A development team from Festo's Bionic Learning Network, a German-based supplier of automation technology, has created a bionic kangaroo.
With a penchant for boxing and the only animal to use hopping as a means of locomotion, we can all agree our Australian bouncing buddies are pretty amazing. But while kangaroos may forever have our curiosity, its recent bionic counterpart currently has our attention.
Key to the bionic kangaroo's success is a good understanding of the wild roo, which is capable of increasing its speed without using large amounts of energy thanks to a unique jumping procedure and its impressive achilles tendon. As the kangaroo bounces, it stores energy on each landing, using it again for the next jump.
The same basic principle was applied to its bionic equivalent.
The "BionicKangaroo" as it's officially known, has the ability to efficiently recover, store and retrieve the energy it expels with each hop, just like the real thing. This has been made possible thanks to two years of perfecting sophisticated control technology and stable jump kinematics.
Specifically, the construction of the bionic roo has been kept as lightweight as possible, with the main "body shell" made of foam. A balanced mix of pneumatic and electric drives power the legs, which allow the kangaroo to leap an impressive 80cm with each hop. "Festo paid particular attention to the mobile energy supply on the artificial kangaroo and even developed two different concepts for this purpose," explains the Festo website. "Either a small compressor or a high-pressure storage device can be placed inside the body. Both supply the compressed air necessary when jumping, which is dosed out exactly by two Festo MHE2 solenoid valves. Lithium polymer rechargeable batteries act as electrical energy storage devices. They supply both the valves and the electric drives, as well as the integrated Festo CECC control system, with the necessary power," says Festo.
Festo explains that a pneumatic, lightweight cylinder is responsible for powering the legs: "The knee and ankle joint are connected via a so-called positive kinematic device, resulting in an interlinked movement sequence. The function of the natural Achilles tendon is adopted by an elastic spring element made of rubber. It is fastened at the back of the foot and parallel to the pneumatic cylinder on the knee joint. The artificial tendon cushions the jump, simultaneously absorbs the kinetic energy and releases it for the next jump."
Thanks to integrated controls, condition monitoring and realtime diagnostics, the kangaroo is able to consistently remain stable while jumping and landing. If the angle of attack, for instance, is slightly off, the system will monitor itself, consider the variables that could result in an unstable take off or touch down and rely on a complex set of algorithms to ensure the bionic hopper does not crash.
Here's how the jumping mechanism works: prior to the jump, the elastic tendon is "pneumatically pre-tensioned". The kangaroo then begins shifting its centre of gravity forwards and starts a tilting process. As it tilts, the the onboard systems identify the ideal angle before the pneumatic cylinders burst into life, releasing the energy from the tendon and blasting the kangroo forwards.
To increase its jumping distance, the kangaroo will then pull its little legs up to its belly, mid flight, thus creating torque at the hip, which is compensated with movement from its tail, keeping the top of the body almost entirely horizontal throughout the process.
As it lands, the tendon is tensioned once more, converting the kinetic energy of the jump into potential energy. This is then stored in the system and used for the next jump: "The landing phase is the critical process for recovering the energy and is responsible for the kangaroo's efficient jumping behaviour. During this phase the tail moves towards the ground and thus back to its starting position," explains Festo.
With so much going inside the robot, it's hard to believe it weighs in at just seven kilos. This is due in part to its outer construction, made of foam, and its specially designed kinematic system, which is made out of laser-sintered parts reinforced with carbon.
As if an energy efficient robotic kangaroo wasn't awesome enough, the whole thing is controlled by gestures, allowing the controller to beckon the roo from across the room. The gestures are recognised by a band worn on the kangaroo operator's arm. A position sensor in the band detects the user's muscle movements and sends signals via Bluetooth to the kangaroo's control system, allowing for human/BionicKangaroo interaction.
The BionicKangaroo may be adorable, but it's also a remarkable demonstration of integrated automation, proving the potential efficiency of combining different automation components, which could eventually shape the future of both everyday or industrial environments. "Other interesting approaches for the automation technology of the future are the concept of recovering, storing and efficiently reusing potential energy as well as the energy supply system thanks to mobile pneumatics," said Festo.
Festo's website has full specs and details of the device.
This article was originally published by WIRED UK
