Tài liệu sưu tầm__Những bài viết hay về UG NX__NX Knowledge Driven Automation

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NX Knowledge Driven Automation

Over the last few releases UGS has been quietly redeveloping its kn
automation tools within the NX portfolio. Al Dean takes a look at where the state of the art is at.

Anyone that’s been following the 3D CAD, PLM, ‘call it what you will’ industry for the past ten years will know that many vendors and their users are examining the technology they use to find additional ways to optimise their efficiency and productivity. Now that we are at the stage where the creation of pure geometry is rapidly reaching levels of maturity, one of the next frontiers is going to be taking the wealth of knowledge contained within an organisation and distilling that information into a re-usable format that can be retained and built upon as an organisation moves onwards and upwards.

Part of this is the sudden (or not so sudden) realisation that we are faced with a rapidly ageing workforce, which holds much of the knowledge that has built up over the past decades and given time will simply disappear - taking that critical information with it. In addition, the need to ensure that the products we deliver to market improve upon their predecessors has never been more critical and using innovation as a source of gaining competitive advantage means that we need to ensure that mistakes are not repeated and that knowledge gained with each product iteration is capitalised upon. So, how can technology assist with this process?

In this feature, we look at the tools available within UGS’ NX product portfolio that allows you to do exactly what we describe above and, as ever, this is encapsulated under the tidy banner of Knowledge Driven Automation.

However, before we push ahead with that, it’s perhaps worth taking a few minutes to look at the background work done within Unigraphics (and now NX) that has given way to the new set of functionality. Until the NX release, the Unigraphics product line had a wide range of kn
engineering methods that could be deployed - Knowledge Fusion, Journaling (creation of macros), and programming (using C, C++ and Grip).

The problem with these separate languages was that they all had differing degrees of Application Programming Interface (API) coverage within NX and UGS’ development team had to maintain each language’s API libraries in isolation. Post-NX3, UGS added .Net and Java to its language offerings and the new common API layer meant that if one development department adds an API call in the language they are responsible for (for example Java) then this new API can now be rapidly enabled across all the other languages thus enabling the UGS development team to maintain and improve the functionality coverage of all APIs across all languages.

The situation now is that NX’s Knowledge tools are all built on a single, common API that talks directly to the very core of the NX product set. While there are still various methods of creating and maintaining the kn
processes and functionality (more on those shortly), it means that whichever approach you take, you’re now working with the same base level layer of technology. And to prove the point, this is also the very same set of tools that the NX development team uses to build NX in house. In the scope of this article we’re going to take a look at the various methods of incorporating knowledge capture and reuse into your workflow and organisation and to do that, it’s perhaps best to split it into different target user groups or levels of complexity.

Tools for engineers

The base level knowledge integration technology available to NX users is found in two areas: Journaling and DesignLogic. Journaling is a term that’s been in the IT lexicon for some time and describes its use pretty succinctly – it’s the recording of a series of actions that makes up a frequently used process – or to use a more common term, a macro. The difference between previous journaling tools and the post NX 3 tools is that the information captured is much more descriptive and standardised. Pre NX 3 it was possible to record all of your interactions with the system (in terms of input, keystrokes, mouse movements) and such, then replay those to carry out common tasks. Post NX 3, the tools are much more closely linked to the core functions of NX, as it’s using the
access we discussed earlier. Recording a journal is still an easy process, but the code you generate is much more integrated into NX and adaptable. What this means is that if you want to dive in an adapt it, you can, because the data is output in standard VB code and fully annotated – making the whole process much more efficient.

DesignLogic differs in that the knowledge capture process is much more interactive and done within the standard NX user workflow, using the standard dialogs. While journaling essentially allows you to record a series of steps, DesignLogic is much more interactive. As you’re defining your parametric model, you have the ability (at almost any point) to start to integrate more sophisticated variables, calculations and look-ups. For example, while the basis of parametric modelling is the linking of dimensions within a geometric model, with DesignLogic this is extended to allow a model to contain more complex calculations, formulae, functions or references. You’re not just defining geometry characteristics, but integrating knowledge about function, performance, specifications – all of the information that defines a part or feature’s function that truly drives the product’s form, rather than just pure geometry.

NX is delivered with a wide range of standard calculations and formula building tools that can be linked to intelligent measures as well as standard geometry dimensions, so you can get up and running quickly, but you also have a wide range of standard, in-UI tools that allow you to create very specific functions within your model. The results can get as complex as you require and if you choose to do so, you can define your own rules or functions that can be deployed through your organisation. But these two methods are intended to be used by the designer and engineer almost on an ad-hoc basis. Yes, through the Function Builder you can formalise standard calculations for reuse by others within your organisation, but these represent the entry-level of kn
and to some extent automation – so how do you get a lot more in-depth?

Tools for automation

The tools for true Knowledge capture reuse and process automation are found in three different areas of NX. As we’ve said, they all reference the same underlying API c
, but the method you use from here on in differs with the results you’re trying to achieve. The concept is that over and above the tools available to assist in driving geometry creation (based on functions), the true Knowledge Driven Automation tools allow you to incorporate all manner of information, inputs and variables that can drive a product’s development. These range from the physical attributes of the model (geometry, material type, functional constraints), through process information *(such as how the product is analysed, manufactured and tested) through to more esoteric, but equally critical information such as cost – or to put it more concisely, “adding the ‘how’ and ‘why’ to the ‘what’ of the design.”

UGS’ solution comes under the banner of Knowledge Fusion, and it has several advantages over scripting-based processes used by other vendors. Because the system is tied so closely to NX’s underlying code, you’re dealing with root level access and this means that any Knowledge Fusion tools are integrated directly into the system – rather than by a script. Why is this important?
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Figure 1: Knowledge enabled UDF (Here a Knowledge Fusion driven UDF has been created to assist with the creation of standard splines. However this UDF also has some extra inputs about material and operational requirements that allow a calculation for compressive stress to be embedded within the feature itself. The feature will notify the engineer if the compressive stress exceeds allowable limits and suggest some remedial actions.)


The answer is that with scripting, you’re essentially giving the system a series of commands to run through, from beginning to end. With the Knowledge Fusion approach, the intelligence you build into it is always available in the NX update cycle – making use and deployment much more efficient, as they are “always on.” It also means that it can gain access to a much wider portion of NX functionality, whether that’s referencing analysis and simulation or linking to activities carried out by data management systems (such as Teamcenter). In this regard, UGS leads by example as several of the new tools introduced to the system are built using the very same tools.

The new Product Validation tools such as Check-Mate, Quick Check use it, as do some of the Process-based Wizards such as F
machining and the Mould and Optimisation Wizards. While there are several methods of doing this (of which I’m not going to bore you with the details), its capabilities are perhaps best illustrated by example. The base level use of these tools is intelligent User Defined Features (UDF). While UDFs are common in most 3D CAD applications, when combined with Knowledge Fusion, they can do a great deal more, in terms of both standardising common practices and automating common workflows. See Figures 1 and 2.
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Figure 2: Knowledge Fusion Feature (Here a Knowledge Fusion Feature has been created to assist with the creation of standard plastic bosses. With the definition of a simple circle as the interface point for the plastic boss, a dialog has been created which allows the user to define the boss using engineering functions and basic references to the model. By defining the boss diameter, projection direction, draft angles and other variable (such as number of support ribs), a complex piece of geometry is created automatically.)

Of course, features are one thing, but what about driving the creation of a more complex part or indeed, assembly. While examples are manifold, a good solid one is a wizard that’s been developed to assist with the design of autosport wishbones. This shows that you have the ability to incorporate all manner of specification, non-geometry type data and inputs into the design process. See Figure 3

Process Studio

Alongside the creation of User Defined Features, Parts and Assemblies, Knowledge Fusion can be used in much more involved design processes that step outside the realms of traditional part design. By using the Process Studio (introduced with NX 3), you can integrate downstream processes into a cohesive whole that not only handles the process of defining the geometry of a product but also incorporates all manner of other associated activities. Using a flowchart style approach, The Process Studio allows you to build up a series of stages that a part or assembly must go through to achieve completeness. You have the ability to add additional steps alongside geometry handling that can look out to analysis and simulation, even machining, to ensure that the product you create at the end confirms to all of your requirements – in terms of functionality, performance and manufacturability. Interestingly, the processes created are also fully interoperable with Teamcenter, so these process wizards can be version controlled with TeamCenter like the parts themselves. You work through the steps you require, which are managed (in terms of sign-off) when required and fully documented.
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Figure 3: The design of autosport wishbones. (The starting point is the surrounding assembly, from which the basic interface points are extracted. You kick off the wishbone wizard and select the Forward Inner, Rear Inner and Outer Points as the starting point. You then define the number of cross sections required to drive the form of each arm of the wishbone. As you add angles, the system automatically updates the geometry, so you can see the effect of your design modifications in terms of both output, performance and on-screen geometry – this is an excellent example of why having Knowledge Fusion built directly into the NX update cycle is a good idea.)

Full help can be created for the wizard. Here, standard aerodynamics and regulations are linked to directly from the interface to add context to the work you’re carrying out, as the arms are fleshed out in solid (see green geometry onscreen). The final output from the wizard shows the basic wishbone in place.

Implementation


Now that we have a much wider understanding (hopefully) of how Knowledge Driven Automation can be integrated into your daily workflows and organisational best practices, it’s perhaps best to take a quick look at the front loading requirement to firstly create, then implement them. While traditionally kn
engineering has been perceived as a time and consultation-heavy process, the facts are that, with a much wider range of IT skills becoming commonplace amongst today’s engineers and designers and much easier, more standardised methods of knowledge capture, this type of work can truly become a standard part of your workflow.

Looking back a number of years I can remember slaving away for weeks writing custom scripts to extract
vertices from an AutoCAD drawings of ventilation products to transfer them to Moldflow for injection moulding analysis. But things are much different with today’s systems and within NX particularly. The plastic boss example we looked at took less than a day to develop. This might sound like a lot, but with the effect of reducing the creation of a single, complex feature to a few seconds and considering that in this type of component there would be many such features, the time saved is tangible to say the least.

The wishbone example, due to the complexity of the process, the inputs, calculations and ensuring that it all stood up to FIA regulations, took longer - estimated at around the four to five day mark. Again it sounds a lot, but consider the end results when deployed. This wizard reduced a complex design process from four hours to a mere 15 minutes per member. There’s the additional benefit that because the groundwork had been done, there were no additional steps required to ensure that the subsequent form adhered to FIA regulations, which could take an additional half day per member.

Even at a base level, using DesignLogic to integrate standard or customised engineering calculations into your product means that you can ensure that you’re building intelligence into your model, so that geometry is defined by part or assembly function, rather than pure geometric relationships. Moving on, the creation of standardised UDFs means that the whole design team can create features and entire parts that conform not only geometrically to your organisation’s (or international standards) requirements, but also according to functional, specification driven or manufacturing requirements.

But it’s when you take the Knowledge Driven Automation technology to its current state of the art with Knowledge Fusion and Process Studio that you begin to realise the potential to automate hugely complex processes. Indeed, many of UGS’ current customers are doing this to assist with the development of very complex products in all manner of fields, through the usual bastions of aerospace and automotive into the realms of medical implants and consumer goods.

Knowledge for all?

One question we haven’t explored is who this technology is applicable to. The answer is pretty wide open, but can distil down to a few key criteria. Most obviously, you should be looking to remove the bottleneck of repetitive processes or repetitive development of ‘similar but different” parts or assemblies. You might have the need to build or configure assemblies “on the fly” or to order. You might be looking to automate an iterative design process. Also, if you’re looking at it in its truest sense, you should be looking to integrate external non-CAD data into the product development process and to gain more than pure geometry output from your product model. And of course, it goes without saying that you need to be able to formalise, capture and reuse rules for downstream processes.

In conclusion

UGS isn’t alone in the Kn
Product Development technology game – other vendors are working towards similar goals – albeit with mixed results in terms of sophistication and flexibility. As it currently stands, the KDA tools within NX offer the user a wealth of functionality that, due to the common platform on which they’re built, is easy to adopt in the first instance, but then scalable in terms of functionality, capabilities and sophistication as you move up the chain. If your organisation is looking toward the real future of today’s and tomorrow’s product development technology and your products fit, then there is a great deal of benefit (in terms of standardisation of process and method, capture of knowledge and optimisation of development time) to be gained by exploring the potential for Knowledge Driven Automation.
 

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ctm3k49

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bác Huy Thanh à, em rất ngưỡng mộ về tầm hiểu biết của bác.em đang nghiên cứu về UGS NX5 nhưng do bản crack nên có nhiều thứ linh tinh và không đầy đủ. Hơn nữa lại thiếu tài liệu nên toàn phải mò mẫm thôi. Về phần cad thì em đã hòm hòm rồi, nhưng còn các phần còn lại thì chỉ biết đọc cái file hướng dẫn thiết kế cơ bản thôi, chẳng biết làm gì khác cả. nên không thể tìm hiểu một cách toàn diện về các mô dun của nó đươc. bác có kiến thức và kinh nghiệm nhiều mong bác chỉ giáo giúp, nhất là phần mold ,simulation, menufactury thì em chịu. còn phần die mold nữa. em thực sự muốn tìm hiểu hết các tính năng của nó chứ không phải là gia công cơ bản như trong hướng dẫn.bác có tài liệu nào thì nhờ bác upload giúp cho mọi người cùng hiểu biết với. địa chỉ mail của em là ctm3k49@gmail.com nếu bác rảnh thì mong bác gửi giúp em với. em rất cảm ơn bác.
 
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