A closer look at Festo's OctopusGripper object grabber
The octopus is an odd creature. The mollusc's large brain makes it a good problem solver, it has the ability to change color in double quick fashion, can dart off suddenly in a cloud of blackish ink and the lack of a skeleton allows it to squeeze through the tightest of spaces. But it's the creature's prehensile arms that inspired German automation firm Festo to create a versatile gripper for the production line of tomorrow. We brought you a quick introduction yesterday, so now let's take a closer look at the OctopusGripper.
The Future Concepts robot has been designed to safely pick up, securely hold and gently put down objects in the workplace. Rather than being developed with a specific gripping function in mind, the OctopusGripper can multitask – meaning that should the production line change, the flexible device can be adapted instead of replaced, potentially saving costs.
Like the animal that inspired its creation, the OctopusGripper's 22 cm (8.6 in)-long tapered tentacle has two rows of suction cups. Its soft silicone structure has a chamber running along its length that causes the tentacle to bend inwards when compressed air is applied, wrapping itself around objects of varying shapes. Festo's engineers surrounded the chamber with a Lycra fiber cover to restrict its expansion and protect the silicone outer skin from bursting, while a wafer-thin polystyrene film has been installed in the middle of the tentacle to make sure that the structure only bends inwards.
Designed to grip securely but gently, so as not to crush or damage whatever it is holding, the small suction cups at the thin end of the tentacle attach to the surface of an object passively, but eight of the larger cups at the other end are connected to a vacuum line that can be actively engaged during the gripping process. Festo also says that the components installed within the tentacle are elastic and deformable, making for safe human/robot collaboration in the workplace.
The OctopusGripper is controlled and regulated by the world's first pneumatic automation platform – the Festo Motion Terminal – which allows for precise control over compressed air flow rate and activation. This app-based software system can control more than 50 individual components.
Festo's Bionic Learning Network has designed two pneumatic robot arms with which to test the gripper's collaborative working potential. Agonist and antagonist interplay are applied for the movement of the BionicCobot's seven joints, which is programmed using the Motion Terminal interface, though it has a manual control panel on its side, too.
The shoulder has three axes, there's one at the elbow, another in the lower arm and two more in the wrist. A rotary vane with two air chambers has been positioned at each axis, with compressed air allowing for mechanical spring-like adjustment.
Based on an elephant's trunk and the tentacles of an octopus, and a furthering of the work undertaken in 2010 on the Bionic Handling Assistant, the buzz words for the BionicMotionRobot are sensitive, gentle, powerful and dynamic. The arm is made up of three flexible segments that allow it to bend in three different directions at the same time.
Each segment is moved by pneumatic bellows according to instructions programmed into the Motion Terminal, with an optical sensor running through the center of the arm recording overall shape and position. Twelve elastomer bellows are covered with a 3D textile knitted fabric that's reported to allow the structures to expand in one direction while limiting movement in another.
The Future Concepts exhibits will be on show at Festo's booth at the Hannover Messe trade fair next month. The video below shows the OctopusGripper in action.