Visualisation speeds paths to production

In the words of Phil Sholl, managing director of AMTRI, formerly the Advanced Machine Tool Research Institute: "You cannot design a component without thinking about how you are going to make it." At least you can, and engineers all too often do, but it's extremely foolish. Says Andy de Vicq, AMTRI's technical director: "Many companies are talking about integrated design and production engineering, but not many do it. The world is full of designs for components that cannot be made at an acceptable cost. Integrated design needs integrated production engineering and simulation." In short, it is not enough to design it, nor even to design it and then think about how it is going to be made. Engineers need to model the making of the part to see that it is feasible. Nothing new, and CAM (computer aided manufacturing) packages have had this facility for years, while wire frame simulation of machining has gradually given way to rendered solid models. However, such simulations all assume that everything is going to run perfectly, and there are many manufacturing processes that until now could not be modelled at all. AMTRI's Sholl points out that in a bottling plant, "if you change the thickness of the glass, bottles may start popping off." And in a paint spraying operation, there is no way to visualise in real time exactly how much spray will land on the cars and how much elsewhere. This, however, is about to change, and the breakthrough comes from the computer games industry, where users want to view realistic mass destruction when they unleash their virtual weapons. Ageia Technologies, based in Mountain View, California, is selling a £200 hardware graphics accelerator board called PhysX, and has a library of software based on finite element models and computational fluid dynamics that allows the accurate depiction of material deformation, mechanical failure and the behaviour of fluids, including of molten metal in die casting processes, smoke and dust laden air. Cathartic views AMTRI, which is a licensed developer for PhysX, has now managed to integrate it into a Finnish-authored, object-orientated factory modelling package, Visual Components, for which it is the UK reseller. In a demonstration, Bob Lloyd, who handles the Visual Components side of the business, showed a robot with a cutting tool set up using the '3DCreate' part of Visual Components. The robot was to cut parts from a bar but with an obstacle beneath it onto which the cut parts could fall. On pressing 'initialise dynamics', which starts PhysX, it started making its cuts and, faithful to the uncertainty in direction of falling and bouncing, the cut parts could be seen usually going in one direction, but sometimes in another. Such behaviour could be of great significance, in, for example, decommissioning a nuclear reactor. Another demonstration concerned the behaviour of objects going down flexible chutes, leading to distortion effects that caused items occasionally to become lodged. Similarly, the same approach can be used to model bottles or other parts going along a conveyor. Lloyd describes the library as, "academically rigorous", but he adds: "We are not offering it as an alternative to finite element analysis, because it is not set up to produce graphs and numbers. It's a way of visualising processes and deformation. A lot of the time, if you can visualise a process, you can get a better handle on what is happening. There is nothing else out there that will do this in real time with such compelling results." One of the functions already available is draping and tearing of fabrics. In AMTRI's eyes, this translates into the behaviour of carbon and glass fibre layup in the manufacture of composite products, a field that AMTRI has majored in for some time. One of its ideas is to use the system to develop the technology to support production of functionally integrated components, like composite car bumpers that possess not only structural strength and the ability to absorb some impacts without damage, but incorporate LED arrays instead of light clusters, sensors to activate air bags, and radar antennae for cruise control and near object detection. Says de Vicq: "If there are built-in sensors, how are we going to make the parts without temperature affecting them?" More than 60 software developers are currently using PhysX in 100+ games but AMTRI is the first organisation harnessing it for serious engineering applications - although Microsoft Robotics Studio has been using it in a project mainly aimed at robotics research, especially mobile robots. Slightly more conventionally, first results are now available from studies of the use of Aesthetica from Icona Solutions in Heywood, Lancashire, at Warwick Manufacturing Group (WMG) in a project that's part of its Premier Automotive Research and Development (PARD) programme. Aesthetica simulates and generates interactive, photo-realistic visualisations of automotive vehicle assemblies and subassemblies as they would appear in real life at any point within the manufacturing tolerances set up during design. By applying the results of tolerance stack-ups directly to CAD geometry, design and production engineers take the effects of possible manufacturing variations into account at the design stage. Photo realism Unlike conventional tolerance analysis software products, Aesthetica resizes and repositions the components in an assembly to reflect the tolerances applied, and generates a photo-realistic visualisation. From a histogram of the results of earlier tolerance analysis runs displayed in the Aesthetica environment, the user selects worst case, best case or any other case. The facility has recently been enhanced by the addition of a JT (Jupiter Technology) open data import module for the reliable transfer of 3D product model data directly into the Aesthetica environment. Alan Olifent, lead engineer, Simulation Project, PARD programme at WMG's International Automotive Research Centre, says: "The project has gone very well. The main part of our research has been to undertake calibration studies with regard to real products. We have performed a simulation of an assembly from an OEM involving a number of panels and taken them forward through three subassemblies into an assembly. "We have measured what goes in and what comes out and compared it with predicted results. We have confirmed that the software still needs a bit of work. For example, joining a thin panel to a thick panel means that the thin panel will tend to conform to the shape of the thick one, and the software does not yet take this into account. "Furthermore, we assumed that the means are centred on nominal, but in the real world, this is not necessarily true. Within the calibration process, there is also a need to consider long-term dimensional variability, which the specification represents, compared to short-term variability from measurements taken of the small-scale build. Assuming that short-term data is representative, which is what we have had to do, can lead to error." Meanwhile, visualisation software of a different kind saved millions of dollars in the development of the Land Rover Discovery - by allowing engineers to begin tooling development at a very early stage and well before design freeze. In this case, the software was ICEM Surf, used to generate digital surface model data from 3D scans of the clay styling model. That data was used directly within Catia to enable tooling design to be updated in parallel with design development of the vehicle's body skin and interior trim in ICEM Surf. The same ICEM Surf software was also used by Land Rover for the design development of the body and interior of the Land Rover Freelander 2, which goes on sale about now.