Milan Zeljković

Automatic design of the technological process for NC lathes by the use of SAPOR-S system

Abstract In the paper is given the original information about the SAPORS system for the automatic design of technological process for NC lathes. The SAPOR-S system is developed at the Laboratory of Machine Tools of the Institute of Production Engineering, Faculty of Technical Sciences, Novi Sad. The model of the system is briefly stated as well as principle of formalizing the input information about the part and some examples of intermediate and final results. Some particularities are emphasized and advantages of the SAPOR-S system over the similar ones. Finally, the directions of further development of the SAPOR system are established

Automated Acquisition of Proximal Femur Morphological Characteristics

Abstract The success of the hip arthroplasty surgery largely depends on the endoprosthesis adjustment to the patients femur. This implies that the position of the femoral bone in relation to the pelvis is preserved and that the endoprosthesis position ensures its longevity. Dimensions and body shape of the hip joint endoprosthesis and its position after the surgery depend on a number of geometrical parameters of the patients femur. One of the most suitable methods for determination of these parameters involves 3D reconstruction of femur, based on diagnostic images, and subsequent determination of the required geometric parameters. In this paper, software for automated determination of geometric parameters of the femur is presented. Detailed software development procedure for the purpose of faster and more efficient design of the hip endoprosthesis that ensures patients’ specific requirements is also offered

Program Suite for Conceptual Designing of Parallel Mechanism-Based Robots and Machine Tools

In the development of robots and machine tools, in addition to conventional and serial structures, parallel mechanism-based kinematic structures have been used over a longer period of time. Aside from a number of advantages, the irregular shape and relatively small dimensions of the workspace formed by parallel mechanisms rank among the major weaknesses of their application. Accordingly, this fact has to be taken into consideration in the process of designing parallel mechanism-based robots or machine tools. This paper describes the categorization of criteria for the conceptual design of parallel mechanism-based robots or machine tools, resulting from workspace analysis as well as the procedure of their defining. Furthermore, it also presents the designing methodology that was implemented into the program for the creation of a robot or machine tool space model and the optimization of the resulting solution. For verification of the criteria and the programme suite, three common (conceptually different) mechanisms with a similar mechanical structure and kinematic characteristics were used.

Achievements in the development and future development of SAPOR-S systems for automatic programming of NC lathes

Abstract This paper reviews the present state of the development of a SAPOR-S system for the automatic design of technological processes for rotational parts production and automatic programming of NC lathes. The SAPOR-S system model and the principles on which the procedure for forming the technological database is based are described. Some results obtained during the design of the technological process for the short shaft are also presented. The second part of the paper discusses intended improvements of the SAPOR-S system, e.g. in graphical support, interactive work, microcomputer. The concept of the integral SAPOR software package which is capable of generalization and is thus applicable to flexible manufacturing systems (FMS) for rotational parts production is also discussed.

Methodology of Knee Bones Models 3D Printing Based on CT Series of Images

In this paper a methodology for knee bones models 3D printing from DICOM series of images is presented. It would be very useful for doctors to see real models of knee bones and ligament attachment sites onto both bones before the ACL reconstruction. With physical bone model, orientation and position of operative equipment (tibial and femoral guides) could be planned before the operation. This could lead to more precise ACL reconstruction. In the introductory part of this paper ACL reconstruction method and some problems that may occur are presented. After that, model of procedure for knee bones 3D printing is shown. First, a procedure for 3D knee bone models generation is shown. For this purpose a program system is developed based on the VTK library. Generation of femoral transverse axis which enables tibial bone to rotate about femoral bone is very important. This axis enables knee flexion and extension and in ACL reconstruction, doctors rotate tibial bone about femoral bone which is fixed. Point clouds of femoral bone condyles are used for calculation of centres of best fit spheres of both condyles by least squares method. After that bone models are prepared for 3D printing. Because of the MakerBot Replicator 2X printer limitations, model of the knee is printed in two parts which are then glued together.