Stepper motors:
A stepper motor’s shaft has permanet magnets attached to it. Around the body of the motor is a series of coils that create a magnetic field that interacts with the permanet magnets. When these coils are turned on and off the magnetic field causes the rotor to move. As the coils are turned on and off in sequence the motor will rotate forward or reverse. This sequence is called the phase pattern and there are several types of patterns that will cause the motor to turn. Common types are full-double phase, full-single phase, and half step. To make a stepper motor rotate, you must constantly turn on and off the coils. If you simply energize one coil the motor will just jump to that position and stay there resisting change. This energized coil pulls full current even though the motor is not turning. The stepper motor will generate a lot of heat at standstill. The ability to stay put at one position rigidly is often an advantage of stepper motors. The torque at standstill is called the holding torque.
Photosensors or photodetectors are sensors of light or other electromagnetic energy. There are several varieties:
Most optical detectors are quantum devices in which an individual photon produces a discrete effect.
* Chemical detectors, such as photographic plates, in which a silver halide molecule is split into an atom of metallic silver and a halogen atom. The photographic developer causes adjacent molecules to split similarly.
* Photoresistors or Light Dependent Resistors (LDR) which change resistance according to light intensity
* Photovoltaic cells or solar cells which produce a voltage and supply an electric current when illuminated
* Photodiodes which can operate in photovoltaic mode or photoconductive mode
* Photomultiplier tubes containing a photocathode which emits electrons when illuminated, the electrons are then amplified by a chain of dynodes.
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Photo Detectors ...
Robosapien Version 2 is the next generation of Robosapien technology and personality from Wowwee. This new member of the robotic family comes with more advanced dynamic motion, interactive sensors, new program functions, speech capability, and a personality all his own. It’s clear from the start that he enjoys bowling, dancing, and having conversations.
Movement
RobosapienV2 is able to walk forward in four different styles, or gaits. He normally uses his IR vision and touch sensors built into his feet and hands to avoid obstacles, but if put into bulldozer mode, he will walk forward or backward and try to push his way through anything.
Beyond controlling him manually with the included remote controller, RobosapienV2 can explore his environment independently in free roam mode. You can also direct his movements by using the remote’s targeting feature–just point the beam to a spot on the floor and he will walk toward it.
RobosapienV2 has been designed with a full range of motion. He can turn his head just like humans. So, too, can he turn at the hips and can move them forward and back and from side to side. RobosapienV2 can move each arm independently, and his hands can grab, pick up, and throw light objects, such as the included bowling balls and pins. He even comes preprogrammed with a selection of dance moves.
In electronics, a comparator is a device which compares two voltages or currents and switches its output to indicate which is larger. More generally, the term is also used to refer to a device that compares two items of data. Output voltage will “switch” whenever the input voltage (at the inverting input) reaches the reference voltage Vref (at the non-inverting input). It is very useful for comparing signals and working with sensors
Simple comparator shown below:
Note that R2 and R1 form a voltage divider. Use a potentiometer in place of R2 for an adjustable reference voltage.
Comparator cicuits can be built with opamps, but there are also comparator ICs with large slew rates and short propagation delays – good for high speed switching.
A dedicated voltage comparator will generally be faster than a general-purpose op-amp pressed into service as a comparator. A dedicated voltage comparator may also contain additional features such as an accurate, internal voltage reference, an adjustable hysteresis and a clock gated input.
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Voltage Comparator ...
Line Follower ROBOT
Plermjai Inchuay, plermjai@loxinfo.co.th
Award winner from VingPeaw Competition 2543, the robot built with 2051, L293D, and four IR sensors. Simple circuit and platform, quick tracking and easy-understand program using C language.
I designed my Robot, which use two motors control rear wheels and the single front wheel is free. It has 4-infrared sensors on the bottom for detect black tracking tape, when the sensors detected black color, output of comparator, LM324 is low logic and the other the output is high.Microcontrollor AT89C2051 and H-Bridge driver L293D were used to control direction and speed of motor.
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Line Follower Robot ...
The Robonova I offers educators, students and robotic hobbyists a complete robot package. The advanced and stable Robonova I can walk, run, do flips, cartwheels, dance moves and once programmed, is ready to compete in any Robo One Class “J” competition. This kit version of the Robonova I allows you to enjoy building your new friend from the ground up. The Robonova I kit was designed for easy assembly in six to eight hours using only a screwdriver. On the other hand, if you prefer instant gratification, you can choose the Robonova I in a pre-built, ready-to-walk version.
Built Tough
The custom gold anodized metal servo brackets serve as a strong and lightweight exoskeleton. Robonova I also features durable plastic body case components that protect the control board and battery from damage.
ASIMO, the world’s most advanced humanoid robot, can’t drive his own car yet, but he is helping manufacturers make vehicles safer.
Twenty-one years of technology have allowed the all-seeing, all-hearing and sometimes-dancing Asimo to evolve from a disembodied set of legs that took up to 20 seconds to pace a single step into a robot that can slalom through road cones and run at 6 kmh.
The latest version of the Asimo robot is touring Australia and will be in Sydney until December 2.
Its engineering achievements have required scientists for the car maker Honda, the company behind Asimo, to master the skills that govern locomotion, such as how humans shift their weight as they walk. This technology has subsequently been adapted to help prevent vehicles from swerving, according to Hongsiri Suesattabongkot, a Honda engineer and former robotics student at the University of NSW.
The mechanical midget, which at 1.3 metres tall would barely be able to peer over a steering wheel, has also been responsible for a technology that warns drivers about impending collisions.
Wowwee’s Roboreptile is an often startling robotic toy that, once you get the hang of its wonky controls, is actually pretty fun. Like other Wowwee robots, there’s a preprogrammed animation that goes off when it is first powered up. It’s impressive: growling, snapping jaws and a whipping tail. In short, Roboreptile looks like something out of the future and moves like something out of the past.
The Roboreptile has infrared “vision” sensors where its eyes would be and stereo “hearing” sensors on the sides of its face. Its sounds, though a bit tinny, are menacing. During a tail swipe, it lets out a sort of Eagle cry, harkening back to the shared avian/reptile ancestry.
Controlling the Monster
Controlling the Roboreptile with the remote is a bit of a strain. First, because the remote uses an infrared beam and the pick-up sensor is located in its head. You won’t be able to control it from far away, and it’s difficult to control while walking away from you.
SAN FRANCISCO (Dow Jones) — A small green and tan dinosaur slowly wandered across the table in an airy Emeryville, Calif., office space. As it plodded to the end of the table, one plastic hoof started to step off the ledge and instead it felt thin air. It slowly backed up and murmured a little cry.
The 20-inch-long toy is a much-anticipated robotic device named Pleo, and it will finally ship next month to consumers after a year’s delay. Created by the same team who brought the world the Furby, the Pleo will also mark an advance in robotics, as it packs much of the functionality of far more expensive robotics toys into a much lower cost design.
Some industry futurists believe robotics will be the next big thing. The nascent area has sometimes been compared to the early days of the personal computer industry, when tinkerers gathered in garages and at computing clubs to swap ideas and parts.
“There is a revolution in the offing,” said
Paul Saffo, a Silicon Valley technology forecaster. “It’s coming in the next couple of years.”In 2006, a start-up company called Ugobe demonstrated Pleo at an industry conference, with plans to ship by fourth quarter 2006. The little robotic dinosaur got a lot of attention in the press.
But the company, co-founded in 2003 by Furby co-creator
Caleb Chung, missed that target. It had more work to do and Ugobe’s founders wanted Pleo to be great. It now is on track to ship the first Pleos next month, to customers who pre-ordered one of the
$350 robots, and to several Web-based retail partners. The Pleo is often compared with the Aibo, the robotic dog put to sleep by
Sony Corp. (SNE) when it shuttered its robotics research last year.
Build and program a high-quality, complex robot with a BASIC Stamp 2 microcontroller runnig on a Board of Education project platform. With the Boe-Bot Robot kit you can do over 40 hands-on activities! Program your Boe-Bot Robot to navigate on its own with touch, light and infrared sensors. Easy to build and program and easily expandable, this Boe-Bot Robot kit will launch you into the world of robotics!
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