A practical household helper for the home or office. Inexpensive and easy to program. Who wouldn't want that? Igus has now addressed the issue of collaborative robotics - the interaction between man and machine - with its low-cost robotics division Robolink. Lightweight and cost-effective were the requirements for the components.

The result is the Rebel joint, which Igus presented to a specialist audience for the first time at the Hannover Messe 2018. "Alexa, get me a glass of orange juice!" could become a reality in conjunction with voice control. The new low-cost robotic concept differs fundamentally from the previous Robolink joints and enables robot builders to develop new solutions. Instead of stepper motors, brushless DC motors (BLDC motors) are used, which are already state of the art in service robotics.

A flyweight thanks to plastic components

Thanks to their small size, the BLDC motors can be installed for the first time in the maintenance-free shaft gearbox of a Rebel articulated joint to save space. The control technology is also built into the axes, making an external control cabinet superfluous. "The cables can now be routed directly in a robot arm as a BUS system," explains Martin Raak, Robolink Product Manager at Igus. "Another idea is to equip new joints with absolute encoders that store the position of an arm even in the event of a power failure," Martin Raak continues.

For the first time, the Rebel enables the sixth rotational axis in the Robolink modular system and thus the complete accessibility of positions. Lubricant-free and smooth-running Xiros plastic ball bearings are used as bearings. Most of the gears are also made of polymers, which makes the Rebel system particularly lightweight. The BLDC motors also contribute to the weight reduction, as they are lighter than the stepper motors previously used.

A butler for everyone thanks to a low price

Injection molded parts are to ensure the low price of the Rebel joint and thus the robot arms. "Our vision is for manufacturers to be able to offer six-axis service robots for a price of 1,000 euros without a controller or for a maximum of 5,000 euros with an integrated controller," emphasizes Martin Raak. "From machine manufacturers to private individuals, we want to enable lightweight and cost-effective robot arms and applications." In addition to tasks in the private sector, pick-up and delivery services and pick-and-place applications in factories are conceivable; the new system is particularly suitable for mobile applications in which the robot arm is mounted on a moving platform, for example. as