Adaptive Process Control in Noncircular Grinding

Conventional process control in noncircular grinding requires high efforts concerning adjustment and optimization. The increasing demands on multi-product-ability as well as small lot sizes or single piece production do no longer allow these efforts. Furthermore, process relevant information like normal or tangential forces is not monitored, consequently there is no possibility for process quality control to support a constant workpiece quality. This article introduces a hybrid adaptive control which consists of three components: The contour pre-filtering unit converts the contour data into a nominal value curve that is twice differentiable. Limited dynamic ranges of the drives, especially at high rates of workpiece rotations, are considered in the predictive feeddrive position control unit. The normal force control unit keeps the swelling of the machine at a constant value and therefore improves the dimensional accuracy of noncircular workpieces like e.g. cams. The hybrid adaptive control dramatically reduces the setup time of the process and results in improved workpiece quality.