“We are very pleased to add Kaman Industrial’s selling capability and the value added approach they brings to their customers to our already strong distribution channel.” said John Hegel, President of Minarik Drives.  “Kaman’s penetration into the user and OEM markets will open doors for us that had been previously inaccessible and will help us serve a greater cross section of business across the U.S.”

Minarik Drives is an independent company that specializes in low to medium power electric drive and power applications.  It has been a standard, and a leader, in the DC drive business for almost 60 years.  With design engineering and manufacturing headquartered in S. Beloit, Illinois, it provides standard and customized solutions at a globally competitive price.  More information about Minarik Drives is available at www.minarikdrives.com or by calling 815-624-5959.

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The IRB 2600 is the second introduction from ABB’s fourth-generation of midrange industrial robots, a structured portfolio redesign that began with the 2009 introduction of the IRB 4600 family of robots in the 20 to 60 kg payload range.  At weights of 284 kg and 435 kg respectively for the heaviest models, the IRB 2600 and IRB 4600 are among the lightest robots available in their payload ranges.

The IRB 2600 offers:

–Flexible mounting.  It can be floor-, wall-, invert- or shelf-mounted, reducing floor space requirements and increasing access to the equipment being served. Wall-mounting is a new possibility for a robot of this size. These features enable more creative cell designs, more efficient use of available space and easier integration into existing production lines.

–Compact and lightweight:  The robot has a total arm weight of less than 300 kg and occupies less floor space than other robots in its class. This makes it easier for the arm to reach down below its own base, allowing for smaller production cells.

–Speed and improved cycle times:  The IRB 2600 is quick and can improve production cycle times by up to 25%. The high joint speeds and quick acceleration are achieved by combining new lightweight mechanical linkages and ABB’s patented second generation QuickMove™ motion control technology.

The IRB 2600 family contains three versions: two short arm variants (1.65 m) for 12 or 20 kg payloads, and a long arm variant (1.85 m) with a 12 kg payload.  With the wrist vertical, up to a 27 kg payload is achievable for pick and place packaging applications. The robot has as standard Ingress Protection (IP) 67 rating and “Foundry Plus 2,” a further protection level, is available as an option.

ABB Robotics
www.abb.com/robotics

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The Land Crawler xTreme robot offers its master a ride on top of  its square platform top, provided you don’t weigh more than 175 pounds. As it ambles around, it definitely doesn’t look like the smoothest or speediest way to get around the place, but it sure has got plenty of style doing it.

Funny thing is the maker of the robot says he made the Land Crawler eXtreme as a toy for his 2-year old son because he told him that he wanted to ride on a robot. Why couldn’t we all have dads who were that handy with robotics?

technabob.com

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Here we find a completely different approach to a universal gripper. Individual fingers are replaced by a single mass of granular material that, when pressed onto a target object, flows around it and conforms to its shape. Upon application of a vacuum the granular material contracts and hardens quickly to pinch and hold the object without requiring sensory feedback.  The volume changes less than 0.5% suffice to grip objects reliably and hold them with forces exceeding many times their weight.

The universal gripper utilizes ground coffee beans inside of a balloon.  The coffee beans offer an interlocking grain that proved better than other materials tested that ranged from sand to ground rubber tires.

The Universal Gripper uses ground coffee beans inside of a balloon

Veiw full photo gallery here

The operating principle is the ability of granular materials to transition between an unjammed, deformable state and a jammed state with solid-like rigidity. They delineate three separate mechanisms, friction, suction, and interlocking, that contribute to the gripping force. Using a simple model we relate each of them to the mechanical strength of the jammed state. This advance opens up new possibilities for the design of simple, yet highly adaptive systems that excel at fast gripping of complex objects.

Universal Gripper Demonstration

Universal Gripper Pouring Water

www.pnas.org

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Clean rooms are classified according to the number and size of the particles permitted per volume of air. For example, a Class 10 clean room denotes that no more than ten particles of 0.5 µm or larger and zero particles of 5.0 or larger are permitted per square foot of air. Contaminants come from people, process, facilities, and equipment. In order to control contaminants that are invisible to the human eye, the manufacturing cell and in many cases the entire room must be controlled. Robots used in this environment must meet stringent clean room certification requirements to prevent them for acting as a source of contamination.

Much of the hardware used in a clean room robot is the same as any other robot with the important exception of a combination of sealed covers to prevent particles from escaping the robot, stainless steel hardware, proper non-gassing lubricants and vacuum to evacuate any internally generated particles. Robots for clean room processes have special considerations for harnesses, . . . “which can be a serious particulate generator and a major design challenge for clean applications,” said Scott Klimczak president of CHAD Industries, a pioneer in the area of wafer and substrate handling WLP I (Wafer Level Packaging) applications.

As a matter of practice, materials prone to particle generation are substituted or coated to eliminate the potential for contamination.

Certification is done by counting the number of particles generated when the robot is in motion. For this process the industry uses particle counters that are calibrated to meet or exceed the standards set by NIST (National Institute of Standards and Technology). In addition to NIST traceable practices, other standards of particle counter calibration include Japanese Industrial Standard (JIS) B 9921, Light Scattering Automatic Particle Counter, and ASTM F 328-98, Standard Practice for Calibration of an Airborne Particle Counter Using Monodisperse Particles. Adept Technology, Inc. a leading manufacturer of clean room robots tests robots both internally and through third party testing and certification to ensure integrators and end-users deploy their equipment appropriately to meet manufacturing cleanliness requirements.

There are two accepted clean room specifications, the ISO 14644-1 spec and the Fed 209E spec.

Depending on the cell design and the robot style selected, a lower class robot may be used and still meet the overall system requirements if the system is designed appropriately. For example, for a semiconductor wafer application, if a robot can operate under the wafer with a vertical laminar flow of clean air present sweeping the particles away from the product, the ultimate requirement for the robot may be less stringent.

Installing the clean room robot requires attention to cleanliness. “Robots built for Class 1 environments are wrapped in several layers to protect them as they are shipped to the site,” said Kevin Lonie, application sales manager for Clear Automation, a Connecticut based automation integrator specializing in the design, engineering, fabrication and installation of integrated robotic and machine vision systems. “Then at the site the equipment is moved through progressively cleaner spaces as the wrapping is wiped down and finally removed before entering its ultimate clean room destination.”

Once wiped down with clean room wipes to remove any foreign particles, it is a good practice to connect the robot to the plant’s vacuum system and evacuate the robot for several hours to make sure all particles are purged completely.

www.adept.com

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Here’s what happened in a multi-year collaboration among engineers and scientists at New Scale Technologies, austriamicrosystems and TDK-EPC to simultaneously develop the motor, mechanics, electronics and control systems for the M3 piezoelectric micro motor.

Larger-scale mechatronic systems include this integrated size 17 stepper motor and IDEA drive from Haydon Kerk.

Piezoelectric micro motors satisfy the need for linear motion in miniature products. These millimeter-scale motors are less than half the size of solenoids or traditional electromagnetic micro motors. They are more efficient at small sizes, and produce direct linear motion without gears or drive trains. They also offer longer travel, higher precision and higher force than solenoids or shape memory alloys (SMAs). These features make them suitable for use in portable battery-powered devices, such as miniature focus systems for cameras in phones or industrial laptops, or any application requiring small size and high precision. These include machine vision, optical fiber and RF tuning devices, medical devices, and military systems for vision, targeting and control.

Since 2006, SQUIGGLE piezo motor systems have shrunk in size from (at right) a 12 mm diameter motor with 51 x 76 x 14 mm drive card, to (at left) a 2 x 2 x 5 mm motor with a flip-chip drive ASIC (shown on the dime). This enabled the creation of integrated micro-mechatronics modules such as the M3-L module (center) – complete closed-loop motion systems in housings of less than 7 x 12 x 30 mm.

Designing with piezoelectric (piezo) motors requires a different mindset than that used with traditional servo or stepmotors. The traditional approach of specifying the motor and then buying or designing the control system works for servo and stepmotors because there is a vast body of “cookbook motor” control solutions and experienced drive teams available for traditional motor implementation. This is not the case for piezo motors, which require special drive circuits to create and maintain ultrasonic resonant vibrations in the motor.

In addition, piezo motors are most effective when the mechanics, electronics, control system, software – and even the motor design itself – are developed in concert. In this way the piezoelectric ceramics, the silicon, and the system can be tuned to work together for optimal performance. It is a perfect illustration of the benefits of a mechatronic design process.

Miniaturization meets mechatronics
The last five years have seen impressive miniaturization of piezo motors. One example is our SQUIGGLE motor. Recent innovations have yielded dramatic reductions in the size of the drive electronics. Such reductions were possible in part through collaboration with TDK-EPC to develop new, lower-voltage piezo actuators and eliminate the need for voltage boost circuits; and in part by work with analog IC experts at austriamicrosystems to incorporate more intelligence into the piezo drive ASIC.

These advances enabled new integrated micro-mechatronic modules: small closed-loop actuators that serve as simple “drop in” subsystems in OEM product designs. The system designer provides high-level commands to the module through a standard serial interface. A 3.3 Vdc battery provides power. The mechanical coupling is customized to the application: to move a lens, adjust a grating, push a valve, and so on.

Such micro-mechatronic modules typically provide as much as 50 grams force with precision of one-half micron and closed-loop accuracy measured in tens of microns.

Mechatronics compared to micro-mechatronics
In some ways these micro-mechatronic modules are analogous to larger versions. However, there are important differences. For example, Haydon Kerk combines its IDEA drive with a size 17 stepper motor to create an integrated 60 x 40 x 70 mm mechatronic system that is PC-programmable. According to Haydon Kerk’s Ray LaChance, this integrated drive system is for designers who need a few thousand units per year. Design teams making higher-volume products typically create their own drivers, relying on experienced in-house drive teams and libraries of standard drive approaches.

In contrast, driving piezo motors requires specialized knowledge and experience to create control systems that optimize the motor and drive performance under a range of conditions (including varying input voltage, duty cycle, environment, and load). Load coupling techniques are also important for maximum performance and operating life.

The latest drive ASIC for the SQUIGGLE motor incorporates numerous drive functions that in earlier versions were implemented off-chip. The result is a reduction in overall system size.

Innovation miniaturizes components
Our initial focus was to reduce the size of the motor. The SQUIGGLE motor design has proven to be highly scalable, shrinking by a factor of 100 since the first model was introduced in 2004. The current model measures less than 3 x 3 x 6 mm with housing.

Unlike other piezo motors, where the piezo elements push directly on a stator, this design uses ultrasonic vibrations of the piezo elements to create resonant orbital vibrations in a nut. These minute vibrations drive a threaded screw forward or backward, creating direct-drive linear motion. In this design the piezo ceramics are decoupled from the load path, enabling high force and robustness.

The innovations that allowed miniaturization of this motor included the ability to machine tiny screws with precision threads, greater material choices, fine-tuning the geometry of the piezo ceramics, and creating micro-manufacturing processes for semi-automated and automated assembly of the tiny components.

Next the company turned its focus to miniaturizing the drive electronics. The input to the piezoelectric elements is a set of phase-shifted waveforms that match the resonant frequency of the motor. While other techniques are used, motor speed is typically controlled by varying the amplitude of the voltage.

In the push to miniaturize the drivers, the team zeroed in on the need to reduce the voltage level required to excite the piezoelectric elements. Like most piezo motors, SQUIGGLE motors employ “hard” PZT ceramic material to minimize dielectric losses and associated temperature rise. This material requires an applied voltage of around 40 V to create motion. For battery-power operation, this necessitated a dc-to-dc step-up converter in the drive ASIC, as well as external components to regulate and boost voltage. While total drive footprint for these components was approximately 6 x 9 mm, many OEMs wanted even smaller drivers. Some, especially in medical applications, were uncomfortable with the presence of 40 V in the system even though the drive IC operated on 3.3 V battery power.

In 2008, we partnered with TDK-EPC to develop a piezoelectric drive element with reduced input voltage requirements. The resulting element consists of multiple thin layers of hard piezo ceramic material, co-fired into a single plate. It has the same dimensions and performance as the original monolithic element, but requires only 2.8 V applied voltage.

This change eliminated the need for the step-up converter and boost circuits, and allowed austriamicrosystems to create a smaller driver for the reduced-voltage motor. With this iteration, austriamicrosystems also moved from QFN packaging to wafer-level chip scale packaging (WLCSP), shrinking the drive ASIC from 4 x 4 mm to 1.8 x 1.8 mm. Only two external capacitors are needed, for a total drive circuit footprint of 2 x 3 mm.

At the same time, the design teams packed more features into the smaller chip to enhance motor and system performance. For example, on-chip frequency generation eliminated the need for an external clock. Hybrid full-bridge/half-bridge drivers replaced half-bridge versions, allowing the driver to regulate the voltage to the motor and automatically switch drivers to conserve power at slower speeds, or deliver constant speed as the battery voltage drops. These features reduced system power consumption by more than 30%, providing an additional benefit for battery-operated applications.

Other features in the new ASIC include patent-pending technology to monitor motor performance and adjust the drive frequency to maintain a lock on the mechanical resonant frequency of the motor, which can vary with temperature. This ensures optimal motor performance over wide temperature ranges and high duty cycles.

Miniaturization enables micro-mechatronics
With the drive electronics now smaller than the motor itself, the design team created closed-loop control systems using these components.

SQUIGGLE motors have good position resolution: pulsing the drive signal can cause the motor to move distances as small as half a micrometer per pulse. However, the motor speed—and hence distance travelled per pulse—will vary with applied load and device friction. A closed-loop control system is needed to achieve exact positioning, repeatable bi-directional positioning, or precise speed.

The ability to integrate closed-loop controls into a micro module was aided by recent advances in non-contact position sensors and microprocessors.

The TRACKER position sensor, a joint development by New Scale and austriamicrosystems, is a non-contact magnetic encoder that gives direct digital output, eliminating the need for external pulse counters. At only 3 mm total height including the magnet, it is smaller than optical encoders with glass slides and does not require a light source, which is of particular benefit in optical lens positioning applications. The sensor has a built-in zero reference and 0.5 μm resolution.

A 2.4 x 2.4 mm mini microprocessor integrates into a module with the motor, driver and position sensor. The microprocessor is small and inexpensive enough to allow the company to add intelligence to the module with negligible impact on cost or size. The microprocessor receives position information from the position sensor, and uses on-board PID control to adjust the motor drive signal based on proximity to the target position.

Embedded in a system, the module accepts high-level ASCII commands from the system controller through standard serial interface (I2C or SPI). The command set includes commands to set the motor speed, move, halt, move a specified distance, and move to a target position.

Thus the module could be used in a number of motion tasks. The move-to-target-position command allows the module to travel to any number of pre-set positions, for example moving a grating to tune a laser to selected wavelengths. The move and halt commands can be used to move the actuator until a given condition is reached, for example in an auto focus system. Camera module developers use their auto focus algorithms to command the actuator to move a lens in either direction and halt when focus is achieved.

Motor, driver, position sensor and microprocessor are integrated to provide closedloop linear motion with simple high-level command input via standard serial interface

The ability to use high-level ASCII commands to move the actuator dramatically simplifies the task of embedding precise micro motion into a system design. For evaluation and testing, a USB adapter lets users connect the module to a PC and end commands to the module using the graphical user interface of New Scale Pathway software.

The M3 micro-motion modules demonstrate the advantage of using the mechatronic design process. Today engineers are using this tiny system-level actuator to add motorized focus to compact biometric sensing and machine vision cameras and create compact RF and optical tuning systems.

New Scale Technologies
www.newscaletech.com

austriamicrosystems
www.austriamicrosystems.com

Haydon Kerk
www.haydonkerk.com

TDK-EPC
www.tdk-epc.us

Mechatronic Tips

View a full photo gallery here

The wearable robotics suit is being designed to help with the many logistics challenges faced by the military both in and out of theater. Repetitive heavy lifting can lead to injuries, orthopedic injuries in particular. The XOS 2 does the lifting for its operator, reducing both strain and exertion. It also does the work faster. One operator in an exoskeleton suit can do the work of two to three soldiers. Deploying exoskeletons would allow military personnel to be reassigned to more strategic tasks. The suit is built from a combination of structures, sensors, actuators and controllers, and it is powered by high pressure hydraulics.

Representatives from Paramount Home Entertainment, including the actor Clark Gregg (aka Agent Phil Coulson of the Marvel® Movie franchise) were in attendance to capture footage of XOS 2 to include in a video that’s being produced to support the release of Iron Man® 2 on DVD and Blu ray.

www.raytheon.com

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Smart engineers copy ideas. Great engineers copy nature. Festo’s Bionic Handling Assistant is a robot arm modeled on an elephant’s trunk (or Dr. Octavius if you’re a Spiderman fan), and it has all the supple flexibility of the original. Using hollow plastic chambers that change size with air pressure, the Bionic Handling Assistant can move through an incredible range of motion in three dimensions. It’s designed to provide gentle forces, and to give when pushed, making it safe for working with humans in a working environment.

The Bionic Handling Assistant was developed through Festo’s Bionic Learning Network, a coordinated group of industrial and academic research partners interested in bringing nature inspired concepts to robotics.  However, all this biology inspired innovation is really only going to be useful if we can find the right applications. Opportunities for the Bionic Handling Assistant in medicine, manufacturing, and mechanical repair are shown below.

For a better idea of how the pressurized air allows the Bionic Handling Assistant to move, here’s a more detailed animation of the robot arm:

No matter where it eventually is applied, the Bionic Handling Assistant is a good sign that engineers have a lot to work with when mimicking natural structures. With all the humanoid robots running shuffling around it’s important to remember that the primate form is only one of many successful architectures we should be copying. Robots that swim like fish, fly like insects, and form colonies like bees could all have crucial applications in the years ahead as we continue to explore the world. It will be interesting to see which animals the Festo Bionic Learning Network pursues next.

www.festo.com

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The lab-tested material responds to almost the same pressures as human skin and with the same speed, they reported in the British journal Nature Materials.

Important hurdles remain but the exploit is an advance towards replacing today’s clumsy robots and artificial arms with smarter, touch-sensitive upgrades, they believe.

The “e-skin” made by Javey’s team comprises a matrix of nanowires made of germanium and silicon rolled onto a sticky polyimide film.

The team then laid nano-scale transistors on top, followed by a flexible, pressure-sensitive rubber. The prototype, measuring 49 square centimetres (7.6 square inches), can detect pressure ranging from 0 to 15 kilopascals, comparable to the force used for such daily activities as typing on a keyboard or holding an object.

A different approach was taken by a team led by Zhenan Bao, a Chinese-born associate professor at Stanford University in California who has gained a reputation as one of the top women chemists in the United States.

Their approach was to use a rubber film that changes thickness due to pressure, and employs capacitors, integrated into the material, to measure the difference. It cannot be stretched, though.

The achievements are “important milestones” in artificial intelligence, commented John Boland, a nanoscientist at Trinity College Dublin, Ireland, who hailed in particular the use of low-cost processing components.

In the search to substitute the human senses with electronics, good substitutes now exist for sight and sound, but lag for smell and taste.

Touch, though, is widely acknowledged to be the biggest obstacle.

Even routine daily actions, such as brushing one’s teeth, turning the pages of a newspaper or dressing a small child would easily defeat today’s robots.

Bao added important caveats about the challenges ahead.

One is about improving the new sensors. They respond to constant pressure, whereas in human skin more complex sensations are possible.

This is because the pressure-sensing cells in the skin can send different frequencies of signal — for instance, when we feel something painful or sharp, the frequency increases, alerting us to the threat.

In addition, Bao warned, “connecting the artificial skin with the human nerve system will be a very challenging task”.

“Ultimately, in the very distant future, we would like to make a skin which performs really like human skin and to be able to connect it to nerve cells on the arm and thus restore sensation.

“Initially, the prototype that we envision would be more like a handheld device, or maybe a device that connects to other parts of the body that have skin sensation.

“The device would generate a pulse that would stimulate other parts of the skin, giving the kind of signal ‘my (artificial) hand is touching something’, for instance.”

In the future, artificial skin could be studded with sensors that respond to chemicals, biological agents, temperature, humidity, radioactivity or pollutants.

berkeley.edu



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The embedded PC, which features a DDR3 memory and an Intel Core2 processor, is free of wear from moving parts, such as hard disks and fans. This compact motion control system provides maximum flexibility and accommodates centralized or decentralized machine concepts for PC-based applications or for applications that require a compact size.

It is designed for many different motion control applications with its multiple onboard interfaces. They support communication over Profinet, the open industrial Ethernet standard, as well as Ethernet interfaces that run at 10 / 100 / 1000 megabit speeds. Four USB interfaces make it simple to connect a keyboard, USB stick, printer or other devices. A DVI port rounds out the links so users can attach a display or monitor. The Simotion P320-3 can also be used in a “headless” configuration without a display, monitor or front panel.

LEDs on the front indicate the operating states, making self-diagnosis easy. The integrated power supply bridges temporary power failures. In the buffered SRAM memory, the process data is saved securely even in the event of a sudden voltage drop. Monitoring functions for the batteries, temperature and program execution are also included. The Windows Embedded Standard 2009 operating system, which increases the reliability of the system, is pre-installed. Additionally, the Simotion runtime system comes installed on the Simotion P320-3.

www.sea.siemens.com

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Previously, we covered mechanical considerations for electrical engineers. Now, we give the other side a chance to speak. Here are five targeted pieces of advice for mechanical engineers responsible for electromechanical systems, from the perspective of an electrical engineer.

Mechatronics systems intelligently integrate mechanical and electrical elements to perform increasingly complex and demanding functions. When designing electromechanical systems, mechanical engineers and electrical engineers may tend to emphasize the technologies, components, and design principles from their single area of expertise—which can lead to systems with higher operating costs, increased maintenance demands, and less than optimal performance. As an electrical engineer involved in helping OEMs and manufacturers design and build mechatronic systems, I’ve seen how inefficiencies and unnecessary complexity can be unintentionally designed into machines.

A clean design balances mass and motion: sturdy, durable framing withstands years of vibration and shock, combined with lighter-weight components helps to reduce mass and enable the use of smaller motor/drive components.

Better mechatronic systems can be created when mechanical engineers consider five crucial concepts while designing manufacturing systems, to derive the greatest value and efficiency electronics systems can offer to the manufacturing process.

1: Create a clean design
Good mechatronics design starts with good mechanical design – the best electronics and electrical systems cannot compensate for poor mechanical design. The most successful designs are “clean.” They feature a strong, rigid frame, using materials and structural principles to ensure that, whatever motion the machine undergoes, its long-term stability is “engineered” in.

Make sure that rigid bearings and support are used where motors are mounted on machines; this helps prevent shafts from being sheared off due to microfractures that occur because the motor shaft is mounted out of alignment with a pillow block bearing or gearbox input planetary gear. Place motors on the machine in the best location so that operators aren’t accidentally stepping on cables and connectors and causing damage; and design machine guarding with easy access points to get to motors mounted under the wing base of the machine while still protecting them against harsh environments.

Most importantly, a clean design balances mass and motion: sturdy, durable framing that withstands years of vibration and shock, combined with lighter-weight components for the moving parts of the machine. This combination helps reduce mass, delivers more energy-efficient motion, and makes it easier to size-up smaller motor/drive components for the machine. We’ve seen a lot of very innovative mechanical machine designs over the years, and a clean design makes the largest contribution to a machine’s longevity, robustness, and lowest overall cost of ownership.

2: Directly couple the motor to the load
Effective mechatronics starts with a “clean slate” design. In the past, machines were often built around a single ac motor powering a machine line shaft, to which were attached gearboxes, pulleys, sprockets, chain drives and other mechanical devices for moving individual areas of the machine in synchronization – an approach to powering manufacturing that literally can be traced back to the dawn of the Industrial Revolution.

A clean design makes the largest contribution to a machine’s longevity, robustness and lowest overall cost of ownership.

Consider replacing this architecture with individual servomotors coupled directly to the load you are moving. There are multiple design, machine cost, and operational advantages to this idea (which a surprising number of machine designs do not use). First, consider cost: every time you add a gearbox, you add multiple costs: it’s an additional point of failure, it has to be lubricated, and it needs spare parts. Plus, you add mechanical backlash that must be compensated for during machine commissioning every time you have a product changeover – motion and axes synchronization complexity that today’s intelligent drives and servomotors eliminate.

When you strategically locate servomotors as close as possible to the area of motion they are serving, the incremental cost of electric drive components is almost completely offset by eliminating the cost of mechanical components and labor that must be purchased, machined, assembled and configured. In particular, not having to stock multiple sets of sprockets, gears and cams, as well as the time involved in changeovers with mechanical drives, can really drive down the total cost of ownership for the machine.

Ultimately, this design approach greatly reduces windup and backlash, as well as improves machine commissioning time; and current state-of-the-art direct drives, direct motors, and linear motors let you run higher gains and improve the machine’s performance.

Consideration #3: Use electronic gearing and camming
Today’s electronic drives and motion control platforms give mechanical engineers, a powerful, flexible tool to improve the accuracy and performance of the machines you design. This technology lets you create a virtual “electronic line shaft” that can electronically synchronize all the drives and motors on the machine, eliminating the mechanical line shaft. In the process, you can dramatically improve axes synchronization and accuracy – from 1/16th or 1/32nd of an inch typical with mechanical line shafts, down to motion precision closer to hundredths or even thousandths of an inch with electronic line shafting.

And this synchronization can be accomplished with zero mechanical backlash – and fewer product jams. It also eliminates a host of mechanical adjustments to bring the machine online, as well as the operator adjustments each time the machine is stopped and restarted.

Electronic gearing and camming makes machine changeover completely programmable: For example, the use of FlexProfile technology lets operators load machine recipes with the touch of a button on the HMI screen, and the changes are made in the control and servo system to run the next product.

The FlexProfile camming technology makes it possible to build multisegmented cam profiles based on position, velocity, or time-based motion profiles. When you change a section of the electronic cam with a recipe change through the HMI, the control platform will automatically optimize the rest of the cam profile across all of the machine’s motion elements. This enables the machine to run a shorter cycle time, or provide smoother dynamics for the machine, even though a change has occurred such as a different bag seal time or flap tucking cam position on a cartoning machine.

Consideration #4: Incorporate energy-efficient technology
One of the fastest growing costs for any manufacturing operation is energy – and good mechatronic design can help control these costs through the application of electric drive and motor systems designed to save energy.

In machines that use servomotors directly coupled to critical axes of motion, and that also use electronic synchronization and camming, the proper sizing of the servo system can create a highly energy efficient machine.

Proper sizing requires an accurate assessment of several motion factors (motor by motor): How fast the axis needs to accelerate, the size of the mass you’re trying to move, and how precise the acceleration and deceleration needs to be. Undersizing will lead to strains on the drives and motors; oversizing will draw too much power to do too little work.

Some of today’s most cutting edge systems, such as the Rexroth IndraDrive Mi integrated drive/motor systems, include a highly energy efficient feature: bus sharing. Multiple drives are daisy-chained together and share power from the same bus; in many multi-axis machines, as some motors are accelerating up to speed (drawing power), others are decelerating (regeneration power). With bus sharing, rather than having to deliver maximum power to the accelerating motors and bleed off the decelerating motors into heat across a bleeder resister, power is shared, so the machine’s power consumption is significantly reduced.

A further energy-efficient technology is called regenerative power supplies. In many machines, multiple servomotors will decelerate at the same time, boosting the voltage to excess levels on the power bus. Older generation electrical drives would bleed that excess electrical energy as heat – wasting the power, and adding to the factory floor’s heat production, requiring additional cabinet cooling. With regenerative power supplies coupled to a shared bus system, what was once wasted power can now be fed back through the shared bus and sold back to the electric company.

The use of direct drive, direct motors and linear motors versus mechanical couplings lets you design a system to run higher gains.

Consideration #5: Use HMI’s for better troubleshooting
User-friendly intelligence is now available through today’s touchscreen HMIs. Machine layout drawings and schematics can be incorporated into control menus and diagnostic tools, to better manage the machine’s day-to-day operation and troubleshooting. Drawings and interactive instructional tools can not only show the precise point where a problem is – they can also step the operator through the tasks to restart production.

Advanced graphics like this can be combined with the distributed intelligence inherent in servomotor-driven machines, to prevent machine failures or faults before they happen. With such predictive maintenance, this capability lets you or machine designers set fault tolerance bands in drives and then monitor drive performance. Electric drives and motors allow a broad range of conditions to be monitored – conditions that are directly associated with mechanical performance; variations in load, temperature, vibration, torque, belt tightness, gear meshing are all mechanical events that generate changes in the torque profile of an electric drive and motor moving those machine elements. Mechanical engineers can set tolerance bands for these components, and if they exceed them, then predictive maintenance alerts can be clearly and intelligently displayed through the HMI to operators, along with specific advice about next steps to take to correct the issue before it becomes a serious production problem or something that can damage the machine.

With Rexroth’s IndraDrive Mi integrated motor/drive system, multiple drives are daisy-chained together and share power from the same bus, significantly reducing energy consumption.

Blending technologies for optimal value
Every electromechanical system should perform its designed function with the minimal use of energy, motion and components required to get the job done – that’s the fundamental goal of any engineer. Electrical drive and servomotor systems now offer a wealth of reliable, energy-efficient, digitally intelligent platforms to power the integrated vision of mechatronics to greater value and more innovative manufacturing and automation solutions.

Hopefully, the five considerations described here demonstrate the advantages that today’s electric drives and controls offer, helping you simplify certain mechanical design and engineering challenges and provide new resources for driving innovation and creativity in machine design.

www.boschrexroth-us.com

Mechatronic Tips

Obviously, this type of metric will vary wildly depending on how highly automated a particular industry is.  The beverage industry is highly automated and doesn’t have a large employee staff to generate finished products.  But interestingly, the companies that build machinery for the beverage industry have fairly high employment because it takes a combination of technically trained skilled workers to make the machinery that makes the beverage products.

The agricultural economy has grown dramatically with the introduction of machinery to assist in the process. Complex machines have been developed for many applications to increase productivity.  The latest round of enhancements are tilling and planting equipment that uses Global Positioning Satellite information to keep the tractors in a straight line and computer plots of the land to maximize the planting area per acre.  Pretty amazing stuff.

In the automotive area, there are some interesting statistics.  In the ten year period from 1998 to 2008 the industry increased its gross output per employee by 33%.  This is a huge statistic and represents the long term impact of automation on the manufacture of vehicles.  The other interesting statistic is that the average internal price of a car today is the same as that ten years ago.  Given that the US industry has pushed it’s quality to compete with the Japanese cars that were perceived as superior to US in quality, this is an amazing feat.

Of greater interest is the comparison of total vehicle shipments.  The most cars and light trucks ever shipped by the US Auto makers was in the year 2000 when we shipped 17.8 million units according to Ward’s Auto which reports on the car industry.  This feat was almost duplicated in 2005 when 17.4 mil units were shipped.

A relatively stable manufacturing base over the years, the US auto industry hit a disastrous slide in 2008 shipping an anemic 13.49 mil units followed by an even worse 2009 when we shipped 10.6 mil cars and trucks.  This was the year in which the Chinese automakers topped the US manufacturing rate for the first time ever.  A point that the Chinese press made with great vigor in spite of the fact that the majority of Chinese automakers are actually joint ventures with foreign companies, the single original Chinese auto maker being in great difficulties due to poor product quality.

The 2009 US auto showing is particularly dismal when you consider the “cash for clunkers” incentive which spent $1.4 billion taxpayer dollars to generate 200,000 additional unit sales.  A small showing in the scheme of things even if the market was 10 million units.

Will the US auto market pick back up? Certainly, but not to the former highs of 2000 and 2005.  2009 shipments were off by 40% from the 2005 high, and that is too much of a gap to be easily recovered.  Especially when unemployment continues to be running in the 10% range and higher.

Is there hope?  Yes.  Serious electric hybrids and battery manufacturing for the US automakers will create tens of thousands of jobs in the next couple of years.  Demand for foreign hybrids has been running at over 400,000 units per year, and will likely increase once there are quality US made products available.

States that pay attention to the needs of the industries they provide locations for are States that will thrive with low unemployment and low deficits.

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Caterpillars have a unique “two-body” system of movement that may have implications for robotics and human biomechanics, U.S. researchers say.

The scientists found that the gut of the crawling hawkmoth caterpillar moves forward independently of and in advance of the surrounding body wall and legs, instead of moving with them. This is the first time this type of movement has been reported in an animal, the study authors noted.

“Understanding this novel motion system may help efforts to design soft-bodied robots. It may also prompt re-examination of the potential role soft tissues play in biomechanical performance of humans and other animals,” study senior author Barry Trimmer, a professor of biology and of natural sciences at Tufts University, said in a university news release.

The findings are published online July 22 in the journal Current Biology.

Hawkmoth Caterpillar That may look like a snake, but it’s actually a hawkmoth caterpillar

“Although internal tissue movement caused by locomotion has been identified in many organisms, the caterpillars seemed to be propelling themselves by means of a two-body system — the body wall container and the gut it contained. This may contribute to the extraordinary freedom of movement seen in these soft-bodied crawlers,” first author Michael Simon said in the news release.

Further research is needed to determine if this type of movement offers caterpillars an evolutionary advantage, and how this finding may prove valuable in robotics, added Simon, who conducted the study as part of his doctoral research in Trimmer’s lab.

“The focus to date has been on robots’ external design, but we also have to look at how it’s most advantageous to arrange the inside of the robot and any payload. Would motion be enhanced, for example, by packing more mass toward the rear, as these caterpillars seem to do?”

A grant from the U.S. National Science Foundation funded the research.

www.nsf.gov

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Army researchers call it the Robotic Tentacle Manipulator, a developmental project that expands on snake robotics research introduced at Carnegie Mellon University’s Robotics Institute, an ARL-funded effort through its robotics Collaborative Technology Alliance initiative.

This new work has resulted in the arrangement of the bases of several snakes in a circular array that functions like a team using multiple parts of their bodies to manipulate an object, scan a room or handle improvised explosive devices.

This snake-robot is scalable; it can be built however large or small as a subsystem to a larger platform like iRobot’s rugged system Warrior, which travels over rough terrain and climbs stairs. The number of tentacles or snakes determines the breadth or scope of its search capabilities. The number of links on each of those tentacles supports each snake’s length or reach into an area, as well as its ability to crawl, swim, climb or shimmy through narrow spaces all while transmitting images to the Soldier who is operating the system.

The subsystem comes equipped with sophisticated electronic sensors, among them laser detection and ranging, or LADAR, to render 3-D representations of object shapes and physical properties like faces, mass and center of mass.

“The technology is leading to more than just the very tip of the snake being used in the object manipulation effect,” said Derek Scherer, a researcher who works within ARL’s Vehicle Technology Directorate. “Consider that snakes push off rocks or roots to propel their bodies. We are using this same concept in development.”

Scherer said that with increased manipulator dexterity, Soldiers can offload more tasks to the robotic platform. “When the platform is tasked with inspecting a potential IED threat, the extreme adaptability of the tentacle manipulator will allow the platform to rummage with precision,” he said.

Its ‘touch sensitivity’ allows the snake-robot to balance objects and feel where forces are being applied as it rotates devices.

“It allows it to lift and reposition objects, including IEDs, for examination, and do so in a controlled fashion that is unlikely to detonate any ordnance.” Scherer noted. “These same capabilities would improve inspections during cargo and checkpoint missions.”

Researchers predict the technology may one day solve the “opening a door” problem, which has been a consistent obstacle in robotics, Scherer said. High levels of articulation in the manipulator could prove to be effective for grasping and rotating different types of door handles using knobs, handles, levers and bars.

“Solving the door problem would greatly improve indoor robot missions,” Scherer added.

The developmental hardware includes a large-screen laptop, which presents a simple user interface. Each 24-centimeter tentacle is directed by a master controller system, which communicates with the motors that are embedded in each of the links found on the tentacles. The motors essentially direct individual tentacle movement and the master controller directs the entire amalgamation of snakes, or tentacles.

“This is a distributed intelligence framework that permits advanced manipulation algorithms to run on a complex but affordable hardware platform,” Scherer said.

www.army.mil

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Using a joystick and a small keypad, Allen demonstrated how to operate the legs to stand, walk, and even go up and down steps. The Rex has to be custom fitted to each user, it took about three days for Allen to get the hang of it. However, now he is capable of strapping the device on himself, without any assistance.

The inventors of Rex are Richard Little and Robert Irving. They are two childhood friends originally from Scotland. Seven years ago after Irving was diagnosed with multiple sclerosis, the duo came up with the idea. Over the next few years, they refined Rex into a 38kg (84lb) device. All their work was top secret; even Allen, who agreed to be the Rex test pilot, kept his family in the dark about the project until the launch.

“It was all top secret and what we didn’t know, we didn’t need to know anyway. But seeing him here today, it’s just blown us away. It’s brought tears to our eyes really,” Allen’s father said in a statement. Allen has been in a wheelchair since injuring his spinal cord in a motorcycle accident five year ago. When he heard what Little and Irving were planning, he jumped on board. “They brought me in and I said ‘I want to be part of that.’ I couldn’t walk away — or roll away — from that,” he stated.

The investors in the venture capital company put up the $7.5 million which was needed to create the prototypes. The device is expected to be on the market worldwide by mid-2011. The cost of the custom made device will cost around $150,000 each. However, it is priceless for people who never thought they would walk again.

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