Machine tool controls with AI learn on the job

Advanced machine tool controls infused with artificial intelligence (AI) can learn about your machining processes. With this knowledge, a CNC can automatically take action that boosts machining speed and accuracy, as well as slash unplanned downtime for maintenance.

Learning takes several forms with CNCs made by FANUC America Corp., Hoffman Estates, Ill. Among the available learning options is a feature called high-precision learning control.

Daniel Knepp, senior CNC applications engineer at FANUC, explained how the feature would work in a grinding process used to produce crankshafts. To grind the crankpins, the machine would be set to “pin-chasing” mode, wherein the grinding wheel follows the rotating part to stay in contact with the surface of the eccentric pins. As the wheel rapidly moves back and forth to chase a pin, machining error occurs with every revolution of the part.

A FANUC CNC with learning control, however, would compensate for error by adjusting the machine’s motors for the next revolution. After a number of revolutions, the applied compensation can reduce machining error by 90 percent or more, Knepp said.

If the error were 10µm, for example, the application of learning could reduce it to 1µm or, perhaps, even to a submicron level if conditions were ideal, he said.

Featuring deep learning-infused AI, Okuma’s OSP-P300A can be used to predict when machine tools will experience problems if preventive maintenance isn’t done beforehand. Image courtesy of Okuma America.

Machines without learning control would have to be run slower to achieve the required part accuracy. With the feature, manufacturers could speed up their processes—if their tools allowed it—and still get the desired accuracy, Knepp said.

Of course, there’s a price to pay for these benefits. Learning control and FANUC’s other learning features add costs to a control because they require additional memory and software, Knepp noted.

Another learning-capable control product is available from Okuma America Corp., Charlotte, N.C. Okuma has introduced what it calls deep learning-infused AI for CNC machining. This AI capability, which resides in the control processing unit of the company’s OSP-P300A CNC, allows the control to run diagnostics without human intervention. The idea is for the CNC to spot potential problems before they become major issues that could cause some type of failure in a machine tool.