Trends and R&D in virtual and robotized product disassembly
Trends and R&D in virtual and robotized product disassembly
Paul G. Ranky
Introduction
At the time of writing there are over 110 million computers waiting to be demanufactured in the USA alone. These include a variety of PCs, laptops, minis and some mainframes. The task is complex, because the configuration and the condition of these machines are very different. The accurate international figures are not known, nevertheless one can assume that there are hundreds of millions of computers, and other types of electro-mechanical, and other devices(including television sets, automobiles, washing machines and others) that are waiting to be demanufactured in warehouses, and other sites around the world.
The drivers are economic as well as political. Economic because demanufacturing (and disassembly, which is part of the broader demanufacturing process) can be profitable; political because the new generation demands, very rightly so, "green design and manufacturing" practices.
It is obvious that in the twenty-first century engineering management teams,besides functionality, appearance, quality, cost and other traditional design and manufacturing issues, have to focus on multiple life-cycles, on demanufacturing, disassembly, recycling and the environment. The good news is that demanufacturing is good business, at least in the USA, as it should be elsewhere, since there are several companies that attempt to reuse components four even six times during the life-cycle of a product family. (As examples,consider a 40Mbyte hard drive that is disassembled from a modern computer and becomes a second generation drive in a word processing computer, or CRT glass that becomes industrial glass building material, or PC power supplies and keyboards and rack systems that can carry on working in new products, or the significant amount of gold that can be recovered from the PCBs of such devices.)
In particular in Europe, by law, following the internationally accepted ISO 9000x and ISO 14000x total quality and environmental standards, important rules and lessons learned will be fed back to all support systems and personnel, most importantly to the multi-lifecycle engineering, manufacturing and quality teams,enabling them to create environmentally friendlier products in the future. Furthermore, in Europe the well promoted "take back" programs are beginning to make an impact, although at a price pre-paid by the customers.
In the USA the overall approach is less standardized, and mostly economically driven by individual corporations, rather than nationwide government-led controls. As an example, large computer manufacturing companies offer customers around US$30 for a typical first generation, non-functioning PC, a demanufacturing price that clearly yields good profits for them. In many cases there are excellent systems in place that even supercede many European solutions and yield profit. These include processes and systems for separating household waste, including electro-mechanical products that have ended one of their useful-life cycles and can be recycled. The fundamental issue here is to have a good system in place that can cope with a town's demanufacturing, recycling and then remanufacturing challenges, including collection, separation,demanufacturing/ disassembly, and e-commerce solutions that enable buyers to search for and then purchase reusable components and sub-assemblies/ units over the Web.
Design for Environment (DfE) education at universities and colleges, and related standardization in terms of choosing environmentally-friendly materials,processes and components/objects very early at the conceptual design stage, with a strong commitment to environmentally-friendly manufacturing and demanufacturing processes are the way to go, nevertheless, until then we have to deal with the current situation.
Solutions
There are several approaches proposed within the mainly US, Japanese and European communities to this engineering and management challenge:
One major stream of R&D and consequent industrial deployment thrust focuses on electronic support systems, that enable and guide safe virtual disassembly over the Web, in 3D interactive multimedia mode, under browser control, literally anywhere and anytime. This development is most welcome in demanufacturing factories around the world, that must follow set procedures,standards and have no information (e.g. manuals, maintenance records,experience, reusability factors) attached to the physical devices they receive for demanufacturing.
The other closely related main stream of activities for demanufacturing focuses on automating the processes using smart robots.
Application software development for Web-oriented, virtual product disassembly and identification using 3D virtual reality (VR) requires robust analytical methods, object-oriented (OO) modeling and engineering multimedia for knowledge management and communication. The objective of this research is to develop the methodologies, algorithms and technologies to create a Web-based virtual electronic product disassembly and management system. With this Web/computer-based tool, teams of engineers and technicians can virtually assess and visualize the scope of the disassembly problem, identify critical parts of the product, and then create a disassembly process plan.
The novel aspect of this concept is that teams can share disassembly and product identification solutions over the Web in a virtual, concurrent and global fashion. The proposed solution is 3D VR multimedia-based using real images taken from actual objects and then manipulated digitally, nevertheless always retaining the accuracy of the real 3D world. As an example, the Web-enabled virtual disassembly system (WebVDM, Web-based Disassembly Manager)developed at the New Jersey Institute of Technology, a public research university, by Professors Ranky, Caudill and Das, MERC/NJIT, with significant DOD and industrial support by CTC Inc., IBM, Lucent Technologies and others,enables demanufacturers to identify hazardous components quickly – such as batteries, cadmium-coated parts or mercury switches – and proprietary components, information and data. The user can then evaluate over the Web various disassembly process sequences to maximize value of recovered materials with minimum effort and expense. Integrated into CAD/DfE modules, difficulties in disassembly become clearer and solutions more obvious to product designers,manufacturers, quality engineers and others.
The challenge to automate the demanufacturing and disassembly processes are significant. This is because literally every aspect of the processes and their attributes are less known, or often not known at the demanufacturing versus at the new (clean) product assembly stage. As an example, consider that many computers are returned with a variety of undocumented changes, in terms of different cards, hard drives installed, memory configurations and displays. Other items, such as laser printers often have foreign objects trapped inside,coffee poured in and oil and dust damage. This creates an environment in which every machine is different, therefore the disassembly task is different too.
Successful robotized disassembly should rely on the optimization procedures performed prior to the actual disassembly process, preferably in a 3D virtual mode, based on photo-realistic images and simulation in 3D (illustrating wear and tear, dust, etc.) as well as on real-time sensor technology helping robots to be smarter. Currently, the few commercially operated automated or semi-automated demanufacturing and disassembly facilities in the USA, Europe and Japan are successful because they rely on only a very few types of products with very little variation, and because of using sophisticated sensors, mostly vision systems, that can dynamically adjust pre-programmed robots to a limited number of variations.
To summarize, assuming that schools, universities, industry and the society take the DfE educational and practical aspects seriously, by means of standardization, based on the application of environmentally friendly,multi-lifecycle design and manufacturing/assembly and collection rules, the cleanup process of our planet is gradually possible. It can yield profit for this generation, is sustainable, nevertheless overall it will take much longer and cost much more than it took to pollute it … From the robotics perspective, the main direction should include intelligent sensor technology,advanced program generation, real-time adaptation and re-generation of robot path and activity, including tooling optimization using virtual 3D modeling concepts discussed above, prior to the actual disassembly processes on the factory floor.
