Ljubinko Kevac

Graphical representation of the significant 6R KUKA robots spaces

Trajectory planning for serial 6 degree of freedom (DOF) machinery systems is demanding due to complex kinematic structure which affects the machinery tool fame, position, orientation and singularity. These three characteristics represent the key elements for production planning and layout design of the manufacturing systems. Both, simple and complex machine trajectory is defined as series of connected points in 3D space. Each point is defined with its position and orientation related to the machines base frames. To visualize the machines reachable space, the work envelope is calculated and graphically presented as very well known machines property. A methodology to predetermine regions of feasible tool orientation (work window) is analytically and graphically presented. The work envelope boundary is generated using the filtering points algorithm, while work window is generated using either empirical or analytical methods. The singularity regions are calculated by finding the determinant of the reconfigurable Jacobian matrix. These three tool path characteristics represent three different spaces which are identified both analytically and graphically and plotted in Cartesian space using MATLAB tools. The singularity regions will be represented within the workspace and work window for a single machinery kinematic structure. The KUKA KR robot family is used as a case study.

Contribution to the modeling of cable-suspended parallel robot hanged on the four points

This paper describes a novel mathematical model of the Cable-suspended Parallel Robot. The complex system is made to accurately carry camera in the 3D space. The geometric relationship between the camera motion in the Cartesian coordinates and motors angular positions is defined by the Jacobian matrix, which represents the solution of the kinematic problem. The solution of the calculated matrix directly depends on the systems geometry. The adopted Jacobian matrix is used for calculation of the dynamic model of the Cable-suspended Parallel Robot. Two numerical examples are used to illustrate practical usefulness of the proposed mathematical model and its validation. The final goal of this research is to ensure the accurate and highly automated guidance of the camera in 3D space with the minimal involvement of the human factor for the task generation.

The rigid S-type cable-suspended parallel robot design, modelling and analysis

†Mihajlo Pupin Institute, The University of Belgrade, Volgina 15, 11000 Belgrade, Serbia ‡Wayne State University, 4855 Fourth St. Detroit, MI 48202, USA §School of Electrical Engineering, The University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Belgrade, Serbia ¶Innovation center of School of Electrical Engineering, The University of Belgrade, Bulevar Kralja Aleksandra 73, 11000 Belgrade, Serbia

Comparative analysis of two configurations of aerial robot

The aim of the research in this paper is to define the aerial robot (Cable-suspended Parallel Robot-CPR). CPR is hanged on four points and it is able to follow and record a moving object with high precision wherever the object moves in its workspace. Each contribution is a step closer to the achievement of highly automated systems which would precisely lead camera in the area with as less involvement of human interference as possible. Two new CPR structures are proposed. The mathematical model (kinematic and dynamic) is defined for both versions of the solution. It is assumed that all the parameters of systems are the same and therefore the comparison of these systems will be easier. It is evident that the choice of construction of CPR significantly affects the response of this system.

Effective Work Region Visualization for Serial 6 DOF Robots

Optimal serial 6 degree of freedom (DOF) robot path planning has challenges due to the kinematic structures, singularity conditions, and the practical reach limits due to the a path-fixture-end effector orientation and design-robot structure combination. Previous research has been done to define and visualize the functional reach limits for a robot-end effector orientation-end effector tool geometry set. This is expanded and combined with singularity region analyses to be able to visualize the total effective travel path regions for a target application (i.e., FANUC, ABB, or Comau robot families) using the MATLAB toolbox. Visualization tools that represent both the functional work region or work window and singularity regions are presented. This research will provide designers the ability to assess a wide range of industrial robot configurations comprehensively at the design or redesign stages as the valid bounded region defined in this work can be employed for subsequent downstream optimization related to velocity and acceleration control.

The mathematical model of aerial robot in purpose increasing of its autonomy

The purpose of this research is to implement the presented results and possibly improve the model for the future modernization, autonomy and intelligent behavior of the aerial robot named Cable Suspended Parallel Robot -CPR. Visionary speaking these high-set goals were a strong incentive to define highly reliable kinematic and dynamic model of the CPR system, which will be used for the control purposes.

Future directions for implementation of aerial robot

The aim of this paper is to highlight the importance of forming a mathematical model of Cable-suspended Parallel Robot - CPR (aerial robot), since only that way CPR provides precise guidance in the area. Only highly intelligent control systems, based on high authentic system mathematical model, can provide the realization of very complex tasks. The established mathematical model provides an opportunity to modernize CPR significantly and to make its application become much wider.

Singularity Analysis for a 6 DOF Family of Robots

Path planning for serial 6 degree of freedom (DOF) robot based systems is challenging due to their kinematic structure, the behaviour of robot based on the configuration, and singularity conditions. Understanding the singularity conditions and zones is critical for both single robot applications, and robot cells. Visual representations of singularity zones will help process designers develop valid travel paths and layout designs. MATLAB tools are employed to represent the singularity zones using fundamental kinematic equations. The target application for this research is the FANUC family of serial 6 DOF robots, and the identified singularity regions are plotted in 2D and 3D Cartesian space.

The trajectory generation algorithm for the cable-suspended parallel robot—The CPR Trajectory Solver

Abstract The CPR Trajectory Solver is a procedure defined in this paper which is used to generate a smooth reference trajectory of CPR system’s camera which has a task to monitor and track the object in real time. We have generated a data base of four primitive trajectories (primitives) which are chosen by the CPR Trajectory Solver during the generation of camera’s complex reference trajectory. For trajectory generation, the CPR Trajectory Solver uses the knowledge about the current positions and velocity orientations of the camera and object and then it defines the goal position and velocity orientation of the camera. The CPR Trajectory Solver chooses one of the generated primitives for interconnecting the current and goal positions of the camera. After completing the chosen primitive, the CPR Trajectory Solver establishes the new positions and velocity orientations of the object. This process is repeated cyclically until the real time object monitoring and tracking task is completed. For the purpose of analysing and using the defined algorithm, we have synthesized a program package: CPRTS ( CPR T rajectory S olver). By using this program package, the simulation experiments of the camera’s trajectory generation for the purpose of the object monitoring and tracking are presented. By using the CPR Trajectory Solver, motion autonomy of CPR system’s camera is increased. The camera has a task to follow and monitor the chaotically moving object.

A NEW WINCH CONSTRUCTION FOR SMOOTH CABLE WINDING/UNWINDING

New constructive solutions of the winches for single-row radial multi-layered cable smooth winding/unwinding are described. Two new structural solutions of winches are defined. The nonlinear phenomenon of a cable smooth winding/unwinding process on the winch by using one of the two proposed constructive solutions is defined and analyzed. To facilitate understanding of this concept, the cable winding/unwinding process on only one winch is analyzed. The obtained variables which characterize the kinematics of the cable smooth winding/unwinding process are nonlinear and smooth. This result is important because the systems for the smooth cable winding/unwinding process on the winch could be parts of any cable driven mechanism. These systems can be used in various fields of human activity. For the verification of the presented theoretical contributions, a novel software package named SMOWIND – OW has been developed using MATLAB.