Djidrov, Marjan
Preferred name
Djidrov, Marjan
Official Name
Djidrov, Marjan
Main Affiliation
9 results
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Item type:Publication, Kinematic modeling and analysis of serial manipulator(2019); ; The purpose of this paper is modelling and simulation of serial manipulator type RRRR. CAD model was developed by using the software SolidWorks for modelling the serial manipulator. Simulation model of serial robot is made by conversion from SolidWorks to Matlab/Simulink. The serial robot can be shown schematic as a kinematic connection of rigid bodies that are interconnected using rotary kinematic pairs. The manipulator movement is defined so the movement of each member is related to the previous one. The position and orientation of the gripper must be defined to ensure safe handling. In this paper, the steps needed to model the serial manipulator together with all its components, its transfer into Simulink and its PID controlling and simulation is described. The obtained results for velocity and acceleration in kinematic pairs contribute in detailed analysis of kinematics and control design. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mathematical Model of New Type of Train Buffer Made of Polymer Absorber—Determination of Dynamic Impact Curve for Different Temperatures(2018-10); ; ; Previous experimental knowledge has confirmed that one of the most influential factors affecting the performance of polymer friction absorbers embedded in buffer housing as part of the buffer and chain coupler is the temperature. This paper defines a mathematical model of a friction-type polymer absorber, PMKP-110. The presented mathematical model specifically includes the influence of the environment temperature on the dynamic impact curve for −60 °C and 15 °C. The dependence between the initial pre-tension of the buffer and the ambient temperature is calculated. The model involves an equation of motion for moving parts of the absorber, and the solution of the differential equation is achieved in Matlab. Results are given as diagrams of the impact deformation and impact speed of the polymer block, with assumed zero initial impact speed. The model can be used to analyze the action of the longitudinal forces that occur during transient conditions of the movement of the carriages. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Modeling of mechanism with linear hydraulic drive system(2019-06); This paper presents computational modeling results of a mechanism with hydraulic drive system that performs linear or transversal motion. This mechanism is commonly used in the construction mechanization and the simulation model analysis is obtained by using Matlab/Simulink. Connection of mechanical and hydraulic elements makes this mechanism quite specific and the linking of the mechanical and hydraulic parts is presented. The simulation modeling allows the force and velocity of piston from hydraulic cylinder to be obtained which are necessary components for further projecting of hydraulic drive system. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Dynamic modeling and simulation of three-member robot manipulator(2018-10); ; Dynamic model analysis of manipulator as mechanical structure is presented for further purpose in actuator selection and process for establishing control strategy. Control problems involves determination of control forces and moments applied in manipulator joints that will ensure movements along a certain defined trajectory. Trajectory design is the basis for the manipulator control process. This problem is quite complex because the manipulator is a connected system in which the movement of a member affects the movement of other. Therefore, in following is presented a method for forces and moments determination in kinematic joints of a three-member manipulator analytically and also by using simulation dynamical model in the Matlab/Simulink program package. The friction forces in the kinematics joints are not taken into account. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Estimation and analysis of various influential factors in the braking process of rail vehicles(2019-08); ; Braking distances play an important role in the organization of rail traffic and exploitation of rail vehicles. The braking distances of rail vehicles affect several factors that cannot be defined and determined precisely. In this paper, a mathematical model, for train moving through braking, is presented by taking into account the relevant train braking resistance and a procedure is given for solving a differential equation of movement of the rail vehicle during braking. The procedure allows determining influential factors that have an effect on the length of braking distances. The influence and the changes of specific resistance during the movement of the train, braking force, and adhesion between wheel and rail during the braking process are presented. The results obtained with the presented mathematical model are accurate and match with the results obtained experimentally. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Wire-arc additive manufacturing: recent developments and potential(The Academy of Applied Technical Studies Belgrade Katarine Ambrozic 3, Belgrade, 2023); ; ; Wire-arc additive manufacturing (WAAM) is a promising technology for producing medium and large components without traditional subtracting technologies. It is a hybrid of two manufacturing techniques: additive manufacturing and welding. The use of this technology has grown significantly due to advantages such as material and energy savings while achieving high deposition rates and low cost. However, there are some issues with microstructure homogeneity, and properties are affected due to the complexity of the arc-induced thermal cycles and metallurgical mechanisms, resulting in high residual stresses, distortion, porosity, cracks, and delamination. This article summarises the progress made in the field of wire additive manufacturing, with a focus on welding systems, tool path design software, material analysis, and control systems. It also highlights some critical aspects that must be addressed to ensure high-quality production, such as control and diagnosis mechanisms for defect monitoring, the effects of parameters and their optimisation possibilities for improving quality, ensuring process stability, and possible post-deposition heat treatments. The conclusions suggest further improvements to the wire-additive manufacturing process in terms of accuracy, reliability, and efficacy, as well as future applications of the technology and research activities. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Overcoming industrial robotics challenges and the role of offline programming(Faculty of mechanical engineering - Skopje, Mechanical Engineering – Scientific Journal, 2024-06-24); ; Peciovski, DamjanIndustrial robots play a pivotal role in modern industrial production, with robotic welding standing out as a crucial application. This paper analyzes the utilization of online and offline programming methods to optimize robotic welding processes, with an application of Gas Metal Arc Welding (GMAW) techniques. GMAW offers exceptional versatility, including adaptability to various plate thicknesses, high productivity rates, compatibility with diverse materials, and the ability to weld coated metals. The synchronization of robotic movements and positioners plays a crucial role in ensuring precise welding execution. This complexity is particularly evident in scenarios involving welding complex curves, where coordinated movement between the robotic arm and positioner is essential for successful outcomes. In this study, an experiment involving the welding of a pipe-pipe joint using a robot with 6 and positioner with 2 degree of freedom is presented. By applying synchronized movement, seamless welding operations are achieved, highlighting the importance of advanced programming techniques and synchronized operations in enhancing the efficiency and precision of robotic welding in industrial production. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, WIRE-ARC ADDITIVE MANUFACTURING: RECENT DEVELOPMENTS AND POTENTIAL(The Academy of Applied Technical Studies Belgrad, 2023-12-15); ; ; Wire-arc additive manufacturing (WAAM) is a promising technology for producing medium and large components without traditional subtracting technologies. It is a hybrid of two manufacturing techniques: additive manufacturing and welding. The use of this technology has grown significantly due to advantages such as material and energy savings while achieving high deposition rates and low cost. However, there are some issues with microstructure homogeneity, and properties are affected due to the complexity of the arc-induced thermal cycles and metallurgical mechanisms, resulting in high residual stresses, distortion, porosity, cracks, and delamination. This article summarises the progress made in the field of wire additive manufacturing, with a focus on welding systems, tool path design software, material analysis, and control systems. It also highlights some critical aspects that must be addressed to ensure high-quality production, such as control and diagnosis mechanisms for defect monitoring, the effects of parameters and their optimisation possibilities for improving quality, ensuring process stability, and possible post-deposition heat treatments. The conclusions suggest further improvements to the wire-additive manufacturing process in terms of accuracy, reliability, and efficacy, as well as future applications of the technology and research activities. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, KINEMATICS ANALYSIS OF 6 DOF INDUSTRIAL MANIPULATOR AND TRAJECTORY PLANNING FOR ROBOTIC WELDING OPERATION(Faculty of Mechanical Engineering, Ss. Cyril and Methodius University in Skopje, North Macedonia, 2024-05-28); ; Dejan ŠiškovskiRobotic manipulators are commonly used in the manufacturing industry for tasks such as assembly, welding, painting, and palletizing. In these applications, precise control over the position and orientation of the robot's end-effector is crucial for efficient and accurate operation. Both inverse and forward kinematics play crucial roles in the design, programming, and operation of industrial robotic manipulators, helping to ensure their effectiveness, efficiency, and safety in various manufacturing environments. In this paper the forward and inverse kinematic model of 6 degrees of freedom (DOF) industrial manipulator are presented. Additionally, the study focuses on analyzing single pass welding across a range of different scenarios. These cases involve welding paths that have different geometric shapes, with a goal to join the materials together and form a closed shape. Maintaining a vertical orientation of the welding torch was achieved, because it is important for realizing uniform heat distribution, consistent weld bead geometry, and better control over the welding process, ultimately contributing to the effectiveness of the robotic welding operation.