Control and Measurement System for a Compressing Unit

Abstract

Pulp for making paper is produced in grinding machines whose operation principle is based on the compression of logs against a grinding stone. The aim of this Master Thesis is to develop and implement a control and measurement system for a laboratory compressing unit which carries out this first step in paper making process. For this purpose, a hand drive and a computer interface are designed and configured. The thesis is divided in three sections. In the literature study the theories involved in the research work are analyzed. Control and measurement methods are detailed as well as the hydraulic system needed to operate the compressing unit. In the second section the development of a control and measurement method suitable for the unit is carried out. It is based on the study of the most important variables involved in the process. Last section focuses on the implementation of the control and measurement system. A hand drive and a computer interface are considered. The latter is developed using LabView software. In this section, the hand drive design is analyzed and the LabView code is explained. In addition, a measurement approximation method is implemented in order to display the correct variable values. Finally a verification of the whole system is carried out. The results of this study suggest that the control and measurement system satisfies the requisites needed to develop future researches related to this compressing unit. The values displayed by the hand drive and computer interfaces are similar to the theoretical ones and the control system avoids dangerous situations. This Master Thesis suggests future research work in order to improve the accuracy of the control and measurement system. /Kir10