Jozef Svetlík

Implementation of Computer System for Support of Technological Preparation of Production for Technologies of Surface Processing

This paper describes attributes of newly designed variant approach of computer support system of technological preparation of production. Knowledge system for automation of production of technological documentation was developed for technology of surface processing of metal. The paper describes the design of coding system for sorting mechanical parts into groups with similar mechanical parts, either by their shape, dimensions or used technology. Subsequently, it points out to attribute of the system – uploading and modification of sample technological documentation.

The calculations of Jordan curves trajectory of the robot movement

Calculation of the moving mechanism on a trajectory described by a planar differentiable curve is challenging. The difficulty arises in compliance with high-precision movement. The new method of calculation based on the intrinsic properties of the plane is proposed. The method is based on mathematical linguistics and relational algebra. First, these disciplines are applied to analyze the intrinsic properties of the Euclidean plane. Calculation of classic and new methods for moving point for the flat rod is shown for comparison. Analytical formulas for Jordan curves can be obtained in some cases. The experiments in the areas of geometric modeling and control of a robot are listed briefly. The analytic solution was obtained by nontraditional methods not only for centrally symmetric conic sections but also for Jordan curves.

Degradation of renovation layers deposited on continuous steel casting rollers by submerged arc welding

The factors that affect the life of continuous steel casting rollers were investigated. Rollers that were removed from a manufacturing line because they had failed were renovated by submerged arc welding and subjected to working conditions until they again failed. The welding parameters (welding current, welding voltage, welding speed, current polarity, preheating temperature, interpass, postheating, and cooling conditions of clad) and chemical reactions and compositions had important effects on roller lifetime. Chromium has a dominant influence on the abrasion resistance of hard martensitic structures of the roller. Cr produces several types of precipitates (M3C, M23C6, M7C3, and M3C2). Alloying elements Mo and V in welding wire form fine carbides Mo2C and VC in weld layers. In low-carbon welding wires, precipitation hardening by N2 is used, by formation of chromium nitrides CrN and Cr2N. This article analyzes the process of failure of the functional surfaces of the repaired roller, in order to identify the origin and propagation of the cracks and share of corrosive environment on the tribo-degradation processes.

Searching for collisions between mobile robot and environment

This article is focused on the search for potential collision of a moving object (as a mobile robot is) with the environment. Application of the proposed and presented method requires existence of the three-dimensional model of the environmental space. In this case, the models are generated automatically with the help of mobile measurement platform developed by authors and are available to other applications. Models of moving objects are loaded by the proposed application from external files. The method is based on data fusion, using data from a laser scanner, global positioning system, and inertial navigation system; however, it can also be used for data obtained by other ways. Its correctness was experimentally proved by several experimental tests. Output is in the form of calculated coordinates of the point in which a moving object would potentially collide with the environment if no avoiding action is taken. Such an object may represent an oversized load transferred by a truck, train, ship, the transport means itself or even a person.

Principles of Modular Architecture in the Manufacturing Technology

The article deals with the issue of modularity as a tool for flexible and efficient production systems. When having closer look at implemented terms in production structures there emerges amount of terms used, such as: flexible, modular, modular manufacturing systems, which are often viewed from a subjective point of view. Due to efforts to standardize and clarify the terms referred above this paper brings definitions of flexible production structures terminology, their relationships and new idea for the efficient division.

Virtual Machining and its Experimental Verification

Virtual Machining and its Experimental Verification Research, verification and implementation of various methods of rapid prototyping are getting more intensified in the recent time. One of possible rapid prototyping techniques is a virtual machining which allows testing the properties of designed machine tool using its mathematical model. This article presents the example of virtual machining on a virtual small centre lathe and experimental verification of obtained results.

The Effectiveness of a Three-Temperature Heat Pump System

Three-temperature heating systems consist of a heat engine and a heat pump, enabling thus maximum usage of the primary thermal source for the heating of buildings. This analysis has revealed obvious advantages and disadvantages that the combining of thermodynamic systems has in future development, also with respect to environmental and economic issues. It appears that the combination of a Stirling engine or a similar heat drive with a heat pump is especially suitable. In order to analyze the effectiveness of such a system, a comprehensive calculation procedure is used: its basis lies in accounting for all types of energy and their relationship to the original natural resource. The present paper aims to point out that the combination of Stirling engine and a heat pump is a useful solution thanks to the most favorable resultant economic impact if compared to the usage of a diesel, four-stroke gas, or, most commonly used, electric drive.

SECONDARY PROPOSAL OF COUPLING MECHANISM ROTATION UNIVERSAL MODULE

The authors focus on the adjustment of coupling mechanism Rotation Universal Module that offers unlimited rotation of movement. The module has been designed to achieve different kinematic structures by use of an identical module. A unique interface mechanism, which has undergone several modifications and amendments, has been designed for this module. The main objective is to achieve efficient and more secure initial solution of connecting two adjacent modules. The amendments of primary solution that will contribute to achieve desired outcomes and smooth functioning of the entire device are described in detail.

Production Aspects Affecting the Final Precision Machining of Advanced Materials

When creating products of modern construction materials has a great influence on their endpoints right way and the quality of working on machine tools. The article deals with positioning accuracy of machine tools which is carried out in an unloaded condition, according to international standard ISO 230-2. Overall accuracy of working machining is determined mainly static rigidity, geometrical accuracy of mechanical components, positioning accuracy and dynamic stiffness. Static stiffness is defined in new machine tools in a limited workspace. Therefore, the article deals with the definition of static stiffness in the expanded work area and also defines its impact on the positioning accuracy at individual points in workspace of the machine tool.

Control system for the haptic paddle used in mobile robotics

A haptic interface is a kinaesthetic link between a human and some real or virtual environment. In this article, we discuss whether the haptic technology (virtually touching objects and feeling forces) could be effectively implemented in the industrial applications. As an example, we will examine the virtual wall which is a fundamental component of almost all virtual objects. Typically, it is based on a simple spring and damper model with constraints that allow the user to make contact with an object. Various factors lead to an unstable behaviour in a controlled system such as the virtual wall. Main causes of disturbances are the sensor (e.g. the signal resolution) and the actuator (e.g. the dynamics of the system which are not covered by the controller design). Some of these disturbance mechanisms can be excluded by mechanical design, and others are more difficult to eliminate – following two are discussed in the article: First one is the zero-order hold effect caused by sampling and the second one is the shifted synchronization of the wall threshold crossings with the sampling times. Both have unwanted effects on the sampled data within the virtual wall system.