Robots moved a step closer to human dexterity here this
week, as engineers demonstrated a small industrial robot with two arms, two
hands and opposable thumbs.
Known as the SDA5D, the
robot surprised passerby at the Automate
2011 Show by lifting spherical objects, such as a baseball bat, bottle and
football from a nearby table. Engineers said that the dual-armed robot,
introduced last year, is starting to make in-roads in industrial applications
ranging from automated assembly and distribution to logistics and palletizing.
"People are finding their own opportunities to use
dual-armed robots," noted Erik Nieves, technology director for the Motoman Robotics Division of Yaskawa America
Inc. "They have an intuitive sense of what these robots can do because they
can identify with the idea of having two arms."
Nieves said that the SDA5D's "bigger brother," introduced
three years ago and known as the SDA10D, is beginning to be employed in
automotive assembly plants and for de-gating operations in plastics
manufacturing. It's also being used by the National Aeronautics and Space
Administration (NASA) for space simulation operations.
Motoman engineers believe that the concept of a two-armed
robot is important for factory automation and assembly. Industrial robots,
which are celebrating their fiftieth year in existence in 2011, have long used
single-arm designs. Problem is, single-arm robots can't do some simple
operations, such as lifting and manipulating non-rigid objects and grabbing
"Robots are already prevalent in any operation that you can
do with one hand," Nieves said. "But if you're going to grow your area of
application into assembly, you need to endow the robot with the same kind of
dexterity that a human operator has."†††††††
Nieves said that Motoman succeeded in bringing dual-armed
operation to robots because its engineers found a way to eliminate the
traditional motor shaft from the servo mechanisms that move robotic arms. By
doing so, they endowed the new robot arm with seven axes of movement, which in
turn enabled the two arms to work without interfering with one another.
"Instead of having traditional servo motor construction, we
got rid of the motor shaft," Nieves said. "That opened it up for the
flexibility that's needed for seven-axis construction."
Motoman then supplemented that flexibility by incorporating
an adaptive gripper from Robotiq
ends of the SDA5D's arms. The gripper is considered a significant addition to
the dual-armed concept because it adds two fingers and an opposable thumb to
each robotic arm. Each gripper employs one motor in each finger and in the
opposable thumb, and incorporates a fourth motor that helps position the
fingers and thumb in relation to one another. By having fingers and a thumb,
the robot is able to lift long baskets of parts and odd-shaped components. (See a video
of the robot
and grippers in action.)
Nieves said he expects that robot's dexterity and human-like
qualities to make in-roads in a broad new array of industrial applications.
"People have these wonderfully agile end effectors, called hands, on the ends
of each arm," he said. "But even so, there are a lot of tasks that require two
arms to do."