Speed control of a conveyor system by means of fuzzy control aided PLC

Programmable logic controllers are microprocessor based control systems which manage a machine or an industrial foundation by means of change of situations and a program edited before. Basically, a PLC is composed of a microprocessor, a power supply and input/output units. Beside these units mentioned above, some certain units were developed which respond to requirement of faster and more effective processing in industrial control systems. These special units, such as high speed counters, heat controllers and pH controllers increase the control performance of PLCs. Application of fuzzy logic theory in control systems proved to be superior to the conventional control systems. Fuzzy logic controllers can infer coherent results in uncertain conditions when it is necessary to control a complex system which is impossible to model using mathematical ways. In this paper, fuzzy control applications on PLCs are investigated under two captions, the first of which is the applicability of a special unit to PLCs which is controlled by a software that performs fuzzy logic processes by means of improvement on a real industrial control system, and the other is realization of fuzzy control algorithms by basic PLC instructions.