Giddings & Lewis, LLC

Amca International Corporation

Eugene A Olig

Lee R Ladwig

Bruce R Beadle

An adaptive control for a turning machine which adjusts the machining rate to maintain the actual horsepower dissipated at the cutter tip at a constant set point despite changing workpiece and cutter parameters. The machining rate is adjusted by control of the machine drive and tool feed to achieve required SFM and IPR values, respectively, within maximum and minimum SFM and IPR limits. 'Speed' and 'Axis' override controls are also provided. The rate of adjustment of SFM and IPR to a deviation of the cutter tip horsepower from the set point is inversely proportional to the measured system gain so that the response factor of the control loop is maximized. The commanded machining rate of (SFM) (IPR) product is periodically determined by estimating the actual machining rate and multiplying the estimate by the ratio of the set point to the cutter tip horsepower. The cutter tip horsepower is determined by subtracting the electrical loss, mechanical friction loss, and the net power required for net acceleration of the drive, from the measured electrical power supplied to the drive motor. The cutting efficiency is monitored to perform tool wear, tool breakage, and tool protection functions. The adaptive control also has soft engagement and soft disengagement functions for initiating and terminating the adaptive machining process.

Adaptive control for machine tools

An adaptive control for a turning machine which adjusts the machining rate to maintain the actual horsepower dissipated at the cutter tip at a constant set point despite changing workpiece and cutter parameters. The machining rate is adjusted by control of the machine drive and tool feed to achieve required SFM and IPR values, respectively, within maximum and minimum SFM and IPR limits. 'Speed' and 'Axis' override controls are also provided. The rate of adjustment of SFM and IPR to a deviation of the cutter tip horsepower from the set point is inversely proportional to the measured system gain so that the response factor of the control loop is maximized. The cutter tip horsepower is determined by subtracting the electrical loss, mechanical friction loss, and the net power required for net acceleration of the drive, from the measured electrical power supplied to the drive motor. The cutting efficiency is monitored to perform tool wear, tool breakage, and tool protection functions. The adaptive control also has soft engagement and soft disengagement functions for initiating and terminating the adaptive machining process.

Methods and apparatus by which a member is moved automatically to any one of a plurality of predetermined positions each of which is precisely established by guiding lock-up means such as a shot pin, and characterized in that inaccuracy of a feedback signal representing actual position of the member is determined prior to each movement toward a different position to create a correction signal used during subsequent repositioning so that the lock-up means will engage when such different position is reached.

Methods and apparatus for automatic movement of a member to precisely

A numerical control contouring system in which successive path segments are executed according to successive blocks of command signals making up a path program, the system being interruptable at any time by a feedhold signal to stop the controlled movable member at a random point on the path. The system is characterized by the improvement of preventing the system from resuming normal operation unless and until the member is returned to the path stopping point after it has been, for any reason, displaced therefrom under manual control or the like. In one embodiment, the axis component displacements of the member from the stopping point are represented by signals created and displayed, and the operator's restart pushbutton switch is rendered ineffective until the displayed displacement signals are reduced to zero. In another embodiment, the axis component displacement signals are utilized to create a non-program block of command signals, and means responsive to a restart signal first cause the member to be moved back to the path stopping point before the system is automatically restored to normal operation. In a third embodiment, after each movement of the controlled member following its arrival at the stopping point, the axis components for that movement are signaled and stored, and means responsive to a restart signal first utilize such stored signals to execute such movements in reverse order and senses to return the member to the path stopping point, and next restore normal operation of the system so that movement along the path is resumed.

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Fond Du Lac, WI, United States of America

Eugene A Olig