TITAN is a bit of a hulk. It can lift a BMW into the air with just one arm, swing it around and then set it down again in exactly the same spot with barely a quiver. Moving cars is a piece of cake for the world's strongest robot. Built by KUKA, a large German robot-maker, Titan lifts 1,000kg and with its arm extended is as tall as a giraffe. It works out by moving huge concrete structures, steel-castings and pallets loaded with glass.

At just 1.4 metres in height, Partner Robot is a wimp—but its talent is versatility, not strength. Made by Toyota, Partner Robot is humanoid. Rather than being bolted to the floor like Titan, it can walk on two articulated legs. One version can even run a little. Instead of a single giant limb, it has two arms each with four delicate fingers and a thumb. With a violin tucked under its chin, Partner Robot can make a decent fist of the tune to “Land of Hope and Glory”. If you give Partner Robot a shove, its sense of balance is good enough to stop it from falling flat on its expressionless face.

As different as these two machines are, they share a common ancestor: the industrial robot. The first factory robots appeared in the 1960s. They could do only simple, monotonous and mundane things, like moving objects from one production line to another—they were drudges, like the slaves Karel Capek described in 1920 in the play that coined the term from the Czech word robota, or “forced labour”. By the 1990s factory robots had become adept at cutting, milling, welding, assembling and operating warehouses. The cost of industrial robots has also fallen sharply against the cost of people (see chart), which has helped to boost their numbers to more than 1m worldwide. Most of them are built in Europe and Japan, with about half at work in Asia.

Today, thanks to the relentless increase in the power of computing, the latest robots are being fitted with sophisticated systems that enable them to see, feel, move and work together. Robot engineers call this “mechatronics”: the union of mechanics, optics, electronics, computers and software. Some factory robots are now smart enough to be released from their safety cages to work among humans. And as they become cleverer and more dexterous, they are starting to move from factories to offices and homes.

A robot is defined not by its appearance, but by how it is controlled. The more automated it is and the more it can determine its behaviour, the more likely it is to count as a robot. Many single-function service robots are already familiar. They could be vacuuming the floor, cutting the grass or guarding your property while you are away. In some clinics transport robots ferry around paperwork and medicine; or they may be cleaning the office windows. Thousands of robots are also enrolled in the armed forces where they defuse bombs, fly reconnaissance and attack missions in Iraq and Afghanistan, and meander under the sea. They do not look at all human: most are blobs on wheels or, if they are airborne, they may look like insects. But they are robots nonetheless.

Partner Robot is a guess at what a multi-skilled service robot may one day look like, but for the time being it lives in a laboratory. There is a lot of work to do before it and other humanoid machines, like Honda's ASIMO, can be sent to earn their living in the outside world. Even now, humanoid robots greet people or guide them through exhibitions, but they are curiosities rather than something for people to buy and use at home. Eventually, advanced humanoid robots will escape from the laboratory. Indeed, Toyota and Honda expect domestic robots to become a huge market in the future, with machines working as a family helper.

Until humanoid robots are mass produced, robotic blobs, arms and devices that resemble spiders will pave the way. A lot more of these are coming to work in offices and homes, and some will do more than one thing. That, at least, was the message broadcast loud and clear last week at Automatica, a two-yearly robotics trade fair held in Munich. Among a bewildering array of robots that can now do most jobs in a factory there were also machines that could fly, fetch, carry, talk and even perform surgery (see article)—a far cry from the factory drones of 50 years ago. Four trends were on show: robots are rapidly becoming more responsive, cheaper, simpler to program and safer. Take each in turn.

See me, feel me

Aptly for Munich, home of the Oktoberfest, the fair introduced Roboshaker, an automated bartender, created by PAAL, a German company that specialises in packaging systems. Roboshaker, based on a small robot made by Japan's FANUC, can mix a fair cocktail and clear up afterwards. Whenever it picks up a can of drink to add to the ingredients, it examines the lid with a camera so that it can work out where to find the ring-pull. PAAL knows very well that Roboshaker is not about to replace the mädchen serving armfuls of frothing beer. Its job is to demonstrate just how much more capable robots become when they have machine vision.

Vision gives robots the power not only to do more in factories, but also to spread into other industries, such as the food and drinks business, which struggles to find people to do lots of boring, repetitive and unpleasant jobs. Robots with machine vision check to see that bottles and jars are filled to the right level, that the tops and caps fit, that the right labels are stuck on (and neatly, mind). They can recognise and sort pretty much anything extremely accurately and rapidly. Robots put chocolates into a box, sort apples, make salads and wield knives in chilly abattoirs, butchering carcasses without having to take a rest or visit the toilet. Robots even work in bakeries, slicing cakes—because they are more accurate than people and if you make thousands of cakes a day, all those wasted crumbs add up.

Robots are also gaining a sense of touch. Sensors can analyse the surface of materials and, using the amount of resistance they show, work out the force to apply to an object. Giving robots touch allows them to be gentle and to handle things that come in many shapes and materials. Different grippers may be needed for different jobs, and instead of using several robots, some machines now automatically swap hands; for instance choosing flat paddles to lift a box onto a production line and then hands with fingers to pick up small things to put into the box.

Robots need this flexibility now that production managers are having to cope with increasingly varied product lines in their factories. Even the car industry, which pioneered factory robots and which still accounts for some 60% of their use, now makes different models on the same assembly line. The carmakers want to tailor each vehicle to a customer's order, so they are buying robots that can recognise different models and adapt accordingly.

Then there are more ingenious ways of helping robots navigate their surroundings. Even though the arms of industrial robots can twist and turn like a contortionist, they have limitations. When spot-welding, for instance, a robot has to touch the metal with an electrode. This can be awkward inside complicated structures such as the shell of a car. Lasers, however, can be aimed to weld a join from a distance. Comau, an Italian robot specialist, now produces a 3D remote-laser welding system that helps make the new Fiat 500. It transmits a laser beam through an optical cable to a robot, which angles lenses and mirrors in the end of its arm to aim the laser towards the parts that need welding. Using a laser, the robot can make highly accurate welds and position itself for each one a lot faster than it could if it were spot-welding in the normal way.

Big, sophisticated robot systems used on car-production lines can cost millions of dollars. One reason for the high costs of automation in the past is that the price of a robot could sometimes count for only a quarter of the total cost of installing and maintaining it, according to Martin Hägele, who heads SMErobot, a European Union-backed initiative to develop robots for small and medium-sized companies. But now costs are coming down. Robots are continuing to get cheaper—a medium-sized robot able to stack goods onto pallets now goes for about $50,000. And the cost of installing and maintaining them is falling as they become better adapted.

“Some companies think robots are too big, too costly and can only be justified with high-volume manufacturing,” Mr Hägele says. “But robots can now be made that are flexible and much quicker and easier to program.”

The falling cost of computing power makes it practical to give robots features like vision, touch and awareness, says Charlotte Brogren of Sweden's ABB Robotics. The producers that are part of the SMErobot initiative are starting to make light robots small enough to sit on a workbench. When the job is done, they can be picked up and moved somewhere else. That may appeal to carpenters and small engineering firms.

Different sorts of low-cost robots are also emerging that do not look at all like the bulky beams of factory robots. This type of robot contains rigid frames and tubes that use linear motors to slide and swing tools into position for welding, cutting, gluing and assembly. The robot can easily be taken to bits and moved to the next job in another part of a factory.

Such robots are useful in foundries that cut and grind components. These processes often have to be done by hand, because production volumes in small firms are too low for automation. They are expensive, because the law protects workers from the long-term injury caused by vibrations, restricting the hours they can work. The new frame-type robots are flexible and cheap enough for smaller foundries to buy, reckons Peter Haigh, in charge of R&D for Castings Technology International, a British consultancy. “When you have installed robots, you also tend to design things to use them more effectively, which increases their return on investment.”

A lot of effort is going into making robots easier to program. “If we want to sell more robots, we need to make robots easier to use,” says Jürgen Schulze-Ferebee, of KUKA. His company was one of the first to introduce PC-based programming, instead of the specialised code that only the engineering departments of big firms could understand. Some robots are also set up from hand-held devices called “pendants”, which can often program more than one robot at the same time. Robots are getting better at co-operating with each other: in some car plants a big robot now lifts a small one inside the vehicle to assemble components.

Robots are also learning how to understand direct instructions. Some can be “led by the nose”—when an operator moves the arm of a robot around to show it what to do. The software is intuitive, so the robot can describe a perfect circle, say, if the operator shows it just a few points. Some robots also respond to speech.

Obey the law

If robots are to be widely used in offices and homes, they must be safe. They need to learn Isaac Asimov's first law of robotics: a robot may not injure a human being or, through inaction, allow a human being to come to harm. Many robots today are treated like wild animals, caged behind security fences. The working area is often called a robot “cell”, and nobody can enter it until the machine is switched off. This is for a good reason: a heavy, blind robot arm swinging heedlessly from one position to another could kill anyone in its path.

AFP

Highly strung

Making robots safer means giving them more sense of their environment. If the doors to their cells open and someone wanders in they must slow down or stop. Vision and touch are improving fast enough for the cage soon to be removed.

At that point, robots could help a carpenter, or an assembly worker on a production line. Toyota already uses a partly automated robot to lift a 50kg dashboard into a car, which enables a single human worker to position and install it. “One of our goals is to move robots from the factory to the home without any safety fence,” says Toru Miyagawa of Toyota.

The next task will be to write programs that meet Asimov's second law—that a robot must obey orders given to it by human beings, except where such orders would conflict with the first law. The third law asks a robot to protect its own existence so long as that does not conflict with the first or second law. When robots are safe and aware of their surroundings, they will start to encroach on complicated, unstructured places such as offices and houses. Eventually, sophisticated multi-task service robots should be able to comply with all three of Asimov's laws and fulfil many of science fiction's promises.

These service robots may be humanoid—after all, they will be working in an environment designed for humans. But then again, many may continue to assume entirely different forms. As with industrial robots, the first service robots to enter production will be shaped by their job.

For instance, it makes sense for a robot that carries someone to look like a wheelchair. A robot chair could be told where to go. It would know how to steer itself without banging into anyone. Later this year Toyota aims to put two-wheeled robotic chairs, able to stabilise themselves, into a Japanese shopping centre and some of its company hospitals. They look a bit like large Segways.

A few other service robots are already making their way into the wider world, and they do not look human either. Care-O-Bot is a single-armed robot that rolls along on spherical wheels. It is a butler, fetching and carrying, working appliances and making telephone calls. It is built by Germany's Fraunhofer Institute with parts from SCHUNK, a robotics specialist, and is the type of service robot that is closest to production. Care-O-Bot can sidle up to Roboshaker, fetch a drink and serve it on a silver salver. But, if you value your ears, don't ask it to play the violin.