Interactive assembly simulation with haptic feedback

Purpose – The paper aims to present interactive simulation with haptic feedback as a valid method for solving complex assembly problems in the context of industrial product development. Its purpose is to clarify the position of interactive simulation with respect to other methods, and to emphasize its specific value for design engineers. Design/methodology/approach – The paper describes the challenges faced by design engineers in the context of design for assembly and assembly process planning. It introduces and compares automatic path planning and interactive simulation as two different approaches for checking the feasibility of assembly tasks. It provides a review of the scientific challenges and technical issues faced when implementing interactive simulation with haptic feedback in this context. It presents recent research results in the domains of final insertion and human model simulation. Findings – The paper provides an overview of the scientific, technological and practical aspects of interactive simulation with haptic feedback. It explains how this method benefits from the manual skills and cognitive capabilities of the human operator for solving complex assembly problems. It proposes an assessment of the technical maturity using the Technology Readiness Level approach. Originality/value – The paper gives insights about the maturity and usability of interactive assembly simulation with haptic feedback, for the benefit of design engineers seeking new ways to decrease product development time and costs while increasing quality

Real-time impluse-based rigid body simulation and rendering

The purpose of this thesis is to develop and demonstrate a physically based rigid body simulation with a focus on simplifications to achieve real-time performance. This thesis aims to demonstrate that by improving the efficiency with simplified calculations of possible bottlenecks of a real-time rigid body simulation, the accuracy can be improved. A prototype simulation framework is implemented to evaluate the simplifications. Finally, various real-time rendering features are implemented to achieve a realistic look, and also to imitate the game-like environment where real-time rigid body simulations are mostly utilized. A series of demonstration experiments are used to show that our simulator does, in fact, achieve real-time performance, while maintaining satisfactory accuracy. A direct comparison of this prototype with a commercially available simulator verifies that the simplified approach improves the efficiency and does not damage the accuracy under our test conditions. Integration of rendering elements like advanced shading, shadowing, depth of field and motion blur into our real-time framework also enhanced the perception of simulation outcomes

가상 의복의 생성, 수정 및 시뮬레이션을 위한 조작이 간편하고 문제를 발생시키지 않는 방법에 대한 연구

학위논문 (박사)-- 서울대학교 대학원 : 자연과학대학 협동과정 계산과학전공, 2016. 2. 고형석.This dissertation presents new methods for the construction, editing, and simulation of virtual garments. First, we describe a construction method called TAGCON, which constructs three-dimensional (3D) virtual garments from the given tagged and packed panels. Tagging and packing are performed by the user, and involve simple labeling and two-dimensional (2D) manipulation of the panelshowever, it does not involve any 3D manipulation. Then, TAGCON constructs the garment automatically by using algorithms that (1) position the panels at suitable locations around the body, and (2) find the matching seam lines and create the seam. We perform experiments using TAGCON to construct various types of garments. The proposed method significantly reduces the construction time and cumbersomeness. Secondly, we propose a method to edit virtual garments with synced 2D and 3D modification. The presented methods of linear interpolation, extrapolation, and penetration detection help users to edit the virtual garment interactively without the loss of 2D and 3D synchronization. After that, we propose a method to model the non-elastic components in the fabric stretch deformation in the context of developing physically based fabric simulator. We find that the above problem can be made tractable if we decompose the stretch deformation into the immediate elastic, viscoelastic, and plastic components. For the purpose of the simulator development, the decomposition must be possible at any stage of deformation and any occurrence of loading and unloading. Based on the observations of various constant force creep measurements, we make an assumption that, within a particular fabric, the viscoelastic and plastic components are proportional to each other and their ratio is invariant over time. Experimental results produced with the proposed method match with general expectations, and show that the method can represent the non-elastic stretch deformation for arbitrary time-varying force. In addition, we present a method to represent stylish elements of garments such as pleats and lapels. Experimental results show that the proposed method is effective at resolving problems that are not easily resolved using physically based cloth simulators.Chapter 1 Introduction 1 1.1 Digital Clothing 1 1.2 Garment Modeling 5 1.3 Physical Cloth Simulation 7 1.4 Dissertation Overview 9 Chapter 2 Previous Work 11 2.1 Garment Modeling 11 2.2 Physical Cloth Simulation 15 Chapter 3 Automatic Garment Construction from Pattern Analysis 17 3.1 Panel Classification 19 3.1.1 Panel Tagging 19 3.1.2 Panel Packing 22 3.1.3 Tagging-and-Packing Process 23 3.2 Classification of Seam-Line 24 3.3 Seam Creation 25 3.3.1 Creating the Intra-pack Seams 26 3.3.2 Creating the Inter-pack Seams 27 3.3.3 Creating the Inter-layer Seams 30 3.3.4 Seam-creation Process 31 3.4 Experiments 32 3.5 Conclusion 34 Chapter 4 Synced Garment Editing 39 4.1 Introduction to Synced Garment Editing 39 4.2 Geometric Approaches vs. Sensitivity Analysis 41 4.3 Trouble Free Synced Garment Editing 43 Chapter 5 Physically Based Non-Elastic Clothing Simulation 49 5.1 Classification of Deformation 50 5.2 Modeling Non-Elastic Deformations 53 5.2.1 Development of the Non-Elastic Model 55 5.2.2 Parameter Value Determination 60 5.3 Implementation 61 5.4 Experiments 65 Chapter 6 Tangle Avoidance with Pre-Folding 73 6.1 Problem of the First Frame Tangle 73 6.2 Tangle Avoidance with Pre-Folding 75 Chapter 7 Conclusion 81 Appendix A Simplification in the Decomposition of Stretch Deformation 85 Bibliography 87 초 록 99Docto

Simulation der Phakoemulsifikation im Augenoperationssimulator Eyesi

Diese Arbeit beschäftigt sich mit der Simulation der Phakoemulsifikation zur Ausbildung von Augenchirurgen. Besonderer Wert wurde auf die Übertragung der für die reale Operation benötigten Phakomaschine in die virtuelle Realität gelegt. Damit entstand der einzige Trainingssimulator, der über eine Maschinensimulation verfügt