Kustannustehokas ja luotettava ohjausjärjestelmäarkkitehtuuri puupohjaisessa levytuotannossa
Olli Juhani Elomaa · Tampere University Institutional Repository (Tampere University) · 2016
Keywords: Control system, PLC, Proximity sensors, Reliability, S7-1500, TIA Portal, Variable-frequency drive Increased competition has increased the need to be more cost effective in the wood-based board manufacturing industry. One way of achieving this is a more cost effective controlling principle. In this thesis the reliability and the costs of the current and recommended controller systems are analysed. Additionally time to implement the controller systems is analysed. Controller system can be made more cost effective by implementing variable-frequency drive control in the programmable logic controller. This allows more freedom in choosing different vendors supplying variable-frequency drives. Additionally more cost effective proximity sensors used in the field can increase cost effectiveness. The relative component costs for both systems are calculated and compared. Reliability of the current and the recommended control system are analysed with statistical methods by using the manufacturers’ reliability data. Costs are calculated by using suppliers’ product prices and quotes. More cost effective field devices were tested in a particle board manufacturing plant in order to determine their reliability in a production environment. The total relative costs of the control system when including direct component and electrical cabinet manufacturing costs can be reduced by 15 % when using the recommended controlling principle. Theoretical reliability of the control system will improve by 0,6 % when using the recommended controlling system.