Issue: Volume: 24 Issue: 7 (July 2001)

A New Breed




Engineers create a digitally designed watchdog

By Karen Moltenbrey

Establishing a new breed of a dog, especially one that can perform specific functions, can be a decades-long challenge. For instance, German pound keeper Louis Dobermann carefully bred his stock of mongrels, terriers, and herding dogs for years in the late 1800s before achieving his goal of the ideal companion/watchdog, known today as the Doberman Pinscher. Yet when designer Nick Wirth recently "engineered" his new breed of dog, he accomplished the feat in just seven months.

Through computer-aided design, Wirth created RoboDog, an electromechanical robotic dog believed to be the largest and most technically advanced autonomous "legged" robot sold commercially. Unlike the litters of interactive dog-like robotic toys such as Poo-Chi, which were introduced in the last few years, RoboDog is a breed apart in that it's a "working" dog rather than a mere toy. Standing 27 inches tall, RoboDog is the approximate size of an adult Labrador Retriever, yet it's strong enough to raise itself onto hits hind legs while lifting twice its own body weight of 26 pounds.

According to Wirth, RoboDog takes leading-edge technology out of the laboratories and puts it directly into people's homes. "We're working toward the universal robotic concept, where a lightweight machine that carries its own power source can be used for a variety of functional tasks," says Wirth, a former Formula One Grand Prix racecar designer, who co-founded RoboScience, creator of RoboDog.
To show off its robotic technology, Robo Science created RoboDog, which the company designed and engineered in seven months using computer graphics.




"If a robot is ever going to complete specific tasks that will make our lives easier-such as emptying a dishwasher or scrubbing floors-it has to be large and strong enough to do these things, and it needs a significant run-time before its power supply runs out," Wirth continues. "No matter how sophisticated they get, those 6-inch robotic dogs that were the big trend last Christmas will never be powerful enough to perform meaningful tasks."

Not only bred for strength, the RoboDog is also intelligent. With an onboard PC, the robot can understand and act on 60 verbal instructions. An integrated camera and radio link enables the dog's owner to log on to the robot remotely via the Internet and "walk" the dog through its environment. In this "watchdog" mode, the owner can see and hear everything happening at the robot's location in real time. The robot can also see in color and read e-mails aloud, using a permanent wireless Internet connection. When placed in autonomous mode, RoboDog can "think" and act on its own, without human intervention.

More than a year ago, Wirth and partner Mark Oates formed RoboScience, a Northants, UK, company specializing in next-generation robotics technology. When researching the "ideal" body construction for a demonstration model, the engineers discovered that the general public found independently powered robots unsettling, especially those that resembled the human form. "We wanted to be able to show a prototype and have people look at it and say, 'I can imagine living with something like that in the future,' " Wirth notes. "We wanted people to be comfortable and not intimidated by its functionality. So we settled on the form of man's best friend."

Because form was as important as functionality, the engineers designed the robot from the outside in so it wouldn't lose its intended shape. But that was no easy feat considering the robot's complexity. Using UGS's (Cypress, CA) Unigraphics CAD/ CAM software, the designers placed more than 3000 components-including the PC, color camera, miniature microphone, navigational system, temperature sensor, range-finder, and more-inside the sculpted body shape of a dog. While doing so, they also had to ensure that the machine's weight stayed within a certain range so that it wouldn't adversely affect the run-time of the battery. "People will never accept even the most sophisticated robot if it has only a 15-minute run-time before needing recharged," notes Wirth.
Far from a toy, RoboDog is a robot that can tackle chores such as carrying bags of groceries and fetching slippers, depending on how it is "trained" by the user. To perform these tasks yet have an acceptable battery run-time, the dog's joints had to h




Far from cute and cuddly, RoboDog is constructed from Kevlar and carbon fiber, resulting in a lightweight but strong product that uses less energy so it can operate for more than 90 minutes at a time. The outer skin is a strong, rigid enclosure that houses the robot's controls and gears. "When you work within a design restraint like this, typically you don't have enough space at the end to fit some vital component," says Wirth. To overcome this issue, the group coordinated changes in surface modeling with internal structural alterations using the software's real-time parametric design features, enabling the designers to create functional components that fit into the overall aesthetics of the robot.

To create this smart, strong, agile robot, the designers used a number of mathematical design tools based on Microsoft Excel to drive the core engineering work. They also used a proprietary stress analysis program, but all the styling and engineering design decisions were made within the Uni graphics modeling environment. Because aesthetics were important, the group again found the software's parametric feature especially useful, which updated the data each time improvements were made to the outer shell.

"With the parametrics feature of Unigraphics Version 16, we could work quickly, whether it was updating the design or testing the effect of material properties," Wirth says. "We never could have completed this project as fast as we did four years ago, without this feature."

He credits parametrics with enabling the group to create working prototypes of the robot's strong, flexible joints in less than a month, giving RoboDog the ability to fetch, play ball, and romp. "The joints we developed can be thought of as the robot's muscles, combining elements, which are usually separated, in a way that provides a far superior power-to-weight ratio than conventional designs-one of the secrets of RoboDog's advanced motive abilities and run-time," explains Wirth. In all, the design contains 16 degrees of freedom: three for the head, three for each of the four legs, and one for the tail.

Another feature that helped reduce development time was the use of Unigraphics' collaborative tools, which enabled the disparate team-working within a 50-mile radius from the company's headquarters-to share complex design information over the Internet. As a result, the group produced a working RoboDog prototype quickly and accurately, notes Wirth.

To minimize costs and save time, the development team decided not to create a physical mock-up before building a working production model. "We decided on the final styling issues within the CAD environment, using UG/Visualize, a photorealistic rendering system," notes Wirth.

The Internet also played a major role during manufacturing. Using UGS's Parasolid XT format, the team transmitted the final design files over the Web to external suppliers, which man u factured the robot's components.

Like all good breeders, RoboScience has committed to producing a limited number of its unique dogs. The company plans to ship no more than 200 RoboDogs in September to customers who have pre-ordered the $30,000 robots. However, Robo Science plans to license its technologies to other industries, which could spur development of new interactive robots for home usage, al though more important is RoboDog's usefulness in dangerous situations such as an oil rig disaster, nuclear reactor incident, or military situations.
Aesthetics were important to RoboDog's overall design. To ensure that the form did not change during the engineering process, the team designed the robot from the outside in, using the software's parametrics feature to create functional, complex c




"We never intended to mass-produce RoboDog. Rather, we built it as a technology statement. But I have to say that RoboDog has been incredibly successful in attracting attention to our company's technology," Wirth says. "I believe that RoboDog can spawn new applications that can lessen the risk for a person working in a dangerous environment such as law enforcement, firefighting, or mining."

No wonder RoboDog is positioned as man's best friend.





Unigraphics, UGS (www.ugs.com)

Images courtesy RoboScience.
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