Sensor elements

To track down any corrosion damage or cracks in oil and gas pipelines, the workers use UCSD "go-devils" equipped with Baytec P sensor strips. Because Baytec P has such high elasticity, the sensor elements can always stick close to the pipe wall, even when they pass over pipe bends or travel through narrow cross-sections, thus minimizing measuring errors.
Other specifications made on the elastomer are particularly high resistance to wear and tear and outstanding swelling resistance.

Helios movie projector

A cabinet can be far more than a handy, light and robust case. This has been proved by the Helios video projector and its sophisticated exterior made of Baydur® polyurethanes from BaySystems®. Available in a variety of colors, it is perfectly at home in its environment, whether at conferences or presentations.

The Helios digital video projector from the Italian company Vidikron Industries S.p.A. has a special visual appeal in more than one sense. The highly sophisticated electronics packed inside the set are protected by a cabinet manufactured by 2a.effe of Lissone, Italy, using polyurethanes Baydur® 60 and Baydur® 110 from BaySystems®. In addition to offering a perfect combination of design and functionality, these two materials also provide a number of structural benefits, including an excellent surface finish that is ideal for high-grade coatings and gives the projector a distinctively elegant appearance

H-Bridge for Robots with High Current DC Motors

DC Motors which need high current and high voltage usually give high velocity and high torque. For small robots like line follower robot or fire fighting robot, I think IC motor driver L298 (up to 2A total current) is better choice. While for large and heavy robot, you need high current DC motors also H-Bridge suit to your DC motor.

This article sould be useful for you to build high current H-Bridge. H-Bridge schematics provided…

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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.
H-Bridge

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.

MOSFET, Transistor
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:
H-Bridge A

H-Bridge B

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.

Square Wave for Pulse Width Modulation PWM
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.

Robots In CIS Applications

Robots have started receiving greater attention in medical/surgical applications. Tasks beyond human manipulation/precision capabilities are being trusted to assitant systems that only perform that small portion of the procedure, under human supervision. Despite intial skeptical response due to safety, and cost concerns the role of robots in surgery is likely to grow.

Surgical robots present an environment unlike most other applications where robots are applied. e.g. industrial plants. Mechanical components of surgical robots tend to be simpler, slower than their industrial counterparts, but the electronics, safety, and guidance systems are usually far more complex. A set of complex planning, guidance, and safety systems (often redundant) are involved in operating a surgical robot.

A team designing a surgical robot is faced with several difficulties. A complex system takes several years to develop, and development is often sequencial. E.g. The guidance system can not be tested until the hardware is available, and software developing and testing is highly dependent on availability of functioning hardware. Surgical robots are developed to deal with specific surgical procedures, and so each application results in the repetition of the design cycle.

A modular system allows software development to be independent of hardware design. It also allows existing modules to be used for new applications. It improves design clarity and testing and finally develops interfaces making interoperability between different systems easier.

There are several ways to develop modular/flexible software to control a robot: use/develop a programming language with all the facilities of object oriented design. But this would create yet another language, with a learning curve and user acceptance issues. An alternative approach is to develop interfaces, and implementations of the same in an acceptable programming language. This provides libraries that can be shared, swapped, and developed independently of each other. Furthermore, it allows the programming language to be changed, while preserving the interfaces (most programming languages provide ways of calling other language libraries, if need be).

The modular robot control(MRC) library is one such library. While the set of robots under consideration is mostly serial manipulators, the interface design can be easily extended to parallel architectures. The interface design is independent of the programming language, and the first implementation uses C++ classes. The library classes have a layered structure, each new Layer inheriting significant functionality from its parents.

This documentation is for the MRC library version 1.1 The class most commonly used by an application as an instantiable robot is the mrcRobot class and this should also be the base for all derived robot classes. Detailed implementation documentation exists separately.
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Silver-Coated Future

Nanotechnology, fast becoming a three-trillion-dollar industry, is about to revolutionize our world. Unfortunately, hardly anyone is stopping to ask whether it's safe.

For an industry that trades in the very, very small, projections about the potential scope of nanotechnology are gigantic. Estimates are that the industry will grow at a staggering pace in its first decade, reaching close to $3 trillion globally by 2014. The National Nanotechnology Initiative, created by President Bill Clinton in 2000, has called it "the next industrial revolution." Enthusiasts say that nanotechnology may someday enable scientists to build objects from the atom up, leading to entirely new replacement parts for failing bodies and minds. It may enable engineers to make things that never existed before, creating nanosize "carpenters" that can be programmed to construct anything, atom by atom -- including themselves. Or it may make things disappear, with nanowires that get draped around an object in a way that makes the whole package invisible to the naked eye.

As difficult as it is to comprehend how huge is the promise of nanotechnology, it's just as hard to wrap your head around just how tiny "nano" is. A nanometer is defined as one billionth of a meter, but what does that mean? The analogies are mind-boggling but not necessarily enlightening. Hearing how small things are when you're working at the nano level doesn't help you visualize anything, exactly; all it does is make you sit back and say, "Wow." If you think of a meter as the earth, goes one analogy, then a nanometer would be a marble. If you think of a meter as the distance from the earth to the sun, then a nanometer would be the length of a football field. A nanometer is one hundred-thousandth the width of a human hair. Or it is, in a particularly kinetic description, the length that a man's beard will grow in the time it takes him to lift a razor to his face.

"Things get complex down there, in terms of the physics and the chemistry," says Andrew Maynard, chief science adviser for the Project on Emerging Nanotechnologies, established in 2005 at the Woodrow Wilson International Center for Scholars in Washington, D.C., in partnership with the Pew Charitable Trust. "When you have small blocks of stuff, they behave differently than when you have large blocks of stuff."

At the nano level, some compounds shift from inert to active, from electrical insulators to conductors, from fragile to tough. They can become stronger, lighter, more resilient. These transformed properties are what account for the infinite potential applications of nanoparticles, defined as anything less than about 100 nanometers in diameter.

The field is a textbook example of exponential growth. According to Lux Research, an emerging-technologies research and advisory firm based in New York that has tracked the industry since 2001, the total value of all products worldwide that incorporated nanotechnology was $13 billion in 2004. That figure grew to $32 billion in 2005 and to $50 billion in 2006, and Lux Research projects it will reach $2.6 trillion by 2014.

Nanotechnology holds great potential for improving our lives. It might benefit the environment, for instance, by reducing our dependence on oil through the creation of a new power grid based on carbon nanotubes -- which can carry up to 1,000 times as much electricity as copper wiring without throwing off heat -- and solar energy farms that use thin, cheap, flexible nano-engineered solar panels.

Nanostructures offer better options for rechargeable batteries, for instance, including the ones to be used in the next generation of hybrid cars. One such battery, made with nanostructured lithium-iron- phosphate electrodes, is smaller and lighter, less environmentally toxic, and can hold more energy, take a charge more quickly, and maintain a charge longer than conventional lithium batteries, according to Michael Holman, a senior analyst with Lux Research. "It's not the compound itself that's nanoscale, but the surface of the material," Holman says. The surface of the battery electrode contains nanosize bumps and ridges, "which make the surface area much higher, allowing the electrons to flow in and out of it more quickly."

In the medical field, nanotechnology is expected to lead to dozens of innovations: new methods of cancer treatment that deliver chemotherapy directly to the tumor, earlier cancer detection using nanowires that can spot derangements in just a few protein cells, new methods of blood vessel grafting during heart surgery using nanoglue formed from nanospheres of silica coated in gold.

In cancer treatment, one application involves gold nanoshells: gold-coated glass spheres no more than 100 nanometers in diameter. These nanoshells enter tumors by slipping through tiny gaps in blood vessels that feed the malignancy. Once enough nanoshells accumulate in the tumor, scientists shine a near-infrared laser through the skin, heating up the gold particles and burning away the cancer. This technique, developed at the University of Texas Health Science Center, has worked in animal experiments and is about to be used in humans.

However, the real impact of nanotechnology, at least in the short term, will not be at the dramatic level of cancer cures or a new energy grid. For now, the technology will have to prove itself in the more mundane arena of commerce: washing machines that fight germs, antiseptic computer keyboards and kitchen utensils, windshields that repel the rain, sunscreens that rub on easily and block the full spectrum of ultraviolet rays. Nanoparticles are being put into stain-resistant clothing (Haggar NanoTex pants with NANO-PEL), super light tennis rackets (Wilson nCode), antiwrinkle face creams (Lancôme Rénergie Microlift), sunscreens (Blue Lizard), computer peripherals (IOGEAR), and a wall paint made by an Australian company, Nanovations, that says the paint can "achieve better energy ratings for buildings, better indoor air quality and fewer allergy-related illnesses."

But before we hurtle off toward a nano-utopia, we need to step back and ask ourselves whether this is a direction in which we really want to go.

When an industry grows this quickly, there may be neither the time nor the inclination to ask some tough questions about possible risks. First of all, there are the health and environmental hazards. Would nanotechnology bring unacceptable risks to workers making these materials or consumers who use the final products? Would it affect air or water quality near where the nanomaterials are dispersed? Very little is known about nanotoxicology, which might be very different from the toxicology of the same materials at normal scale (see "Smaller Is Weirder").

Then there are the social, even existential, consequences. If the hype about nanotechnology contains even a smattering of truth, the technique could shake up our most basic assumptions about our place in the universe, turning us from its residents to the architects of its most fundamental elements. Might that act of hubris somehow subvert us as a species?