Small-price service robotics thanks to low-cost robot joint

Serving orange juice, loading the dishwasher or sorting purchases. The new low-cost igus robotics concept from Treotham is intended to make these tasks possible.

Under the name ReBeL, igus presented a new kind of joint, driven by a strain wave gear, at Hannover Messe 2018 as a single component for the first time and also showed a study of a 6-axis service robot. The new joint is fundamentally different to the previous robolink models: instead of stepper motors, brushless direct-current motors are used in the joints for the first time.

Thanks to maintenance-free injection-moulded parts, the new ReBeL series is set to become a real bargain for robot manufacturers.

A practice household assistant for the home or in the office. Easy to program at a reasonable price. Who does not want this? The topic of collaborative robotics – interaction between people and machines – has now been taken up by igus with its low-cost robotics in the form of robolink. The requirements for the components were that they must be light and cost-effective. The result is the ReBeL joint.

“Alexa, bring me a glass of orange juice,” could thus become reality when the product is used in combination with a voice control system. The new low-cost robotics concept is fundamentally different to that of the previous robolink joints and makes it possible for robot manufacturers to generate new solutions. Instead of stepper motors, brushless direct-current motors (BLDC motors), are used.

Due to their small size, the BLDC motors can now be installed in the maintenance-free strain wave gear of a ReBeL joint. The control equipment is also built into the axes and thus renders an external control cabinet superfluous. “The cables can now be routed directly inside a robot arm as a BUS system”, says Martin Raak, robolink product manager at igus GmbH.

“A further idea is to equip new joints with absolute encoders, that remember the position of an arm even when a power failure occurs,” adds Raak.

The ReBeL now makes it possible to have the 6th rotation axis in the modular robolink system and thus allows all positions to be reached. For bearing purposes, lubrication-free and smoothly operating xiros plastic ball bearings are used. As the gearboxes are also mostly made of polymers, the ReBeL system is very light. The BLDC motors also contribute to weight reduction as they are lighter than the previously used stepper motors.

Injection-moulded parts ensure the small price of a ReBeL joint and therefore of the robot arms.

“We want to make cost-effective robot arms and applications possible for mechanical engineering companies and even private persons.” says Raak.

The new system is suitable not only for tasks in the private area but also for other functions such as collection and delivery services or pick-and-place applications in factories, especially in the case of mobile applications where the robot arm is mounted on a moving platform.