Workers guarded against RSI

A Mitsubishi Electric Automation Systems product story

Edited by the Engineeringtalk editorial team Mar 19, 2007

Three powerful robots are protecting human workers from the risks of RSI (repetitive strain injuries) at a manufacturer of suspended flooring panels.

Three powerful robots are protecting human workers from the risks of RSI (repetitive strain injuries) at a manufacturer of suspended flooring panels.

Suspended flooring systems are becoming almost obligatory in new-build offices and other working environments where computers are used.

The space beneath the floors allows cabling to be run freely to each workstation without looking unsightly or causing a trip hazard.

Access to the cabling is by lifting one or more panels, a procedure so simple that it does not hamper the regular reconfiguration and update needed by professional computer networks.

The robots are RV12SLs, the largest and most powerful made by industrial automation giant Mitsubishi Electric, and installed by systems integrator Barr and Paatz.

The panels are made of steel clad chipboard and weigh in at 12kg each.

Originally a conveyor belt collected them from the production cells, transporting them to the packing area, where they would be manually stacked 38 high onto fork lift truck pallets.

"This was hard physical labour", comments Sterling Paatz who led the design and installation team.

"The first few panels onto the pallets had the operatives bending over, and the last few had them stretching up".

"Additionally every other panel has to be inverted so that the polished steel surfaces face each other, rather than risk them being scratched by contact with the chipboard side".

It was realised that the best way to protect personnel from RSI and back injuries was to design out manual lifting from their processes.

Barr and Paatz are recognised for their expertise in automating materials handling processes.

"We started by listing the givens", recalls Paatz.

"These included that the panels have to be stacked on fork lift pallets because that is essential for efficient distribution and logistics".

"We also had to protect the polished steel face of each panel".

There are many stacking mechanisms, and thought was given to using these and interleaving the panels with protective liners.

However it was soon realised that robots would provide a better solution as they could be programmed to turn over alternate panels in the industry-standard way and would provide a simple, reliable 'one machine' arrangement and would be easy to adapt for future developments.

"Having decided to go down the robot route, we set about finding the best for the job".

"They had to be able to lift a 12kg panel and needed a reach of 1.2m".

"Additionally they had to have the dexterity to perform the inversion, the accurate repeatability for neat and secure stacking and speed to spare for expected increases in production".

The solution was found in the Mitsubishi RV12SL.

These have a payload of 14kg and reach of 1.4m, so comfortably able to cope, and with six axes of motion the manipulation was easily accomplished.

Mitsubishi Electric offers a full range of articulated-arm robots, from small units that can be installed directly next to or even inside machinery and systems for handing small components, to the mighty RV-S series.

The latter are the latest generation of six-DOF (degrees of freedom) robots from Mitsubishi Electric.

The RV-12SL offers repeatability of +/-0.05mm and speeds of up to 9.5m/s.

Paatz sums up: "Using robots to protect people for potential injury is very much an emerging trend".

"It seems that suddenly robots have broken out of car plants and into every industrial sector".

"Amongst other jobs, they are great for the repetitive heavy lift and manipulating tasks where the risks of back injuries and RSI would hang over human operatives".