# US 10,503,142 B2 · Method and device for controlling a milling machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,503,142 B2 - Document ID: US10503142B2 - Status: Granted - Kind: B2 - Application number: 15/660,880 - Filed: 2017-07-26 - Published: 2018-02-08 - Granted: 2019-12-10 - Earliest claimed: 2016-08-02 - Assignees: Dr. Johannes Heidenhain GmbH - Applicants: DR. JOHANNES HEIDENHAIN GmbH - Inventors: Frieder Kohler - Web page: https://patentgrep.com/patent/US10503142B2 ## CPC - G05B 19/406: characterised by monitoring or safety (G05B19/19 takes precedence) - G05B 2219/34427: Diagnostic, monitoring incorporated in controller - G05B 2219/45145: Milling - 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 In a method for controlling a milling machine, a milling operation is able to be monitored on the basis of a temporally variable parameter of a numerical control in that the parameter is monitored for the exceeding or undershooting of a limit value during the milling operation. The method includes filtering out the tooth-meshing frequency in the time characteristic of the parameter (Iqnom). ## Claims ### Claim 1 A method for controlling a milling machine, comprising: monitoring a milling operation with the aid of a temporally variable parameter of a numerical control; monitoring the parameter for exceeding or undershooting a limit value during the milling operation; filtering out a tooth-meshing frequency of a milling tool in a time characteristic of the parameter; and processing the parameter, measured in a fixed clock rate, by a scanning-rate converter, the scanning-rate converter outputting the parameter with a variable clock pulse for further processing; wherein the variable clock pulse corresponds to a multiple of the tooth-meshing frequency of the milling tool, the tooth-meshing frequency corresponding to a product of a rate of rotation of the milling tool and a number of cutting blades of the milling tool; and wherein the tooth-meshing frequency is filtered out of the parameter output with a variable clock rate by averaging, by a moving-average filter, across a number of values that corresponds to the multiple of the tooth-meshing frequency. ### Claim 2 (depends on 1) The method according to claim 1, wherein the variable clock pulse corresponds to (a) five to twenty times and/or (b) ten times the tooth-meshing frequency of the milling tool. ### Claim 3 (depends on 1) The method according to claim 1, further comprising integrating the parameter in the moving-average filter in an integration stage and subsequently differentiating the parameter in a differentiation stage. ### Claim 4 (depends on 3) The method according to claim 3, wherein the differentiation stage includes a shift register having a number of register slots that corresponds to the multiple of the tooth-meshing frequency, through which consecutive parameter values are shifted at a time delay. ### Claim 5 (depends on 4) The method according to claim 4, wherein the shift register includes ten register slots. ### Claim 6 (depends on 1) The method according to claim 1, further comprising converting the parameter at an input of the moving-average filter from a floating point number to an integer number, and converting the parameter at an output of the moving-average filter from an integer number to a floating point number. ### Claim 7 (depends on 1) The method according to claim 1, further comprising triggering a warning and/or a termination of the milling operation in accordance with a comparison of the parameter output at an output of the moving-average filter with a limit value. ### Claim 8 A numerical control for controlling a milling operation on a machine tool, comprising: a monitor unit adapted to monitor a temporally variable parameter of the numerical control with the aid of a limit value; an averaging filter adapted to filter out a tooth-meshing frequency of a milling tool from a time characteristic of the parameter; and a scanning rate converter adapted to process the parameter, measured in a fixed clock rate, and to output the parameter with a variable clock pulse for further processing; wherein the variable clock pulse corresponds to a multiple of the tooth-meshing frequency of the milling tool, the tooth-meshing frequency corresponding to a product of a rate of rotation of the milling tool and a number of cutting blades of the milling tool; and wherein the tooth-meshing frequency is filtered out of the parameter output with a variable clock rate by averaging, by a moving-average filter, across a number of values that corresponds to the multiple of the tooth-meshing frequency. ### Claim 9 (depends on 8) The numerical control according to claim 8, wherein the averaging filter includes a moving-average filter having an integration stage and a downstream differentiation stage. ### Claim 10 (depends on 9) The numerical control according to claim 9, wherein the differentiation stage includes a shift register having a number of register slots that corresponds to a multiple of the tooth-meshing frequency, the shift registers adapted to store consecutive parameter values. ### Claim 11 (depends on 10) The numerical control according to claim 10, wherein the shaft register includes ten register slots. ### Claim 12 (depends on 8) The numerical control according to claim 8, wherein the scanning-rate converter is connected upstream from the averaging filter. ### Claim 13 (depends on 8) The numerical control according to claim 8, wherein the variable clock pulse corresponds to (a) five to twenty and/or (b) ten times the tooth-meshing frequency of the milling tool. ### Claim 14 A numerical control for controlling a milling operation on a machine tool, comprising: a monitor unit for monitoring a temporally variable parameter of the numerical control with the aid of a limit value; an averaging filter for filtering out a tooth-meshing frequency of a milling tool from a time characteristic of the parameter; and a scanning rate converter for processing the parameter, measured in a fixed clock rate, for outputting the parameter with a variable clock pulse for further processing; wherein the variable clock pulse corresponds to a multiple of the tooth-meshing frequency of the milling tool, the tooth-meshing frequency corresponding to a product of a rate of rotation of the milling tool and a number of cutting blades of the milling tool; and wherein the tooth-meshing frequency is filtered out of the parameter output with a variable clock rate by averaging, by a moving-average filter, across a number of values that corresponds to the multiple of the tooth-meshing frequency.