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By Jason Brett, April 17, 2013
When a freight train rumbles past me at a rail crossing, the words "intelligent schematic" are not the first ones to pop into my head. I tend to think "awesome" and "powerful," as the diesel-electric locomotives weighing hundreds of tons shake the earth hauling thousands of tons of loaded cars. Others think "industry" and "economy" in reflecting on the importance of the rail network and the engines that drive a lot of the country’s gross domestic product. The more romantic may think "history" and "adventure," wondering where the goods have come from, where they are headed to, and making associations to the storied histories of railways around the world.
A select few, however - such as electrical and mechanical engineers, they with an intimate understanding of the complex systems inside these incredible machines - think of the thousands of hours of design that go into making these machines efficient, economical and reliable. They visualize miles of power and control cabling, myriad routes of pneumatic and hydraulic lines, throbbing diesel hearts of the machines and the almost unbelievable electromagnetic fields that turn the wheels. For them, that is the true beauty of the modern diesel-electric locomotive, and it is likely they spend much of their working day seeking to enhance it.
Just as automobiles and airplanes have developed over the past decades to incorporate ever more complex communication and control systems, so has the diesel-electric locomotive. On the outside a train might look just like the ones I admired as a child, but on the inside they are running more cleanly, more safely, and more efficiently than before. And just as with the automobile, a large part of this development has come from the ever increasing complexity of electrical and electronic control systems.
It is in this environment of continuous technological advancement where electrical and systems engineers are working to develop the intelligent schematic. The term refers to a way of accelerating the electrical design process while enhancing the reliability of the final manufacturing process. In a sense, the basic idea behind the intelligent schematic is not new; engineers have for decades tried to develop systems for managing schematics intelligently. The traditional approach was to use a series of independent schematics and wiring diagrams, then invest thousands of hours in cross-referencing the schematics to the wiring diagrams and then developing documentation. This process was improved somewhat by modifying mechanical CAD packages to manage the drawings and to provide some links to the documentation. While this was a step forward, it still failed to address the fundamental dichotomy in electrical and electronic design, the fact that schematics are an abstract representation of the logic of the system, while wiring diagrams and parts lists represent physical components - wires, connectors, relays and motors. The abstract and physical documents have to match perfectly!
One approach to the problem is to use a CAD package that is specifically designed from the ground up to address the intricacies of electrical design, such as Zuken’s E3.series. E3.series doesn’t simply address the logical-physical gap; it eliminates it completely through the use of object-oriented design. In E3.series every cable, every connector - in fact every component of the system is represented by a software object. The object contains all the information about the component, both logical and physical. A schematic diagram will show the logical representation of the component, a wiring diagram will show the physical representation of the component, and a parts list will include the detailed part numbers of the component, but each different view refers back to the original object. If an engineer makes an adjustment to a component in one diagram, it is automatically updated in all the other views.
The object-oriented design of E3.series software allows for hierarchical design. Engineering teams can begin by building up a database of commonly-used components, then arranging them into modules representing more complex components. This not only simplifies the design process, but ensures that the entire design team is working from a standardized selection of pre-approved components. While E3.series ships with a library of thousands of standardized components, cables, and connectors, it is easy for the design team to add to this library either by modifying existing parts or creating new ones.
Linking logical designs to physical diagrams using object-oriented hierarchical design is only the first step in developing intelligent schematics. E3.3D Routing Bridge represents the next step by allowing the data in the schematic to be exported to a number of popular mechanical CAD formats for cable routing. This allows the electrical team to design a complete electrical system, and then share their work with the mechanical design team. The mechanical team can perform all necessary cable routing tasks, confident that they have received complete information on cable diameters and connector dimensions. Once they have routed the cables, they can return cable length data to E3.series for use in developing wiring harnesses using E3.formboard.
For a schematic to qualify as intelligent, however, it needs to track the development of the design. This is where modules such as E3.redliner come into play. Designers use the Redliner module to mark up drawings to suggest design changes and track as-built modifications. E3.redliner documents are reviewed by the design team before being incorporated into the final design. This not only creates efficiencies when developing new designs, but also encourages design re-use as engineers can take proven, existing designs and quickly modify them to solve new problems or work in new situations.
Intelligent schematics are also ideal for publishing electronic documentation. Rather than producing thousands of pages of blueprints for maintenance teams to track down, E3.series allows design teams to publish accurate, up-to-date virtual diagrams in a variety of languages. Maintenance teams can take advantage of the object-oriented design to quickly highlight components and cross-reference them in other drawings, reducing down-time and enhancing productivity.
Perhaps the most crucial element involved in creating intelligent schematics is that Zuken includes access to an Application Programming Interface (API) which allows end users to modify how the software interacts with people and with other software packages. E3.series users can modify the software to optimize it for the specific design challenges in their industry, which is why end users from a wide range of industries, from automotive to aviation and from industrial equipment to electrical utilities have found success using Zuken’s software to address both electrical and fluid power design needs.
A modern diesel electric locomotive has over seven thousand wires of various lengths that carry everything from low-voltage digital data to massive power conductors carrying hundreds of amps at thousands of volts. Optimization pays significant dividends. As engineering teams work to squeeze all possible efficiencies from the manufacturing and operating aspects of locomotive design, and tweak various locomotive designs to address differences in operating conditions and regulatory environments around the world, they need a system that is flexible and reliable enough to go beyond simple drawings and charts. They need intelligent schematics.
So the next time I am stopped at a rail crossing, I’m going to turn on my virtual x-ray vision and visualize the power flowing inside the locomotive. The giant diesels turning alternators; the rectifiers and inverters developing just the right frequency to drive the motors; and the myriad data, communications, and control systems that bring it all together. I’m going to think about the careful design that has gone into the system and how the hierarchical, object-oriented design of Zuken’s E3.series software has allowed locomotive designers to develop intelligent schematics. Well... I’m going to try to do all that... but won’t be easy. After all, it is kind of fun to just smile and enjoy as that kind of awesome power rolls on by.
|Jason Brett teaches electronics and materials science in the Technology Teacher Education Program at the British Columbia Institute of Technology. He 13 years of experience in technology education. More...|