igus UK, more commonly associated as the innovator of plastic bearings, energy chains and cabling products, has developed robolink a multi-axis joint for humanoid robots and lightweight automation applications. A complete modular system, robolink combines enormous design freedom with simplicity and is particularly well-suited where masses are to be kept as low as possible. The design and development of robolink is testament to how igus supports its customers in areas that it hasn’t typically been associated and won the renowned ‘iF product design award 2011’.
“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,” says Justin Leonard of igus UK. “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.”
At the heart of the robolink modular system are the lightweight, maintenance and corrosion-free joints with tribologically optimised plastic bearings that are driven via cables and can rotate and swivel freely. “The elasticity, light weight and possibility of a central drive system are a real innovation in the field of low-cost robotics,” adds Leonard.
Prior to launch, igus beta-testers were provided with 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, used 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 industry, as well as in the field of animatronics.
To articulate the multi-axis joints, igus has developed a range of flexible Bowden cables with high-performance polymer jackets that combine low friction values with a long service life. The igus Bowden cables have extremely small bending radii, making highly flexible movements possible and are suitable wherever frequent relative movements take place. The plain bearings inside the joints are made of iglidur J.
A comprehensive range of complementary accessories has also been developed by igus; these include flange shaft blocks for attaching the arms, interior divisions for the organised routing of the drive and data cables and a cable tensioner for straight forward re-tensioning of the system, as well as a cable pulley range for guidance.
On the electro-mechanical side, igus has developed space-saving drive units, available in different performance classes, with four or five drive motors in a housing. In addition, an individually configurable drive disc is available that can be attached to a wide range of different motor or gear shafts and then connected to the wear-resistant cables. Simple control software is in development to intuitively program and store all the movements of a 4-axis jointed arm.