Controlling of overfilling in food processing

World-wide interest in the environment has promoted significant commercial attention to the elimination and disposal of waste products and hazardous m aterials. In addition, despite less publicity in the media, there has been a growing research base in the elimination of waste resulting from ineffici ent production processing. In food processing, considerable waste produce a rises in the form of 'giveaways', in overfilled containers, or through 'thr owaways' as non-conforming underfilled products which end up in rubbish bin s. The major aim of the current research programme is to investigate the us e of ultrasound monitoring, as a means of on-line measurement of fluid leve ls in food containers. Ultrasound monitoring has the potential to be an acc urate measurement technique which is capable of being combined with an appr opriate control strategy to provide the most suitable method of reducing or eliminating the waste problem. The objective of the research described her ein was to investigate controller design methodologies for a bottling proce ss. The bottling process was modelled using MATLAB(R) and SIMULINK(R) packa ges and controller designs were implemented to improve the response charact eristics of the process. Both digital control and fuzzy logic controller de sign methods were investigated. The digital controller was designed using t he direct digital design method and resulted in an improved system performa nce. However, when different carousel delays were considered, the performan ce varied significantly. Fuzzy logic control operates with a pre-determined set of rules and has been shown to function very well with a bottling syst em. Bottle fill times and the resulting stability with respect to changing carousel delays were improved. Available data indicates that fuzzy logic ca n be used efficiently and effectively, which could provide a valuable asset to the food processing and allied industries. (C) 1999 Elsevier Science S. A. All rights reserved.