Antoni Świć

Application of Fuzzy Logic in Assigning Workers to Production Tasks

The paper demonstrates the concept of selecting workers for production tasks with the use of fuzzy logic. Mamdani-type fuzzy inference method was used to design a controller whose task was to aid the decision-making process. Fuzzy interference system converted a number of qualitative features into quantitative variables, which enabled calculating deviations and their comparison. Moreover, a simulation model of a discrete manufacturing system with an implemented fuzzy controller was developed. conducted simulation provided detailed data regarding the investigated selection process.

A Knowledge-Based Approach to Product Concept Screening

This paper is concerned with developing a knowledge-based approach for selecting portfolio of product concepts for development. The critical success factors for new product development are identified on the basis of information acquired from an enterprise system, including the fields of sales and marketing, project management, and production. The model of new product screening consists of enterprise functional domains and business information systems. The model has been described in terms of a constraint satisfaction problem (CSP) that contains a set of decision variables, their domains, and the constraints. Knowledge base is specified according to CSP framework and it reflects the company’s resources and relationships identified. The illustrative example presents the use of fuzzy neural network to estimating the success of new products and constraint programming to product concept screening in the context of the different search strategies.

Application of Fuzzy Logic Controller for Machine Load Balancing in Discrete Manufacturing System

The paper presents a concept of control of discrete manufacturing system with the use of fuzzy logic. A controller based on the concept of Mamdani was developed. The primary function realized by the controller was the balancing of machine tool loads taking into account the criteria of minimisation of machining times and costs. Two models of analogous manufacturing systems were developed, differing in the manner of assignment of production tasks to machine tools. Simulation experiments were conducted on both models and the results obtained were compared. In effect of the comparison of the results of both experiments it was demonstrated that better results were obtained in the system utilising the fuzzy inference system.

Mathematical Model of the Hole Drilling Process and Typical Automated Process of Designing Hole Drilling Operations

The paper is devoted to the mathematical modelling and optimal control of hole drilling. Drilling feed is considered as control action while the cutting force is controlled variable. Transfer functions of the regulators were obtained, with the cutting force variance being used as quality criterion for the automatic control system. In the article has been presented also, questions connected with the structure of typical automated process projecting of the hole drilling operation. The block pattern of the typical process automated projecting was introduced. The processed algorithms of setting of the parameters of regulators according to a priori technological information and program protection were also introduced, to automate letting the process of the study of the automatic control system for the operation of the hole drilling.

Modelling And Systemic Analysis Of Models Of Dynamic Systems Of Shaft Machining

The specifics of modelling the dynamic system of turning as well as straight and plunge grinding of low rigidity shafts is presented in the paper. Methodology of developing models while machining shafts in elastic-deformable condition is shown. The specifics of processing of low rigidity elements is taken into account by introducing equations of constraint reflecting additional elastic strain in equation describing the control force effect. Systemic analysis of the developed models is performed and main hierarchical structure levels are given.

Accuracy Control in the Machining of Low Rigidity Shafts

The study determines the most suitable pattern of alignment and fixing of low-rigidity shafts; it also presents factors that determine such choice. The part is fixed both by force closing and kinematic closing. A new method for machining low rigidity shafts is developed to control the elastic-deformable state of these shafts in a technological system and to produce parts with the required accuracy during turning. To implement this new developed method for low rigidity shafts, an apparatus is designed. The apparatus allows to increase the rigidity of shafts during machining by the application of axial tensile force to the workpiece. Rational prime costs of preparing technological alignment centers at the stage of production preparation are determined; knowing these costs, it is possible to select a suitable machining technology for low rigidity shafts, to produce a technology-oriented design, and to reduce the costs of machining these shafts.

Method of control of machining accuracy of low-rigidity elastic-deformable shafts

The paper presents an analysis of the possibility of increasing the accuracy and stability of machining of low-rigidity shafts while ensuring high efficiency and economy of their machining. An effective way of improving the accuracy of machining of shafts is increasing their rigidity as a result of oriented change of the elastic-deformable state through the application of a tensile force which, combined with the machining force, forms longitudinal-lateral strains. The paper also presents mathematical models describing the changes of the elastic-deformable state resulting from the application of the tensile force. It presents the results of experimental studies on the deformation of elastic low-rigidity shafts, performed on a special test stand developed on the basis of a lathe. An estimation was made of the effectiveness of the method of control of the elastic-deformable state with the use, as the regulating effects, the tensile force and eccentricity. It was demonstrated that controlling the two parameters: tensile force and eccentricity, one can improve the accuracy of machining, and thus achieve a theoretically assumed level of accuracy.

Mathematical Models for Manufacturing Systems Capacity Planning and Expansion – An Overview

When planning a new manufacturing system, the optimal investment in the system capacity is a major decision to make. The problem of capacity planning is not an easy because of the unpredictable character of the market demand and multi-criteria optimization character of the task. Therefore there is still no one complex methodology of the capacity planning and management. In this paper some mathematical models for capacity planning which can be used at the stage of manufacturing system design or expansion are presented.

Human Resource Selection for Manufacturing System Using Petri Nets

Proper selection of personnel constitutes a frequent challenge for the management of many enterprises. In this paper the above problem has been defined using three objective functions which required simultaneous optimisation. To solve this problem, computer modelling based on Petri nets was proposed. The model was subjected to iterative computer simulation, during which various variants of workstation assignment were tested. This resulted in the emergence of a variant which best fulfilled the assumed optimisation criteria.

Simulation Based Analysis of Reconfigurable Manufacturing System Configurations

Nowadays, manufacturers seek customers’ satisfaction by increasing products variety and customization while striving for agility and productivity. To remain competitive, companies must design manufacturing systems that not only produce high-quality products at low cost, but also respond to market changes in an economical way. One of the critical problems of manufacturing systems design is to decide which of possible configurations is the most advantageous for a company. This article presents the possibility of using simulation methods in the process of analysis of possible configurations of Reconfigurable Manufacturing System according to maximization the productivity of the system.