New bio-process control scheme: Decentralized autonomous control system

Since the economic recession in Japan, many plants are forced to function with fewer operators. However, if control and instrumentation engineers understand the static and dynamic characteristics of a plant, it is not so difficult to design a fully automatic control system for that plant. Nevertheless, the behavior of a biochemical or chemical production plant is not easily measured and understood. If a plant in an organization does not perform a vital role or does not require very accurate control, a relatively simple control system, i.e. only to maintain the plant at its current state or prevent it from moving into abnormal states, may be sufficient from the point of view of reducing the operative personnel. In the present paper, a decentralized autonomous system based on recent computer technology is proposed for such a purpose. Furthermore. a common objective function-the 'Happiness Index'-is introduced. The novel concept has been applied onto and tested for an example bioprocess case by simulation. (C) 1997 Elsevier Science B.V.