Students Create Vacuum-Cleaning Robot

Three Harvard graduate students have developed a revolutionary new way to operate a vacuum cleaner.

Although exasperation with household chores was not the motivation for their invention, the three participants in a Harvard science program have created a breakthrough mechanism which enables the vacuum cleaner to operate on its own.

What the student scientists finally did, in fact, is make a robot. "We didn't make the robot for its efficiency, although it's close to what we want," says Paul M. Jury, one of the machine's creators.

Completed this past summer, the contraption--a one-foot high, triangular arrangement of plastic orange panels, ultrasonic sensors, and wheels--is the only one of its kind in the country, according to its makers, Jury, Patrick J. Lusk and Tim S. Farlow '84.

The three graduate students conceived of the robot in a computer software engineering course they took two years ago. "We started talking about it in the course as a project using computer software," says Farlow, who was responsible for the computer end of the project. "We thought about making a robot that was programmable through a real computer on the robot. As it turned out, we used a radio link and programmed it through a separate computer."

The "Tiger Vac," as they call it, holds a small, relatively simple computer in its body which takes signals from the main computer--in this case, the Apple "Mackintosh"--and translates them into actual movements.

Building the "Tiger Vac", also known as a "programmable mobile platform," involved the intricate and lengthy construction of separate components, which ultimately were placed on the robot's main structure. The students did most of the building in conjuction with a Physics 123 course they were taking.

Household Objects

With the aid of computers, "Popular Electronics" magazines, a car battery, tiny flashlights, a complex system of computer algorithms, meters, wires, antennas, over $1500, and an inveterate approach of trial and error, the three graduate students finally completed the project, which will likely be marketed, although in a somewhat different form.

As their next step, the builders will add the robot--after some comprehensive modification--to a vacuum cleaner, a practical use not part of the original design. While the machine was not originally designed for housecleaning purposes, it can be programmed through the communication of its two computers to perform a certain movement or series of movements--a vacuum cleaner following a programmed map, for example.

Another function which enhances the robot's utility, according to its creators, is its ability to perform a series of movements on its own through the use of its ultrasonic sensors. These sensors are in the form of strips on the side panels that send signals back to the computer's Central Processing Unit of the main computer in case the robot--or in this case the vacuum cleaner--bumps into an object on the floor that it must evade.

More important is the mechanism which actually steers the robot, a camera which sends out a signal and gets reflections from objects back--in the same way a radar does--and adjusts its direction accordingly, Jury says.

This "sensory" function is what makes the robot unique, according to Jury. In general, robots are "open--loop robots" that go to a specific point and perform a specific function.

Stanford University's Science Department developed a robot with visual--and not sonar--capacity: a camera on the robot takes pictures of a room and changes direction according to the pictures, visually "mapping out" the room. But this robot "is too expensive and takes eight hours to get across a single room because of its process of taking pictures and then programming," says Jury.

Having been somewhat limited in resources and money--which was raised largely by the Harvard Science Department--the students would like to somehow raise more money on their own to make a better one.

"If we did it all over again we could make it half the size. Conceivably, we could go to a computer company and give them the design of the entire board (the main mechanism in the robot, about two square feet in size), and they could put it all on a single chip," says Jury.

Although the three inventors have yet to obliterate the tasks of ironing, dusting, or doing laundry, they have brought society a little closer to the world of Woody Allen's Sleeper with their motile vacuuming contraption.

"Everybody said it couldn't be done," says Jury, "But we finally did it."