# US 2017/0227945 A1 · Real time machining process monitoring utilizing preprocess simulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0227945 A1 - Document ID: US20170227945A1 - Status: Published application - Kind: A1 - Application number: 15/015,860 - Filed: 2016-02-04 - Published: 2017-08-10 - Earliest claimed: 2016-02-04 - Assignees: Makino, Inc. - Applicants: Makino Inc. - Inventors: Zhigang Wang; Shogo Nakashima; Mark W. Larson - Web page: https://patentgrep.com/patent/US20170227945A1 ## CPC - G05B 19/182: {characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control (G05B19/21 - G05B19/40 take precedence)} - G05B 19/402: characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position (G05B19/19 takes precedence) - G05B 19/4062: Monitoring servoloop, e.g. overload of servomotor, loss of feedback or reference - G05B 19/4069: Simulating machining process on screen (G05B19/4068 takes precedence) - G06F 30/20: Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) - G05B 2219/42306: Excess in error, compare reference with feedback - G05B 2219/49001: Machine tool problems - G05B 2219/50197: Signature analysis, store working conditions, compare with actual - 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) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A pre-process simulation may calculate operating conditions of a machine tool by simulating a NC program and calculate predicted values indicative of the operating conditions. A real time monitoring system may compare actual values from the actual operation of a machine tool actually executing the NC program to the predicted values and determine whether to initiate a response. The operating conditions may be machine tool operating conditions. The comparison of actual values to predicted values may be based on a dynamic limit within which the predicted values fall which may vary based on the tool position, and the dynamic limit may include upper and lower limit boundaries. ## Claims ### Claim 1 A method of monitoring operation of a machine tool, the method comprising in real time: a. determining at least one respective actual value of an associated operating condition experienced by said machine tool during operation; b. comparing said at least one respective actual value to a respective limit corresponding to said associated operating condition. ### Claim 2 (depends on 1) The method of claim 1, wherein at least one of said associated operating condition comprises a machine tool operating condition. ### Claim 3 (depends on 1) The method of claim 1, wherein said associated operating condition of at least one of the at least one respective actual value is selected from the group consisting of radial load on a tool holder of the machine tool, bending moment on the tool holder, bending moment at the tool holder/spindle interface, torque of the machine tool, load on one or more axis servo of the machine tool and temperature of the tool. ### Claim 4 (depends on 1) The method of claim 1, comprising determining at least one respective actual temperature value of a tool used in the operation of the machine tool and comparing said actual temperature value to a respective limit corresponding to temperature of the tool. ### Claim 5 (depends on 1) The method of claim 1, wherein operation of the machine tool causes a tool carried by the machine tool to move along a tool path, the tool path comprising a plurality of sequential tool positions, and wherein the steps of determining at least one respective actual value of an associated operating condition and of determining at least one respective actual value are repeated for a plurality of the plurality of sequential tool positions. ### Claim 6 (depends on 1) The method of claim 1, wherein operation of the machine tool causes a tool carried by the machine tool to move along a tool path, the tool path comprising a plurality of sequential tool positions, and wherein each respective limit corresponding to said associated operating condition is dependent on the tool position of the tool. ### Claim 7 (depends on 1) The method of claim 1, wherein each respective limit comprises a respective range containing a respective predicted value of the associated operating condition. ### Claim 8 (depends on 7) The method of claim 7, comprising determining at least one of said respective predicted value by simulating operation of the machine tool on a computer. ### Claim 9 (depends on 8) The method of claim 8, wherein the step of determining at least one of said respective predicted values by simulating operation occurs prior to actual operation of the machine tool. ### Claim 10 (depends on 8) The method of claim 8, wherein the step of determining at least one of said respective predicted values by simulating operation occurs after actual operation of the machine tool has started. ### Claim 11 A method of monitoring operation of a machine tool, wherein operation of the machine tool causes a tool carried by the machine tool to move along a tool path, the tool path comprising a plurality of sequential tool positions, the method comprising in real time: a. determining at least one actual value of an associated respective operating condition experienced by said machine tool during operation while at an associated one of said plurality of sequential tool positions; b. comparing the at least one actual value to a respective limit corresponding to the associated operating condition, wherein the respective limit is dependent on the associated one of the plurality of sequential tool positions. ### Claim 12 (depends on 11) The method of claim 11, wherein the steps of determining at least one actual value of an associated operating condition and of determining at least one actual value are repeated for a plurality of the plurality of sequential tool positions. ### Claim 13 (depends on 12) The method of claim 12, wherein the respective limits of corresponding associated operating conditions for at least two of the plurality of sequential tool positions are not equal. ### Claim 14 (depends on 12) The method of claim 12, wherein each respective limit comprises a respective range containing a respective predicted value of the associated operating condition. ### Claim 15 (depends on 14) The method of claim 14, wherein the respective predicted value of at least two of the plurality of sequential tool positions are not equal. ### Claim 16 (depends on 14) The method of claim 14, comprising determining the respective predicted value by simulating operation of the machine tool on a computer. ### Claim 17 A method of simulating operation of a machine tool, the method comprising: a. simulating execution of a plurality of motion steps corresponding to a NC program; and b. for at least one respective simulated operating condition corresponding to each respective one of a plurality of the plurality of motion steps, calculating at least one respective predicted value for each of the at least one simulated operating condition, wherein at least one of the simulated operation conditions comprises a simulated machine tool operation condition. ### Claim 18 (depends on 17) The method of claim 17, wherein the step of simulating execution of a plurality of motion steps is executed in a sequence of one motion step at a time and the step of calculating at least one respective predicted value is executed for one of the plurality of motion steps before proceeding to the next motion step of the sequence. ### Claim 19 (depends on 17) The method of claim 17, comprising for each motion step simulated the step of determining whether any predicted value for that motion step exceeds a limit which is relevant to the simulated operating condition of that predicted value. ### Claim 20 (depends on 19) The method of claim 19, comprising revising the NC program if any predicted value exceeds the limit. ### Claim 21 (depends on 17) The method of claim 17, wherein the simulated machine tool operation condition is selected from the group consisting of simulated radial load on a tool holder of the machine tool, simulated bending moment on the tool holder, simulated bending moment at the tool holder/spindle interface, simulated torque of the machine tool and simulated load on one or more axis servo of the machine tool. ### Claim 22 A machining system comprising: a. a real machine tool, the real machine tool configured to provide, to a monitoring system, for each respective one of a plurality of sequential tool positions at least one respective actual value of each of at least one operating condition resulting from operation of the machine tool at that respective one of the plurality of sequential tool positions; b. a computer configured to: i. simulate operation of the machine tool by modeling the execution of a plurality of motion steps corresponding to a NC program; ii. for at least one respective simulated operating condition corresponding to each respective one of a plurality of the plurality of motion steps, calculate at least one respective predicted value for each of the at least one simulated operating condition; and c. the monitoring system configured to: i. compare each respective actual value to the predicted value of the corresponding simulated operating condition that corresponds to the operating condition of the respective actual value at the tool position that matches the motion step; ii. send a command to the real machine tool if any respective actual value falls outside of a range which contains the predicted value. ### Claim 23 (depends on 22) The machining system of claim 22, wherein the real machine tool is configured to adjust tool feed rate based on content of the command sent by the monitoring system. ### Claim 24 (depends on 23) The machining system of claim 23, wherein the monitoring system is configured to send said command if said respective actual value falls outside of the range for more than a predetermined period of time. ### Claim 25 A machining system comprising: a. a real machine tool, the real machine tool configured: i. to operate at least one tool to machine a workpiece; and ii. to provide at least one respective actual value of an associated operating condition experienced by said machine tool during operation; and b. a monitoring system configured to compare said at least one respective actual value to a respective limit corresponding to said associated operating condition. ### Claim 26 (depends on 25) The machining system of claim 25, wherein said machine tool comprises a machine tool controller, the machine tool controller being configured to provide data indicative of said at least one respective actual value. ### Claim 27 (depends on 26) The machining system of claim 26, wherein said machine tool comprises at least one sensor which senses the respective actual value of the associated operating condition. ### Claim 28 (depends on 25) The machining system of claim 25, wherein said monitoring system is configured to send a command to said machine tool controller if said at least one respective actual value is not within said respective limit for more than a predetermined period of time. ### Claim 29 (depends on 28) The machining system of claim 28, wherein said predetermined period of time is zero seconds. ### Claim 30 (depends on 28) The machining system of claim 28, wherein the machine tool controller is configured to act in response to said command, the act being selected from the group consisting of adjusting the feed rate of the tool and stopping the operation of the tool. ### Claim 31 (depends on 25) The machining system of claim 25, wherein each respective limit comprises a respective range containing a respective predicted value of the associated operating condition. ### Claim 32 (depends on 31) The machining system of claim 31, wherein said machine tool comprises a machine tool controller, the machine tool controller being configured to execute a NC program to cause said at least one tool to move along a tool path, and comprising a computer configured to determine each said respective predicted value by simulating the NC program. ### Claim 33 A machining system comprising: a. a real machine tool, the real machine tool configured to provide for each respective one of a plurality of sequential tool positions at least one respective actual value of each of at least one operating condition experienced by said machine tool during operation of the machine tool at that respective one of the plurality of sequential tool positions; b. a monitoring system configured to compare said at least one respective actual value to a respective limit corresponding to said associated operating condition, wherein the respective limit is dependent on the associated one of the plurality of sequential tool positions. ### Claim 34 (depends on 33) The machining system of claim 33, wherein each respective limit comprises a respective range containing a respective predicted value of said associated operating condition. ### Claim 35 (depends on 34) The machining system of claim 34, comprising a display, said display comprising: a. the actual value of a plurality of the at least one operating condition experienced by said machine tool at and prior to a current tool position; b. a plurality of the respective ranges for the current tool position, previous tool positions and future tool positions. ### Claim 36 A machine comprising a computer configured to: a. simulate operation of a machine tool by modeling the execution of a plurality of motion steps corresponding to a NC program; b. for at least one respective simulated operating condition corresponding to each respective one of a plurality of the plurality of motion steps, calculate at least one respective predicted value for each of the at least one respective simulated operating condition, wherein at least one of the simulated operation conditions comprises a simulated machine tool operation condition.