Pino robot teaches himself to walk, no lie

Pino robot teaches himself to walk, no lie
TOKYO — Humanoid robots like Honda's Asimo and Sony's SDR-4X are complex, high-tech creatures that arose out of huge corporate investments. And then there's Pino, who was developed in the image of a modern Pinocchio. This pint-size robot stands about 28 inches tall and was expressly developed for simplicity. Like his more sophisticated brethren, Pino walks. But thanks to a so-called genetic algorithm, he learned to do it all by himself.

"We started development of Pino as an attempt to make a humanoid robot as simple as possible," said Fuminori Yamasaki, Pino's chief developer at the Kitano Symbiotic System Project at Japan Science and Technology Corp. (JST). Pino was one of the early results of a program to study a new control system for bipedal walking.

The design and name have been licensed to ZMP Corp. here, which is selling the robot, mainly to universities and research institutes, at about $30,000.

At the same time, the Kitano team has made public all the Pino technology — from the blueprint and circuitry to the software (source code) and a list of components — at the Open Pino Web site online. The aim is to promote robotics research using Pino as a model, much as Sony Corp. hopes to do by opening the Open-R architecture of its Aibo robot.

When Pino development was started in 1999, the only humanoid robots around were Honda's. "It gave people the impression that humanoid robots were complex, high-precision gadgets eating up a lot of development money," said Yamasaki, who set out to show that need not be the case.

Yamasaki was then a student working at Sony to help Hiroaki Kitano, senior researcher at Sony Computer Science Laboratories Inc., get an entry together for the RoboCup robotics-competition league. Kitano, who did early development work on Sony's animal-like Aibo entertainment robot, was running a three-pronged robotics program for JST, which is under the jurisdiction of the Japanese Ministry of Education, Culture, Sports, Science and Technology. Besides Pino, the Kitano Symbiotic System Project has also developed SIG and Morph, designed to study intelligence and sensors that will be required if robots are to live together with humans.

Kitano recruited the young designer for the Pino team, along with art director Tatsuya Matsui, who said he designed the shell of the robot with the image of "Pinocchio in 2000" in mind.

Simple steps

Yamasaki, whose job title was research assistant in the project's symbolic-intelligence group, said he wanted to prove that humanoid robots can walk using motors that are nowhere near as powerful as those used in commercial robots like Asimo and SDR-4X.

"Using less-powerful motors, I pursued a solution that makes the robot walk with high energy efficiency," he said. He chose motors slightly short in torque to do the job.

The usual route to making a robot walk is to analyze the human gait and devise real-time control of the robot's joints to mimic it. Honda's and Sony's humanoid robots are controlled in this way. Yamazaki first tried the same approach, "but inexpensive motors do not have enough torque. So I switched to a genetic algorithm," he said. At first, motors with a maximum torque of 25 kg-cm could not make Pino walk, but now, equipped with the genetic algorithm, he steps smartly using 7-kg-cm-torque motors, Yamasaki said.

In this algorithm, robots "learn" how to walk by themselves through trial and error. For example, large steps in many trials are evaluated and the successful ones "inherited" in the next generation of the walking-control software. "At the very beginning, Pino was just wiggling. But overnight, it had learned by itself to walk so long as the evaluating parameter is properly set," Yamazaki said.

Yamazaki, Matsui and Kitano started the Pino project in October 1999. Pino stood in April 2000 and started walking two months later, in June. That's less than a year from concept to working model.

A little more than a year after that milestone, in a move timed to coincide with the Humanoid Conference 2001 in November, the team opened up the Pino platform for other developers' use. The name "Pino" and Matsui's Pinocchio-like body design remain registered trademarks, but the rest is up for grabs. "At the beginning, it was just my hope to open the technology," Yamazaki said. "But we wound up opening the technology thoroughly, well beyond my expectation."

Anybody can download source code, revise and redistribute it. Based on the information posted on the Web, developers can build a robot using off-the-shelf motors and CPUs defined in the parts list. Yamasaki said he deliberately used components that can be easily found in parts shops, in the hope that Pino's architecture would be opened.

Pino's basic architecture is a combination of Futuba Corp. servo modules — 26 in all, falling into three types. The controller consists of two components: an SH2 processor (SH7065) as the master and a complex programmable-logic device (FLEX10K30A) as slave. The SH2 is connected to a PC via RS-232C.

Frugally redundant

To reduce production costs, the design uses the same components — Pino has 600 components in all — as many times as possible. That leads to some redundancies in the mechanical architecture. But Pino can be built with relatively inexpensive parts. Yamasaki toted up his version's components and materials cost at roughly $15,000.

The Open Pino Web site is based on the GNU General Public License (GPL) method. "We wanted to open Pino technology so that all people who are interested in Pino can use it. But at the same time, we want to make clear who has the copyright," said Yukiko Matsuoka, spokesperson of the Kintano Project. The Linux operating system is a famous example of a GPL open-source agreement, "but Pino is not software, so there is no exactly suitable method. We use the GPL framework and if some trouble occurs, we'll discuss it," Matsuoka said.

JST and the Kitano Project have licensed Tokyo-based venture company ZMP to use the name "Pino" and the exterior design. The robotics startup produces its version of Pino using both the licensed and the public specifications. "Orders are increasing, surpassing our production capacity," said Hisashi Taniguchi, president of ZMP. By summer, ZMP plans to work with another manufacturer to increase production and intends to lower the price to around $20,000 per unit, he said.

Yamasaki, meanwhile, has wrapped up his part in the Pino development and is moving on. He said he now wants to build a robot with high energy efficiency — one that can boogie all day on the power from a few dry cells

. He returned to the Osaka graduate school of engineering in April to join Asada Laboratory, one of Japan's leading labs in robotic technology.