Rodney Brooks: I grew up in Adelaide, Australia. No one in my family had finished high school, and I was smart at mathematics, so I became an academic and got my Ph.D. in computer science at Stanford. I didn’t set out to be a businessperson.

Colin Angle: I grew up mostly in Schenectady, N.Y. From an early age, building and creating things was a real passion for me. I fixed a toilet when I was 3 years old. My mom was a single parent, and when the toilet broke, I’d just read Richard Scarry’s How Things Work in Busytown, and said, “Mom, if you read me the words, I’ll fix the toilet.” Sure enough, I figured out what was wrong. If I was told to go make the bed, I’d immediately think, How could I build a robot to do it?

Helen Greiner: I was born in London and grew up on Long Island. My dad brought a computer home in 1978, when I was 10, and it became mine. Then I saw Star Wars and fell in love with R2-D2. He had such personality. MIT was the only school I applied to, and that’s where I met Colin.

Brooks: I moved to MIT from Stanford in 1984 to teach, and became the founding director of MIT’s Computer Science and Artificial Intelligence Lab.

Angle: In 1988 a friend was going to interview for a job building robots with Rod, so I went too. We were asked to fill out a form about electromechanical devices we’d built. An hour later I had an epiphany that this is what I love to do.

Brooks: Colin was one of three undergrads I hired, and the project I gave him was to build a walking machine.

“People were rooting for us to succeed because they want robots to live up to the promise of Jetsons”
—Colin Angle

Angle: I built Genghis, a six-legged walking robot. Rod did the high-level intelligence, and I built the low-level software, electronics, and sensing. It helped earn Rod tenure, and I won the Adler Prize for outstanding thesis in electrical engineering. That was the beginning of a wonderful partnership that led to building Attila, a prototype for a rover that could explore another planet, for NASA’s Jet Propulsion Lab [JPL].

Greiner: During graduate school Colin and I both worked at JPL one summer. I had two internships there and did my master’s work at MIT and JPL.

Angle: One day Rod said, “I’m thinking of starting a robot company.” I said, “Okay, I’m in.” So in 1990 we founded IS Robotics Inc., focusing on building practical robots. We needed more of a team, so we brought Helen in.

Greiner: I’d started another company to commercialize JPL technology. I thought the opportunity to work with Colin and Rod was an even better one, so I jumped in. In academia robots are built for demonstrations and to investigate new technologies. Starting the company was a way to build robots that would actually be used by people.

AYE, ROBOTS
Robotics are projected to achieve record sales this year. *2014 ProjectedChart Source: Robotics Industries Association

Brooks: We started with no clear idea of who our customers would be. We had no capital, so we did contract research for people. The three of us made a good team. Colin did the electrical, Helen did the mechanical, and I did the software. We had to move quickly to come up with new solutions for our clients. Projects ranged from making toys for Hasbro to military robots for the government.

Angle: The name iRobot comes from Internet-connected robot. We felt that would be the future of the business, so we changed the company name to iRobot in 2000. It’s taken us a long time to realize that dream. In the past year we came out with RP-VITA, used by doctors to remotely diagnose stroke patients and treat those in the ICU and ER.

Greiner: Large companies may do innovation and disruption in the labs, but they have trouble pushing it out into the real world, in part because it’s potentially disruptive to their own business. When you’re a small company like iRobot, you really push on one thing, and that helped us get from research to mainstream products.

Brooks: At one point I spent a lot of time in China, figuring out how to do low-cost manufacturing, which led to being able to make our Roomba vacuum cleaner cheaply. In 2001, Electrolux had introduced the Trilobite, a robot vacuum cleaner in Europe, but theirs cost 2,000 euros, and ours sold for $200.

Angle: The first two or three years, it was just Rodney, Helen, and me. We hired five or six people and built slowly after that. We went 6 years never starting the month with enough money in the bank to make payroll, but we always made it. There was nothing stable about anything we were doing.

Greiner: We’d put our expenses on credit cards and didn’t pay a lot of bills.

Angle: We figured out which suppliers had not put us on a credit hold and went to them for parts. We survived by getting paid half upfront for building robots we’d sell to research labs. People were rooting for us to succeed because they want robots to live up to the promise of The Jetsons. At the 12-year mark, we made about $15 million.

Brooks: That’s when I knew we were on to something that could be sustainable. It’s only fairly recently that we’ve had lower-cost computer components available. The cellphone market has brought down the cost of cameras and small computer systems. The laptop industry helped with battery performance.

Greiner: The challenge in the early years was that while Colin and I were building robots, nobody was running the company. We had to switch from being the innovator in technology to being an innovator in business practices. In 1998 our first venture capital of $2.5 million came from Acer, a large computer company that was looking for MIT startup companies, and First Albany, which was investing in disruptive technologies. After that, I took on the venture capital responsibility before we went public.

Angle: The turning point was 2002. We had our first layoff, which was a crushing blow, but one of our robots explored the Great Pyramid of Giza in Egypt with National Geographic, we sent robots to Afghanistan to help clear caves in the hunt for al Qaeda, and we launched Roomba that fall. Our revenue went from $15 million in 2002 to $95 million in 2004. We went from being a cool company to a business.

Greiner: If you look at building a company the way you look at building a robot, it’s a systems challenge. You have to build both so they’re efficient.

Clockwise, from top: 310-SUGV: This remote controlled machine can be used for military reconnaissance or to remotely view a dangerous scene without risking lives; Roomba: iRobot’s best-known invention, this circular vacuum navigates a room on its own. It also plays a recurring, supporting role in YouTube videos in which cats are seen surfing them; 0510-Packbot: Used to detect and defuse bombs, it was also used to explore the earthquake- and tsunami-damaged Fukushima nuclear reactor; RP-VITA: Say ahhh: This device allows doctors to see (and be seen) and treat patients from a distance.Photos courtesy of iRobot

Angle: For a time the defense side of the business was paying the bulk of the bills. Helen took a lead role in establishing relationships with key decision-makers in the Pentagon. She succeeded in getting contracts that typically went to companies larger than we were. In 2003 we brought in Vice Admiral [Ret.] Joseph Dyer, and Helen moved to chairman, focusing on partnerships and acquisitions.

Greiner: People remembered me because I’m female. I was the robot lady. People have figured out that women buy 80% of things in this country, and not having women involved in developing and marketing products is shooting yourself in the foot.

Brooks: In 2008, I decided I wanted to begin a new venture, so I started Rethink Robotics. We build factory robots that a person can learn to train in just a few minutes. In May 2011, I stepped off the iRobot board.

Greiner: After 18 years at iRobot, I wanted to get back to pushing the boundaries with innovative things, so I founded CyPhy Works in 2008 and stepped down as iRobot executive chairman in 2011. At CyPhy Works, we’re building UAVs [unmanned aerial vehicles], which are flying robots. Most people call them drones.

Angle: People are fascinated by robots because they’re machines that can mimic life. We’ve gotten the industry to where it’s starting to fulfill its promise.

Angle, at age 8, in a robot costumePhoto Courtesy of iRobot

Brooks: When I came to the U.S. in 1977, there were three operational research robots in the world. Now iRobot has delivered millions of robots. That’s a big change, and I’m very proud of that.

Angle: We’re facing an emerging global crisis of caring for our aging population, and we need new technology to help people continue to live independently in their homes. I think that’s the true promise of robots.

Greiner: I’m proudest of the lives saved by our PackBots and getting robots into millions of homes. iRobot is one of the biggest overnight successes that was 12 years in the making.

Our Advice: Angle, Brooks, and Greiner
Founders of iRobot
MANAGE BY CORE PRINCIPLES. Having an innovative culture requires buying into the challenge of being innovative. If someone’s comfortable only with black-and-white cost optimization, that person won’t deal well with the risk of failure that comes with something new.

DON’T WAIT FOR PERFECTION. We knew the Roomba needed an automatic charging station, but the first ones didn’t have that. We wanted to get it on the market and get feedback. You can develop a better product as you go along.

APOLOGIZE FOR THE INCONVENIENCE AT ALL COSTS. We didn’t count on people using our vacuum cleaner every day. At first they were killing the Roomba after six months. So we put a lot of money into a no-questions-asked policy, replacing customers’ robots while we fixed the durability issue. When people have a problem and you fix it, they’ll give you product loyalty.

SEE: Gallery of past and present iRobot products.

This story is from the September 1, 2014 issue of Fortune.