# US 11,113,489 B2 · Coding and identifying plate-type workpieces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,113,489 B2 - Document ID: US11113489B2 - Status: Granted - Kind: B2 - Application number: 16/851,220 - Filed: 2020-04-17 - Published: 2020-10-01 - Granted: 2021-09-07 - Earliest claimed: 2017-10-19 - Assignees: TRUMPF Werkzeugmaschinen GmbH + Co. KG - Applicants: TRUMPF Werkzeugmaschinen GmbH + Co. KG - Inventors: Daniel Bossert; Klaus Bauer; Andreas Popp; Eberhard Wahl - Web page: https://patentgrep.com/patent/US11113489B2 ## CPC - G06K 7/1413: {1D bar codes} - G06K 19/06: characterised by the kind of the digital marking, e.g. shape, nature, code - G06K 1/12: otherwise than by punching - G06K 7/082: {using inductive or magnetic sensors} - G06K 19/06028: {using bar codes} - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS ## Abstract Methods and devices for coding and identifying plate-type workpieces are provided. The methods include: coding a workpiece by producing a code with a local modification in a material structure of a base material of the workpiece within a coding region, reading out the code by performing an eddy-current measurement of a local distribution of an electrical conductivity and/or a permeability of the base material by an eddy-current sensor along a reading-out section in a reading region at least partially including the coding region, a signal calibrated to a distance of the eddy-current sensor from a surface of the reading region being determined for reading out the code, storing the read-out code in a storage device, repeating the reading out of the code by repeatedly performing the eddy-current measurement, and identifying the workpiece by comparing the stored read-out code in the storage device and the repeated read-out code. ## Claims ### Claim 1 A method of coding and identifying a plate-type workpiece, the method comprising: coding the workpiece by producing a code with a local modification in a material structure of a base material of the workpiece within a coding region; reading out the code by performing an eddy-current measurement of a local distribution of at least one of an electrical conductivity or a permeability of the base material of the workpiece by an eddy-current sensor along a reading-out section in a reading region, wherein the reading region at least partially comprises the coding region, wherein an eddy current signal calibrated to a distance between the eddy-current sensor and a surface of the base material of the workpiece is determined for the reading out of the code, and wherein the determined calibrated eddy current signal in the reading region is independent from the distance and is associated with the read-out code; storing the read-out code in a storage device; repeating the reading out of the code by repeating the eddy-current measurement; and identifying the workpiece by comparing the stored read-out code in the storage device and the repeated read-out code. ### Claim 2 (depends on 1) The method of claim 1, wherein, by at least one of the coding or another workpiece treatment, a change in a surface contour of the base material of the workpiece is generated before a first reading out of the code. ### Claim 3 (depends on 2) The method of claim 2, further comprising: between the coding and the reading out of the code, shaping the base material in the reading region such that the change to the surface contour of the base material is eliminated within the reading region. ### Claim 4 (depends on 1) The method of claim 1, further comprising: detecting a surface contour of the base material of the workpiece along the reading-out section; and when the code is read out, carrying out a contour correction to cancel out a signal modification from an eddy-current signal detected by the eddy-current sensor, wherein the signal modification results from a modification to the surface contour along the reading-out section. ### Claim 5 (depends on 1) The method of claim 1, further comprising: detecting a thickness of the base material of the workpiece along the reading-out section; and when the code is read out, carrying out a thickness correction to cancel out a signal modification from an eddy-current signal detected by the eddy-current sensor, wherein the signal modification results from a modification to the thickness of the base material along the reading-out section. ### Claim 6 (depends on 1) The method of claim 1, wherein the reading-out section comprises an isoline along which the base material of the workpiece has at least one of a unitary thickness or a planar surface. ### Claim 7 (depends on 1) The method of claim 1, wherein, after a first reading-out of the code, the workpiece is subjected to a further treatment, and wherein coding the workpiece comprises: generating a microstructure change in the base material due to the coding such that, at least in a sub-region of the coding region, a modification to the at least one of the electrical conductivity or the permeability resulting from the code is greater than that resulting from the further treatment. ### Claim 8 (depends on 7) The method of claim 7, wherein the further treatment comprises at least one of painting, bending, or punching. ### Claim 9 (depends on 1) The method of claim 1, wherein identifying the workpiece comprises: in response to determining that the repeated read-out code matches the stored read-out code in the storage device, displaying a part number linked to the stored read-out code and referenced in the storage device. ### Claim 10 (depends on 1) The method of claim 1, further comprising: producing a basic code pattern or a check code in a vicinity of the local modification in the material structure of the base material of the workpiece. ### Claim 11 A metal workpiece working machine comprising: an eddy-current sensor configured to detect eddy-current signals; an evaluation device configured to extract information from the detected eddy-current signals; a storage device configured to store at least one of the extracted information or the detected eddy-current signals; and a controller configured to control operations comprising: coding the workpiece by producing a code with a local modification in a material structure of a base material of the workpiece within a coding region; reading out the code by performing an eddy-current measurement of a local distribution of at least one of an electrical conductivity or a permeability of the base material of the workpiece by the eddy-current sensor along a reading-out section in a reading region, wherein the reading region at least partially comprises the coding region, wherein an eddy current signal calibrated to a distance between the eddy-current sensor and a surface of the base material of the workpiece is determined for the reading out of the code, and wherein the determined calibrated eddy current signal in the reading region is independent from the distance and is associated with the read-out code; storing the read-out code in the storage device; repeating the reading out of the code by repeating the eddy-current measurement; and identifying the workpiece by comparing the stored read-out code in the storage device and the repeated read-out code. ### Claim 12 (depends on 11) The working machine of claim 11, wherein the eddy-current sensor, comprises at least one of: an acceleration sensor, a gyro sensor, or a receiver for location determination. ### Claim 13 (depends on 11) The working machine of claim 11, wherein the working machine comprises a laser processing machine or a shaping treatment machine. ### Claim 14 (depends on 11) The working machine of claim 11, wherein the working machine is configured to: detect a surface contour of the base material of the workpiece along the reading-out section, and when the code is read out, carry out a contour correction to cancel out a signal modification from an eddy-current signal detected by the eddy-current sensor, wherein the signal modification results from a modification to the surface contour along the reading-out section. ### Claim 15 (depends on 11) The working machine of claim 11, wherein the working machine is configured to: detect a thickness of the base material of the workpiece along the reading-out section, and when the code is read out, carry out a thickness correction to cancel out a signal modification from an eddy-current signal detected by the eddy-current sensor, wherein the signal modification results from a modification to the thickness of the base material along the reading-out section. ### Claim 16 (depends on 11) The working machine of claim 11, wherein the reading-out section comprises an isoline along which the base material of the workpiece has at least one of a unitary thickness or a planar surface. ### Claim 17 (depends on 11) The working machine of claim 11, wherein, after the reading-out of the code, the workpiece is subjected to a further treatment, wherein the working machine is configured to code the workpiece by generating a microstructure change in the base material such that, at least in a sub-region of the coding region, a modification to the at least one of the electrical conductivity or the permeability resulting from the code is greater than that resulting from the further treatment. ### Claim 18 (depends on 11) The working machine of claim 11, wherein the evaluation device is configured to extract the local distribution of the at least one of the conductivity or the permeability of the workpiece from the calibrated eddy current signal. ### Claim 19 (depends on 11) The working machine of claim 11, wherein the working machine is a sheet metal working machine.