A unique robot-based system for the laying of street paving slabs has been developed by Dutch company Robostreet, cutting operating costs, time and eliminating the huge problem of on-the-job injuries, particularly back-strain.

Streetwise 1200 is the first of a range of machines from Robostreet and already 22 have been sold to the local authority in Rotterdam. At the heart of each vehicle are either four or five Commander SK AC drives from Control Techniques, including the new ultra-compact 5.5kW size D model that controls the hydraulic pump.

“We recognised that there was a significant market need for such a vehicle,” explains Mr A. van Wijngaarden, Technical Director of Robostreet. “Here in Holland, the heavy work involved in street paving is a major contributor to some 5% of employees being off sick through back injuries – a national cost of around €120.000.000. And most countries of the world have a similar problem. Local health and safety legislation is now limiting the amount that can be laid manually and the race is on to build street paving machines that are accurate, safe, fast and cost-effective.”

A group of multi-disciplinary entrepreneurs accepted the challenge and, together with system integrator, Axoll, initiated a study of how bricks are laid and the development work began. Control Techniques’ Rotterdam drive centre was approached to provide drives to control a hydraulic pump as well as a compressor and drives for the servo adjustment of a camera system and a rotating laser system.

An on-board diesel generator produces 400V AC, but this can drop by as much as 200V on heavy load and, on testing other types of drive this caused a trip-out. However, with the Control Techniques Commander SK, there was sufficient DC residue to allow the drive to ride through the dip without tripping. A further factor in its choice was its size. The space available on the panel is extremely limited and the new 5.5 kW Commander SK size D, which is some 30% smaller than its predecessor, fitted in with no problems.

During development, the versatility of the Commander SK proved valuable, with different operating modes being tested under operating conditions to find the most successful.

A 3 kW Commander SK provides compressor control and two small 0.25kW Commander SK drives provide rotation control for two rotating positioning lasers. A further small SK is used to provide precise height positioning of the camera in the vision-control system.

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Courtesy of Control Techniques