver further comprises controlling an input flow to the spindle driver. ### Claim 6 (depends on 4) The method as defined in claim 4, wherein controlling the output effort of the spindle driver further comprises maintaining a desired effort level. ### Claim 7 (depends on 4) The method as defined in claim 4, wherein controlling the output effort of the spindle driver further comprises stabilizing control of the spindle driver. ### Claim 8 (depends on 7) The method as defined in claim 7, wherein stabilizing control of the spindle driver further comprises of using spindle flow feedback. ### Claim 9 (depends on 8) The method as defined in claim 8, wherein maintaining the desired power input level through control of the output effort of the spindle driver further comprises increasing the output effort of the spindle driver in response to a decrease in the spindle flow. ### Claim 10 (depends on 8) The method as defined in claim 8, wherein maintaining the desired power input level through control of the output effort of the spindle driver further comprises decreasing the output effort of the spindle driver in response to an increase in the spindle flow. ### Claim 11 (depends on 1) The method of claim 1, wherein the friction stir tool is a welding tool. ### Claim 12 A friction stir system for controlling power provided to a friction stir zone during friction stir operations, said system comprised of: a friction stir tool; a spindle that is coupled to the friction stir tool; a spindle driver that is coupled to the spindle to thereby cause the friction stir tool to rotate; an active controller for controlling operation of the friction stir tool, wherein the active controller adjusts an output effort of the spindle driver that is used to drive the friction stir tool to thereby control power provided to a friction stir zone. ### Claim 13 (depends on 12) The friction stir welding system as defined in claim 12 wherein the active controller is further comprises means for receiving spindle flow feedback. ### Claim 14 (depends on 12) The system of claim 12 wherein the active controller is further configured to approach and maintain a desired temperature for the friction stir zone. ### Claim 15 (depends on 12) The system of claim 12, wherein the active controller comprises a multi-stage nested control loop. ### Claim 16 (depends on 12) The system of claim 12, wherein the friction stir tool is a welding tool. ### Claim 17 (depends on 15) The system of claim 15, wherein the multi-stage nested control loop comprises an inner control loop configured to maintain a desired power input level through control of the spindle driver effort, and an outer control loop that adjusts the power provided to thereby maintain a desired temperature in the friction stir zone.