In this paper a real-time model-based geometric control system is proposed for workpiece accuracy in bar turning. An on-line ultrasonic measurement system that operates in the presence of cutting fluid is employed for workpiece diameter measurement. A state space mechanistic model is used to overcome the delay in the feedback loop. A Kalman Filter is used in a predictor-corrector fashion to update model predictions using on-line measurements. A full state feedback controller with an integral control action is designed and used to manipulate the tool position in real-time for machining error compensation. The performance of the proposed control strategy is evaluated through cutting experiments performed on a CNC turret lathe retrofitted with an open architecture controller.

Issue Section:
Research Papers
Topics:
Computer numerical control machine tools, Control equipment, Control systems, Cutting, Delays, Error compensation, Feedback, Fluids, Kalman filters, Machining, Pole placement, Predictive control, Turning, Ultrasonic measurement
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