Z. Binder

A TABU SEARCH HEURISTIC FOR THE SINGLE VEHICLE PICKUP AND DELIVERY PROBLEM WITH TIME WINDOWS

The single vehicle pickup and delivery problem with time windows is a generalization of the traveling salesman problem. In such a problem, a number of transportation requests have to be satisfied by one vehicle, each request having constraints to respect: a pickup at its origin and a delivery at its destination, and a time window at each location. The capacity of the vehicle has to be respected. The aim is to minimize the total distance traveled by the vehicle. A number of exact and approximate solution methods exists in the literature, but to the authors knowledge none of them make use of metaheuristics, still promising with other vehicle routing problems. In this paper we present tabu search and probabilistic tabu search. Results obtained on classical traveling salesman problems and a class of randomly generated instances indicate that our approach often produces optimal solutions in a relatively short execution time.

Integrated approach for disassembly processes generation and recycling evaluation of an end-of-life product

An integrated approach for noble recycling is presented that puts forward the functional value of products and components. In a first step, the approach determines all feasible automatic disassembly sequences and in a second step all applicable recycling activities. This allows one to determine the most appropriate recycling process for an end-of-life product considering concurrent recycling techniques. The feasible automatic disassembly sequences are established by simulation in a virtual environment. The required generic disassembly product model, as well as the generic disassembly activity model, is presented by means of static and dynamic object-oriented diagrams. The recycling evaluation establishes an efficient solution responding to economic and ecological decision criteria. It is calculated applying a Goal-Programming approach transforming the multi-objective linear problem into a monocriteria linear program. The techno-economic decision model applied is Linear Activity Analysis. It allows one to integrate the generated disassembly processes based on single disassembly activities as well as other recycling techniques.

Hierarchical fuzzy controllers

Abstract The paper presents Fuzzy Logic Controllers (FLC) with hierarchically structured rule base as nonlinear blocks used in a control system for direct control or supervision of standard controllers. Unified approach based on Fuzzy Logic Neural Networks (FLNN) is used to reveal the essential functions of a FLC. The FLNN is then extended to the case where decomposition of a rule base leads to simplification of controller design and tuning. Two structures of hierarchically organized groups of rules are discussed. Singlestage decision making structure with groups of rules organized hierarchically according to their specificity and a multi-stage decision making architecture with chained rules. Data induced error backpropagation technique for fine tuning of parameters of the second structure is derived.

Socio-technical design and evaluation of production systems

The socio-technical breakdown of production systems into three levels is proposed, The structural level deals with groups of machines and the related human operators; this level is further developed. The qualitative level analyses man-machine assignment with structure constraints. Finally, the quantitative level suggests a plant simulation for sharing a task between human operator and machine.

Fuzzy Supervisory Control

Abstract Multimodel control methodology can be a good alternative in control of complex nonlinear systems. In this case, the selection of good controllers and the bump less transfer between different controllers are important. This paper presents a supervisory control based on the Takagi-Sugeno fuzzy model used as a two level controller. A learning phase is added to change the T-S fuzzy model parameters, shapes of membership functions of reference fuzzy sets, to achieve a better performance of the control system.

About a Multimodel Control Methodology, Algorithms, Multiprocessors Implementation and Application

Abstract A multivariable control methodology using several models representing a physical system in different operating points is presented. The algorithmic structure can be expressed by a division into two parts; firstly, the location of the different models using a linear filter theory and, secondly, the tracking control. This algorithm is characterized by a parallel structure, and its implementation is carried out in parallel multimicroprocessor systems developed in our laboratory. Using this system, an application exempIe is presented.

Multi-Agent Interactions under Organizational Hierarchy

Abstract This paper studies multi-agent interactions under organizational hierarchy. It aims at exploring compromise structuring of systems of both hierarchy manifested in organization and decentralization prescribed in multi-agent systems.

Disassembly system modelling, supervision and control

Abstract A generic recycling platform is presented, implementing the concept of ≪ noble recycling ≫ for manufactured products and taking into consideration collect, diagnostic, repair and disassembly as well as its integration in a platform-network. Its disassembly workshop is based on different cells but mainly on the flexible disassembly cell. Its architecture is divided in the Information, Decision and Operation Subsystems with each level assuring certain functions. The functions concerning the disassembly cells supervisory control are modelled with Interpreted Coloured Petri Nets (ICPN). The Colours are defined according to the functions requirements and carry the necessary information for their realisation.

Multivariable Control of Distillation Columns

Abstract The paper expose briefly the aims of process control and propose its realization through a tracking approach. Therefore a linear quadratic input-output tracking algorithm is presented and completed with the constraints satisfaction. To overcome the modelling errors and the linear model limitations, two approachs are proposed. First, the output feed back integral correction. Second, multimodel te chnique with two parts : location and control synthesis. The linear optimal filtering is used for the process models location. Based on the quality of models a global control synthesis is realized from weighted combination of the individual models control values. The experimental results on a binary distillation column are discussed. The output feedback corrector is applied for the control around one operating point and the multimodel control in the case of transition from one operating point to another.

About a Hierarchical Control for Complex Dynamic Systems

Abstract The stability and the way of using a hierarchical representation of complex systems is presented. The treatment and the respect of mutual constraints existing between subsystems is considered. The whole methodology is based on tracking considerations. It could be applied to systems coupled serially or according to loops. Finally experimental results performed on a pilot plant are presented.