# US 2019/0171176 A1 · Thermal compensation method and thermal compensation control system for machine tools > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0171176 A1 - Document ID: US20190171176A1 - Status: Published application - Kind: A1 - Application number: 15/855,924 - Filed: 2017-12-27 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: Industrial Technology Research Institute - Applicants: Industrial Technology Research Institute - Inventors: Sheng-Ming MA; Ta-Jen PENG; Yung-Chih LIN; Chien-Hung CHEN; Ke-Hen CHEN; Shin-Tzong SU - Web page: https://patentgrep.com/patent/US20190171176A1 ## CPC - G05B 19/048: Monitoring; Safety - B23Q 11/0007: {by compensating occurring thermal dilations (B23Q15/18 takes precedence)} - B23Q 17/22: for indicating or measuring existing or desired position of tool or work {(B23Q16/005 takes precedence)} - G05B 17/02: electric - G05B 19/18: Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of program data in numerical form (G05B19/418 takes precedence) - G05B 19/404: characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia (G05B19/19, G05B19/41 take precedence) - B23Q 17/20: for indicating or measuring workpiece characteristics, e.g. contour, dimension, hardness - G05B 2219/39192: Compensate thermal effects, expansion of links - G05B 2219/49169: Compensation for temperature, bending of tool - G05B 2219/49209: Compensation by using temperature feelers on slide, base, workhead - G05B 2219/49219: Compensation temperature, thermal displacement - 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) - B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT ## Abstract A thermal compensation control system for a machine tool having a milling cutter and a cutter driver includes a tool setting probe, a temperature sensor, a workpiece touch probe, and a controller. The cutter driver is connected to the milling cutter to drive the milling cutter to process the work piece based on a control signal. The tool setting probe is configured to detect a cutter length of the milling cutter. The temperature sensor is configured to sense a measured temperature of the cutter driver or the milling cutter. The workpiece touch probe is configured to measure processing errors of the processed work piece. The controller is configured to generate the control signal based on a processing instruction, a temperature compensation model, the cutter length, and the measured temperature. The controller is further configured to determine whether to modify the temperature compensation model based on the processing errors. ## Claims ### Claim 1 A thermal compensation control system for a machine tool, with the machine tool having a cutter and a driver for driving the cutter or a work piece, the system comprising: a tool setting probe configured to detect a cutter length of the cutter; a temperature sensor configured to detect a measured temperature corresponding to the cutter or the driver; a workpiece touch probe configured to measure a set of processing errors of the work piece; and a controller electrically connected to the driver, the tool setting probe, the temperature sensor and the workpiece touch probe, is configured to generate a control signal for controlling the driver according to a processing instruction, a temperature compensation model, the cutter length and the measured temperature; wherein the controller further determines whether to modify the temperature compensation model or not according to the set of processing errors. ### Claim 2 (depends on 1) The thermal compensation control system for the machine tool according to claim 1, wherein the controller generates an error compensation instruction according to the temperature compensation model, the cutter length and the measured temperature, and the controller generates the control signal according to the processing instruction and the error compensation instruction. ### Claim 3 (depends on 2) The thermal compensation control system for the machine tool according to claim 2, wherein the controller further obtains a rotating speed instruction from the processing instruction, and generates the error compensation instruction further according to the rotating speed instruction. ### Claim 4 (depends on 2) The thermal compensation control system for the machine tool according to claim 2, wherein the controller further obtains a rotating speed value from the driver, and generates the error compensation instruction further according to the rotating speed value. ### Claim 5 (depends on 1) The thermal compensation control system for the machine tool according to claim 1, wherein, when determining whether to modify the temperature compensation model or not, the controller determines whether the set of processing errors is within in a first error range or not according to the set of processing errors, and the controller determines to modify the temperature compensation model when the set of processing errors is not within in the first error range. ### Claim 6 (depends on 1) The thermal compensation control system for the machine tool according to claim 1, wherein the controller further has a storage medium, the controller writes the set of processing errors into the storage medium as a plurality of sets of history errors and the controller determines whether to modify the temperature compensation model or not according to latest N sets of history errors among the plurality of sets of history errors, wherein N is a positive integer greater than one. ### Claim 7 (depends on 6) The thermal compensation control system for the machine tool according to claim 6, wherein the controller calculates an error average value of the latest N sets of history errors and determines whether the error average value is within a second error range or not, and the controller determines to modify the temperature compensation model when the error average value is not within the second error range. ### Claim 8 (depends on 6) The thermal compensation control system for the machine tool according to claim 6, wherein the controller further calculates an error standard deviation of the latest N sets of history errors and determines whether the error standard deviation is greater than a tolerance or not, and the controller determines to modify the temperature compensation model when the error standard deviation is greater than the tolerance. ### Claim 9 (depends on 8) The thermal compensation control system for the machine tool according to claim 8, wherein the controller modifies the temperature compensation model according to the error standard deviation when the controller determines to modify the temperature compensation model. ### Claim 10 (depends on 7) The thermal compensation control system for the machine tool according to claim 7, wherein the controller modifies the temperature compensation model further according to the error average value when the controller determines to modify the temperature compensation model. ### Claim 11 A thermal compensation method for a machine tool, with the machine tool having a cutter and a driver, the method comprising: detecting a cutter length of the cutter; detecting a measured temperature corresponding to the cutter or the driver; generating a control signal according to a processing instruction, a temperature compensation model, the cutter length and the measured temperature; driving the cutter to process a work piece according to the control signal; measuring a set of processing errors of the work piece; and determining whether to modify the temperature compensation model or not according to the set of processing errors. ### Claim 12 (depends on 11) The thermal compensation method for the machine tool according to claim 11, wherein generating the control signal comprises: generating an error compensation instruction according to the temperature compensation model, the cutter length and the measured temperature; and generating the control signal according to the processing instruction and the error compensation instruction. ### Claim 13 (depends on 12) The thermal compensation method for the machine tool according to claim 12, further comprising: obtaining a rotating speed instruction from the processing instruction, and generating the error compensation instruction further according to the rotating speed instruction. ### Claim 14 (depends on 12) The thermal compensation method for the machine tool according to claim 12, further comprising: obtaining a rotating speed value and generating the error compensation instruction further according to the rotating speed value. ### Claim 15 (depends on 11) The thermal compensation method for the machine tool according to claim 11, wherein determining whether to modify the temperature compensation model or not according to the set of processing errors comprises: determining whether the set of processing errors is within a first error range; and determining to modify the temperature compensation model when the set of processing errors is not within the first error range. ### Claim 16 (depends on 11) The thermal compensation method for the machine tool according to claim 11, wherein determining whether to modify the temperature compensation model or not according to the set of processing errors comprises: recording the set of processing errors for a plurality of times for obtaining a plurality of sets of history errors; and determining whether to modify the temperature compensation model according to latest N sets of history errors among the plurality of sets of history errors, wherein N is a positive integer greater than one. ### Claim 17 (depends on 16) The thermal compensation method for the machine tool according to claim 16, wherein determining whether to modify the temperature compensation model according to the latest N sets of history errors among the plurality of sets of history errors comprises: calculating an error average value of the latest N sets of history errors; determining whether the error average value is within a second error range or not; and determining to modify the temperature compensation model when the error average value is not within the second error range. ### Claim 18 (depends on 16) The thermal compensation method for the machine tool according to claim 16, wherein determining whether to modify the temperature compensation model according to the latest N sets of history errors among the plurality of sets of history errors comprises: calculating an error standard deviation of the latest N sets of history errors; determining whether the error standard deviation is greater than a tolerance or not; and determining to modify the temperature compensation model when the error standard deviation is greater than the tolerance. ### Claim 19 (depends on 18) The thermal compensation method for the machine tool according to claim 18, further comprising: modifying the temperature compensation model according to the error standard deviation when determining to modify the temperature compensation model. ### Claim 20 (depends on 17) The thermal compensation method for the machine tool according to claim 17, further comprising: modifying the temperature compensation model according to the error average value when determining to modify the temperature compensation model.