An Integration Framework for Digital Progressive Die Design and Manufacturing

This paper reports an effort to develop an intelligent integration framework for digital progressive die design and manufacturing. Both data-and process-centric integration functions are provided by the framework as if a special ight-weight PDM/PLM (Product Data Management/Product Lifecycle Management) and WM (Workflow Management) system is embedded in the integrated engineering environment. A flexible integration approach based on the CAD (Computer-Aided Design) framework tenet is employed to rapidly build up the system while the intrinsic characteristics of the process are comprehensively taken into account. Introduction of this integration framework would greatly improve the dynamic performance of the overall progressive die design and manufacturing process.

A comprehensive survey of augmented reality assembly research

In the past two decades, augmented reality （AR） has received a growing amount of attention by researchers in the manufacturing technology community, because AR can be applied to address a wide range of problems throughout the assembly phase in the lifecycle of a product, e.g., planning, design, ergonomics assessment, operation guidance and training. However, to the best of authors＇ knowledge, there has not been any comprehensive review of AR-based assembly systems. This paper aims to provide a concise overview of the technical features, characteristics and broad range of applications of AR- based assembly systems published between 1990 and 2015. Among these selected articles, two thirds of them were published between 2005 and 2015, and they are considered as recent pertinent works which will be discussed in detail. In addition, the current limitation factors and future trends in the development will also be discussed.

Haptic and visual augmented reality interface for programming welding robots

It is a challenging task for operators to program a remote robot for welding manipulation depending only on the visual information from the remote site. This paper proposes an intuitive user interface for programming welding robots remotely using augmented reality （AR） with haptic feedback. The proposed system uses a depth camera to reconstruct the surfaces of workpieces. A haptic input device is used to allow users to define welding paths along these surfaces. An AR user interface is developed to allow users to visualize and adjust the orientation of the welding torch. Compared with the traditional robotic welding path programming methods which rely on prior CAD models or contact between the robot end-effector and the workpiece, this proposed approach allows for fast and intuitive remote robotic welding path programming with- out prior knowledge of CAD models of the workpieces. The experimental results show that the proposed approach is a user-friendly interface and can assist users in obtaining an accurate welding path.

A holistic decision support tool for remanufacturing： end-of-life （EOL） strategy planning

Remanufacturing is a key enabler for sustainable production due to its effectiveness in closing the loop on material flows, extending product life cycle and reducing production waste and emission. In this paper, a holistic decision support tool to facilitate the product end-of-life （EOL） strategy planning, specifically using remanufactur- ing as a key strategy is presented. The proposed model incorporates checklist methods to evaluate the viability of conducting remanufactufing for a product and its compo- nents. An optimization model for determining the Pareto set of optimal EOL strategies that correspond to maximum economic profit and minimum environmental impact is presented. Since determination of this Pareto set via enu- meration of all EOL strategies is prohibitively time-con- suming, even for a product with a small number of components, genetic algorithm （GA）, specifically NSGA-II has been utilized to achieve rapid calculation of the set of optimum EOL strategies. This NSGA-II method permits extensive sensitivity analysis to understand thoroughly the impact of situational variables, such as reverse logistic cost, technology and replacement part availability, etc., on the EOL decision making, i.e., Pareto front, and thus leading to improved strategy planning and better product design. The case study involving EOL treatment of two types of desktop phones is described to illustrate the utility of the proposed methodology.

Adaptive pass planning and optimization for robotic welding of complex joints

Current industrial robotic welding systems can- not achieve automated solutions for multi-layer multi-pass welding of complex joints due to the presence of non- uniform and irregular welding groove geometries. This paper presents an adaptive pass planning approach for robotic welding of such complex joints. The welding groove is first segmented considering both the variation in groove dimension and the reachability of the robot welding torch. For each welding segment, the welding passes are planned to be in accordance with welding practices, viz., keeping the same number of welding passes in each layer while maintaining consistent welding parameters. An adaptive pass adjustment scheme is developed to address the discrepancies between the simulated results and the actual welding deposition after finishing a few layers of welding. Corresponding robot paths are generated and optimized to ensure minimum joint movement subject to three constraints, viz., reachability, collision-free and singularity avoidance. The proposed approach has been sim- ulated with the arc welding of a Y-type joint found typically in offshore structures.