Filip Górski

Application of Virtual Reality Techniques in Design of Ergonomic Manufacturing Workplaces

This paper presents possibilities of application of the immersive VR and the haptic technologies during the complex process of design and virtual prototyping of the manufacturing workplaces characterized with a high level of ergonomic quality. Two case studies are presented: a workplace for stud welding and a set of two workplaces, for hole drilling and manual assembly. In the first case study, haptic device with force feedback effect was used to improve ergonomics of main operator activities. In the second case study, immersive approach was used, namely Head-Mounted Device, tracking and gesture recognition systems, to test and improve ergonomics of the whole workplace. Application of VR techniques allows to present the virtual prototype of the workplace in its real operation environment, limiting the need for use of real mock-ups. Therefore, Virtual Reality allows to conduct a number of analyses related to designed prototypes, such as: dimensions of devices and possibilities of adjustment to height of the human operator, and arrangement of control and signaling devices according to the rules of ergonomic design. To conduct these analyses, full interaction between user and workplace must be programmed, including collision detection, kinematics of the devices and possibilities of activating their various functions in relation with other objects in the virtual scene.

Virtual 3D Atlas of a Human Body - Development of an Educational Medical Software Application

Abstract This paper presents a process of building a prototype of an educational application for teaching anatomy with elements of physiology, with use of a Virtual Reality environment. Preparation of mesh models of individual human organs is described, along with further visualization techniques, which were used to ensure a proper level of a visual representation. Stages of user interface preparation are also described – both visual and functional aspects covered – with a detailed review of a visual programming process, which was used to obtain a logical structure of connections inside the VR environment. Process of preparation of dynamic graphical data-namely animation of the pulmonary alveoli – and integration it with the virtual environment is also presented. The final application can be used in a number of ways, including large-screen stereoscopic projection with on- screen graphical user interface and single-user immersive stereoscopic projection using a head-mounted device with an optical tracking system. Results of assessment of the application advantages and disadvantages at the current stage of development allowed to formulate several directions of further advancement.

INFLUENCE OF PROCESS PARAMETERS ON DIMENSIONAL ACCURACY OF PARTS MANUFACTURED USING FUSED DEPOSITION MODELLING TECHNOLOGY

The paper presents the results of experimental study – part of research of additive technology using thermoplastics as a build material, namely Fused Deposition Modelling (FDM). Aim of the study was to identify the relation between basic parameter of the FDM process – model orientation during manufacturing – and a dimensional accuracy and repeatability of obtained products. A set of samples was prepared – they were manufactured with variable process parameters and they were measured using 3D scanner. Significant differences in accuracy of products of the same geometry, but manufactured with different set of process parameters were observed.

Computation of Mechanical Properties of Parts Manufactured by Fused Deposition Modeling Using Finite Element Method

The paper focuses on a problem of evaluation of strength of products manufactured using Fused Deposition Modelling technology. The presented research was aimed at developing a method for computation of deformation and stresses in any product manufactured using FDM technology, with consideration of important, strength-affecting process parameters. Finite Element Method calculations were realized using digital CAD models of the products, obtained by simulation of FDM process in a virtual environment. These models represent the macrostructure of additively manufactured elements. Results of calculations for sample geometries were verified by experimental studies. The obtained results are mostly correct, changes in approach are needed to make the computations possible to be performed in shorter time and with better results.

STRENGTH OF ABS PARTS PRODUCED BY FUSED DEPOSITION MODELLING TECHNOLOGY – A CRITICAL ORIENTATION PROBLEM

Numerous experimental studies, including experiments performed by the authors, have shown that the part orientation during layer deposition has a very strong influence on final strength of a product manufactured by additive Fused Deposition Technology. The paper presents the results of tensile, bending and impact strength tests performed on samples of various orientations, made out of ABS material using FDM technology. The results of these tests allowed discovering a unique phenomenon – with the changing orientation, not only the values of strength indexes change, but macroscopic material behavior under load as well. The transition between a “yield point” and “brittle” material usually happens in a certain range of orientation values, named a critical orientation by the authors. The paper indicates supposed ranges of critical orientation for various types of loads.

Application of additively manufactured polymer composite prototypes in foundry

The paper presents a method, developed by the authors, for manufacturing polymer composites with the matrix manufactured in a layered manner (via 3D printing – Fused Deposition Modeling) out of a thermoplastic material. As an example of practical application of this method, functional prototypes are presented, which were used as elements of foundry tooling – patterns for sand molding. In case of manufacturing prototype castings or short series of products, foundries usually cooperate with modeling studios, which produce patterns by conventional, subtractive manufacturing technologies. If patterns have complex shapes, this results in high manufacturing costs and significantly longer time of tooling preparation. The method proposed by the authors allows manufacturing functional prototypes in a short time thanks to utilizing capabilities of additive manufacturing (3D printing) technology. Thanks to using two types of materials simultaneously (ABS combined with chemically hardened resins), the produced prototypes are capable of carrying increased loads. Moreover, the method developed by the authors is characterized by manufacturing costs lower than in the basic technology of Fused Deposition Modeling. During the presented studies, the pattern was produced as a polymer composite and it was used to prepare a mold and a set of metal castings.

Design and Implementation of a Complex Virtual Reality System for Product Design with Active Participation of End User

The paper presents studies on design and implementation of a complex Virtual Reality system for product design. Main objective of work presented in the paper was to obtain a tool suitable for on-line work with the clients on configuration of visual features of customized city buses. A complex product such as a city bus can have more than 100 visible features (options), which can be changed to obtain infinite configuration possibilities. The paper presents the overview and functions, as well as development process of the created system. Efficiency of the system in the visual configuration process was confirmed by representatives of the company. Capabilities of the system were tested using a sample of users from all the company departments involved in the bus design process. It confirmed high effectiveness of the system in terms of presenting variability of the product features in a clear visual way and improvement of the whole configuration process.

Virtual Reality Production Training System in the Scope of Intelligent Factory

The paper presents a prototype Virtual Reality system for learning of operation in an intelligent factory, working according to the concept of Industry 4.0. The SmartFactory laboratory—example of part of intelligent factory—is described. The VR prototype system and process of its building is also presented, starting from digitalization of the real smart factory, through logic programming and connection of peripheral VR devices. Functions of the training system are presented, along with directions of future studies and development.

Application of Polystyrene Prototypes Manufactured by FDM Technology for Evaporative Casting Method

e-mail: filip.gorski@put.poznan.pl The paper describes possibilities of using additive manufacturing technologies to manufacture single use casting tooling. The foundries usually cooperate with pattern workshops, which manufacture tooling using conventional processes. In case of patterns of complex shapes, it translates into higher costs and longer time of production. An alternative can be use of additive manufacturing (3D printing), proposed by the authors. The additive manufacturing allows to manufacture complex shapes as quick and cheap as simple shapes, being more fit for the more demanding patterns. The studies performed in this paper were aimed at determination if it is possible to effectively manufacture polystyrene (HIPS) patterns using the low-cost machine working in Fused Deposition Modelling technology and use them directly to manufacture castings out of GJS500-7 cast iron in the investment (burnt pattern) casting process. The paper presents examples of products that can be manufactured this way and also shows problems that appeared during the manufacturing processes.

Mandibular Reconstruction with Osteo-cutaneous Free Flaps in a Patient afterExtensive Surgery Supported with 3D Printed Models

Introduction and objective: The aim of the study was to evaluate usefulness of 3-D models utilizing generated incremental techniques from thermoplastic materials in mandibular reconstruction with utilization of free osteocutaneous fibular and scapular flaps. Methods: 12 patients were treated due to an advanced oral cavity squamous cell carcinoma (T4b). In four patients with a mandibular defect a physical 3-D model consisting of the reconstructed and unaffected sites was prepared for a reconstruction protocol. The 3-D models were designed based to high resolution CT scans. Results: Assessment of comparative functionality (stability of junction, mobility, mastication ability), and cosmetics was examined in both groups, following an 8- week healing period. Conclusion: Applying 3-D models for mandibular manufacturing using a three dimensional printing technologies allows for obtainment of better functionality of restored mandible in comparison to the traditional method. Utilization of mandibular and fibular model significantly decreases time of the operation and allows for achievement of desired shape and esthetic effect within the 1/3 of the lower face.