Vladimir Kvrgic

Mihajlo Pupin Institute | IMP

A robot dynamic model is time variable, highly non-linear and characterized by coupling effects among the robot joints. Consequently, a derivation and implementation of a robot dynamic model, which is used for purposes of control, simulation, and mechanical design, often represents a challenging task. The last couple of decades saw a great amount o...

The indirect identification of the geometric errors (GEs) in the rotary axis of a machine tool yields six equivalent GEs (EGEs) that are position-dependent; through an analytical proof, this study demonstrates that these errors also represent four position-independent GEs of the axis. Moreover, a novel algorithm using ball bar measurements to calcu...

The robot dynamic model is essential for the precision and reliability of robot design, motion control, and simulation. A robot inertia matrix, whose elements are coefficients of joint accelerations within the robot equations of motion, plays an important role in the robot's control design. During robot motion, elements of the inertia matrix are fu...

Safe and efficient training using flight simulation training devices (FSTD) is one of the fundamental components of training in the commercial, military, and general aviation. When compared with the live training, the most significant benefits of ground trainers include improved safety and the reduced cost of a pilot training process. Flight simula...

A development of a robot control system is a highly complex task due to nonlinear dynamic coupling between the robot links. Advanced robot control strategies often entail difficulties in implementation, and prospective benefits of their application need to be analyzed using simulation techniques. Computed torque control (CTC) is a feedforward contr...

Conventional methods for solving robot forward dynamics are characterized by high com- putational complexity. Recursive Newton-Euler algorithm (RNEA) is the most efficient com- putational method used for deriving a manipulator’s dynamic equations of motion. In order to solve robot forward dynamics using RNEA in the most widely used Walker and Orin’...

The use of robotic models with the main functionalities of real objects together with the implementation of innovative technologies, augmented reality (AR) in this case, is the focus of the paper. Therefore, the concept of a simplified robotic model (SRM) is presented. This concept is important because it is useful for achieving the goals of engine...

Building robotic models for the purposes of achieving goals in engineering projects, and its usage as a strategy advantage of such projects, are the main topics of this paper. Also, implementation of innovative technologies, like augmented reality (AR) and internet of things (IoT), on simplified robotic models (SRM) are at the focus in the paper. T...

The framework for Cyber-Physical Manufacturing Metrology Model (CPM3), are based on integration of digital product metrology information through metrology features recognition, and generation of global/local inspection plan for CMM. As the identification and compensation for errors of the machine tools could significantly enhance their accuracy and...

Augmented reality (AR) and internet of things (IoT), technologies that have recently expanded in various fields of theory, scientific researches, and business practice, provide innovative approach for development of projects and their implementation. In this paper, one approach of the implementation is undertaken as an experimental use case, applie...

This paper presents a dynamic model-based design of a control system and an approach toward a drive selection of a centrifuge motion simulator (CMS). The objective of the presented method is to achieve the desired performance while taking into account the complexity of the control system and the overall device cost. An estimation of a dynamic inter...

The paper considers the problem of optimization of the rectangular box section of the double beam bridge crane. Reduction of the girder mass is set as the objective function. The constrained optimization applied in Matlab Optimization Toolbox was used as the methodology for determination of optimal geometrical parameters of the rectangular box sect...

Pilots of modern combat aircraft are exposed to the devastating effects of high acceleration forces and unusual orientation. The pilots’ ability to perform tasks under these extreme flight conditions must be examined. A centrifuge flight simulator (CFS) for pilot training is designed as a three-degree-of-freedom 3DoF manipulator with rotational axe...

Design of user-friendly and at the same time powerful robot programming methods is the subject of significant efforts undertaken by the international robotics community. For the purpose of facilitating robot programming, with regard to the most common present-day applications in industry, it would be useful to develop programming procedures for fre...

The paper considers the problem of optimization of the box section of the single-girder bridge crane. The focus of this paper is to explore the influence that has the position of the webs longitudinal stiffeners on optimum geometrical parameters of box section of the main girder, as well as its mass. For the positions of longitudinal stiffeners are...

Robotic machining systems play an important role in modern manufacturing. The paper proposes the application of virtual robots for off-line programming. The reconfigurable machining robot, programmed in G-code, which can be directly used by CNC machine tool programmers and operators, is presented. The subject of study are 5- and 6-DOF vertical arti...

The paper considers the problem of optimization of the box section of the main girder of the single-girder bridge crane. Reduction of the area of the box cross section is set as the objective function. The algorithm of generalized reduced gradient (GRG2 algorithm) was used as the methodology for determination of optimum geometrical parameters of th...

This paper presents the development of reconfigurable virtual environment for programming, control, simulation, and monitoring of multiple robots and its application in the process of education. During the development special attention is devoted to the fulfillment of the modularity, scalability, and openness that represent the basic requirements o...

Flexible and user-friendly virtual environment, Lola Robot Simulator, was developed to simulate and supervise robot cells. 3D graphic visualisation of robots and their environment, automatic and manual movement of virtual robot axes and end-effector trajectory tracing are implemented through open-source tools on Linux platform. In this paper, a sho...

In this paper, we present results of the robust stability analysis for the class of nonlinear uncertain singularly impulsive dynamical systems. We present sufficient conditions for the robust stability of a class of nonlinear uncertain singularly impulsive dynamical systems. The problem of evaluating performance bounds for a nonlinear-nonquadratic...

Modern combat aircraft can fly at unusual orientations. The spatial disorientation trainer (SDT) examines a pilot's ability to recognise these orientations, to adapt to unusual positions and to persuade the pilot to believe in the aircraft instruments for orientation and not in his own senses. The SDT is designed as a four-degree-of-freedom (4DoF)...

Pilots of modern combat aircraft are exposed to the devastating effects of high acceleration forces. The pilots׳ ability to perform tasks under these extreme flight conditions must be examined. A centrifuge motion simulator for pilot training is designed as a 3DoF manipulator with rotational axes. Through rotations about these axes, acceleration fo...

An algorithm for reducing the influence of geometrical, thermal, kinematic and stiffness errors in five-axis machine tool components on the desired tool position and orientation is given. This new algorithm is based on the calculation of the cutting tool error matrix for orthogonal machine tools. In the new model of this matrix, all angular errors...

Formulation of proper and efficient algorithms for robot kinematics is essential for the analysis and design of serial manipulators. Kinematic modeling of manipulators is most often performed in Cartesian space. However, due to disadvantages of most widely used mathematical constructs for description of orientation such as Euler angles and rotation...

This paper presents the kinematic characteristics of a human centrifuge for pilot training. The focus is placed on the influence of the tangential acceleration on human centrifuge performances. The main planetary motion is expressed with an ordinary first-order nonlinear differential equation, which is solved numerically. (© 2013 Wiley-VCH Verlag G...

To achieve predefined Gz load profile in high G training in human centrifuge, it is necessary to determine angular velocity and acceleration of a planetary axis (centrifuge arm). Initial value problem that can not be solved in closed form was obtained. Several discretization methods for calculating angular velocity of centrifuge arm driven by DC se...

Parser testing represents the basis of compiler testing because the accuracy of parsing execution directly affects the accuracy of semantic analysis, optimization and object code generation. It should include tests for correct and expected, but also for unexpected and invalid cases. In this paper, techniques for testing the parser, as well as algor...

Android platform based devices are powerful mobile computers with a rich variety of built-in sensors and permanent Internet connectivity. Because of its powerful capabilities, as well as open architecture, they became promising candidates for a number of industrial applications. This paper describes the process of implementation and use of applicat...

In this paper we introduce a new class of systems, the so-called singularly impulsive or generalized impulsive dynamical systems with time delay. Dynamics of these systems is characterized by a set of differential and difference equations with time delay, and by algebraic equations. They represent a class of hybrid systems where algebraic equations...

In this paper, the advantages of applying software packages for the optimisation of the relevant technological parameters of casting and their implementation and control in production processes using the example of a cast piston are presented. The micro- and macrostructural characteristics of two different modes of solidification are given. In prev...

In this paper for the class of continuous time nonlinear uncertain singular time delay dynamical systems we present robust stability analyze results. Next, we consider a control problem for nonlinear continuous time uncertain singular time delay dynamical systems involving a notion of optimality with respect to an auxiliary cost which guarantees a...

This paper presents a proposed approach to the classification of rolling element bearing faults. The approach consists of vibration signal acquisition, digital signal processing, feature extraction from the vibration signal and classification into functional or defective rolling element bearing. Digital signal processing includes signal decompositi...

In the process of defining commands and developing algorithms for movements of complex and massive devices, such as human centrifuge, it is unsafe and demanding to perform testing on the real machine. Getting overview of devices operations might be of great importance especially before the final realization. This paper presents a system for program...

This paper presents the kinematic characteristics of a human centrifuge for pilot training. The focus is placed on the influence of the tangential acceleration on human centrifuge performances. The main planetary motion is expressed with an ordinary first-order nonlinear differential equation, which is solved numerically.

Beside the explaination of the process of soil remediation and thermal desorption, the paper contains elaboration of the assessed hazards and risks in those processes. The appropriate measures for safe and healthy work are established and prevised accordingly. A systematic approach, the basic principles of behavior at work and the structure of the...

This paper presents advantages of using open architecture for the real-time control of robot manipulators, parallel kinematics machine tools and other multi-axis machining systems. In order to increase their competitiveness, companies need to follow the global economy requirements. The constant incorporation of new technologies into existing contro...

In this paper for the class of nonlinear uncertain singularly impulsive dynamical systems we present optimal robust control and inverse robust optimal control results. We consider a control problem for nonlinear uncertain singularly impulsive dynamical systems involving a notion of optimality with respect to an auxiliary cost which guarantees a bou...

In this paper we introduce new class of system, so called singularly impulsive or generalized impulsive dynamical systems with time delay. Dynamics of this system is characterized by the set of differential and difference equations with time delay, and algebraic equations. They represent the class of hybrid systems, where algebraic equations repres...

Aircrew of a modern combat aircraft is exposed to hazardous effects of high G-forces and high angular velocities. In order to protect human lives and to avoid material losses, High-G training in human centrifuge is used to artificially increase accelerative force under controlled conditions. In this paper, centrifuge is modeled as 3 DoF revolute ro...

It is very useful to accomplish turning and five-axis milling, drilling and boring in only one setup, which is possible on five-axis turning centres. In this paper, we present a control algorithm for this machine with two translational and three rotational axes. The turning centre has a two rotary axis head with axes that do not intersect. This inc...

In this paper we present singular and singularly impulsive model of genetic regulatory networks. Concrete example consists of two gene - two proteins simple synthetic network, and posses two fundamentally present parts in biochemical networks - positive and negative feedback loops. These are important structural parts of biochemical networks and ar...

This paper concerns three genes model of synthetic network that carries out many essential functions in living cell. It is designed network of genes with mutual inhibition and/or activation resulting in triple negative, double negative (i.e. positive feedback) or classical negative feedback or positive feedback. Mathematical model which describes t...

In this paper we present mathematical model of well known Delta-Notch signaling system in form of nonlinear, singular, impulsive and singularly impulsive dynamical systems. This example is interesting since it posses phenomena of lateral inhibition recognized to be underlying element in mechanism structures in many living organisms. It is character...

In this paper principles of modeling of a human centrifuge for pilot training, as a 3 DoF manipulator, are presented. The basis is a kinematic and dynamic model of the manipulator. The centrifuge represents a manipulator with three revolute joints. According to the D-H convention transformation matrices for the manipulator were derived. The problem...

This paper presents distributed real-time robot control system implemented on the client and server modules. The client module is used to control the real robot and send commands to the server module. An application on the server side receives the commands that contain positions of robot joints read from encoders, displays current robot coordinates...

L-IRL (Lola Industrial Robot Language) is procedural language for industrial robot programming. Offline and real-time programming system are main parts of robot programming system based on L-IRL programming language. System for robot programming is using object code as one of the main communication tools between different elements of the system. In...

In this paper, the issue of the main drive selection for a Human Centrifuge is is explained, starting from the flight envelope that needs to be simulated. The main objective is to emphasize the complexity of choosing a drive, since it is a high power drive. The methodology for the main drive selection of a Centrifuge for pilot training, which is a...

Parallel kinematic machines (PKM) are still a research-and-development topic in many laboratories although many of them, unfortunately, have no PKM at all. Therefore, the use of a desktop educational 3-axis parallel kinematic milling machine is suggested as a help in the process of acquiring basic experiences in the field of PKM. The developed desk...

Abstract: Information technology and virtual manufacturing of castings enabled shortening the time to develop a product, as well as high quality castings fabrication at first attempt, what can be the crucial contribution in achieving the increased engineering adequacy and economic competitiveness of foundries in Serbia. Matching the global market d...

It is well known that the shape and volume of the workspace are one of the greatest weaknesses of parallel kinematic machine tools (PKM). Hexaglide and Triaglide mechanisms are examples where workspace extension is achieved by elongating one axis as a principal motion axis that is a common feature of all Cartesian machines. With the idea of princip...

This paper proposes a new method for computing the grasping forces of object grasped by multiple cooperating manipulators or a multifingered robot hand. The intention is to find grasping forces that ensure safe grasp on the object during arbitrary manipulation. The grasp should be with minimal internal loading of the object. The finger/object conta...

The paper presents high level robot language L-IRL. The language is based on the new German standard for robot languages, designed with reference to the Pascal family. L-IRL was designed to support the programming of the entire cell, containing robots and other devices. L-IRL offers a solution for multiple robot programming by allowing specificatio...