Naoki Maru may live in Hikone, north of Kyoto, down the road from a samurai castle full of katana swords and armour, but for him, the ancient Japanese art of bushido is best carried out with robots, not people. King Kizer, the Maru family robot, has dominated the Robo-One tourney over the past three years, collecting US$50,000 in prize money. Maru, a factory engineer by day, is trying to perfect a way to make Kizer even more of an arse kicker using a technique he had seen many times in anime: A harness that captures human movements and translates them into robotic attacks and other gestures.
Check out video footage of the harness in action below, plus our exclusive interview, where Maru discusses the what it takes to win a robotic deathmatch.
Maru builds the bots; his sons Kenta and Ryoma operate them in the combat tournaments. For a prizefighter, King Kizer is only 40cm tall but has a lightweight aluminium frame, very rapid servomotors and sensors that help it maintain its balance and detect its enemies. Kizer uses the latter to launch speedy, autonomous attacks on foes.
The harness creates a master-slave connection with Kenta. When the boy moves his upper body during combat, sensors with voltage potentiometers transmit the motions via a Bluetooth link to Kizer, which reproduces them. In the video, you can see that there's a bit of a delay, but apparently robot combat is still clumsy enough for this to not have too great an impact. The lower body is still controlled with a gamepad.
We recently visited the Maru dojo to discuss King Kizer and new fighting-robot technologies:
How does the "master-slave" control technology work? Where did you get the idea? Have you used it in Robo-One tournaments?
The master-slave control idea goes a long way back. The concept has a long history in robot anime, and it has been implemented in surgical devices. I've been using it since I first entered Robo-One.
The equipment affixed to the operator's body is known as a "master suit," and I concentrated on making this lightweight.
The strong point of the system is that it's great for adapting to the requirements of the moment. Other systems can only be operated through preprogrammed robot motions. For instance, in hand-to-hand combat, if you encounter a robot that is shorter than what you expected to go up against, your machine will be punching air instead of metal. But with a master-slave control system, that's not a problem you encounter.
The weak point of my current master-slave system is that it's limited to the upper half of the controller's body. But this is a problem that I believe I can solve. I'm also making improvements to use the system in non-combat applications. As you saw, it can also be used to handle eggs!
How do you build your robots?
When I decided to make my first bipedal robot from scratch, I had to study. The manufacturing process includes making the aluminium panels—cutting, bending and finishing—, plus vacuum form molding, resin casting and other techniques. The design is done in 2D CAD, and then I make a model, printing the frame on paper. Once I confirm the mechanical structure of the paper model, I start creating the actual aluminium panels. Since I don't do it in 3D CAD [just 2D CAD] , this work process is really critical.
I already had computer programming skills, so making the robot's control system wasn't so difficult for me.
What is the role of your sons in your robot activity?
They're more than operators—our team is like the driver and mechanics in an F1 race car team. But their most important role is that they keep me motivated. I give it my all so that my sons can be victorious. I doubt I would have the power to keep winning at Robo-One if I had to create and operate the robots and compete in the tournaments all by myself!
Also, my sons sometimes provide me with unexpected inspiration. As children, their perspectives on robot making are invaluable.
In only three years of robot fighting, you have collected about $50,000 in prize money at Robo-One. Why is the Maru family team so successful?
I could not do this if I were not part of a family team. Most competitors in Robo-One are bachelors—there are few family teams. And I don't want to see my kids cry if they lose at the tournament!
Another reason for our success is not the technological power of our hardware and software, but how we manage our team. There isn't a great difference between competitors. in Robo-One. Fighting really hinges not on the actual winning or losing, but on seemingly trivial factors that are not obvious.
To give you some specific examples, one must consider things like safety parameters that are in your robot's design and how they'll affect performance, readiness for bugs that crop up during a fight, as well as strategies and practice based on your study of opponents. You can't count on having a winning streak if all you have done is create a robot with some cool abilities.
What is special about Japanese robots in general?
For Japanese people, a robot means a humanoid, bipedal robot. It seems Japanese are unique in the world in this way of thinking about robots. Many of the competitors in Robo-One watched robot anime when they were kids and that really influenced them. Robots are part of their childhood dreams, and that is reflected in their robot designs and fighting techniques.
Music for the second clip: "Prelude No. 1" by The Grift; no frikkin' clue what the song in the first clip is.