A 150-centimeter-tall security robot standing in a bank, airport, department store or museum certainly looks unthreatening, but don't underestimate it: its electronic eyes see everything would-be criminals do. The robot transmits images of such suspicious characters to a control center, where they are checked against those of known criminals. If an intruder threatens violence, the robot can also use a stun gun or paintball gun to neutralize or identify the perpetrator.

If it detects smoke or fire while on patrol, it sounds an alarm, seeks the source of the fire, and notifies security personnel and firefighters of the situation.

These tin soldiers cannot be intimidated, have no fear of injury, and need no rest. They can stand guard all night, then transform themselves into amiable tour guides at daybreak. Their built-in touch screens, microphones and speakers enable them to take on a variety of customer service duties, including leading tours, entertaining visitors, and helping guests find other members of their parties.

The Precision Machinery Research and Development Center's new guide robot is child-sized and has expressive eyes that it bats and schrunches up delightfully when happy.

Dual-purpose robots

It wasn't easy designing human-sized robots that can serve as both security guards and tour guides. In fact, the Industrial Technology Research Institute (ITRI), NTU and the PMC all began their research two years ago.

Fu Li-chen, who teaches in NTU's Department of Computer Science and Information Engineering (CSIE), developed a guide robot that went to work showing newcomers around when classes started in mid September. His 150-centimeter-tall blue-gray robot can nod and shake its head, and can make its eyes flash red, green or blue. His robot, the lower part of which is equipped with 12 ultrasonic sensors that enable it to avoid obstacles up to three meters away, can run continuously for up to two hours.

At this point, the campus guide robot's language functions are pre-recorded. The research team has recorded information on the history of seven sites of interest, including the Fu Bell, the Fu Garden, the College of Liberal Arts, and the gymnasium. When the robot reaches a given location, visitors press a button on its chest-mounted screen to play the clip.

Right now, the guide robot can only be seen on the NTU campus, but the security robot jointly developed by ITRI and Shin Kong Security is almost ready to hit the market. It is likely to be the first large humanoid robot mass-produced in Taiwan.

Japan, in contrast, has been developing security robots for 20 years. Japan's Secom Group, parent company of Taiwan Secom, unveiled its own patrol and surveillance robot, Robot X, in 2004. The model, which looks like a small electric car, detects smoke and fires. It can also move at up to ten kilometers per hour--nearly as fast as a human can run--and is intended primarily for deployment in harbors, manufacturing facilities, and other large installations.

(facing page) This September, newcomers to National Taiwan University were amazed by the guide robot that welcomed them to campus during orientation.

Tin soldiers on patrol

What makes ITRI's security robot unique?

"Our technology is on a par with that of the US and Japan," says Wang Wei-han, director of the Intelligent Robotics Technology Division of the Mechanical and Systems Research Lab (MSRL) at ITRI. "And we've created the world's first division of labor [between security robots and installed security systems]." Wang explains that the world's security robots typically operate independently, whereas the ITRI robot's systems work with the fire and intruder detectors that Shin Kong installs into homes. This makes the robot in effect a moving sensor that can transmit its data to a security company's surveillance center at any time.

MSRL has also integrated an earlier, smaller robot into the system. Three of these trail the larger robot like chicks behind a hen, creating a distribution of labor across a team. MSRL hopes to eventually give its larger robot the ability to make decisions independently, so that it will be able to direct the more nimble smaller robots and order them out on their own patrols. But AI technology will have to mature further for this vision to become reality.

Currently, most security robots simply passively patrol and observe. Whether one can actively defend itself or even attack a perpetrator in an actual emergency remains an open question.

"The first of the American science-fiction writer Isaac Asimov's three laws of robotics says that a robot may not harm a human being. But because people control a robot's actions, a robot may indeed harm someone. For example, if an unscrupulous person is controlling the robot or if the robot's programming contains an error, the robot can act in a dangerous manner. The next question is whether a security robot can carry a weapon as a human security guard does. And, if someone were injured by such a weapon, who would bear the responsibility?" Wang Wei-han says that MSRL is considering strengthening their robots' active-defense capabilities with an eye to slowing perpetrators down until a security guard can come to the scene. According to Wang, paint guns and stun guns are both possibilities, but he can't yet reveal the details.

When will it come to market?

According to Wang, domestic components suppliers are all waiting for robots to come to market. MSRL expects to next year begin integrating motor, controller, and chip makers, as well as distributors, and hopes to have the whole up-, mid-, and downstream value chain in place by 2010. At that point, they'll begin mass production.

Localized components

According to the International Federation of Robotics, there were 1.93 million service robots in the world in 2005, 16% of which were security and search-and-rescue robots. While the outlook is bright for security robots, high costs remain an issue.

The Japanese firm TMUSK, for example, produces a wirelessly controlled home surveillance robot that is 26 centimeters tall and weighs 3.25 kilograms. It costs about ¥300,000 (NT$87,000). Sales have so far been mediocre--the company has sold about 1,000 units out of an initial production run of 3,000 units. On the other hand, the company's large security robots sell for an even pricier ¥5 million, and fewer than ten are likely to be produced.

"The near-term objective is to start producing components important in the manufacture of robots, such as sensors, mobile platforms, and servomotors here in Taiwan" says Cyrus Tong, manager of PMC's Science and Technology R&D Division. PMC's robotic tour guide stands 120 centimeters tall, weighs 100 kilograms, and costs NT$600,000. Tong says that mass production of the device is still some time away because some of the key components are simply too expensive.

For example, the guidance and positioning systems that keep robots from running into walls and knocking over furniture currently use NT$200,000 laser sensors imported from the US. A key focus of local research is on developing less costly methods of doing the same job.

Song Kai-tai, a professor in National Chiao Tung University's Department of Electrical and Control Engineering, studies autonomous behavior in robots, e.g. walking and dodging obstacles, and has developed a positioning system that uses radio frequencies to overcome the positioning issue in indoor settings. His solution is to mount a radio receiver on the robot and place three transmitters around the room. As the robot moves, it can figure out where it is based on the difference in the strength of the signals from each of the transmitters.

Integrating into people's lives

"Positioning technology isn't a big issue," says Song. "The real question is working out how to get moving robots to interact with people and the environment and safely avoid obstacles on the fly. A tour space in which visitors are moving around is an extremely variable environment. For example, a visitor's backpack might suddenly fall to the ground, or a child might fall down. A robot has to be able to reliably avoid these unexpected obstacles, or even stop abruptly to avoid inadvertently stepping on or crushing someone. Robots have to be safe if they're going to put people's minds at ease." Adding that robots should be tested for their autonomy and reliability, he notes that many challenges remain.

"Taiwan has a real need for security robots," says PMC's Benjamin Jan. "The prevalence of burglar-barred windows makes that plain." Jan argues that it's possible to imagine any number of applications. For instance, a bank might transport cash and negotiable securities in the belly of a security robot. Such a robot would have a GPS system onboard to allow it to be tracked if stolen. It could also have an automatic incineration mechanism to ensure that any thieves would end up with only ashes for their trouble. These kinds of functions are technologically feasible.

The kinds of large robots that used never to be seen outside of laboratories are now out in the public eye and being integrated into people's lives, putting their social acceptability to the test. As technology advances further, it is very likely that the price issue will be resolved and business opportunities abound for security robots in the home.