11.2007
VOL. 5 NO. 11
SERVO 11.2007
5
28
AUTOFLEX 2.0
by Brian Cieslak
A new and improved autonomous
programming tool for FIRST robots.
32
Killer Robots Are
Our Friends
by Brett Duesing
A look inside the mechanics of
combat robots.
36
Do You Want it Now?
by Fred Eady
Get instant gratification with the
Firgelli PQ-CIB controller hooked up
to their linear actuator.
42
Control a TOPO 1
by Robert Doerr
Breathe new life into an old robot.
47
Building an Android Arm
by Mark Miller
Part 2: Putting it all together.
51
GPS
by Michael Simpson
Part 2: Take a look at the Etek EB-85A,
Copernicus, and Holux GPS modules.
Features & Projects
SERVO Magazine (ISSN 1546-0592/CDN Pub Agree
#40702530) is published monthly for $24.95 per year by
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PAGE 47
PAGE 42
PAGE 32
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TOC Nov07.qxd 10/10/2007 5:20 PM Page 5
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CONTRIBUTING EDITORS
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Gordon McComb David Geer
Pete Miles R. Steven Rainwater
Michael Simpson Kevin Berry
Fred Eady Brett Duesing
Brian Cieslak Mark Miller
Robert Doerr James Baker
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In the commercial robotics world,
all eyes are on the recent iRobot
vs. Robot FX patent infringement
lawsuits, in which iRobot is seeking to
prevent Robot FX from selling any
more Negotiator robots. While there
are a number of facets to the case
destined for the tabloids, one
undisputed part of the story is that
the suit comes on the heels of a
competition between Robot FX and
iRobot for a $280M contract with the
US military. Robot FX won the
contract. Whether iRobot — maker of
the popular Packbot — gets another
crack at the contract, the suit is
important in that it marks an
important milestone in the growth of
the military robot industry.
To follow my reasoning, consider
the Gartner Hype Cycle, a popular
model of technology-based products,
first proposed by the Gartner Group
(www.gartner.com) in 1995 (see
Figure 1). According to the model,
the first phase of a Hype Cycle is
the “technology trigger,” marked by
a significant breakthrough, public
demonstration, product launch, and
related events that generate press and
industry interest.
The next phase — the “Peak of
Inflated Expectations” — is marked by
over-enthusiasm and unrealistic
expectations. In reality, there may be
some successful applications of the
technology, but there are more
failures than winners. The only
enterprises making money at this
stage are conference organizers
and magazine publishers. Following
this over-hype and user/investor
frustration from unmet expectations,
technology-based products enter the
“trough of disillusionment.” Because
the press usually abandons the topic
and the technology, this is the end for
many products.
Products that survive the trough
of disillusionment – which may last
months, years, or decades – are kept
alive by companies that understand
the technology’s applicability, risks,
and benefits. The “slope of
enlightenment” marks the time when
there is practical, commercially-viable
application of the
technology – that is,
some companies enjoy
cash flow.
Finally, the product
and underlying technology
reach the “plateau of
productivity,” which is
marked by the appearance
of stable, accepted,
second, and third
generation products.
Because it’s often
difficult to directly
track the few companies
that are commercially
successful during the
Mind / Iron
by Bryan Bergeron, Editor
Mind/Iron Continued
6
SERVO 11.2007
VISABILITY
TIME
Technology
Trigger
Peak of
Inflated
Expectations
Trough of
Disillusionment
Slope of
Enlightenment
Plateau of
Productivity
GARTNER HYPE CYCLE
FIGURE 1
Mind-Feed Nov07.qxd 10/10/2007 9:54 AM Page 6
“slope of enlightenment,” external events — such as lawsuits
— serve as useful indicators. I’d like to propose this is the
lawsuit point (shown in red in Figure 1) between the ‘trough
of disillusionment” and “slope of enlightenment.”
Historically, companies producing products aren’t
bothered as long as they’re in an academic lab or smoldering
in a company barely making a profit on the technology.
However, as soon as the technology — and market — are
mature enough to generate significant, sustainable revenue,
then holders of patents (and their attorneys) take notice. The
motivation for a suit may be strictly monetary. Some patent
holders develop and hold on to a patent with no intent of
developing a product. Instead, they hope that a technology
will become viable before the term of their patent ends. A
suit may be motivated by competition from a rival in the
marketplace. In some cases, a suit is simply to establish the
right of a company to compete in a given market.
The iRobot–Robot FX suit suggests that the military
robotics industry has survived the trough of disillusionment
and is well on its way to the slope of enlightenment. There
have been lawsuits in medical robotics, a sign that the
robotics industry is making progress in this area, as well.
How long before we see major lawsuits for home robots
or assistive robots is unclear. However, when we do see
lawsuits, it’ll be a sign that the field is maturing. Hopefully, the
robotics companies involved in these suits will be financially fit
enough to not only survive but thrive in the new economic
environment.
SV
Dear SERVO:
Regarding the 09.2007 issue beginning on page 67, “Twin
Tweaks — Robot vs.Wild” . the problem stated was that the
automotive steering vehicle had trouble making tight turns.
The Wooleys solved part of the problem quite accurately with
the Ackermann steering geometry, but you still have a solid
rear axle (wheels, axle, and drive gears acting as a single unit).
Thus, driving both rear wheels with relatively equal force
when you try to turn, the front end gets pushed and you wind
up going in a wider radius than the front wheels are set for. In
the process of turning, the rear wheels want to slip because
the outside wheel is traversing a larger arc than the inside
wheel. If you’re going in a straight line, like drag racers do, a
solid rear end is great. But if you want to make some turns,
then you need a differential. And they almost had it — looking
at the photo on the bottom of page 69 titled ‘Vex Differential.’
You need to cut the axle in two (a loose sleeve joining the two
ends will allow independent motion and still keep the axles
relatively concentric) and put a bevel gear on each axle end so
that they mesh with the third bevel gear that’s attached to the
differential carrier. This will allow continuous power to be
applied to both rear wheels, irregardless of each wheel’s
speed.You guys are doing great — hang in there.You’ll never
know what you can do until you push your limits.
— Phillip Potter
SERVO 11.2007
7
continued on page 75
Mind-Feed Nov07.qxd 10/10/2007 9:55 AM Page 7
8
SERVO 11.2007
Autonomous Refueling
Demonstrated
The Defense Advanced Research
Projects Agency (DARPA, www.
darpa.gov) has added to its bag
of aeronautical tricks with the
Autonomous Airborne Refueling
Demonstration (AARD) program,
through which it has demonstrated
the first-ever robotic system to refuel
airplanes in flight.
In a recent series of tests, the
AARD was fitted to a NASA-owned
F/A-18 Hornet fighter and operated
out of California’s Edwards Air Force
Base. Using inertial, GPS, and video
measurements — along with some
special guidance and control
techniques — the AARD managed to
poke a refueling probe into a 32-inch
basket while traveling 250 mph
at 18,000 ft above the Tehachapi
Mountains. Some tests were conduct-
ed in straight-and-level flight, under
a range of turbulence conditions that
involved as much as five feet of
side-to-side movement of the drogue
(the small windsock at the end of the
refueling hose).
In its most successful configura-
tion, the AARD hit the target in 18
out of 18 attempts. It also managed
to make the connection when the
707-300 tanker and F/A-18 were
executing a turn, which is not usually
attempted with a human pilot. In
the tests, the fighter was operating
autonomously; the pilots shown in
the photo were on board “for safety
purposes.”
UAV for Farmers
Most of the glory in the UAV
arena goes to exotic military and
security aircraft, but a fleet of
miniature planes may soon create a
buzz over the fields and forests of the
heartland, providing surveillance for
farming, environmental monitoring,
and forestry.
MicroPilot, Inc. (www.micro
pilot.com), based in Stony Mountain,
Manitoba, offers a range of UAVs,
autopilots, and software products,
including the MP-Vision airplane.
Earlier this year, MicroPilot’s Crop
Cam division (www.cropcam.com)
introduced a version that has been
configured specifically for agricultural
operations.
The CropCam AUV is a GPS-
guided craft that covers a
preprogrammed flight pattern over a
quarter section (160 acres) and
takes digital photos along the way.
With an overall length of four feet
and a wingspan of eight feet, the
six-pound plane can climb to 2,200
feet and complete a survey in about
20 minutes. Guidance is provided by
a Trimble GPS unit, and you can
choose among three Pentax camera
models to get up to eight megapixel
resolution for stills and 640 x 480, 30
fps, in video mode.
Power is provided by a 0.15 cu in
engine that draws from a six-oz tank,
but it appears that you can also get
one that is driven by an Axi brushless
motor and lithium polymer batteries.
Rumor has it that it will run you
about $7,000.
Bionic Hand Now Available
The Touch Bionics’ (www.touch
bionics.com) i-LIMB Hand, formally
introduced in July at the 12th World
Congress of the International
Society for Prosthetics and
Orthoticsin Vancouver, Canada,
looks like a great innovation for
patients who are missing a
hand through accidents, acts
of war, or birth defects.
Designed to look and operate
like the real thing, it is said to
be the world’s first commercial-
ly available prosthetic device
with five individually powered
digits.
The device operates on an
intuitive control system that
uses a traditional myoelectric
signal input to open and close
its fingers. Myoelectric controls
The AARD system performs
“better than a skilled pilot.”
Photo courtesy of DARPA.
Image taken by a CropCam AUV.
Photo courtesy of Cropcam, Inc.
The i-LIMB Hand looks and
acts like the real deal.
Photo courtesy of Touch Bionics.
by Jeff Eckert
Robytes
Robytes.qxd 10/9/2007 7:56 AM Page 8
use electrical signals generated by
muscles in the remaining portion
of a patient’s limb, with the signal
being picked up by skin-mounted
electrodes. Not shown in the photo is
the available “cosmesis” covering,
which makes it appear more lifelike in
use. The device is already being fitted
to patients in many clinics in the US
and Europe.
Build Your Own ROV
It’s not pretty, but at least it’s
pretty cheap. Designed for ages 12
and up, the ROV-in-a-Box kit from
!nventivity (www.nventivity.com)
sells for $249.95 and includes all of
the required parts (frame, motors,
light, camera, tether, controller,
and battery), plus an instruction
manual. It also comes with
propellers, switches, connectors,
“buoyancy devices” (presumably the
chunks of plastic foam shown in the
photo), and pretty much everything
else. All you have to provide is PVC
cement, tools, and a video monitor.
According to the vendor,
independent left and right props give
it good controllability and zero-radius
turning, and the light is bright
enough to allow night missions.
See the company’s website for a six
minute video.
Interactive Boybot
He looks quite a bit like the
Japanese comic book character
Astro Boy, but the new Zeno bot
from Hanson Robotics (www.hanson
robotics.com) is actually named
after the inventor’s son. Zeno’s
main claim to fame is how well he
imitates human facial expressions,
but he also walks, talks, and can
learn to recognize individual human
beings (using a camera located
behind one of his eyes) and address
them by name.
Like other Hanson creations (recall
the familiar talking Einstein bot), Zeno
is based on AI capabilities that help
him learn and interact with his
environment, a complex range (62, to
be precise) of facial and neck
expressions, his somewhat weird
Frubber™ polymer skin, and the ability
to develop a unique personality.
According to Hanson, Zeno and his
pals can be used in education,
psychiatry, military training, and
character development for animation.
Some people find him adorable,
and others have described him as
“creepy,” so you’ll have to judge for
yourself. Zeno is still a prototype, but
the plan is to have a commercial
version on the market in two years for
about $300.
SV
Robytes
The ROV-in-a-Box kit comes
more or less complete.
Photo courtesy of !nventivity LLC.
Zeno — a 17-inch mechanical boy —
walks, talks, and interacts
on a personal level.
Photo courtesy of Hanson Robotics.
SERVO 11.2007
9
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10
SERVO 11.2007
I
n 2007, the Worcester Polytechnic
Institute (WPI) supported
Massachusetts Academy of
Mathematics and Sciences at WPI (or
MASS Academy, Team 190) won the
FIRST Robotics World Championship
in the Georgia Dome in Atlanta on
April 14. Team 190 designed and
constructed the winning robot —
Goat-Dactyl — early in the season.
Goat-Dactyl is a wheel-locomotive
robot with sensors for autonomous
control and R/C for remote. Team 190
designed the robot to accomplish
specific, competition-related tasks as
part of the FIRST 2007 competition.
The robot completes the tasks as part
of a game in competition and collabo-
ration with other teams’ robots.
This year’s competition game —
called “Rack ‘N’ Roll” — tested the
students’ and their robots’ ability to (1)
hang inflated colored tubes on pegs,
configured in rows and columns, on a
10-foot-high center “rack” structure;
(2) program a robotic vision system to
navigate the robot; and (3) “lift” other
robots more than 12 inches off the
floor, according to Brad Miller, a Team
190 member.
The leaders of the competition
formed the aforementioned rack
structure out of eight columns with
three pegs each on which robot teams
could place their tubes.
“Every other column had a green
light. The teams calibrated their
robots’ cameras to track the light.
Six robots took the field during a
match. Officials assigned the robots
to either the blue or red alliance
for competition. The teams earned
points by hanging their alliance-colored
tubes on one or more of the rack
pegs,” says Miller.
According to Miller, each hung
tube was worth two points unless it
was contiguous (either vertically or
horizontally) with another hanging
tube of your alliance color. “The
total point count in this case was
equal to two raised to the power
corresponding to the length of the
matched tube row or column (e.g., one
tube = two points, two tubes = four
points, three tubes = eight points . a
full circle of eight tubes = 256
points!),” Miller explains.
Team 190 made the Goat-Dactyl
robot from a kit that every team had to
adhere to. The kit includes parts for the
robot’s pneumatic and electrical
systems, as well as a choice of motors.
The robot itself consists of four
CIM FR801-001 motors, which drive
the robot.
The large, broad metallic gripper
that is the primary capability of the
robot opens and closes with the aid of
an RS-540 gear motor (Banebots). Two
Globe 409A587 motors actuate the
robot’s ramps.
The team machined both the
Contact the author at geercom@alltel.net
by David Geer
2007 FIRST Robotics
Competition Winners
The FIRST (For Inspiration and Recognition of Science and Technology)
Robotics Competition pits high school robotics teams against each other
(and themselves!) with a different robot kit and task each season.
Students with Goat-Dactyl competition
robot and control console queuing up
before a match. The driver is thinking
about strategy. Dan Jones, robot
operator, is in the foreground and
Colin Rody, driver, is in the background.
Goat-Dactyl, mouth wide open, just
before completing the lift of alliance
partners. Dan Jones, operator, operating
the controls in the background.
Photos are courtesy of Brad Miller,
Team 190 member.
Geerhead.qxd 10/9/2007 7:53 AM Page 10
GEERHEAD
chassis and gripper elevator from
scratch. They used 6061 aluminum
C-channel and Lexan materials. They
cut the lifting ramps via laser out of
5052 aluminum sheet metal. They
used sheet metal in gauges ranging
from .02” to .065” in thickness.
Team 190 folded the aluminum
ramps over, dimpled them with holes,
and then riveted everything together.
The gripper top is Lexan; the gripper
bottom is fiberglass.
The pneumatics included a
Thompson compressor, accumulator
tanks from Clippard, solenoid
valves from SMC and Parker, and
Bimba actuators.
The actuator specs included three
1.5” bore by 3” stroke cylinders per
side of the robot, which presented
sufficient force to lift competing
robots off the floor by more than
a foot. The robot also featured a
.75” bore by 8” stroke cylinder for
grabbing onto and lifting the large
inflated rings.
Both of these maneuvers were
useful for competition scoring.
Computer Controlled
Each team is constrained to a
kit that includes two PIC 18F8722
microprocessors. One is the slave and
one is the master processor. The
master processor controls the motor
and communications and interfaces
with the human operator.
The slave contains all the original
programming from the team’s coders.
The robot passes some data between
the master processor and the slave to
process the actuators’ values.
Team 190 coded the robot’s
program in the C language. The
coders used both the Microchip
tools that come with the kit, and the
Eclipse IDE.
While teams in the FIRST competi-
tion can stick with Microchip’s tools
that come with the kit, they are free to
use other programming tools.
“Our students use Eclipse as the
development environment (IDE) for
their in-class projects and are very
familiar with it. So, we adapted some
work developed by other teams to
make a development environment
that suited us. Eclipse has a huge
number of collaborators so even
though it’s free, it is much higher
quality than many of the commercial
products,” says Miller.
Team 190 also uses a software
library named WPILib, which is a
development framework that supports
the standard FIRST devices like speed
controls, the CMU camera, and gyros,
for example.
Command and
Control
Team 190, as other teams, built a
custom control system for interfacing
with the competition-specified
operator interface. That interface is the
controls that enable the drivers and the
robot to “talk” to each other.
The FIRST supplied controller
connects with joysticks, switches,
potentiometers, and other control
hardware. The controller transmits
“control positions” to and from the
robot. This enables the robot’s driver to
manipulate the robot in competition
while designing a unique set of
controls for their purposes.
Team 190 used two joystick
controls for driving, and a separate
control box of “arcade buttons”
and switches to control the tube
manipulator and robot-lift functions,
according to Miller. Two operators
handle the robots, one controlling
the drive and the other controlling the
manipulator and peripheral functions.
The robot has many sensors,
which help automate tasks such as
lowering the robot’s lifts and
raising the tube manipulator to
SERVO 11.2007
11
Team 190 members Dan Jones, operator,
(back) and Paul Ventimiglia, mechanical
lead (front) making last minute repairs
on the robot between matches.
Team 190 putting a tube on the
rack despite blocking attempts by
a robot from the red alliance.
Team 190 hanging a tube on the
middle section of the rack.
During selection for team allies
before competition, Team 190
chose teams with compatible designs
and tactics.
“Through our excellent scouting
and “intelligence” program, we were
able to pick teams that we knew
would make our alliance strong. Little
did we realize that they would also
make us look good, as well,” says Brad
Miller, a Team 190 member.
From among all the possibilities,
Team 190 ended up collaborating with
teams that all had maroon team shirt
colors similar to their own.
“Denying that matching team shirts
was one of our selection criteria, we
nonetheless took this as a good
sign and have since celebrated this
occurrence by producing “Don’t Mess
With Maroon” championship shirts,”
says Miller.
SELECTING ALLIES
Geerhead.qxd 10/9/2007 7:53 AM Page 11
12
SERVO 11.2007
pre-specified heights.
The goals for the robot were to
endow it will the best abilities to win
the game set before all the robots
while staying within competition limits.
The major constraints for the robots
include weight — 120 lbs and under —
total size, the ability to recognize
other robots, compete better than
other robots, and to stay within
cost limitations.
The Answers
In response to these goals and
limitations, Team 190 worked on
lowering their bot’s weight while
attaining its overall goals.
“Our original robot-lift design was
double the acceptable weight. We
went through many different design
approaches, including using aluminum
honeycomb surfaces or making our
own foam-core sheets, before finally
settling on a unique sheet-metal box
structure which was dimpled for
improved strength. This same approach
was used in nearly all aspects of the
design,” says Miller.
The tube gripper lays in front of
the robot to grab tubes from the
ground and catapult them high in the
air to rack them up for scoring. (The
tube gripper is in the front of the robot
that can grab tubes from the ground
and lift them to any height on the rack
for scoring.)
“Two of the unique features of
the gripper are: It can grab tubes
on the fly, without requiring the
robot to come to a stop to pick them
up; and second, it closes and lifts
using a mechanism driven by a
single pneumatic actuator. Usually
two motions like this would require
two actuators, but due to some
clever design, only one is needed,”
Miller explains.
The team mounted the tube
gripper on an extension mechanism
(elevator) to get it to the right height
after it grabs the tube and sets it to
the proper angle, Miller further
explains. The gripper is empowered
by a single air cylinder that both
closes the robot’s claw and raises the
tubes up to a 55 degree angle in a
single motion.
“In addition,” says Miller, “the
top digit of the claw is a four bar
articulated linkage that curls around
the tube, giving us maximum
wrap, while allowing it to fit within our
starting box.”
SV
GEERHEAD
Worcester Polytechnic Institute
www.wpi.edu/index.html
WPI FIRST Robotics Resource Center
http://first.wpi.edu
WPI Robotics Engineering Major
www.wpi.edu/Academics/Majors/RBE
WPI Winning Robotics Team 190
http://users.wpi.edu/~first
RESOURCES
Goat-Dactyl using its tube gripper to
lift a tube during competition.
The robot’s tube gripper is mounted on
an extension mechanism (an elevator)
that it uses to get it to the right height
after it grabs the tube and sets it to
the proper angle.
Team 190 between finals matches, on
the field resetting the robot to play
again while being overlooked by
head ref, Aidan Browne.
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Geerhead.qxd 10/9/2007 7:54 AM Page 12
SERVO 11.2007
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Full Page.qxd 10/10/2007 11:40 AM Page 13
14
SERVO 11.2007
Q
. It is my understanding that
the HSR-8498HB servos that
are used in the Robonova
humanoid robot have position
feedback capabilities, so I bought a
couple of them from Tower Hobbies.
I have been trying for several days
now to figure out how to get position
data from these servos.
From what I have seen on the
Internet, all I have to do is send the
servo a 50 microsecond pulse, and
it will return a position signal that is
similar to the regular pulse width
to move the servo. I am missing
something here. Can you help me?
— Pete Senganni
A
. The key to doing this is to use
a pullup resistor on the signal
line. This is required for
bi-directional communication since
the signal line is an open collector.
Figure 1 shows a simple schematic for
connecting an HSR-8498HB servo to
a BASIC Stamp. Here, I used a 1K ohm
resistor as a pullup resistor on the
signal line. Without the resistor,
you will not receive a signal back
from the servo. Figure 2 shows a
sketch of the PWM (Pulse Width
Modulation) control signal timing that
is required for this servo to return its
current position.
To obtain the current position of
the servo, you need to send a 50 µs
pulse to the servo then wait for a
minimum of 2 ms before measuring
the width of the return pulse. The
critical element required to measure
the pulse width is to make sure that
the servo signal line that is connected
to the microcontroller is changed from
an output signal line to an input signal
line immediately prior to measuring
Tap into the sum of
all human knowledge
and get your questions answered here!
From software algorithms to material selection, Mr. Roboto strives to meet you
where you are — and what more would you expect from a complex service droid?
by
Pete Miles
Our resident expert on all things
robotic is merely an Email away.
roboto@servomagazine.com
P1
P5
P7
P6
P3
P4
P2
VSS
P0
SIN
ATN
SOUT
P14
BA
S
I
CS
TAMP
2
FAMILY
P10
P8
VSS
P9
P12
P11
P13
P15
RES
VDD
VIN
1KΩ
+5V
SIGNAL
GND
4.8-6.0V
+4.8 - 6.0V SERVO POWER
HSR-8498HB SERVO AND CABLE
SERVO
Figure 1. Connecting an HSR-8498HB servo to a BASIC Stamp for positional bi-directional control.
MrRoboto.qxd 10/9/2007 10:34 AM Page 14
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