Fuzzy Logic has been successfully applied to a large number of control applications. The most commonly used controller is the proportional-plus-integral-plus-derivative (PID) controller, which requires a mathematical model of the system. Fuzzy logic controller provides an alternative to PID controller since it is a good tool for the control of systems that are difficult in modeling. The control action in fuzzy logic controllers can be expressed with simple “if-then” rules. Hardware implementation of the controller can be achieved in a number of ways to create new products. The most popular method of implementing fuzzy controller is using a general-purpose microprocessor or microcontroller.
Generally, an 8-bit microprocessor can handle most of the necessary computations. Microprocessor based controllers are more economical and flexible, but often face difficulties in dealing with control systems that require high processing and input/output handling speeds. Rapid advances in digital technologies have given designers the option of implementing a controller on a variety of Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), etc. One of the hardware solutions is the ASIC, which is used in situations where high-speed operation is required, and is faster than general-purpose microprocessors. The disadvantage of ASIC is that no change can be made once the chip is created. Another hardware solution is the use of an FPGA, which is suitable for fast implementation and quick hardware verification. FPGA based systems are flexible and can be reprogrammed unlimited number of times.