Modeling and Optimization of Olive Stone Drying Process

Abstract:- Olive oil can be extracted from dried olive stones. Drying of olive stones is a procedure difficult to model. The equations describe heat transfer inside the drying cylinder are highly non linear and therefore the mathematical models used to simulate the drying process are complicated. Here we suggest fuzzy and neurofuzzy techniques to control the drying procedure. A fuzzy controller is designed based on available expertise, while a neuro-fuzzy controller is built using the Adaptive Neuro Fuzzy Inference System (ANFIS) based on experimental data. Both controllers tested in various operation conditions and extensive comparative results are presented. Key-Words:- Rotary dryer, Olive stones, Fuzzy logic control, Process control

A Fuzzy Logic Approach to Flow Control of Reentrant Manufacturing Networks

Abstract:- We consider reentrant manufacturing networks with finite buffers and unreliable machines that can operate at various processing rates. The processing rate of each machine is the outcome of a fuzzy logic based control system. The control objective is to meet the demand and the same time to keep work-in-process inventories as low as possible. The workflow at each production stage is balanced and the extreme events of idle periods due to machine starving or blocking, are significantly reduced. After a series of simulation runs, it has been observed that the proposed approach is suitable for reentrant flows with no additional modifications of the basic control modules in which a non-reentrant network may be decomposed. Key-Words:- Reentrant networks, work-in-process, flow control, fuzzy logic.

OPTIMIZED FUZZY SCHEDULING OF MANUFACTURING SYSTEMS

An Evolutionary Algorithm (EA) strategy for the optimization of generic Work-In-Process (WIP) scheduling fuzzy controllers is presented. The EA is used to tune a set of fuzzy control modules which are used for distributed and supervisory WIP scheduling. The distributed controllers objective is to control the rate in each production stage so that satisfies the demand for final products while reducing WIP within the system. The EA identifies the parameters for which the fuzzy controller performs optimal with respect to WIP and backlog minimization. The proposed strategy is compared to known heuristically tuned fuzzy control approaches. Simulation results show that the EA strategy improves system’s performance.

Fuzzy logic based autonomous skid steering vehicle navigation

Abstract – A two-layer fuzzy logic controller has been designed for 2-D autonomous navigation of a skid steering vehicle in an obstacle filled environment. The first layer of the fuzzy controller provides a model for multiple sonar sensor input fusion and it is composed of four individual controllers, each calculating a collision possibility in front, back, left and right directions of movement. The second layer consists of the main controller that performs real-time collision avoidance while calculating the updated course to be followed by the vehicle. The two layer controller applicability and implementation is demonstrated through experimental results and case studies performed on a real mobile robot

A Low Cost Modular Robot Vehicle Design for Research and Education

Abstract — In this paper the development of a low cost robotic vehicle for research and education is presented. The vehicle was designed considering minimum cost and maximum capabilities. As a base for testing devices and different type of sensors, a commercially available vehicle was used and modified. Two different version of the prototype vehicle were developed accompanied by the proper software that allows the end user to operate the vehicles as an educational or research platform. The functionality of the vehicles was verified after extensive experimentation. I

P.: Design and testing of a fuzzy logic controller for an autonomous underwater vehicle

Abstract-- This paper deals with the application of a fuzzy logic based algorithm to the control of Autonomous Underwater Vehicles (AUVs). Fuzzy controllers are of simper design since they don’t require explicit modeling of the vehicle dynamics. Furthermore, they may be tuned for optimal performance, and replace existing controllers designed using conventional or nonlinear control theory techniques. The discussed fuzzy logic controller has being designed for the Naval Postgraduate School (NPS) Phoenix AUV. The aim of the controller is the vehicle autonomous navigation in an ocean environment. The vehicle’s speed, heading, pitch and depth are simultaneously controlled for various simulated test cases considering the presence of undersea currents. Testing is based on the already derived hydrodynamic model and data of the NPS Phoenix AUV, with minor modifications in the added mass coefficients. The overall navigation performance of the proposed control scheme was encouraging and it may be used to estimate vital AUV issues, such as, the level of maneuverability and energy consumption of the vehicle. I

Fuzzy Logic Based Software Control Architecture for a Skid Steering Vehicle

A sensor-based software control architecture is proposed for autonomous navigation of the Real World Interface (currently iRobot) ATRV-mini skid steering vehicle. The architecture is superimposed over the existing ATRV-mini mobility software that navigates the robot. A two-layer fuzzy logic controller has been implemented: Inputs are the collision possibilities in front, back, left and right directions of movement and the heading angle error. Outputs are the rotational and translational velocities. The paper is the outgrowth of the authors previous work presented in [11]. I

Autonomous Navigation of Unmanned Vehicles: A Fuzzy Logic Perspective,” in Cutting Edge Robotics

Acknowledgement: L. Doitsidis is supported by “HERAKLITOS ” fellowships for research from the Technical University of Crete, EPEAEK II – 88727. Kimo

Studying Multi-assembly Machine Production Systems with Hybrid Timed Petri Nets

Abstract — This paper generalizes the use of the Hybrid Timed Petri Net method introduced in [1] to study multioperational production systems in which incoming or in-process parts are used for different products production. In particular, the proposed multi-assembly machine module is generalized to describe a machine performing multiple assemblies consisting of different initial parts numbers. The applicability of the method is illustrated through an analytical example. I