Alberto Luigi Cologni

A Data-Driven Approach to Control of Batch Processes With an Application to a Gravimetric Blender

In this paper, a data-driven controller design approach for batch processes is proposed. In this strategy, based on a suitable transformation of the input and output signals, a mathematical description of the process dynamics is not needed, and the working cycle is guaranteed to adapt to the desired operating conditions. Throughout this paper, all the steps of the above algorithm are described in detail with the help of an experimental case study dedicated to a gravimetric blender, which is a key element in the plastic extrusion process.

On time-optimal anti-sway controller design for bridge cranes

In this paper, we analyze and discuss the time optimal control problem for bridge cranes. Specifically, we employ the geometric approach introduced in [12] to address the control issue without computing the analytic trajectory of the costate. As a second contribution, we show that an alternative approach based on a proportional controller accounting for the limits of the control action can be tuned to resemble to the time-optimal solution, but with simpler and more robust implementation. The above ideas are validated by means of some simulation examples.

Control System Design for a Continuous Gravimetric Blender

Abstract In this work the control system for a continuous gravimetric blender for polymer extrusion process has been designed. The plant considered in this paper is a blending machine that mixes two different polymers, a bulk one and an additive. Each component of the mix is metered by a dedicated screw meter system. The mass delivered by each meter is measured by a load cell. The two components are poured into a hopper (the mixer) directly embedded on the extruder input. The control objectives are manifold and include: accurate mass flow estimate on the basis of the weight and screw speed measurements; accurate mass flow regulation of each meter; keeping of the relative proportions among all the components that are metered in all the operating conditions; guarantee that inside the mixer there is always material enough to fulfill the mass flow variation request of the extruder.

Fast tuning of cascade control systems

Abstract In this paper, an algorithm for direct data-driven design of cascade control system is proposed and analysed. The procedure is based on the Virtual Reference Feedback Tuning (VRFT) approach but it allows to tune either the inner and the outer loops by means of a single set of experimental data. The main differences between the standard VRFT and the proposed approach are highlighted and analyzed. The design technique is finally applied on a micro-positioning control problem for Electro-HydroStatic Actuators (EHSAs).

Modeling and identification of an Electro-Hydraulic Actuator

In this work, a physical non-linear model of an Electro-Hydraulic Actuator has been developed. Each system component (valves, pipes, cylinders) and their interactions have been modeled by means of conservation and constitutive laws. The actuator dynamics, with lumped-parameter element models, have been treated accurately, with special attention given to modeling friction. Finally, a global parametric-identification procedure has been performed for all unknown parameters. Throughout this paper all the modeling assumptions and results from system identification are verified with experimental data.

Modeling and Identification of an Electro-Hydrostatic Actuator

Abstract The aim of this paper is to develop an accurate model of an electro-hydrostatic actuator (EHSA) and to estimate the model parameters. The physical behavior of each components has been analyzed and a linear model has been obtained. Then, the cylinder friction phenomenon and the cylinder chambers volume variations have been considered and a non linear model has been developed. An EHSA prototype has been produced and used to estimate the parameters and to validate the models. The comparisons between simulation results and experimental data show that the linear model well describes the main dynamics of the EHSA and the non linear model fits the data with an high accuracy.

Remote maintenance system for semi-automated manufacturing machines

The increasing of globalization requires companies to ship their machines all over the world. This growth of exportation of manufacturing systems increased costs of maintenance due to the requirement of sending technicians to the production site where the machine is installed. The strong spread of mobile devices and the increased quality of networks opened new horizons for maintenance and support services. The work presented in this paper describes a real application case and proposes an approach for using mobile internet devices (MID) on the production site for acquisition and transmission of multi-source information that can be used from service personnel to try to resolve issues from the vendor service center. The purpose of this article is to present an approach to implement a remote maintenance system based on a mobile platform that allows hybrid (video and telemetry) logging.

An integrated system for supporting remote maintenance services

In todays marketplace machine producers are shipping their systems all around the world. Maintenance costs are becoming ever greater due to travel costs for sending service personnel to wherever the machines are installed to solve a particular problem. In the majority of cases, a technician solves the problem quickly, so that the travel overhead becomes a large part of the repair cost. This makes remote diagnosis, debugging and repair an obvious advantage. This paper describes a remote maintenance methodology that uses wireless and mobile technology to record and transmit video and machine operational parameters together for remote viewing and analysis. This information is sent to the machine manufacturers headquarters, where a thorough analysis of it is done by experts there, and a solution is then transmitted to the remote site to correct the problem. The structure of this remote diagnostic system is described, and details about its implementation on a real machine used in manufacturing are given.

Modeling and control of an electro-mechanical ballscrew actuator for vibration active damping

The damping of vibrations on aircrafts and rotorcrafts can provide life extension and weight reduction on those structures on which the vibration load is a significant amount of load endurance spectrum. In this work, a hybrid active-passive inertial actuator system is presented. It is based on a ballscrew based actuator, and the power generation is provided by an open windings three phase motor controlled by a dual inverter. Open windings drives allow to achieve greater torque generation with the same DC bus voltage. The PWM is generated accordingly to a novel algorithm based on a combination of two standard SVM algorithms, one for each inverter. The current controller has been tested on a real test bench at the designed working frequency. Also, a force controller has been designed and tested to verify the force values that can be delivered by the actuator at the designed working frequency.

Polymer Flow Control in Continuous Gravimetric Blenders

In this paper, the design of a plastic flow control system for continuous gravimetric blenders used in polymer extrusion processes is discussed. The considered plant is a blending machine that mixes four different polymers, bulks and additives. In order to pursue the desired behavior, three control objectives are considered: plastic flow estimation based on weight and screw speed measurements, plastic flow regulation for each meter and control of the recipe with mass constraints such that the mixer can always satisfy the plastic flow variation needed by the extruder. Simulation results are used to show the effectiveness of the proposed approach.Copyright