New generation of humanoid robots: they sweat and do backflips

Konstantin Sheiko
February 7, 2018

Researchers from University of Tokyo have developed a new type of a robot that is strikingly lifelike in its movement, as well as its appearance. The majority of humanoid robots that we have seen so far did not impress the public that much. These prototypes were stiff, inert, humming and bumbling machines that could not do much except for some basic movements. However, without the test prototypes we would not be where we are now. 

Meet Kenshiro, modelled after a 13 year old male weighing 115 pounds, and its latest iteration Kengoro, which slightly bigger and heavier than its prototype. The ratio of things like foot length and shoulder height to human figures are all almost exact for both robots. Kengoro can play badminton, and it would you believe it, sweats. Mechanic-wise, Kengoro is a new word in the robotic industry. Prior to his unveiling, typical humanoid robots moved relying on actuators, or a motor combined with a gearbox in their joints. 

Instead, Kengoro’s 116 actuators pull on wires that mimic the contraction of human muscles. These ‘muscles’ are even arranged like they are in the human body with some variations. For example, the analog of the human calf muscle is made of two actuators to produce enough force. However, actuators inevitably produce heat as they perform, be it Kengoro or any other robot. 

So the researchers have come up with an ingenious solution to the problem, making Kengoro sweat. Water circulates through its metal frame, which is made of a special porous aluminium. This allows the heated water to escape as vapor, thus releasing heat from the motors. Due to its unique cooling system, Kengoro is able to perform push-ups for 11 minutes straight without interruption.   

Just like us, though, he cannot sweat forever without refueling - the robot requires at least a cup of deionized water every twelve hours to operate. In addition to that, the aluminium construction gives the robot the sturdy, but comparatively lightweight frame. Remember the 1984 Terminator movie, where a cyborg from the future also displayed human-like functions, including bad breath? We are definitely on the right track here, people.  

In comparison with other, more traditional robot humanoids, Kengoro is more flexible, with six times the degrees of freedom. It can stand on its tippy toes, or move its head from side to side, ‘cracking ‘ it. It also has a flexible spine that allows Kengoro to do the sit-ups the way humans do them. All of these functions became possible because of the ‘muscles’ that hold together the robotic skeleton, and they also ensure that the robot is quite powerful - Kengoro can lift its own body in a pull-up.  

Kengoro is not the only newly developed robot that is both dexterous and flexible. Boston Dynamic’s latest iteration of Atlas, marketed as “the world’s most advanced humanoid”, for example, can do backflips. According to experts’ opinion, it is an extremely difficult feat to achieve, and overall, humanoids are not supposed to be able to do this. Moving effectively is already a challenging task to achieve for a bipedal robot, let alone kicking off a tumbling routine. There is a reason why we have had so many four-legged robots developed in the past - their beauty is in their ability to balance easily, both at rest and as they are moving. 

On the contrary, bipeds like Atlas or Kengoro have to balance a bulky upper body on just two legs. Henceforth there has been a long lasting argument that the robotic developers can better spend their time on non-human forms that are easier to master. There are other areas of development where humanoids still struggle. Manipulation, for one, poses a big obstacle, with the researchers trying to come up with a viable substitute for a human hand. Another challenging issue is their battery life that seems to be pretty short with all the balancing. No wonder the Terminator movie cyborgs were powered by two nuclear batteries.   

However, the future looks promising for the bipedal humanoids. The Atlas hardware takes advantage of 3D printing to save weight and space, resulting in a remarkable compact robot with high strength-to-weight ratio and a dramatically large workspace. Stereo vision, range sensing and other sensors give Atlas the ability to manipulate objects in its environment and to travel on rough terrain. Humanoid robots are becoming increasingly more sophisticated and human - like in their performances. 

In all likelihood, Atlas and Kengoro will prove to be a useful invention. Based on its design, the researchers can build new, sophisticated robot rescue machines that can operate in extreme situations like industrial disasters, fires or meltdowns. They can also become a new type of crash dummies since their bodies, equipped with artificial mechanical ‘muscles’ will give a much more accurate picture in terms of what actually happens when the car gets test-crashed. A human-like robotic hand will be developed sooner or later too, and then sky is the limit.    

Over the years, the bipedal robots have become lighter, faster, more dextrous and less prone to fall on their faces. Even if they do tumble, they can now get back up on their own. So it is not hard to see a future when improved Atlas and Kengoro do indeed tread where fleshy humans dare not.