Gigantor by Daniel Roganti

robot_wont_fall_down-150x150This is the second of my Bipedal robots. Pinocchio is my first and Giantor is my second. The construction for the Biped robots are based mostly on materials supplied by PLASTRUCT. Although some parts, such as the Torso and feet came elsewhere. The Torso is from a plastic toy pail I found in Toys R Us . The feet are acrylic soup bowls I found in the grocery store, they’re made by arrow Plastic in Illinois. The plastic materials allow me to customize my own design, with structural integrity , and while keeping the weight reduced. There are currently 2 prototypes which demonstrate bipedal locomotion using a gait similiar to people. I designed this using static equilibrium to simulate the walking gait of a human.

The Robot Calibrator is a measurement system

new-video-robot-calibration-with-the-faro-gage-P34339The Robot Calibrator is a measurement system that includes three string-encoders mounted to a metal base plate and used to measure the position of a robot in three space. Combining the three string ends and attaching them to a robot arm provides an inexpensive and relatively accurate position sensor with respect to the calibrator base. Using a quick-change plate attached to the three string ends, the robot can attach to the plate, maneuver the plate through a calibration routine, and replace the plate completing an in-situ calibration during manufacturing. Errors that can build during repetitive robot motions are thereby compared to the Robot Calibrator measurements and canceled out. String encoders or potentiometers can be used to provide relatively accurate length measurements with respect to their housings and combined as in the Robot Calibrator to triangulate the position of their combined lengths. Since the string-encoders allow only perpendicular string-extension/retraction, steel toriods were machined and attached to the string-encoder housings allowing the string to exit at angles within a hemisphere, as needed for a robot arm.

Here, the robot tested was a 7-axis arm that ran through a series of tests to “calibrate” the calibrator. Calibration included the simultaneous use of a laser tracker with the calibrator providing a direct calibration of three-space points for this robot.

a. Calibrator attached to the robot arm
b, d, e, f. Laser tracker (black object to the right) tracking the robot position simultaneously with the Robot Calibrator.
c. Close-up of the retro-reflector (laser tracker) and strings (Robot Calibrator) attached to the robot.
g. h. Center stand for the calibrator attachment plate with attached strings. The strings attached to the robot attachment plate such that the robot could quick-change to it and replace it on the stand.

Performance Metrics and Test Arenas for Autonomous Mobile Robots

nist_arena_2000Reproducible and widely known challenges can help evolving fields by providing reference problems with measures of performance which allow researchers to compare implementations, communicate results, and leverage each other’s work. The National Institute of Standards and Technology (NIST) developed the Reference Test Arenas for Autonomous Mobile Robots to focus research efforts, provide direction, and accelerate the advancement of mobile robot capabilities. Continue reading

Atlanta Bomb Squad Talks About ‘Bots

pipebombSgt William Briley of the Atlanta PD Bomb knows what he’s talking about. He used to be a bomber for the military, blowing up bridges in Vietnam. He told Kris Tech Robot Magazine that “robots are the key to bomb safety, considering the increased trend of bombing in the U.S.”

Bombings Increasing? Absolutely. Remember the flurry of airlines hijacking in the late 60s and early 70s? Now, Americans should prepare for bombings. In fact, MOST improvised explosive devices are made by CHILDREN. And most would work. In a world where families are less stable, where an increasing number of children, black and white, are living without fathers (and mothers without jobs), proper socialization seems increasingly difficult. The weapon of choice for sociopaths is often a bomb: the anonymous expression of anger, the coward’s subconscious scream for help.

FOTO: pipe bomb, timer, shrapnel and satchel
Movies show the most impressive fiction. They show sophisticated triply booby trapped high tech explosives with digital detonators. And from a small pipe bomb comes a HUGE, city block-busting fireball. What do bomb squad guys think about the movies? I asked Staff Sgt Ray Pfand of the 9th EOD flight at Beale AFB, CA about his “favorite” movies. “Speed,” he says, “It’s hokey, He’s on the phone explaining the different colored wires. That wouldn’t help. There’s no standard for an improvised device.” And what about Mel Gibson and Danny Glover in Lethal Weapon. “Dumb. Why would the bomb give them a countdown to get away? This job really ruins the movies for me.” Check out the police logs in most cities, even small towns, and you’ll find that, mostly, people are tossing cheap black-powder filled pipe bombs onto roofs, into cars and into mailboxes. Most of the time it’s just lethal vandalism, deadly tagging.

That’s How Americans Bomb Americans.
Briley gives a broad brush view of what really happens on the scene of a suspected bomb. Each incident is different, and each one relies heavily on the training of the officer and the type of device. The officer first calls for the Bomb Squad. The next folks on the scene are the Bomb Squad Diagnostic Team.

Once the Diagnostic Team approaches, more decisions have to be made on the spot. Should they take the time to put on an 85-pound blast suit (NOT air-conditioned, by the way), or just carry the bomb to a truck and drive it away? If he can, he’ll call in a robot, always remembering that in the Bomb Squad, DISTANCE IS YOUR BEST FRIEND. So call in the robot.

Some details about the OlyBomb have leaked out, even though APD and the Feds aren’t talking. Using what we know, KrisTech Robot Magazine photographed a mock pipe bomb similar to the one used in Centennial Park. SSgt Pfand and ANDROS posed for pics, showing how an ANDROS robot approaches a bomb. Would he tell us how to disarm it? Would he demonstrate ‘render safe’ procedures? Couldn’t he just swear us to secrecy about operational details? Nope. And even if he would, we wouldn’t publish it. EOD types are justifiably cautious, and they are not about to tell their secrets. Lives are at stake. And although this publisher is PRO-First Amendment, we’re NOT going to help cop killers.

Briley has seen many robots, including one that failed for a dead battery two minutes into its demonstration. So he’s skeptical. But then, he’s been impressed with the ANDROS robot. “The finest robot I’ve been associated with,” he says.

Briley was so impressed with ANDROS, we had to do some more research: Over 400 remote-controlled ANDROS units are at work in almost every continent and hot spot, including Haiti, Bosnia and the Persian Gulf, ‘rendering safe’ explosives, securing airports (Atlanta, for instance ) doing nuclear maintenance, dragging wounded victims to safety, and assisting SWAT ops wearing night vision adapters. It can even open a door with a key. ANDROS attended the Olympics, the Super Bowl and the Democratic National Convention.

ANDROS comes in heavy (all terrain) and light varieties, wheeled and tracked, some capable of being carried in the trunk of a car and lugged by one man. Information supplied by REMOTEC’s Shawn Farrow states that most models climb stairs, and can deliver cameras, microphones and telephones into hostage situations. They can also carry shotguns and X-ray machines.

In Portland, an ANDROS arrested a gunman, by pinning him to the ground! In another case, an ANDROS was SHOT by a crazed gunman during negotiations inside a house. (The robot kept working.) And in Atlanta, the OlyBomb exploded too soon for ANDROS to arrive. But ANDROS did bag a bomb-look-alike hoax device (with a note attached) at an Atlanta hospital during the Olympics. And ANDROS swept planes at Atlanta’s international airport. Considering President Clinton’s call for increased security against bombing, we can expect to see more bomb handling robots in action, on the nightly news, and on the streets.

My Olympic Bombing
There I Was…at treetop level in Centennial Park, with the best view in the house, except for some branches getting in the way. I could see Jack Mack and the Heart Attack playing loud funk on my right, and could hear “Time, time, time…is on my side” on my left. making everybody a little more mellow, especially at 1 a.m. There must have been fifty thousand people in the Global Olympic City that night, a lot of them families. Why would people keep their tiny kids up this late? To the left, Cuban and Argentinian teams are swaying back and forth, looking at the band like almost everyone else, often hooting, chattering and laughing amongst themselves at some observation about American women’s fashions.

At the bottom of a light and sound tower, on a park bench, two heavy-set security cops seem to be more concentrated than I like cops to be. One is peering inside a green knapsack (my heart skips a beat), while the other is quickly but politely asking people to move away. He’s waving his arms to say “Get Back!” to those who can’t hear his shouts above the music. The knapsack cop now fumbles with his mike, draws a deep breath and speaks some measured words into his radio. They both are moving outward from what I hope is simply a suspicious package. But they are moving too quickly, not lazily like bored cops going through the minimum motions of proper police procedure. Each one is hyper-aware, eyes, hips and hands locked in a hesitant five-steps-left, six-steps-right, one-step forward tango as they wave back the crowd. Some folks don’t notice, pierce the invisible police line, and five sit down on the bench next to the knapsack. The cops suddenly run back to the bench and order the people away, but not too politely this time. The crowd is sucked back into the vacuum toward the bench. One of the cops is visibly sweating, now. Their urgency triples, and they begin again to move the people back as other security forces converge and join the frayed invisible police line. Some are in Air Force berets, some in Army camo BDUs, some in Georgia white shirts. Only one has a side-arm. They have never met, have never worked together, but somehow they coordinate perfectly. No chiefs, no Indians, no cop egos. Just a shared and immediate need to move the crowd back without panicking it. My wife is wondering what I’m staring at: I haven’t blinked in two minutes.

I hear a whir and whiz from high torque electric and pneumatic motors behind me. At the walking entrance to the park a buffalump rises up to full mastadon height, its six legs shuffling slowly in an unfamiliar kind of elephant step. Infra-red rings surrounding each leg, feeler wires in each foot, and four video cameras at each rump search for walking obstructions, especially kids and dogs, near the intended footsteps. The buffalump aims toward the sound and light tower. There is a muffled voice coming from the unidirectional horn in the front of it’s buffalo-like head, saying something unintelligible. When the head turns toward me, I’m startled by the booming volume, “Stand back! Watch your children. Zurucktretten! Achtung auf Ihre Kinder.” The crowd parts rather quickly, and the buffalump gains speed. I’ve seen them hit 100kph on the open road on a National Geographic holo-vid before. This one only trots at walking speed, though, since the crowd is so dense and so near. The crowd only half pays attention. Cool aren’t they? Wow, imagine riding one. Ha Ha. But you can’t ride one. The buffalump’s hide is slicker than teflon, and the “skin folds” ripple like a snake’s slithering belly to discourage you from trying. You can’t run under one, either, because the hide droops almost all the way to the ground. Within 30-seconds, the buffalump passes me and slows to a stroll. I’m thinking how silent its footsteps are, how lightly each foot pad touches the ground, when it enters the invisible police line.

The buffalump’s head opens up, and it places its giant walrus-like mouth over the knapsack, engulfing the package with Kevlar armored cheeks. Inside its head, it x-rays the package and makes some independent choices without waiting for the humans at the Olympic Bomb Management Center to review the transmitted images. Noting there are no cop-killer tripwires, the buffalump rips the bag with the claws inside its head (where you expect teeth to be) , then grabs it and the nail-filled tupperware with two different grippers inside of its “throat,” and passes the bomb and shrapnel separately to different portions of its “stomach.”

Surrounded now by three thousand pounds of bulletproof hide impregnated with heat-reactive foam, the bomb is placed in the “pocket,” just below the buffalump’s “blowhole.” If the bomb were to detonate now, the force of the blast would be aimed upward to the sky, with the heat of the explosion sealing the foam around it, thus lengthening the duration of the conflaguration by a few milliseconds. The bomb would fizzle, or at least blow up less forceably.

Accompanied by a whush of white noise, a United Nations hovercopter appears over my head, and two shadows quickly descend. A black package lands first, followed almost instantly by a large man in an 85-pound air-conditioned blast suit with a three-quarter inch face shield. He ignores the package, and shuffles straight to the buffalump’s rear end. He activates a hand-held box, waving it near the buffalump’s butt, and an arm sized opening appears. The technician plugs a cable into it and reviews an image on his clipboard viewscreen. He is satisfied that this is a simple pipe bomb, no booby traps, three galvanized steel pipes taped together with a kitchen timer and a few wires leading to blasting caps. Inside, the buffalump already has several tools trained on various parts of the apparatus: tele-operated wire cutters surround each wire, a water cannon is aimed at the trigger, and censored by law enforcement authorities censored by law enforcement authorities censored by law enforcement authorities censored by law enfor.

Keith Best built this Scooter from Graymark

scooterThe manual that Graymark included with the Scooter kit has four major sections: Electrical theory, electrical construction, mechanical construction, and a testing & debugging section. If electrical construction is completed cleanly and correctly, then the debugging section is unnecessary. It’s a comprehensive, easy to read, step-by-step manual.

Once I was able to distinguish between all the different resisters, electrical construction was a snap. The directions are very clear and easy to follow. A little as left to be desired in the descriptions on the resisters. For example, the resisters used are of the four-color variety. (Three colors designate the value and the fourth color designates the variance in percentages.) All the other electrical parts were easily identifiable via their part numbers printed on the transistors and capacitors.

It does take a little to get used to soldering on a printed circuit board. By the fifth joint, however, soldering was easy.

Once the electrical construction was complete, I began the mechanical construction. The one difficulty I noticed was that, given the small size of the miniature nuts, bolts, and washers, the magnetic force of the motor is stronger than gravity. This made attaching the motor to the chassis especially challenging, but not impossible. Fortunately, the kit does come with about 12 spare nuts, a spare screw, and 5 spare washers.

Construction was completed in just under 7 hrs. Of course, that includes occasional breaks to refill my teacup.

Recommended tools for building the kit (in addition to the tools mentioned in the manual): A shallow bowl and a wet sponge to keep the soldering iron clean, and a relatively strong magnet to pick up all those tiny nuts, bolts & washers. (These have a way of jumping off the table.) Don’t forget some micro-tweezers that clamp on like vice grips.

Unfortunately, however, the Scooter seemed to require brand new batteries (2xAA) to function at all. But then it tends to go zipping off at around 15 -> 20 mph! I think I need to add a rheostat or resister somewhere to slow the motor down. (But that would then affect the timing circuit, composed of two capacitors, 1 mf and 40 mf. At any rate, unless I operate it with my arms around it (forming an arena), it goes zipping off the table to certain destruction!

Graymark’s Scooter Model 601A

scooterHere’s an inexpensive kit from Graymark to help you learn motor theory, transistor switching and R/C time constant circuits. Comes with an excellent instruction book of lessons, schematics and troubleshooting guide. Scooter changes direction when you clap your hands or when it hits an object. See KrisTech’s independent First-Person, First-Robot Review — $16.95 Continue reading

The MD-2 Program

Each MD-2 system comes complete with our DOS-based MD-2 motion control program, which gives you complete control of up to 6 motors from a single computer. Motor speed, travel distance, limits, units, and other parameters can be edited easily and saved to disk. Single and dual-motor moves, including linear and circular interpolation, are also possible. The powerful teach mode feature creates programs automatically as you control motors via the keyboard or joystick. These BASIC-like programs can be maintained with the editor, saved to disk, and recalled whenever needed. On-Line help guides your usage and gives explanations for each motor parameter. The software can be run from floppy or hard disk (1.5MBfree required) and will operate on low-end XT-class as well as high-speed systems. A 386 or faster processor, mouse, and hard disk are recommended for best performance.

MD-2 Program Features

  • Control of up to 6 motors
  • On-line help
  • Keyboard/joystick control
  • Teach mode
  • Absolute/relative moves
  • Linear interpolation
  • Circular interpolation
  • User-definable units
  • Adjustable accel/decel
  • Backlash compensation
  • Programmable soft limits
  • Half and full step modes
  • Use from DOS batch files
  • Program editor
  • And much more . . .

Subroutine Libraries
The MD-2 system also includes a complete set of subroutine libraries written in all popular languages. This allows the creation of custom motion control programs, which provide the features and user interface you desire. The subroutine libraries can be used in conjunction with libraries from data acquisition products to solve complex control and automation tasks. Source code for each of these libraries are supplied along with documentation and example programs. It may be necessary to use third party tools to allow certain languages such as VB4/5, and certain operating systems such as Windows NT to access the parallel printer port. Visit our FAQ for links to these tools.

Specifications and Prices
There are 3 MD-2 sizes to choose from. Notice the different torque values.

Model: MD-2a
The MD-2a is our smallest system and is capable of driving all of our linear and rotary positioning tables with moderate payloads and speed.
Would you like to see a drawing of the MD-2a motor?
Size: #23 motors, 2.3″ dia, 2.3″ long, 1/4″ shaft
Resolution: .9 degree steps, (400 per revolution)
Speed: 10,000 steps per second maximum
Torque: 50 in/oz holding, 15-35 in/oz running
Price: $700.00 US
Shipping weight: 10 lbs.
UPS Shipping cost in U.S.: $10.00

Model: MD-2b
Having 3 times the torque of the MD-2a system, the MD-2b can be used with our X and XY positioning tables to move larger payloads faster.
Would you like to see a drawing of the MD-2b motor?
Size: #23 motors, 2.3″ dia, 4″ long, 1/4″ shaft
Resolution: .9 degree steps, (400 per revolution)
Speed: 10,000 steps per second maximum
Torque: 150 in/oz holding, 50-100 in/oz running
Price: $1,000.00 US
Shipping weight: 15 lbs.
UPS Shipping cost in U.S.: $10.00

Model: MD-2c
The MD-2c is our largest system offering large, strong motors. I/O port also included. Would you like to see a drawing of the MD-2c motor?
Size: #34 motors, 3.4″ dia, 3.7″ long, 3/8″ shaft
Resolution: .9 degree steps, (400 per revolution)
Speed: 10,000 steps per second maximum
Torque: 300 in/oz holding, 100-200 in/oz running
Price: $1,400.00 US
Shipping weight: 20 lbs.
UPS Shipping cost in U.S.: $10.00

MD-2 Stepper Motor Control Systems

md2Would you like to automate a task but don’t know how? Have you looked through some motion control catalogs and been shocked by the complexity? Most vendors expect you to select and match motors, drivers, power supplies, and cables, then write your own software. We’ve cut through the confusion and created the complete motion control solution for those who don’t want to design their own. The MD-2 Dual Stepper Motor System contains everything you need to accomplish motion control with an IBM style personal computer.

No cards to install, no cables to build and no components to match. Simply connect to the parallel port on your computer just like a printer, load the software, and GO! Within minutes you’ll have complete control over the direction, position, and speed of each motor. Up to 6 motors (3 MD-2 systems) can be connected to your computer for those multi-axis projects.

Programming is simple with our interactive motion control programs and DOS command-line interpreter. Custom programs are easy to create using our subroutine libraries. There are 3 MD-2 models to choose from to fill a variety of torque and resolution requirements. Each MD-2 system includes 2 stepper motors, 2 10′ motor cables, printer port cable, 2 home switches, drive/power supply box, software and extensive documentation. The MD-2 system can be operated from an AC outlet or from a battery. You must have an IBM compatible personal computer with a parallel printer port. Need assistance? – give us a call, we’ll be glad to help.

This short article describes the differences between stepper motors and servo motors. Use the MD-2 system to control our XY positioning tables. Increse the torque and resolution of a stepper motor using our PR23 Pulley Reducers.

MD-2 System Features

  • Operates with a standard IBM-style PC
  • Includes motors, cables, driver, software, documentation
  • Easy to install and program
  • Interactive Motion control software included
  • Up to 6 motors on a single PC
  • Operates with data acquisition boards
  • Subroutine libraries in C, Basic, VB, Pascal source
  • Powerful multi-axis coordinated motion
  • General purpose Digital I/O signals provided
  • 3 sizes to choose from
  • No motion control experience needed
  • Cost effective

What is a Stepper Motor?
A stepper motor is a special kind of motor that moves in individual steps which are usually .9 degrees each. Each step is controlled by energizing one or more of the coils inside the motor which then interacts with the permanent magnets attached to the shaft. Turning these coils on and off in sequence will cause the motor to rotate forward or reverse. The time delay between each step determines the motor’s speed. Steppers can be moved to any desired position reliably by sending them the proper number of step pulses. Unlike servo motors, steppers can be used “open-loop” without the need for expensive encoders to check their position. Stepper motors are much more cost-effective than servo systems due to their simplified control and drive circuitry. There are no brushes to replace in a stepper motor, eliminating the need for maintenance. Even though a stepper motor system can not achieve the speed of a servo motor system, their ease of use allows them to be the preferred solution for many of today’s computerized motion control systems.

Solar Robotics

robotOur administrator present a range of materials that can be incorporated in the creation of educational robots, in the last LEGO catalog, presents a solar panel is complemented by the NXT Intelligent Brick, denominate “extra set of renewable energy,” an updated version of the solar panels contained in Continue reading