Adaptive controller for a glass viscoelastic testing process

An adaptive controller has been designed to control the force and pressure of glass pressing tests for viscoelastic properties. The dynamics of the testing process appear to be nonlinear with the characteristic parameters varying drastically from test to test due to changes of glass compositions and the various test conditions. To automate the testing process, a self-tuning controller is designed to automatically search for the appropriate testing condition. The control scheme includes a simplified nonlinear model with unknown parameters, an online parameter estimator, and an adaptive control algorithm combining feedforward prediction and a proportional-plus-integral controller. Experimental results prove that the controller can control the glass-testing process over a wide range of test conditions.<>