# US 11,027,362 B2 · Systems and methods providing location feedback for additive manufacturing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,027,362 B2 - Document ID: US11027362B2 - Status: Granted - Kind: B2 - Application number: 16/199,380 - Filed: 2018-11-26 - Published: 2019-06-20 - Granted: 2021-06-08 - Earliest claimed: 2017-12-19 - Assignees: Lincoln Global, Inc. - Applicants: Lincoln Global, Inc. - Inventors: Jason Kenneth Flamm; Steven R. Peters; William Thomas Matthews; Paul Edward Denney; Jonathan Paul; Levi Mitchell - Web page: https://patentgrep.com/patent/US11027362B2 ## CPC - B23K 9/04: Welding for other purposes than joining, e.g. built-up welding - B22F 10/25: Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS] - B22F 10/38: to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures - B22F 12/22: {Driving means} - B23K 9/042: {Built-up welding on planar surfaces} - B23K 9/0737: {Stabilising of the arc position} - B23K 9/0956: {using sensing means, e.g. optical} - B23K 9/125: {Feeding of electrodes (for stabilising arc B23K9/073)} - B23K 9/126: {Controlling the spatial relationship between the work and the gas torch (between wire tip and piece B23K9/073)} - B23K 9/173: and of a consumable electrode - B23K 11/253: {the measured parameter being a displacement or a position} - B23K 11/258: {the measured parameter being a voltage} - B23K 11/314: {Spot welding guns, e.g. mounted on robots} - B23K 26/342: Build-up welding - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B22F 10/22: Direct deposition of molten metal - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - Y02P 10/25: Process efficiency - 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 - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A system and method to correct for height error during a robotic additive manufacturing process. One or both of an output current, output voltage, output power, output circuit impedance and a wire feed speed are sampled during an additive manufacturing process when creating a current layer. A plurality of instantaneous contact tip-to-work distances (CTWD's) are determined based on at least one or both of the output current, output voltage, output power, output circuit impedance and the wire feed speed. An average CTWD is determined based on the plurality of instantaneous CTWD's. A correction factor is generated, based on at least the average CTWD, which is used to compensate for any error in height of the current layer. ## Claims ### Claim 1 An additive manufacturing system, comprising: a power source; and a material feeder that provides additive material to a 3D workpiece part via a contact tip of a gun, wherein the power source is configured to: sample instantaneous parameter pairs, where each instantaneous parameter pair of the instantaneous parameter pairs includes any two parameters selected from a group comprising a wire feed speed of a wire that provides the additive material to the 3D workpiece part, an output power of the power source, and an output circuit impedance of the power source, during a robotic additive manufacturing process while creating a current layer of the 3D workpiece part; determine an instantaneous contact tip-to-work distance during the robotic additive manufacturing process for, and based on at least, each parameter pair of the instantaneous parameter pairs as each parameter pair is sampled during the creation of the current layer; determine a running average contact tip-to-work distance based on each instantaneous contact tip-to-work distance as each instantaneous contact tip-to-work distance is determined during the creation of the current layer; and generate a correction factor, based on at least the running average contact tip-to-work distance, to be used while creating the current layer of the 3D workpiece part to compensate for deviations in a deposit level from a desired deposit level for the current layer. ### Claim 2 (depends on 1) The additive manufacturing system of claim 1, wherein the two parameters includes a first parameter that is the wire feed speed and a second parameter that is the output power of the power source or the output circuit impedance of the power source. ### Claim 3 (depends on 2) The additive manufacturing system of claim 2, wherein the instantaneous contact tip-to-work distance is further based at least one of a type of hot-wire, a hot-wire diameter, a deposition process, or a shielding gas used in the robotic additive manufacturing process. ### Claim 4 (depends on 1) The additive manufacturing system of claim 1, wherein the robotic additive manufacturing process includes a hot-wire process using the wire. ### Claim 5 (depends on 4) The additive manufacturing system of claim 4, wherein the power source includes a high energy heat source, and the creating of the current layer of the 3D workpiece part includes providing sufficient energy density to the 3D workpiece part to create a puddle, and wherein the wire enters the puddle during the creating of the current layer. ### Claim 6 (depends on 5) The additive manufacturing system of claim 5, wherein an angle of a centerline of the wire as the wire enters the puddle with respect to a surface of the puddle is in a range of 10 degrees to 75 degrees. ### Claim 7 (depends on 1) The additive manufacturing system of claim 1, wherein the running average contact tip-to-work distance is one of a simple running mathematical average of the instantaneous contact tip-to-work distances or a weighted running average of the instantaneous contact tip-to-work distances. ### Claim 8 (depends on 1) The additive manufacturing system of claim 1, wherein the power source is further configured to: generate the correction factor at least in part by comparing the running average contact tip-to-work distance to a setpoint contact tip-to-work distance; and adjust at least one of a travel speed, a duration, or the wire feed speed during creation of the current layer in response to the correction factor. ### Claim 9 (depends on 8) The additive manufacturing system of claim 8, wherein: the adjusting the travel speed in response to the correction factor includes taking into account a preset travel speed; the adjusting the duration in response to the correction factor includes taking into account a preset duration; and the adjusting the wire feed speed in response to the correction factor includes taking into account a preset wire feed speed. ### Claim 10 (depends on 1) The additive manufacturing system of claim 1, wherein the correction factor is further based on at least one 3D model parameter corresponding to the 3D workpiece part or at least one robot parameter provided by a robot controller for a current operation for the current layer. ### Claim 11 (depends on 10) The additive manufacturing system of claim 10 wherein the at least one 3D model parameter includes a designated height of the current layer and the at least one robot parameter includes a designated position of the gun for the current layer. ### Claim 12 (depends on 1) The additive manufacturing system of claim 1, further comprising a robot having a robot controller configured to operatively communicate with the power source. ### Claim 13 (depends on 12) The additive manufacturing system of claim 12, the gun is operatively connected to the robot. ### Claim 14 (depends on 13) The additive manufacturing system of claim 13, further comprising a wire feeder operatively connected to the gun and the power source. ### Claim 15 (depends on 1) The additive manufacturing system of claim 1, wherein the power source is further configured to: determine a total average contact tip-to-work distance based on each instantaneous contact tip-to-work distance determined over an entire current layer; adjust at least one of a deposit duration, a travel speed, or the wire feed speed of the additive manufacturing system during creation of the current layer in response to the running average contact tip-to-work distance; and generate a correction factor to be used when creating a next layer of the 3D workpiece part based on at least the total average contact tip-to-work distance. ### Claim 16 (depends on 15) The additive manufacturing system of claim 15, wherein the power source includes a controller, and wherein the controller is configured to: determine the instantaneous contact tip-to-work distance; determine the running average contact tip-to-work distance; determine the total average contact tip-to-work distance; adjust at least one of the deposit duration, the travel speed, or the wire feed speed during the creation of the current layer; and generate the correction factor to be used when creating the next layer. ### Claim 17 A method of additive manufacturing using a power source and a material feeder that provides additive material to a 3D workpiece part via a contact tip of a gun, the method comprising: sampling instantaneous parameter pairs, where each instantaneous parameter pair of the instantaneous parameter pairs includes any two parameters selected from a group comprising a wire feed speed of a wire that provides the additive material to the 3D workpiece part, an output power of the power source, and an output circuit impedance of the power source, during a robotic additive manufacturing process while creating a current layer of the 3D workpiece part; determining an instantaneous contact tip-to-work distance during the robotic additive manufacturing process for, and based on at least, each parameter pair of the instantaneous parameter pairs as each parameter pair is sampled during the creation of the current layer; determining a running average contact tip-to-work distance based on each instantaneous contact tip-to-work distance as each instantaneous contact tip-to-work distance is determined during the creation of the current layer; and generating a correction factor, based on at least the running average contact tip-to-work distance, to be used while creating the current layer of the 3D workpiece part to compensate for deviations in a deposit level from a desired deposit level for the current layer. ### Claim 18 (depends on 17) The method of claim 17, wherein the two parameters includes a first parameter that is the wire feed speed and a second parameter that is the output power of the power source or the output circuit impedance of the power source. ### Claim 19 (depends on 18) The method of claim 18, wherein the instantaneous contact tip-to-work distance is further based at least one of a type of hot-wire, a hot-wire diameter, a deposition process, or a shielding gas used in the robotic additive manufacturing process. ### Claim 20 (depends on 17) The method of claim 17, wherein the robotic additive manufacturing process includes a hot-wire process using the wire. ### Claim 21 (depends on 20) The method of claim 20, wherein the creating of the current layer of the 3D workpiece part includes providing sufficient energy density from a high-energy beam to the 3D workpiece part to create a puddle, and wherein the wire enters the puddle during the creating of the current layer. ### Claim 22 (depends on 21) The additive manufacturing system of claim 21, wherein an angle of a centerline of the wire as the wire enters the puddle with respect to a surface of the puddle is in a range of 10 degrees to 75 degrees. ### Claim 23 (depends on 17) The method of claim 17, wherein the running average contact tip-to-work distance is one of a simple running mathematical average of the instantaneous contact tip-to-work distances or a weighted running average of the instantaneous contact tip-to-work distances. ### Claim 24 (depends on 17) The method of claim 17, wherein the method further comprises: generating the correction factor at least in part by comparing the running average contact tip-to-work distance to a setpoint contact tip-to-work distance; and adjusting at least one of a travel speed, a duration, or the wire feed speed during creation of the current layer in response to the correction factor. ### Claim 25 (depends on 24) The method of claim 24, wherein: the adjusting the travel speed in response to the correction factor includes taking into account a preset travel speed; the adjusting the duration in response to the correction factor includes taking into account a preset duration; and the adjusting the wire feed speed in response to the correction factor includes taking into account a preset wire feed speed. ### Claim 26 (depends on 17) The method of claim 17, wherein the correction factor is further based on at least one 3D model parameter corresponding to the 3D workpiece part or at least one robot parameter provided by a robot controller for a current operation for the current layer. ### Claim 27 (depends on 26) The method of claim 26, wherein the at least one 3D model parameter includes a designated height of the current layer and the at least one robot parameter includes a designated position of the gun for the current layer. ### Claim 28 (depends on 17) The method of claim 17, further comprising: determining a total average contact tip-to-work distance based on each instantaneous contact tip-to-work distance determined over an entire current layer; adjusting at least one of a deposit duration, a travel speed, or the wire feed speed during creation of the current layer in response to the running average contact tip-to-work distance; and generating a correction factor to be used when creating a next layer of the 3D workpiece part based on at least the total average contact tip-to-work distance.