Cutting-edge motion control simplifies construction of world’s largest flatbed cutter:
The largest flatbed cutter ever constructed is starting commercial operations in Berlin, producing fabric panels up to 260 metres long for a revolutionary new type of cargo airship called CargoLifter.
Developed by Blackman & White, the cutter employs an innovative knife tool which automatically orients the blade as it moves through the fabric - allowing it to generate complex shapes in an environmentally friendly fashion, without the dust or fume by-products of alternative cutting technologies. Flexible motion control software to support the complex real-time rotation of the blade while cutting at speeds up to two metres/second is generated by the Mint motion language from Baldor, running on a PCIbus motion controller card plugged into the system’s host PC.
 The motion controller provides a compact single-card solution for the machine’s cutting movements, controlling two X-Y servo motor axes that move the gantry with its cutting head across and along the flatbed cutting table, plus a third axis to orient the edge of the blade as required. This motion system works autonomously, generating all the real-time positional calculations and servo motor signals, once cutting instructions and operational commands are entered on the machine’s human-machine interface with its graphical Visual Basic control screens.
The controller’s built-in Mint motion language held the key to simple development for this application, as it is purpose-designed to allow high level 'keywords' to be generated for special applications. In this instance, Baldor generated a command called CONTOURMODE which automatically keeps the blade at a tangent to the direction of the X-Y axes. In conjunction with Mint's support for ActiveX - which simplified the interfacing between the host PC and the motion control subsystem - Blackman & White was able to prototype the basic motion control system in just two weeks, helping it to produce this unique machine to the tight timescales demanded by the project.
The NextMove motion controller is a half-size PCI card which plugs directly into the host PC's expansion bus. This PC is mounted inside the gantry which tracks along the flatbed cutting surface by means of a rack and pinion – simplifying the cabling. In this particular project, because of the extreme lengths required, four gantries are used, each covering a length of around 60 metres, at which point the cutting profile is taken over by the next element.
As the controlling PC is housed within the gantry, size and weight of the motion controller were important selection criteria for Blackman & White. Baldor's NextMove card helped to simplify this aspect of the design because it also included enough onboard I/O to handle the system requirements for this application, including the sensors which monitor the suction system used to hold the fabric steady on the work surface, safety sensors, and the solenoid valve actuator for controlling the knife.
The CargoLifter project promises to revolutionise logistics services for mechanical and systems engineering, the construction trade, the on/offshore sector, humanitarian aid etc. - by providing large airships with huge payload capabilities of up to 160 tonnes. These airships will have the capability to deliver heavy and bulky equipment to hard-to-reach locations virtually anywhere in the world without the need for transport infrastructure.
CargoLifter airships will be built in a huge hangar on the outskirts of Berlin. The vessels will transport payloads at typical speeds of 90 km/hour, over a range of up to 10,000 km. The special machine built by Blackman & White for this project, the MasterCut 2100, is designed to produce the fabric panels required for the airship, which will be 265 metres long x 65 metres in diameter. The hanger that currently houses the machine, and eventually the first CargoLifter - which is scheduled to be produced in its prototype form in 2003 - measures 360 metres long x 210 wide x 107 high. This is large enough to slide in the Reichstag, or St Paul's Cathedral, without touching the sides.
MORE INFORMATION:
CargoLifter is a product of CargoLifter Alert GmbH, a company headquartered in Frankfurt:
Blackman and White is an industrial engineering company with 35 years' experience in the design and manufacture of specialist machines. It produces a wide range of machines for flatbed cutting applications in fields such as sailmaking, hot air balloons, tents and marquees, roof structures and replacement windows:
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