Implementation of a fuzzy logic controller via cyclone II FPGA and nios II processor

Abstract

Fuzzy control is an emerging control technique which allows an engineer to design a control system with only an operator's knowledge of the plant being controlled. FPGAs and soft processor cores allow engineers to rapidly prototype and modify systems such as controllers. The combination of these two emerging technologies is discussed in detail in this work.It is shown that the principals of fuzzy sets and fuzzy logic can be the basis of a control system implemented in FPGA hardware with a soft processor core. An Altera Cyclone II FPGA with a Nios II soft processor core is implemented to provide an empirical example of a fuzzy controlled system. The design process id detailed in a step-by-step fashion and a prototype is assembled and detailed. Experiments proving the validity of fuzzy control as a control scheme are designed and run and the results are provided. The experiments consists of a fuzzy system controlling the temperature of air inside of a confined space. The results prove that fuzzy control is a viable control scheme and that the assertions about limited plant knowledge and ease of design are true. A temperature versus time plot is shown for the ambient temperature inside of a confined space in which a heating and exhaust system is controlled by a fuzzy-based controller.