Gain Scheduling Control of a Gravimetric Blender with Vibrant Duct

Blender and feeder are very important devices in a polymer processing plant. The accuracy in delivering the polymer to the plastification unit is a fundamental property for the quality of the final product. To maximize accuracy and precision gravimetric feeder are the best available solution, which measure the weight of the hopper and the feeder. In these devices, it is possible to estimate the delivered flow based on a loss-in-weight method and to design closed loop control systems to regulate the polymer flow. Specifically, in this work vibrating duct feeder are considered which show a peculiar nonlinear dynamics due to the vibrating element. Then, a nonlinear gain scheduling controller has been designed using an implementation which guarantee satisfaction of the so called linearization property.