Within 40 years, the world's economy could be fully automated, and humans could retire.

John Dolan says he wants to build a robot that can be flushed down the toilet--literally--to inspect sewer pipes.

Branislav Jaramaz envisions a RoboChef that can move around the kitchen and cook a meal. But he worries, "Who is going to build the robot to clean the mess behind this one?"

Dolan and Jaramaz are among 40 robotics researchers from Carnegie Mellon University's (CMU) Robotics Institute in the US who met recently to brainstorm about the future of their craft. Each was asked to outline a vision for a useful robot that could be built within the next five years.

Past prophecies about robots have been notoriously off the mark. Experts in the 1950s predicted that robots would be vacuuming our floors, carrying out the rubbish, and doing other mundane chores in just a few years.

A half-century later, we're still waiting.

"The impression was that computers were already at least as powerful as the human mind," says Hans Moravec, a CMU researcher who has spent 40 years building robots. "But it's much, much harder for a computer to vacuum the rug than to prove theorems. It's only when humans do it that it looks the other way around."

Moravec says the brain in an advanced industrial robot today works at about 10 million instructions per second--no smarter than an insect. But he says faster processors will allow robots to evolve to reptilian, then mammalian, and finally to human intelligence over the next 40 years, when they will compute at 100 trillion operations per second.

"By that time, the world economy will be fully automated, and human beings will be retired," he says.

Moravec says he plans to produce by 2003 a 1000-MIPS robot that can navigate by 3-D images 1000 times richer than the 2-D images today's robots use with limited success.

Shortly after, Moravec expects to produce a commercial product called a "navigational head." The size of a basketball, it will contain stereoscopic cameras, 3-D mapping and image-recognition software, and applications. The heads will be retrofitted onto existing industrial vehicles such as robotic cleaning machines.

Today, those machines must be laboriously trained and calibrated at great expense. But with the big new brains grafted on, they will learn new routes after being led through them just once, Moravec says. At that point, the specialty market for robots will explode, he says.

Meanwhile, the Web could solve another fundamental problem with today's robots. Although they can extract limited information from their environments via sensors, robots are constrained by the information built into them.

Now robots can learn from this huge store of knowledge, says David Bourne, a principal scientist at the Robotics Institute. Many strides in robotics will involve teaching robots to access the Web and interpret and act on what they find there, he says.

Interpreting information from external sources is difficult for robots and is likely to remain so for a long time. Bourne says the best robots will be those smart enough to ask for help.

One of CMU's mobile robots does just that, he says. "It goes to the elevator, and if it senses people standing there, it says, 'Would you push the Up button for me?' because it doesn't have an arm."