IEEE Spectrum October, 2012 - 39

cAmerAs

sonAr ArrAy

LcD

computinG

Two cameras on its chest
plus one on its head give
the robot a broad view of
its work space. A camera
on each forearm provides a
close-up view of objects.

Ultrasound sensors detect
humans moving close by and
slow down or stop the robot.

The robot looks in the direction of the current task or to
where it's going next. The LCD
is also the user interface.

Inside the torso is an Intel
quad-core computer running
Linux, plus power electronics
and cooling fans.

user controLs
By holding the robot's arms and
using a knob and buttons, a
user can navigate the interface
and program new tasks.

Gripper
The hand can be switched
between a parallel-jaw
gripper and a suction device.

sonar array and lcd: erico guizzo

Brooks picks up a set of gears and waves it around.
A Pennsylvania shop made them, he says, using a metallurgical
process involving pressed powdered metal, which ended
up being only about a fifth of the cost of traditional gears.
The robot has hundreds of parts like these, and so the savings
add up. Rethink used this design-for-manufacturing approach
for as many parts as possible, eventually procuring 75 percent
of them in the United States-a fact that Baxter advertises with
a big "Made in U.S.A." sign stamped on its back.
he other way Rethink has cut costs is through software. By giving Baxter the ability to autonomously compensate for its own mechanical irregularities as well as
changes in its environment, Rethink has been able to avoid hav-

t

spectrum.ieee.org

ing to use costly components. So Baxter may not have the most
expensive motors or the stiffest bearings or the most precise gearing, but it doesn't need those things. For example, backlash in
the gears-the slack in teeth couplings that may cause motion
loss and vibrations-can be modeled and then adjusted on the
software side so that the arms move smoothly. And the robot can
use cameras to improve the accuracy of its movements, explains
Elaine Chen, vice president of product development. "You don't
need the robot to be able to go somewhere within 0.01-millimeter
accuracy in order to pick something up," she says, "because the
robot is going to see it, get a fix on it, and then pick it up."
This all gets to one of Baxter's key features: compliance.
A robot is said to be compliant when it's not completely rigid and
when it can sense and control the forces it applies to things. "If
octobEr 2012 * iEEE SpEctrum * NA

39



http://spectrum.ieee.org

Table of Contents for the Digital Edition of IEEE Spectrum October, 2012

IEEE Spectrum October, 2012 - Cover1
IEEE Spectrum October, 2012 - Cover2
IEEE Spectrum October, 2012 - 1
IEEE Spectrum October, 2012 - 2
IEEE Spectrum October, 2012 - 3
IEEE Spectrum October, 2012 - 4
IEEE Spectrum October, 2012 - 5
IEEE Spectrum October, 2012 - 6
IEEE Spectrum October, 2012 - 7
IEEE Spectrum October, 2012 - 8
IEEE Spectrum October, 2012 - 9
IEEE Spectrum October, 2012 - 10
IEEE Spectrum October, 2012 - 11
IEEE Spectrum October, 2012 - 12
IEEE Spectrum October, 2012 - 13
IEEE Spectrum October, 2012 - 14
IEEE Spectrum October, 2012 - 15
IEEE Spectrum October, 2012 - 16
IEEE Spectrum October, 2012 - 17
IEEE Spectrum October, 2012 - 18
IEEE Spectrum October, 2012 - 19
IEEE Spectrum October, 2012 - 20
IEEE Spectrum October, 2012 - 21
IEEE Spectrum October, 2012 - 22
IEEE Spectrum October, 2012 - 23
IEEE Spectrum October, 2012 - 24
IEEE Spectrum October, 2012 - 25
IEEE Spectrum October, 2012 - 26
IEEE Spectrum October, 2012 - 27
IEEE Spectrum October, 2012 - 28
IEEE Spectrum October, 2012 - 29
IEEE Spectrum October, 2012 - 30
IEEE Spectrum October, 2012 - 31
IEEE Spectrum October, 2012 - 32
IEEE Spectrum October, 2012 - 33
IEEE Spectrum October, 2012 - 34
IEEE Spectrum October, 2012 - 35
IEEE Spectrum October, 2012 - 36
IEEE Spectrum October, 2012 - 37
IEEE Spectrum October, 2012 - 38
IEEE Spectrum October, 2012 - 39
IEEE Spectrum October, 2012 - 40
IEEE Spectrum October, 2012 - 41
IEEE Spectrum October, 2012 - 42
IEEE Spectrum October, 2012 - 43
IEEE Spectrum October, 2012 - 44
IEEE Spectrum October, 2012 - 45
IEEE Spectrum October, 2012 - 46
IEEE Spectrum October, 2012 - 47
IEEE Spectrum October, 2012 - 48
IEEE Spectrum October, 2012 - 49
IEEE Spectrum October, 2012 - 50
IEEE Spectrum October, 2012 - 51
IEEE Spectrum October, 2012 - 52
IEEE Spectrum October, 2012 - 53
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IEEE Spectrum October, 2012 - 55
IEEE Spectrum October, 2012 - 56
IEEE Spectrum October, 2012 - 57
IEEE Spectrum October, 2012 - 58
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IEEE Spectrum October, 2012 - 60
IEEE Spectrum October, 2012 - 61
IEEE Spectrum October, 2012 - 62
IEEE Spectrum October, 2012 - 63
IEEE Spectrum October, 2012 - 64
IEEE Spectrum October, 2012 - 65
IEEE Spectrum October, 2012 - 66
IEEE Spectrum October, 2012 - 67
IEEE Spectrum October, 2012 - 68
IEEE Spectrum October, 2012 - 69
IEEE Spectrum October, 2012 - 70
IEEE Spectrum October, 2012 - 71
IEEE Spectrum October, 2012 - 72
IEEE Spectrum October, 2012 - 73
IEEE Spectrum October, 2012 - 74
IEEE Spectrum October, 2012 - 75
IEEE Spectrum October, 2012 - 76
IEEE Spectrum October, 2012 - 77
IEEE Spectrum October, 2012 - 78
IEEE Spectrum October, 2012 - 79
IEEE Spectrum October, 2012 - 80
IEEE Spectrum October, 2012 - Cover3
IEEE Spectrum October, 2012 - Cover4
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