Search results for "fuzzy"
showing 10 items of 747 documents
Analysis of operator human errors in hydrogen refuelling stations: Comparison between human rate assessment techniques
2013
Abstract The use of hydrogen as an energy carrier for road transport appears to be an optimal solution for the reduction of greenhouse gas emissions. Nevertheless, the development of this technology depends on the growth and diffusion of production, storage and refuelling infrastructures together with accurate risk analyses to appropriately design the safety and management systems used in these plants. Moreover, to improve safety standards, it is also important to focus attention on the estimation of hazards related to human factors, as this is one of the major causes leading to accidental events, especially in complex industrial technology. The paper reports a case study relevant to operat…
Decision-making Tool for Moving from 3-axes to 5-axes CNC Machine-tool
2016
Abstract Nowadays most of the parts within machine-building industry are machines on CNC machine-tools. According to their mechanical and kinematic structure, CNC machine-tools can be divided into 3-axes and 5-axes ones. Each type has its advantages and drawbacks and choosing between them could be a very difficult process. This paper presents a decision support tool for aiding the process of selecting between using and/or buying either a 3-axes CNC milling machine or a 5-axes milling machine, based upon fuzzy logic. The tool was built using the Fuzzy Logic Toolbox and the fuzzy graphical user interface (GUI) within Matlab software package.
Kinematic Solutions of a 7 DOF Robotic Arm Using Redundancy Circle and Fuzzy Models
2014
In this paper we have presented a method to solve the inverse kinematics problem of a redundant robotic arm with seven degrees of freedom and a human like workspace based on mathematical equations, Fuzzy Logic implementation and Simulink models. For better visualization of the kinematics simulation a CAD model that mimics the real robotic arm was created into SolidWorks® and then the CAD parts were converted into SimMechanics model.
Expert control of DO in the aerobic reactor of an activated sludge process
2001
Abstract An expert control structure is proposed for the control of dissolved oxygen (DO) in a Nitrification Denitrification Biological Excess Phosphorus Removal (NDBEPR) plant to account for the several processes that are influenced by the DO concentration in the aerator. In the scheme a supervisory fuzzy controller determines the set point of an inner DO control loop where an Adaptive Robust Generic Model Control (ARGMC) controller is used. The fuzzy supervisory control has a hierarchical structure. Off-line measurements of biological parameters of influent and effluent streams can be used to periodically update the set points of the fuzzy controllers. The complete control scheme has been…
A Laboratory Project for Advanced Control Methods: Control of a Neutralization Process
2003
Abstract A neutralization process is used in a laboratory project for experimenting advanced control techniques. Students may choose among several techniques to experience the behaviour of advanced controller action: adaptive control, GMG control, fuzzy control, self tuning fuzzy control, neural control, neuro-fuzzy control. The experience in advanced self tuning controller based on fuzzy logic is proposed for the control of a neutralization process. The test of a self tuning controller based on fuzzy logic is a very important case because the resulting structure of the controller is easy to implement and modify: the final results are compared with those deriving from the application of a c…
Adaptive control of hybrid vehicle depending on driving cycle analysis
2013
The most adapted energy management in hybrid electric vehicles depends on the current driving situation. This paper describes a novel control strategy based on driving cycle recognition. A Driving Cycle Recognition Algorithm (DCRA) is firstly presented. It allows recognition between three driving modes: urban, suburban and highway. A real-time control strategy is then defined based on fuzzy logic using DCRA. Results are presented and compared to fuzzy logic controllers parametrized for urban or highway cycles.
The control of indoor thermal comfort conditions: introducing a fuzzy adaptive controller
2004
The control and the monitoring of indoor thermal conditions represents a pre-eminent task with the aim of ensuring suitable working and living spaces to people. Especially in industrialised countries, in fact, several rules and standards have been recently released in order of providing technicians with suitable design tools and effective indexes and parameters for the checking of the indoor microclimate. Among them, predicted mean vote (PMV) index is often adopted for assessing the thermal comfort conditions of thermal moderate environments. Unfortunately, the PMV index is characterised by non-linear features, that could determine some difficulties when monitoring and controlling HVAC equi…
Broken rotor bars detection via Park's vector approach based on ANFIS
2014
Many attempts have been made on fault diagnosis of induction motors based on frequency and time domain analysis of stator current. In this paper, first the Park's vector transformation and frequency analysis for fault detection of induction motors are introduced. Then a smart approach using Adaptive Neuro Fuzzy Inference System (ANFIS) is proposed. This approach uses the time domain features derived from the Park's vector transformation of stator current. By the proposed method, a partial break including 5 mm crack on a bar, one broken bar and two broken bars using experimental data are investigated. It will be shown that features derived from Park's vector compared to features obtained fro…
Control Design for Discrete-Time Fuzzy Systems with Disturbance Inputs via Delta Operator Approach
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher: http://dx.doi.org/10.1155/2013/724918 Open Access This paper is concerned with the problem of passive control design for discrete-time Takagi-Sugeno (T-S) fuzzy systems with time delay and disturbance input via delta operator approach. The discrete-time passive performance index is established in this paper for the control design problem. By constructing a new type ofLyapunov-Krasovskii function (LKF) in delta domain, and utilizing some fuzzy weighing matrices, a new passive performance condition is proposed for the system under consideration. Based on the condition, a st…
H∞ fuzzy control of DC-DC converters with input constraint
2012
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2012/973082 Open access This paper proposes a method for designing H∞ fuzzy control of DC-DC converters under actuator saturation. Because linear control design methods do not take into account the nonlinearity of the system, a T-S fuzzy model and a controller design approach is used. The designed control not only handles the external disturbance but also the saturation of duty cycle. The input constraint is first transformed into a symmetric saturation which is represented by a polytopic model. Stabilization conditions for the H∞ state feedba…