Sensorless feed optimization

A method for sensorless feed speed optimization, said method comprising:

• collecting time-series data, by a machine controller, for a reference machining cycle performed by a machine tool, where the data includes a tool center point position along a tool path and a spindle torque command for a plurality of time steps, and where the spindle torque command has a value which is computed by the machine controller to cause a spindle of the machine tool to maintain a prescribed rotational velocity;
• determining a spindle torque command target value;
• subtracting an air-cut torque value from the spindle torque command target value and from the spindle torque command in the time-series data for the reference machining cycle;
• computing an optimum feed speed profile including, for each time step in the time-series data, computing a new feed speed as an original feed speed from the reference machining cycle multiplied by a ratio of the spindle torque command target value to the spindle torque command for the time step, and pairing the new feed speed with the tool center point position in the optimum feed speed profile;
• and
• using a motion program created with the optimum feed speed profile and a feedback control algorithm, by the machine controller, to control the machine tool performing production machining operations.

A sensorless machine tool feed speed optimization system, said system comprising:

• a machine tool configured for performing an operation on a workpiece;
• and
• a computing device in communication with the machine tool, said computing device being configured to compute and use an optimum feed speed profile by performing steps including;
• collecting time-series data for a reference machining cycle performed by the machine tool, where the data includes a tool center point position along a tool path and a spindle torque command for a plurality of time steps;
• determining a spindle torque command target value;
• computing an optimum feed speed profile including, for each time step in the time-series data, computing a new feed speed as an original feed speed from the reference machining cycle multiplied by a ratio of the spindle torque command target value to the spindle torque command for the time step, and pairing the new feed speed with the tool center point position in the optimum feed speed profile;
• and
• using a motion program created with the optimum feed speed profile to control the machine tool performing production machining operations.