'Personal robots' get ready to walk on the human side

'Personal robots' get ready to walk on the human side
Robotics technology is migrating from the manufacturing floor to the living room. Human-friendly personal robots are about to move in with us and are poised to create a brand new industry.

The plausibility of personal robots was convincingly demonstrated at the turn of the last century when "humanoid" robots from Honda and Sony got up to start walking. Sony's "pet" robot, the Aibo, made its first appearance in 1999 to be followed by a humanoid, the SDR-3X, in November 2000. Coming soon is the SDR-4X, which promises performance greatly enhanced over the first generation.

Honda first began to focus on biped walking technology in 1986 and in November 2000 announced the Asimo as a demonstration vehicle for the company's robotics research activities. Earlier this year Honda began to rent Asimo to companies and public facilities such as museums.

While Sony and Honda are clearly at the forefront, their strategies differ.

"Sony focuses on entertainment robots. Personally, I expect that entertainment robots will account for a large share of the robot market," said Toshinobu Doi, corporate executive vice president of Sony and president of Sony Digital Creatures laboratory. Accordingly Sony's robot division is called Entertainment Robot Company. "To be useful robots do not necessarily need to walk — either on two legs or four. But the basic technologies are common to all robots and in this point, Sony has many advantages over its competitors," Doi said.

Honda, on the other hand, is seeking to build "general purpose robots, that can act as companions to humans. That is the vision we have," said Masato Hirose, senior chief engineer, who leads Honda's robot research projects.

To live a "human" life, a human-shaped robot has merits because "it can go every place where a human goes. It can use the same tools that humans can use," said Hirose.

In the 18 months since their robots debuted, both companies have made progress.

Sony's second-generation SDR-4X sports more sophisticated walking control and richer communication functions.

SDR-4X's real-time integrated adaptive motion control allows it to walk irregular terrain and slopes and also to maintain posture against external pressure. Thus SDR-4X can balance on a moving plate mimicking a surfing motion.

For Asimo, Honda developed an intelligent real-time flexible walking technology called i-Walk. It features a predictive movement control, which enables Asimo to predict the next movement in real-time and then shift its center of gravity in anticipation.

With this walking technology, Asimo can change its walking pitch and speed seamlessly — short or long strides, slow or fast. Hirose claimed that this kind of dynamic walking ability was unique to Asimo.

Data-processing speed and software improvements allow the rental version of Asimo to walk up or down stairs without preprogramming. The earlier version needed to be programmed in advance with the data (width, height, etc.) about the specific stairs.

At present about 20 Asimos are ready for rent, and about eight of them are now working at museums and companies as guide robots and receptionists.

Biped walking
Biped walking, once considered the most difficult of robotic technologies, has developed by leaps and bounds. The first humanoid league, RoboCup-2002, drew a total of 12 teams from eight countries.. There, some robots could compete in walking speed, and in kicking and defending a soccer ball.

Nagara, an 80-cm robot powered by Pentium III, was judged the best of the humanoid robots in the competition. It was a joint development project of the Gifu prefectural government in Japan and local industries in the prefecture. The Nagara team started development of the robot only in April 2001 but succeeded in " developing the robot from square one in just one and a half years," said Isamu Inazuru, an engineer at the design and development division of Yamazaki Mazak, a member company.

Unlike Honda's early research projects, the Nagara team could avail itself of a fast processor and had strong support from universities and research institutes in developing the walking software.

Researchers are working various approaches to biped walking. At present, biped walking controls based on Zero Moment Point control are widely studied. ZMP control is used for Honda's Asimo and Sony's SDR-3X and 4X. But there are new approaches that may be more effective at creating stable and secure walking.

Atsuo Takanishi, professor of Mechanical Engineering at Waseda University, has developed WL-15, a two-legged walking mechanism powered by Pentium III 850 MHz, to demonstrate a new walking mechanism, the parallel link mechanism.

Human walking largely is a serial mechanism with movements passing serially from hip joint to knees and ankles. Biped walking control methods for robots copy human movement by replacing bones with steel frames and muscles with actuators. But because multiple muscles can connect to one joint, human's also have a parallel mechanism at work. WL-15 focused on the parallel link mechanism. "We wanted to prove that biped walking is possible by creating a parallel mechanism as well as a serial mechanism," said Takanishi.

In the prototype WL-15, a leg consists of three sets of two cylinders. Those six cylinders from the pelvis gather at the foot, which means that WL-15 has no knees. The movement at the pelvis conducts directly to the ankles. WL-15 can make 90-degree turns in two steps or in two seconds.

Each cylinder is driven by an actuator. Thus, six actuators are arranged in parallel to move one leg. The load on each actuator becomes smaller compared to a conventional two-leg walking system. "It can carry a heavy thing with low torque. At present, its payload is about 20 kg, but our target is to carry a man," said Takanishi. "We call it bipedal locomotors. In several years, we want to develop a walking 'wheel chair,' "

There are other attempts, such as adaptive dynamic walking technology based on neural system models aimed at walking smoothly on irregular terrain. One of the next big challenges is running. However, today's motors and actuators do not stand the load of running, researchers say. Though, in a laboratory environment, Sony has showed an Aibo running at 70 meters per minute. The running Aibo, co-developed with a U.S.-based company, Boston Dynamics, adds springs to each of the legs. Sensors were also added to each foot to feed back terrain information which is useful for running control.

The pre-cambrian era
"We are opening a new industry," said Sony's Doi. "Robots are at the equivalent of the pre-Cambrian era in biology," he said. Just as the Cambrian era spawned diverse creatures, "a Cambrian explosion will take place in robotics," Doi said.

"Japan will be the first society where robots and humans live together. In this sense, Japan will function as a test bed and it's Japan's mission to tell the world what happens when robots encounter humans," said Minoru Asada, a professor at Osaka University and the next president of the RoboCup Federation.

When robots go on sale, manufacturers will have to consider the product liability implications of these autonomously moving products.

Sony is planning to introduce a commercial model based on SDR-4X sometime within this year. Its price will be "in the range of prices for high-end limousines," said Doi.

Safety measures are the main issues that Sony is working on before marketing can begin. The robot's joints are rounded avoid harming users' fingers. The robots are designed not to stumble easily, but if they do, they will sustain little damage and would even stand up again. "These are minimum requirement for commercial products," said Doi.

Tmsuk Co. Ltd., a robot venture company founded in January 2000, intends to start marketing a robot guard dog in cooperation with Sanyo Electric Co. Ltd. next year and, later this year, a robot patrolman.

The guard dog robot, weighing in at around 40 kg, communicates with the owner by Foma cellular phones, the 3G phone service provided by NTT Docomo. A Foma handset snaps into the mouth of the dog. While the dog autonomously scans the house, the owner can remotely see and hear the images and sounds as seen and heard by the dog. The owner can also order the dog, over the phone, to take some action.

The 185 cm tall patrolman robot, jointly developed with local academic and research institutes in the Kyushu area and Omron, will sell for around $86,000.

The patrolman can autonomously patrol at 3 km/hour. In a building it can use elevators, and it can charge itself. If it finds a fire or an unexpected object, the robot can alert the control center by voice and image and a person on duty can switch the robot to remote control mode.

"We can implement autonomous reaction to robots. But if robots operate autonomously and do something wrong, we, as manufacturers, cannot take the product liability. So we want a human to make the final judgment," said Yoichi Takamoto, CEO of Tmsuk Co. Ltd.

"With current recognition technology, a robot cannot tell a cat from a person. It's dangerous to entrust judgment to the robot," said Takamoto.

Tmsuk has patented technology to control robots remotely by using mobile phones in Japan, Europe and the United States. "Guarding a country house may be a good use of a guard dog robot," said Takamoto.

Matsushita Electric Industrial Co. Ltd. is investigating how humans react to artificial creatures on a daily basis.

It has been conducting a fiveyear field test of a communications robot designed as a partner for elderly people who live alone.

Like a wombat
To make it friendlier, Matsushita designed the 45-cm high robot in the shape of a stuffed animal — it resembles a wombat — powered by the Intel Celeron 600 MHz processor. It does not walk, but it an move its head and arms. "The shape of a familiar animal gave some users an uneasy feeling. People saw it as flawed, somehow," said Koji Kawamoto, group manager of the home life research group at Matsushita Living Environment Development Center. "Thus we chose the shape of an animal that people know somewhat vaguely, but not in detail," he said.

The robot, equipped with voice recognition, helps users to communicate with the local care center. Considering that target users are in their 70s and 80s, operation was simplified and limited to only an on/off switch and voice instructions. The robot talks using 2,000 phrases. During the test, users felt that about 46 percent of conversations on average were meaningful, reported Matsushita.

"We are investigating whether people accept communication with artificial creatures. Our field test showed that people preferred to talk to a robot than to an inorganic electronic communicator. More than half of all users missed it when it was taken away," said Kawamoto.