Valk Welding: 2002

Dycore Systeemvloeren from Lelystad has recently taken two robots in use for the production of concrete floor slabs. One of the robots cuts notches for sewer systems and distribution cabinets from the EPS used to insulate the concrete slab. The other cuts ready for use elements to size. A welding robot and an industrial robot where you would the least expect them.

By Theo Egberts

His pet name is Big Bird, and the resemblance with the large bird from Sesame Street is striking. Big Bird wears an orange overall in an elastic waterproof material. Many stitchings allow large movements and give the workclothes the outlook of a firm suite of feathers. "The size and form complete the picture of Big Bird", adds project manager dr. ir. Gert Sollie. "And because of the splashing and dust here, this suite is no luxury."

Sollie is putting it mildly. When the water-cooled diamond wheel cuts in the concrete floor element, the water splashes around. The saw dust that escapes the jets of water sneaks in everywhere. No logical site for a robot, not even an industrial one.

Logical result
The sawing robot of the Nachi brand is supplied by Valk Welding, better known for its welding robot applications and corresponding system integration. With a handling capacity of over 200 kg, the six axes Big Bird is clearly too large for welding purposes. "But strong enough to lift the concrete saw of 100 kg", says Sollie. "The relation with Valk Welding is the logical result of the other robot that we are using here. That one too is linked with our central operating system. It is only logical that when you have made one interface for one robot, you choose the same track for the other one."

In the establishment in Lelystad, Dycore Systeemvloeren produces concrete floor elements with EPS-insulation, a much sought-after product in the house-building sector. The capacity is about 800,000 m2 per year, but can be increased to 1,200,000 m2 with relatively minor internal adjustments. Recently, drastically automated production lines started to deliver pre-stressed elements. In view of efficient production, several manual jobs have been automated. "These are mainly activities that are no longer acceptable for the labour inspection", says Sollie.

EPS as a base
Automation already starts when receiving the goods. The large, pre-formed EPS-parts are unloaded from the lorry with a fully automated handling robot from Rohako in Nieuwegein. The vision system recognises the type and insulating value. Every day, Dycore processes about 1000 m2 of foam that is being delivered in three widths and one standard length of 2400 mm. The plates are then distributed over the production buffer with extra upper storage channels.

The EPS-parts are then glued together with hotmelt to an infinite strip. When an order is released, the foam is cut to the correct size using hot wire. Between the two production lines, we find the Panasonic robot, replacing the keyhole saw. In comparison to the Big Bird, this frail robot has something of Baby Bear. With a 3 mm thick, U-formed hot wire in its fist, the robot smoothly cuts notches for sewer systems, manholes and holes in distribution cabinets. This is done under slight angle to give the fitting piece its conical form. Should the wire loose its form during use, the robot will independently correct this. The cutting wire is heated to red-hot by a welding transformer and Baby Bear will pull the wire tightly in shape with a mounted hook.

During cutting, an electrically controlled stamp provides counterpressure on the bottom side of the EPS. After cutting, the stamp will press the conical cut notches upwards projecting over the EPS-plate. Then again it's the robot's turn. The head is turned and a thin layer of oil is sprayed with a vaporiser at the side of the projecting EPS-part,  to prevent adherence of the concrete so that after pouring and hardening there is a perfect hole when the fitting piece is removed. Dycore produces according to the sequence of loading the lorry and processing at the building site.

See for yourself with Vision
The EPS-parts are being stored after treatment in an automatic intermediate storage place. From there, the 20 m long moulds are fed and the reinforcement steel is being clamped with 180 kN per wire. After pouring the self-compacting concrete, the moulds go to hardening cells where they will stay for about eight hours. The result is a concrete floor slab with a length of almost 20 m. consisting of individual slabs. Now it's Big Bird's turn.

On the left side of the EPS-plate, two groove-form markings have been applied. When the camera has been mounted, Big Bird will see for itself where to saw with the help of the Vision system. The camera detects the exact location of the cut and the width of the plate. Until then, two Dycore collaborators will whisper the exact dimensions.

The Big Bird of Lelystraat is as good as his television brother. The big orange body bents to the plate, the saw turns and when the deafening noise is over, another floor element leaves the production line. Action!

Ultra flat architecture
It is striking that in the immediate vicinity of both Dycore robots, there is hardly any operating hardware or software to be found. All system elements of the production system are integrated in an ultra flat architecture, named CORBA (Common Object Request Brookering Architecture). Contrary to traditional pyramid structures, CORBA allows the making of simple changes without this having consequences for the underlying or top system layers. "Just because there are none", explains project manager Gert Sollie. "All communication goes via an ethernet connection according to standard TCP/IP-protocols. There is no hierarchy in its own right."

CORBA links the central database of Dycore to other departments, such as drawing room, work preparation, administration, management, production control and the various machines such as Big Bird and Baby Bear. The complete installation is hardware and software independent, as proven by the diversity or programming languages: Java, C++ and Concept are being used simultaneously and without any problems in Unix and Windows NT systems and the Modicon PLC's. "With this approach we can remotely monitor and if need be adjust the production process", says Sollie.

(Source: Metaal & Kunststof nr. 17, nov. 2002)