The H-Bridge is the link between digital circuitry and mechanical action. The computer sends out binary commands, and high powered actuators do stuff. Most often H-bridges are used to control rotational direction of DC motors. And unless you buy a potentially expensive motor-driver, you need an H-bridge to control any robot with a motor.

This is a quickly sketched H-Bridge circuit with supporting circuitry.

First lets talk about what a transistor is. These nifty chips revolutionized the electronics industry and you would be hardpressed to find something electronic that does not have at least a few thousand of these in them. So what do they do? They can control a flow of electrons by applying a voltage to them. The plumbing equivalent would be a water valve. By rotating the valve, a very large flow of water can easily be controlled.

There are several types of transistors, such as the PNP and NPN, but for sake of making your life easy I will only talk about a MOSFET (Metal-Oxide Semiconductor Field Effect Transistor). These neat things have only been around for a decade or two, but are way better than the more traditional transistor. First they are more efficient. They are easier to calculate mathwise. Plus they usually have built in protection diodes so you don’t need to add them in later. They even have PWM (explained later) optimized MOSFET’s.

So to operate a MOSFET, you apply a voltage to the gate (from your microcontroller), and suddenly a current of electrons passes through the other two pins. Connect a motor (M) in line with one of the pins and your robot is set to go. In the above schematic you will notice the letters A and B. These are your two control lines which you apply this logic voltage to. Since you have two pins, and only a binary control, there are four possible things that can happen.

A=0 B=0 : Nothing happens, the motor is turned off
A=1 B=0 : Motor rotates clockwise
A=0 B=1 : Motor rotates counterclockwise
A=1 B=1 : Your circuit explodes into pretty sparks

Here is a ghetto visual graphic of the H-bridge logic chart:

So now lets talk about how to operate the MOSFET’s. Basically all you need to do is attach the gate to your digital output of your controller. When the digital output is turned on, 5V will be applied to the gate, turning the MOSFET on. However it is better to amplify that 5V to a value higher and I will explain why. The gate voltage controls the MOSFET internal resistance. Zero voltage makes the resistance too high for it to work. A very high voltage has a very low resistance. Resistance leads to loss of energy thermally. This means your MOSFET will heat up and possibly burn out. Take a look at the MOSFET picture above and you will notice my finger print in it. That is what happens when you touch a hot MOSFET – pain! So although you do not need to amplify the gate voltage, it is best to do so. You should also put a heat sink on it.

Ok so what if you want speed control, and not just an on/off switch? PWM! Pulse width modulation. PWM is when you send a square wave at a certain frequency to control the MOSFET as shown above. Basically you are telling your controller to turn on and off the motor at very high rates. So through inductance the motor is neither fully on or fully off, but somewhere in between. Such as at a slower speed. Also a note that motor torque, under PWM, remains the same whether fully on or only a percentage on. However, varying voltage for speed control reduces torque. So with PWM you have maximum torque yet slower speeds! You will have to experiment with wave length for both on and off periods, as well as frequency, to optimize your speed control. But a guess usually works.

Make sure the MOSFET you have has built in protection diodes. If not, install them on your circuit as shown. This is to prevent back currents from your DC motor. Also do not forget to put a small capacitor across the leads on your motor to reduce electronic noise and increase motor life. You might also want to refer to the tutorial on robot power regulation to help you design a better power source for your H-bridge.

It is also recommended to put a slow blow fuse after the power supply, resistors of a few 100 ohms on the gate logic, and the additional capacitors on your circuit as shown. This will prevent melting, large voltage surges, and high frequency emission.

taken from societyofrobotics.com

Morphogenetic robotics generally refers to the methodologies that address challenges in robotics inspired by biological morphogenesis. Morphogenetic robotics includes, but is not limited to the following main topics:

• Morphogenetic swarm robotics that deals with the self-organization of multi-robots using genetic and cellular mechanisms governing the biological early morphogenesis;
• Morphogenetic modular robots where modular robots adapt their configuration autonomously using morphogenetic principles;
• Developmental approaches to the design of the body plan of robots, such as sensors and actuators, as well as the design of the controller, e.g., a neural controller using a generative coding gene regulatory network model

Morphogenetic robotics is related to, but differs from, epigenetic robotics. The main difference between morphogenetic robotics and epigenetic robotics is that the former focuses on self-organization, self-reconfiguration, self-assembly and self-adaptive control of robots using genetic and cellular mechanisms inspired from biological early morphogenesis (activity-independent development), during which the body and controller of the organisms are developed simultaneously, whereas the latter emphasizes the development of robots’ cognitive capabilities, such as language, emotion and social skills, through experience during the lifetime (activity-dependent development). Morphogenetic robotics is closely connected to developmental biology and systems biology, whilst epigenetic robotics is related to developmental cognitive neuroscience emerged from cognitive science, developmental psychology and neuroscience.

Source: Wikipedia

Check above youtube video… that’s Nao Robots playing football. They have ability to detect the ball, kick the ball and when they are falling down to the floor, they could standing up their self…

Nao is definitely one of the coolest humanoids around that stands a chance of making it into households as a real product. Aldebaran envisions it as “an autonomous family companion.”

Fully programmable, the 23-inch bot boasts 25 degrees of freedom, affording it an impressive range of motion. Check it out in Nao’s new promo vid after the jump.

Nao can grasp objects with its prehensile hands; process image and sound data; and navigate its environment using its sonars. Multimedia features include high-fi speakers, microphones, and CMOS digital cameras.

The biped runs on an x86 AMD Geocode 500 MHz CPU, 256MB SDRAM, 2GB flash memory, and lithium polymer batteries that last about 90 minutes per charge.

With striking similarities to Sony’s discontinued Qrio humanoid, you’d think Nao was made in Japan. Pas du tout. Aldebaran is based in Paris, though Nao can only speak English.

Nao robots is for sell, one robot costs about 10.000 €. Do you have a plan to own this Nao robot..?

You can download the video in MP4 format HERE.
Prepare your self for next battle…

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When the legendary science fiction writer Isaac Asimov penned the “Three Laws of Responsible Robotics,” he forever changed the way humans think about artificial intelligence, and inspired generations of engineers to take up robotics.

In the current issue of journal IEEE Intelligent Systems, two engineers propose alternative laws to rewrite our future with robots.

The future they foresee is at once safer, and more realistic.

“When you think about it, our cultural view of robots has always been anti-people, pro-robot,” explained David Woods, professor of integrated systems engineering at Ohio State University. “The philosophy has been, ’sure, people make mistakes, but robots will be better — a perfect version of ourselves.’ We wanted to write three new laws to get people thinking about the human-robot relationship in more realistic, grounded ways.”

Asimov’s laws are iconic not only among engineers and science fiction enthusiasts, but the general public as well. The laws often serve as a starting point for discussions about the relationship between humans and robots.

But while evidence suggests that Asimov thought long and hard about his laws when he wrote them, Woods believes that the author did not intend for engineers to create robots that followed those laws to the letter.

“Go back to the original context of the stories,” Woods said, referring to Asimov’s I, Robot among others. “He’s using the three laws as a literary device. The plot is driven by the gaps in the laws — the situations in which the laws break down. For those laws to be meaningful, robots have to possess a degree of social intelligence and moral intelligence, and Asimov examines what would happen when that intelligence isn’t there.”

“His stories are so compelling because they focus on the gap between our aspirations about robots and our actual capabilities. And that’s the irony, isn’t it? When we envision our future with robots, we focus on our hopes and desires and aspirations about robots — not reality.”

In reality, engineers are still struggling to give robots basic vision and language skills. These efforts are hindered in part by our lack of understanding of how these skills are managed in the human brain. We are far from a time when humans may teach robots a moral code and responsibility.

Woods and his coauthor, Robin Murphy of Texas A&M University, composed three laws that put the responsibility back on humans.

Woods directs the Cognitive Systems Engineering Laboratory at Ohio State, and is an expert in automation safety. Murphy is the Raytheon Professor of Computer Science and Engineering at Texas A&M, and is an expert in both rescue robotics and human-robot interaction.

Together, they composed three laws that focus on the human organizations that develop and deploy robots. They looked for ways to ensure high safety standards.

Here are Asimov’s original three laws:

• A robot may not injure a human being, or through inaction, allow a human being to come to harm.
• A robot must obey orders given to it by human beings, except where such orders would conflict with the First Law.
• A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.

And here are the three new laws that Woods and Murphy propose:

• * A human may not deploy a robot without the human-robot work system meeting the highest legal and professional standards of safety and ethics.
• A robot must respond to humans as appropriate for their roles.
• A robot must be endowed with sufficient situated autonomy to protect its own existence as long as such protection provides smooth transfer of control which does not conflict with the First and Second Laws.

The new first law assumes the reality that humans deploy robots. The second assumes that robots will have limited ability to understand human orders, and so they will be designed to respond to an appropriate set of orders from a limited number of humans.

The last law is the most complex, Woods said.

“Robots exist in an open world where you can’t predict everything that’s going to happen. The robot has to have some autonomy in order to act and react in a real situation. It needs to make decisions to protect itself, but it also needs to transfer control to humans when appropriate. You don’t want a robot to drive off a ledge, for instance — unless a human needs the robot to drive off the ledge. When those situations happen, you need to have smooth transfer of control from the robot to the appropriate human,” Woods said.

“The bottom line is, robots need to be responsive and resilient. They have to be able to protect themselves and also smoothly transfer control to humans when necessary.”

Woods admits that one thing is missing from the new laws: the romance of Asimov’s fiction — the idea of a perfect, moral robot that sets engineers’ hearts fluttering.

“Our laws are little more realistic, and therefore a little more boring,” he laughed.

source: sciencedaily.com

This line follower robot is very small and simple. This robot is running fast and follow the line very smoothly. You may see the video here.

Mechanics

All mechanical and electrical parts are mounted on a proto board, and it also constitutes the chasis.

The line following robot is upheld in three points of two driving wheels and a free wheel. The driving wheels are made with a 7 mm dia ball bearing and a rubber tire. The free wheel is a 5 mm dia ball bearing attached loosely. To drive driving wheels, two tiny vibration motors that used for cellular phone, pager or any mobile equipment are used. Its shaft is pressed onto the tire with a spring plate, the output torque is transferred to the wheels.

The steearing mechanism is realized in differential drive that steear the robot by difference in rotation speed between the left wheel and the right wheel. It does not require any additional actuator, only controling the wheel speed will do.

Line detector and Photo reflector

To detect a line to be followed, most contestants are using two or more number of poto-reflectors. Its output current that proportional to reflection rate of the floor is converted to voltage with a resister and tested it if the line is detected or not. However the threshold voltage cannot be fixed to any level because optical current by ambent light is added to the output current like the image shown right.

Most photo-detecting modules for industrial use are using modurated light to avoid interference by the ambient light. The detected signal is filtered with a band pass filter and disused signals are filtered out. Therefore only the modurated signal from the light emitter can be detected. Of course the detector must not be saturated by ambient light, this is effective when the detector is working in linear region.

In this project, pulsed light is used to cancel ambient light. This is suitable for arraied sensors that scanned in sequence to avoid interference from next sensor. The microcontroller starts to scan the sensor status, sample an output voltage, turn on LED and sample again the output voltage. The difference between the two samples is the optical current by LED, output voltage by the ambient light is canceled. The other sensors are also scanned the same avobe in sequence.

Line Detection Signal Processing

Right image shows the actual line posisiton vs detected line position in center value of 640. The microcontroller scans six sensors and calcurates the line position by output ratio of two sensors near the line. Thus the line position can be detected lineary with only six sensors. All the sensor outputs are captured as analog value that proportioning to reflection ratio, and the sensitivity have variety between each one of them. In this system, to remove the variations from the outputs, calibration parameters for each sensor can be held into non-volatile memory. This can be done with online mode. The microcontroler enters the online mode when an ISP cable is attached, and it can be controlled with a terminal program in serial format of N81 38.4kbps. S1 command monitors sensor values, and S2 command calibrates variation of sensor gain on the reference surface (white paper). The ATmega8 must be set to 8MHz internal osc.

Tracking Control

The line position is compeared to the center value to be tracked, the position error is processed with Proportional/Integral/Diffence filters to generate steering command. The line folloing robot tracks the line in PID control that the most popular argolithm for servo control.

The proportional term is the commom process in the servo system. It is only a gain amplifire without time dependent process. The differencial term is applied in order to improve the responce to disturbance, and it also compensate phase lag at the controled object. The D term will be required in most case to stabilize tracking motion. The I term is not used in this project from following resons. The I term that boosts DC gain is applied in order to remove left offset error, however, it often decrease servo stability due to its phase lag. The line following operation can ignore such tracking offset so that the I term is not required.

When any line sensing error has occured for a time due to getting out of line or end of line, the motors are stopped and the microcontroller enters sleep state of zero power consumption.
Notes:

• Development diary [Ja]
• Circuit diagram
• Firmware May 23, 2004
• Following motion with only P control
  This is a video file of line following motion with only P control. The servo system oscllated.
• Following motion with P and D controls
  Adding D control could improve the servo stability. The robot follows the line correctly. Therefore the servo parameter must be optimized for mechanical characterristics to improve the tracking stability.

Source: elm-chan.org

Built based on PIC microcontroller, this robot has multi functions, you might use this robot for several objectives.

The robot’s objectives are the following:

1. Follow a line with sharp turns
2. Maneuver through breaks in the line
3. Detect obstacles and manuever around them
4. Identify colors to be able to locate green and aluminum victims.

You can find the complete tutorial here

Artificial bacterial flagella are about half as long as the thickness of a human hair. They can swim at a speed of up to one body length per second. This means that they already resemble their natural role models very closely.

They look like spirals with tiny heads, and screw through the liquid like miniature corkscrews. When moving, they resemble rather ungainly bacteria with long whip-like tails. They can only be observed under a microscope because, at a total length of 25 to 60

This news comes from ehealtheurope.net. I believe others robots will soon be created to make human life easier…

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French robotics specialist Robosoft and SRI International have demonstrated a new service robot designed to assist the elderly at home.

The RobuLAB, is able to navigate, follow and assist people moving from room to room using SRI Karto navigation software.

The robot is aimed at developers and integrators building home-centric service robots. Robosoft predicts these may become part of everyday life for the ageing population within the next five years.

Vincent Dupourqu

By the time you complete the text and projects you will:

PDA Robotics – Using Your Personal Digital Assistant to Control Your Robot will give you the expertise to create anything. One of many areas that I will touch on is the smart distributed network, where each robot can pass the information that it gains onto the

I’ve collected some schematic diagrams of sound activation as follow:

Sound Activation schematic 1

Sound Activation schematic 2

Sound Activation schematic 3

Sound Activation 4 schematic

Sound Activation schematic 5

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Alexander Stoytchev and his three graduate students recently presented one of their robot’s long and shiny arms to a visitor.

Here, they said, swing it around. And so the visitor tentatively gave the robot’s left arm a few twists and twirls. The metal arm was heavy, but still moved easily at its shoulder, elbow and wrist joints.

Then the graduate students hit some keyboard commands and the robot replayed those exact arm movements.

It was all incredibly quick, smooth and precise.

Stoytchev, an assistant professor of electrical and computer engineering, says it won’t be long before robot technology is something we’ll all see and experience.

“We’ll have personal robots very soon,” Stoytchev said. “We’re waiting for the first killer app. Hopefully, we can contribute to that.”

Star Wars

There’s a little R2-D2-shaped trash can near the door to Stoytchev’s lab in the new Electrical and Computer Engineering Building. Turns out the Star Wars movies were an inspiration to a young Stoytchev back home in Bulgaria.

“My interest in robotics stems from the day I saw Star Wars for the first time,” the 34-year-old said. “I must have been in second or third grade at that time, but the two robots in the movie (R2-D2 and C-3PO) left a lasting impression on me.”

That impression led Stoytchev to his high school’s computer club and then to computer science studies as an undergraduate at American University in Bulgaria. He moved to Atlanta’s Georgia Institute of Technology for graduate work in computer science. He was at Georgia Tech when he started working with robots.

His research specialty is developmental robotics, a blend of robotics, artificial intelligence, developmental psychology, developmental neuroscience and philosophy.

“It’s one of the newest branches of robotics,” Stoytchev said. “People have learned that it’s unrealistic to program robots from scratch to do every task, so we’re looking at human models. Humans are not born knowing everything. It takes a really long time to develop skills.”

Stoytchev and his students are trying to figure out how a robot can learn what children learn over the first two years of their lives. (And child development is something Stoytchev is learning firsthand; he and his wife have a 2-month-old son.)

Graduate work

Stoytchev’s graduate students are working to develop software that will allow their lab robot to learn and use different sets of skills:

Shane Griffith, who’s from Cedar Rapids and is studying computer engineering and human computer interaction, wants the robot to learn on its own which everyday objects can be used as containers and which cannot.

Jivko Sinapov, who’s from Sofia, Bulgaria, and is studying computer science and human computer interaction, wants the robot to learn how to use objects as tools.

Matt Miller, who’s also from Cedar Rapids and is studying computer science, wants the robot to learn language.

Combine that developing software with existing robotics hardware, and you’ve got a useful, smart robot.

“The essential goal of developmental robotics is for robots to learn how to learn,” Miller said. “We want them to learn how to take a situation, adjust to it and learn from it.”

A robot, for example, could learn to use containers by putting a ball in a bucket and seeing what happens when that bucket is pushed across a table. Is the ball pushed along with the bucket? Or is it left behind? The researchers believe that simple interactions like these hold the key to capturing the common-sense knowledge about the real world that comes naturally to people but is so difficult to capture in software code.

A future with robots

Stoytchev was attracted to Iowa State in 2005 by the College of Engineering’s reputation and research capabilities. And now he’s directing Iowa State’s Developmental Robotics Laboratory and making his own research contributions.

It’s work that has him looking ahead.

“In the not-too-distant future, we will have personal robots just like we have personal computers today,” he said. “The robots of the future will be generalists. They will be employed in a large variety of tasks that require a lot more smarts and autonomy than is currently possible. They will have the ability to learn how to perform new tasks on their own without human intervention.”

Yes, he said, “The robots are coming. Are we ready?”

Preface:
In recent years robots have captured the interest of more and more people. Thanks to movies and TV, the notion of the robot as a mechanical companion and servant has become a common concept. As interest in robots grew, a number of books showing how to build robots at home began to appear. These books, however, were very technical, showing how to build computer-controlled mobile platforms that are considered by most to be true robots.

Download Robotics Ebook: Build a Remote-Controlled Robot
Download link 1
Download link 2
Download link 3

Note: this is old book created in year 2002.

Babysitting robots, once the province of speculative fiction, are on the market. They make conversation, recognize faces and keep track of kids. They’re not a replacement for TV or games, but for personal care

Robots can be used for 2 purposes, for good purposes or bad purposes. With the ethics of robotics, robots can be expected to be used for good purposes only. Here the article about ethical guidelines on war robots.

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International guidelines are needed for the ethical and safe use of robots “for care and for war”, according to a leading British scientist.

Professor Noel Sharkey, a robotics expert from the University of Sheffield, warned of the potential dangers posed by new generations of civilian and military robots.

He drew attention to developments which could see battalions of armed and semi-autonomous robots being deployed in battle, both on the ground and in the air.

The US Future Combat Systems project aimed to use robots as force multipliers, with a single soldier initiating large scale ground and aerial robot attacks.

“The ethical problems arise because no computational system can discriminate between combatants and innocents in a close contact encounter,” Prof Sharkey wrote in the journal Science.

In the civilian area the hazards were more subtle but nonetheless real, he pointed out. Large numbers of “personal care” robots had already been developed for child-minding and care of the elderly.

Research had shown that children could become closely attached to robots, often preferring a robot to a teddy bear. But robots were unable to provide the care and attention offered by humans, which could have unpredictable psychological consequences, said Prof Sharkey.

“Because of the physical safety that robot minders provide, children could be left without human contact for many hours a day or perhaps for several days, and the possible psychological impact of the varying degrees of social isolation on development is unknown,” he wrote. “What would happen if a parent were to leave a child in the safe hands of a future robot caregiver almost exclusively?”

Studies had shown that in monkeys, severe social dysfunction occurs if infant animals only develop attachments to inanimate objects.

Care of the elderly was another area where robots were making a big impact, said Prof Sharkey. Examples of such devices already in use included the “My Spoon” automatic feeding robot, the Sanyo electric bathtub robot that washes and rinses, and the Mitsubishi Wakamura robot for monitoring, delivering messages and issuing reminders about medicine.

Robots on a Mission, a rookie team of seventh-grade students from St. Peter Lutheran School in Arlington Heights and home-schooled youngsters, learned about coping skills Saturday during a robotics tournament at Lake Zurich Middle School North.

After being disqualified in the first round because their robot had four motors, one more than the three allowed, the team redesigned the robot and scored well in the second round.

“The boys did a great job of coming together and regrouping,” said their coach Dave Solak. “They looked at the problem, removed one of the motors and made some adjustments and improved their scores in the next rounds.”

ROAM was one of 16 teams from Arlington Heights, Barrington, Batavia, Buffalo Grove, Elgin, Grayslake, Kildeer, Lake Zurich, Mundelein and Palatine competing in the For Inspiration and Recognition of Science and Technology Lego League regional competition.

Lego competitions also were going on Saturday at the elementary school level at Lincoln Middle School in Mount Prospect and at the high school level at the Illinois Institute of Technology in Chicago.

Dressed in matching black team T-shirts boasting a futuristic robot on a gray background, ROAM teammates were among more than 100 children ages 9-14 who went head-to-head with their robots, built and programmed with the Lego Mindstorms system.

“I’ve always been interested in Legos and technical stuff, so I thought that I would like this. I was surprised by how huge this competition was, and by the number of districts competing,” said Kyle Wahlberg, a fourth-grade student from Frederick School in Grayslake who was participating for the first time.

This was the first year that Frederick School participated in the competition and interest was high, said Principal Eric Detweiler.

“We originally thought that we would sponsor one team, but when the number of students interested reached 28, we formed three teams. We even had to turn some away,” Detweiler said.

This year’s theme was Climate Connections, which immersed middle school students in the impact of changing weather patterns. Teams have brainstormed since September and programmed their robots to accomplish tasks during 21/2-minute competition rounds

Teams were judged on how well their robots performed in table action, as well as design and programming. Their research project on climate and their teamwork also were evaluated.

Team STEELE from Kildeer received the Technical Interview Award; Gem Miners from Lake Zurich won the Teamwork award; Gesundheit! from Grayslake won the Robot Table Performance award and Got Robot? from Elgin took the Judges Award. These teams will head to the state tournament Jan. 16-17 at Forest View Educational Center in Arlington Heights. Lego Republic from Lake Zurich received the Research Presentation Award.

Motorola Foundation members have been major supporters of the competition, with many of its engineers serving as mentors and coaches for teams every year

The Bluetooth Boe-Bot Robot Kit for Microsoft Robotics Studio (MSRS) is a Parallax Boe-Bot Robot and an A7 Engineering eb500-SER Bluetooth module. The eb500 module makes it possible for the Boe-Bot robot

Vex Robotics Design System is a robotic kit intended to introduce students as well as adults to the world of robotics. The Vex Robotics Design System is centered around the Vex Starter Kit (which retails for about USD $500). This kit comes with the Vex “brain” (a microcontroller), a hobby-grade remote control, various sensors (2 bumper sensor and 2 limiter switches), three electric motors and a servo, wheels (4 small, 2 medium all purpose, and 2 large high traction tires), gears, and structural parts. Additional sensors (ultrasonic, line tracking, optical shaft encoder, bumper switches, limit switches, and light sensors), wheels ( small and large omni-directional wheels, small, medium, and large regulars), tank treads, motors, servos, gears (regular and advanced), chain and sprocket sets, extra transmitter and receivers, programming kit (easy C) extra metal and rechargeable battery power packs,can all be purchased separately.

This tutorial will show you how to maximize your Vex Robotics Design System. Here are some previews of Vex Robotics Tutorial which will guide you how to get the maximum performance.

You can download the tutorial here;

For the Vex Robotics Kits, you can buy it from Amazon.com: