Special-purpose architectures for fuzzy logic controllers
TL;DR: The design of two dedicated architectures for real-time fuzzy inference are proposed and discussed, the first designed for versatility, being able to handle fuzzy logic controller implementations with arbitrary size parameters, and the second based on a scheme for the reduction of complexity of the fuzzy inference algorithm.
About: This article is published in Microprocessing and Microprogramming.The article was published on 1994-05-01. It has received 10 citations till now. The article focuses on the topics: Defuzzification & Fuzzy electronics.
Citations
More filters
TL;DR: The consequences of the finite wordlength on the performance of a digital fuzzy logic controller (FLC) based on Mamdani's inference algorithm are investigated and the availability of computer-aided design tools that permit the specification of the wordlength is essential to validate the design.
Abstract: The consequences of the finite wordlength on the performance of a digital fuzzy logic controller (FLC) based on Mamdani's inference algorithm are investigated. Digital implementations of FLCs involve three main types of errors due to the finiteness of the wordlength: analog-to-digital errors, membership function errors, and arithmetic errors. First, a statistical evaluation of the consequences of these errors is performed. The effects of the digital resolution on the controller response are discussed. Then, the dynamic behavior of a closed-loop fuzzy system composed of a digitized FLC and a second-order plant is evaluated; a qualitative evaluation of time-domain parameters as a function of the universe discretization is carried out. The results show that, as in the case of conventional control strategies, bias effects and limit cycles are generated as a consequence of the digitization. Although these distortions diminish when the discretization is sufficiently refined, they are very difficult to predict because of the nonlinear nature of both quantization and fuzzy operation. In this sense, the availability of computer-aided design (CAD) tools that permit the specification of the wordlength is essential to validate the design.
16 citations
Cites result from "Special-purpose architectures for f..."
...Another interesting aspect worthy of note concerning Fig. 4 is that the product MAE is constant for within an error close to 5%. The same behavior can be deduced from the results reported by Samoladas and Petrou in a similar experiment [ 14 ]....
[...]
16 May 2002
TL;DR: The characteristics of this design make it adequate for working with a great number of input and output variables and with a high number of rules, and the speed of calculation and the circuit dimensions are optimal.
Abstract: This article describes a pipeline sequential fuzzy controller endowed with great flexibility and high performance. Its design allows for the possibility to implement it on programmable devices at low cost. To optimise the design and performance of the circuit, a number of simplifications over traditional fuzzy algorithms are pointed out. For the manipulation of simplification procedures, some software tools of knowledge acquisition and compilation have been developed. The hardware design is presented at a level of block diagram showing the different components and the solutions adopted in each case. The characteristics of this design make it adequate for working with a great number of input and output variables and with a high number of rules. Under these conditions, the speed of calculation and the circuit dimensions are optimal. It can be used in any field of application where a fuzzy control of high complexity is to be established.
15 citations
01 Jul 1997
TL;DR: This paper presents a pipeline architecture realisation, with intermediate qualities between a microprocessor and a SIMD design, and presents several simplifications to fuzzy logic that make possible the pipeline execution of minimum, maximum, and mean of maximum method.
Abstract: The necessity for fast fuzzy controllers has caused a tendency to use SIMD hardware architecture, with the handicap of flexibility loss. In this paper we present a pipeline architecture realisation, with intermediate qualities between a microprocessor and a SIMD design. Also, we present several simplifications to fuzzy logic that make possible the pipeline execution of minimum, maximum, and mean of maximum method.
11 citations
TL;DR: In this paper, a microcontroller centered fuzzy logic measurement and control embedded system is designed and developed on the existing hybrid biogas and photovoltaic installations, which is able to accurately predict digester stability, quantitatively quantify biogaas output, and carry out Biogas fault detection and control.
Abstract: This study develops a new integrated measurement and control system for intermixed biogas and photovoltaic systems to achieve safe and optimal energy usage. Literature and field studies show that existing control methods on small- to medium-scale systems fall short of comprehensive system optimization and fault diagnosis, hence the need to revisit these control methods. The control strategy developed in this study is intelligent as it is wholly based on fuzzy logic algorithms. Fuzzy logic controllers due to their superior nonlinear problem solving capabilities to classical controllers considerably simplify controller design. The mathematical models that define classical controllers are difficult or impossible to realize in biogas and photovoltaic generation process. A microcontroller centered fuzzy logic measurement and control embedded system is designed and developed on the existing hybrid biogas and photovoltaic installations. The designed system is able to accurately predict digester stability, quantify biogas output, and carry out biogas fault detection and control. Optimized battery charging and photovoltaic fault detection and control are also successfully implemented. The system is able to optimize the operation and performance of biogas and photovoltaic energy generation.
11 citations
TL;DR: The paper presents the ASIC design of a digital fuzzy logic circuit for medical diagnostic applications that uses triangular trapezoidal membership functions for fuzzification patients’ data and has less delay and less power dissipation than the comparable embedded systems reported earlier.
Abstract: The paper presents the ASIC design of a digital fuzzy logic circuit for medical diagnostic applications. The system on chip under consideration uses fuzzifier, memory and defuzzifier for fuzzifying the patient data, storing the membership function values and defuzzifying the membership function values to get the output decision. The proposed circuit uses triangular trapezoidal membership functions for fuzzification patients' data. For minimizing the transistor count, the proposed circuit uses 3T XOR gates and 8T adders for its design. The entire work has been carried out using TSMC 0.35 µm CMOS process. Post layout TSPICE simulation of the whole circuit indicates a delay of 31.27 ns and the average power dissipation of the system on chip is 123.49 mW which indicates a less delay and less power dissipation than the comparable embedded systems reported earlier.
7 citations
Cites background from "Special-purpose architectures for f..."
...Samoladas and Petrou propose two parallel architectures in SIMD mode [22]....
[...]
References
More filters
01 Jan 1973
TL;DR: By relying on the use of linguistic variables and fuzzy algorithms, the approach provides an approximate and yet effective means of describing the behavior of systems which are too complex or too ill-defined to admit of precise mathematical analysis.
Abstract: The approach described in this paper represents a substantive departure from the conventional quantitative techniques of system analysis. It has three main distinguishing features: 1) use of so-called ``linguistic'' variables in place of or in addition to numerical variables; 2) characterization of simple relations between variables by fuzzy conditional statements; and 3) characterization of complex relations by fuzzy algorithms. A linguistic variable is defined as a variable whose values are sentences in a natural or artificial language. Thus, if tall, not tall, very tall, very very tall, etc. are values of height, then height is a linguistic variable. Fuzzy conditional statements are expressions of the form IF A THEN B, where A and B have fuzzy meaning, e.g., IF x is small THEN y is large, where small and large are viewed as labels of fuzzy sets. A fuzzy algorithm is an ordered sequence of instructions which may contain fuzzy assignment and conditional statements, e.g., x = very small, IF x is small THEN Y is large. The execution of such instructions is governed by the compositional rule of inference and the rule of the preponderant alternative. By relying on the use of linguistic variables and fuzzy algorithms, the approach provides an approximate and yet effective means of describing the behavior of systems which are too complex or too ill-defined to admit of precise mathematical analysis.
8,547 citations
01 Apr 1990
TL;DR: The basic aspects of the FLC (fuzzy logic controller) decision-making logic are examined and several issues, including the definitions of a fuzzy implication, compositional operators, the interpretations of the sentence connectives 'and' and 'also', and fuzzy inference mechanisms, are investigated.
Abstract: For pt.I see ibid., vol.20, no.2, p.404-18, 1990. The basic aspects of the FLC (fuzzy logic controller) decision-making logic are examined. Several issues, including the definitions of a fuzzy implication, compositional operators, the interpretations of the sentence connectives 'and' and 'also', and fuzzy inference mechanisms, are investigated. Defuzzification strategies, are discussed. Some of the representative applications of the FLC, from laboratory level to industrial process control, are briefly reported. Some unsolved problems are described, and further challenges in this field are discussed. >
5,502 citations
Journal Article•
TL;DR: The fuzzy logic controller (FLC) based on fuzzy logic provides a means of converting a linguistic control strategy based on expert knowledge into an automatic control strategy.
Abstract: During the past several years, fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory. Fuzzy control is based on fuzzy logic. The fuzzy logic controller (FLC) based on fuzzy logic provides a means of converting a linguistic control strategy based on expert knowledge into an automatic control strategy. A survey of the FLC is presented; a general methodology for constructing an FLC and assessing its performance is described; and problems that need further research are pointed out
4,830 citations
TL;DR: A general overview of VLSI array processors and a unified treatment from algorithm, architecture, and application perspectives is provided in this article, where a broad range of application domains including digital filtering, spectrum estimation, adaptive array processing, image/vision processing, and seismic and tomographic signal processing.
Abstract: High speed signal processing depends critically on parallel processor technology. In most applications, general-purpose parallel computers cannot offer satisfactory real-time processing speed due to severe system overhead. Therefore, for real-time digital signal processing (DSP) systems, special-purpose array processors have become the only appealing alternative. In designing or using such array Processors, most signal processing algorithms share the critical attributes of regularity, recursiveness, and local communication. These properties are effectively exploited in innovative systolic and wavefront array processors. These arrays maximize the strength of very large scale integration (VLSI) in terms of intensive and pipelined computing, and yet circumvent its main limitation on communication. The application domain of such array processors covers a very broad range, including digital filtering, spectrum estimation, adaptive array processing, image/vision processing, and seismic and tomographic signal processing, This article provides a general overview of VLSI array processors and a unified treatment from algorithm, architecture, and application perspectives.
1,633 citations
01 Jan 1988
TL;DR: A general overview of VLSI array processors is provided and a unified treatment from algorithm, architecture, and application perspectives is provided.
Abstract: High speed signal processing depends critically on parallel processor technology. In most applications, general-purpose parallel computers cannot offer satisfactory real-time processing speed due to severe system overhead. Therefore, for real-time digital signal processing (DSP) systems, special-purpose array processors have become the only appealing alternative. In designing or using such array Processors, most signal processing algorithms share the critical attributes of regularity, recursiveness, and local communication. These properties are effectively exploited in innovative systolic and wavefront array processors. These arrays maximize the strength of very large scale integration (VLSI) in terms of intensive and pipelined computing, and yet circumvent its main limitation on communication. The application domain of such array processors covers a very broad range, including digital filtering, spectrum estimation, adaptive array processing, image/vision processing, and seismic and tomographic signal processing, This article provides a general overview of VLSI array processors and a unified treatment from algorithm, architecture, and application perspectives.
1,249 citations