FPGA-Based Fuzzy Logic-Design and Applications – a Review
A large numbers of fuzzy control applications with the physical systems require a real-time operation to interface high speed constraints; higher density programmable logic devices such as field programmable gate array (FPGA) can be used to integrate large amounts of logic in a single IC. This paper reviews the state of the art of FPGA with the focus on FPGA-based fuzzy logic controller. The paper starts with an overview of FPGA in order to get an idea about FPGA architecture, and followed by an explanation on the hardware implementation with both type analogue and digital implementation, a comparison between fuzzy and conventional controller also provided in this paper. A survey on fuzzy logic controller structure is highlighted in this article with the focus on FPGA-based design of fuzzy logic controller with different applications. Finally, we provided the simulation and experimental results form the literature and concluded the main differences between software-based systems with respect to FPGA-based systems, and the main features for FPGA technology and its real-time applications.
Most of the fuzzy logic applications with the physical systems require a real-time operation to interface high speed constraints. The simple and usual way to implement these systems is to realize it as a software program on general purpose computers, these ways can not be considered as a suitable design solution. Higher density programmable logic device such as FPGA can be used to integrate large amounts of logic in a single IC. FPGA becomes one of the most successful of technologies for developing the systems which require a real time operation. For these systems , , , , FPGAs are more sufficient than the simple way because they can cover a much wider range of operating conditions. Semi-custom and full-custom application specific integrated circuit (ASIC) devices are also used for this purpose but FPGA provide additional flexibility: they can be used with tighter time-to-market schedules. FPGA places fixed logic cells on the wafer, and the FPGA designer constructs more Manuscript received June 19, 2009.This work was supported in part by Department of Electrical & Electronic Engineering, Faculty of Engineering, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. Paper titles is “FPGA-Based Fuzzy Logic: Design and Applications – a Review” Corresponding author, Zeyad Assi Obaid , is with the Department of Electrical & Electronic Engineering, Faculty of Engineering, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia.( Phone:0060173539328, Fax: +6086567099). Nasri Sulaiman, M. H. Marhaban and M. N. Hamidon, with the Department of Electrical & Electronic Engineering, Faculty of Engineering, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. Complex functions from these cells .Thetermfield Programmable highlights the customizing of the IC by the user, rather than by the foundry manufacturing the FPGA. Several researchers discussed the design of hardware systems. Numbers of these works were specialized in control application, and were aim to get better control responses, , . FPGA are two dimensional arrays of logic blocks and flip-flops with an electrically programmable interconnection between logic blocks. The interconnections consist of electrically programmable switches which is why FPGA differs from Custom ICs, as Custom IC is programmed using integrated circuit fabrication technology to form metal interconnections between logic blocks. In an FPGA logic blocks are implemented using multiple level low fan in gates, which gives it a more compact design compared to an implementation with two-level AND-OR logic. FPGA provides its user a way to configure: The intersection between the logic blocks and the function of each logic block. Logic block of an FPGA can be configured in such a way that it can provide functionality as simple as that of transistor or as complex as that of a microprocessor. It can used to implement different combinations of combinational and sequential logic functions