New robolink multi-axis joint for robots and automation

Justin Leonard, a Director of igus UK, comments: "This radical departure from the usual igus product portfolio came about during the company's involvement with the Robot Football World Cup (RoboCup) from 2006-2008. RoboCup attracts teams of engineers and computer scientists from around the globe, where they pit their wits against each other in the football-field of robotics and artificial intelligence."

Combining joint modules

At the heart of the robolink modular system are the lightweight, maintenance-free and corrosion-free joints with low-friction, low-wear plastic bearings that are driven via cables; these two-axis joints can rotate through +/-90 degrees and twist through +/-90 degrees. In addition, there is a single-axis joint module. By combining joints in series, it is possible to create robotic arms with two, three, four or five degrees of freedom. The hollow tubular 'bones' between the joints can be manufactured from aluminium alloy, glass-fibre composite or carbon-fibre composite. Leonard adds: "The elasticity, light weight and possibility of a central drive system are a real innovation in the field of low-cost robotics."

Prior to launch, beta-testers were provided with igus robolink prototypes for a wide range of trial applications; these ranged from maritime robots for use with underwater vehicles, through to mobile robots on the ground for handling contaminated or explosive materials. Other examples include humanoid robots, camera guidance equipment and systems for facilitating interaction between man and machine. Further trials were carried out in the medical sector, as well as in the field of animatronics.

To articulate the multi-axis joints, igus has developed a range of Bowden cables with high-performance polymer jackets that combine low friction with a long service life. The igus Bowden cables have extremely small bending radii, which makes highly flexible movements possible, as well as frequent relative movements. The plain bearings inside the joints are made of iglidur J.

A comprehensive range of complementary accessories has also been developed; including flange shaft blocks for attaching the arms, interior divisions for the organised routing of the drive and data cables, a cable tensioner for straightforward tensioning of the system, a range of pulleys for cable guidance; and position sensors.

Drive units

On the electro-mechanical side, igus has developed space-saving drive units, available in different performance classes, with the option of four or five drive motors installed within a single housing. In addition, an individually configurable drive disc is available that can be attached to a wide range of different motor or gear shafts for connection to the wear-resistant cables. Simple control software is in development for intuitive programming of a four-axis arm.

The robolink joint module system is now available from igus. Follow the link for more information about robolink; to keep up to date with future developments, go to www.igus.co.uk/Robotmoduledevelopmentblog.