The Absolute Value of Technology – Part 2

So continuing on a theme, there are many ways to describe value.   In order to measure the value of technology, we must measure it’s cost performance.  There are many elements of the value proposition that need to be considered, such as cost to acquire the technology, installation costs, maintenance cost and life expectancy.  And the benchmark for cost performance is the market price for the old technology.

So taking electricity, for example, any comparison of new technology to deliver electric power must be compared with the present cost to deliver power.  If coal fired powerplants can deliver power, with all of the costs already accounted for, at 10.6 cents per kWh, then any new method must achieve that cost performance or customers must be prepared to pay more for electricity.  If CO2 reduction or eliminating coal combustion pollution are sufficiently high priorities in the consumer’s mind, then electricity will simply have to cost more.   Read more

Link Shaft for Belt Drive Linear Modules

Belt driven linear actuators continue to increase in popularity as designers look to mechatronic systems to move products more quickly, cleanly and efficiently. Larger and faster gantries are being built for an increasing variety of applications in diverse new fields. Pick and place devices, inspection systems, and general material handling continue to take advantage of the speeds and lengths of travel these components offer.
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The Absolute Value of Technology

I read constantly on a variety of subjects.  I am interested in electric cars, wind energy, industrial productivity, electric motors, lots of stuff that would seem to be disconnected.  As someone who is involved in the development of technology, it is important to me to look to the future.  For my consulting clients I must often identify the barriers to entry of markets.  What are the hurdles and how do we overcome them?

In case you haven’t read any of my posts, I am a bit skeptical when government gets involved in developing technology.  I don’t think we the taxpayer have ever gotten a good deal in that regard.  I am particularly concerned by the billions of dollars per year spent by the Department of Energy considering the very few benefits gained for the extraordinary sums that are spent. Read more

Clippard Joins Forces with FIRST

Cincinnati, OH – Clippard Instrument Laboratory, Inc. announced that it is joining forces with FIRST (For Inspiration and Recognition of Science and Technology), a not-for-profit organization founded by inventor Dean Kamen to inspire young people’s interest and participation in science and technology, as a Silver Supplier of the FIRST Robotics Competition.

The FIRST Robotics Competition Silver Supplier level designates a contribution between $10,000 and $50,000. Clippard Instrument Laboratory, Inc. provided air volume tanks for the 2009 FRC Kit of Parts which was distributed to more than 1,680 teams of high-school students on January 3, 2009.

By providing components for the competition, FIRST suppliers are putting the latest technology in the hands of students, giving them the opportunity to apply the same tools used by professional scientist and engineers and ultimately helping them learn real-world skills they will carry into the workplace. The 2009 Kit of Parts contain 604 items, 39% of which are donated.

www.clippard.com

Tips for the Control Side of Mechatronics

By Leslie Langnau, Managing Editor
Design World

In mechatronic projects, the focus is often on the mechanical and electrical aspects of a system as engineers concentrate on throughput, speeds, accuracy, and so on.  How these system goals affect the desired control selection may not be addressed until too late to make changes. Mechanical engineers do their part, then electrical engineers do their part, then, the controls engineers must make it all work.

In addition to finding ways to improve the communication and interaction of the various engineering disciplines, there are other design aspects that affect controls to keep in mind. Robert Muehlfellner, Director Automation Technology, B&R Industrial Automation Corp., offers a few. Read more

Developing a two-wheeled self-balancing transport platform

Annals of a mechatronic system design project

By Professor Kevin C. Craig and Matthew A. Rosmarin
Rensselaer Polytechnic Institute

Figure 1. The Engineering System Investigation Process.

A senior design team at Rensselaer Polytechnic Institute (RPI) set out to develop an interdisciplinary mechatronic system by designing and prototyping a two-wheeled robotic locomotion platform inspired by (and with the permission of) the Segway Corporation, maker of the Segway Human Transporter. The two-wheeled, self-balancing transport platform utilizes parallel-wheel locomotion to provide precise maneuverability while maintaining system stability. The team tackled both the complexity involved in modeling, analyzing, and controlling the platform, as well as the implementation of two fully operational prototypes in a four-month time period.
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Mechatronics: New answers call for new questions

By Richard Vaughn, Product Engineer
Bosch Rexroth Corporation–Project Management Dept.

In a short time, mechatronics has evolved into a universally accepted engineering concept. It integrates mechanics with electronics – and with engineering itself. The result is expanded technological capabilities and assembly-line successes like the Cartesian multi-axis robot. Because it enables more flexible automated production, users can precisely control parameters such as weight, speed, reach, and work envelope. That is why mechatronics can be the answer to a variety of design challenges.

Mechatronics enables the development of creative designs that extend the capabilities of existing robotics and controls to new levels.

But obtaining the right answers requires asking the right questions – from the very first stage of a design. A mechatronics approach is a 3-stage ongoing process:
—Design – configure the system to accomplish a specific task.
—Integration – determine how components work together.
—Implementation – achieve optimum value in daily operations, and prepare for future changes.

As an example, consider the parameters involved in an application such as pin insertion in automobile underbodies traveling on an assembly line. Proper design begins with the determination of mathematical factors such as payload, travel distance, desired speed, and axes size. Then there are questions of machine control, motor size to deliver proper speed and torque, and even the operator HMI. There is also the key question of how much it all will cost.

The design of a mechatronics system requires a multidisciplinary focus — to root out potential difficulties before they grow into time-consuming, costly and distracting problems.

Here are a few specific mechatronics challenges—and some tips for handling them.

Keep envelope restrictions in mind. Consider work envelope restrictions including walls, supports, and safety barriers to avoid physical interference. The difference between length of a module and length of stroke is also crucial, especially when selecting linear actuators. A rodless actuator’s “dead length” means the actuator’s stroke is shorter than the apparent length of the cylinder. The best approach is to use a 3D simulation, rather than reconfigure system elements later in the project.

Find a proper protocol. Approach the marriage of controls and drives from different sources cautiously – it can lead to problems, especially when using off-the-shelf protocols such as PROFIBUS, DeviceNet or Ethernet. Some off-the-shelf protocols, such as Bosch Rexroth’s IndraControl components, can communicate with many proprietary controllers, but this may not be true of all protocols. Problems may arise if a controller running DeviceNet is added to a platform running PROFIBUS. Similarly, if your plant runs Ethernet, you may not be able to “plug in” a component from any vendor. During the specification phase, you should ensure that compatible off-the-shelf control systems are available for expansion or reconfiguration.

Consider the implications of specifications. Specifications can have powerful, difficult-to-foresee implications for mechatronics. For example, a 480 V 3-phase motor may be ideal for a servo application, but not if your drive amplifier is only capable of 220 V – which may require retrofitting a transformer. A change from Class 1000 to Class 100 semiconductor production clean room conditions may require third party specification.

Build in cable management. Often, this is the last challenge addressed, leading to last-minute scrambles to avoid interference with motion and parts pickup. Rather, cable management for a gantry pick-and-place application should be one of the first factors considered. A program such as Bosch Rexroth’s camoLINE can offer predefined cable management and 3D modeling, letting you “drop in” components to ensure all components work cleanly together.

Cable management is an important and often overlooked consideration during mechatronic system design.

Find the right tool for the job. An application that requires complex interpolative motion, such as cutting or gluing circular seals on catalytic converters, requires an interpolative motion controller and device. Attempts to adapt point-to-point controllers for these applications can be time-intensive and deliver inadequate precision. The best approach is to determine the circular interpolation path and identify the needed controller performance; that in turn will guide the selection of drives, power requirements, I/O and other elements to achieve that performance.

Following some basic tips like these can help avoid common – and costly – problems like either over engineering and over sizing machines (resulting in heavy-duty capabilities that are rarely if ever used) or under sizing machines (not accounting for occasional increases in payload or run speed).

Either situation can unnecessarily increase automation costs, which might discourage implementation of mechatronics – another reason why asking detailed questions is essential.

Integration
Mechatronics is clearly a cross-disciplinary science, requiring expertise in mechanical and electrical engineering as well as electronics and computers. But few have a background in all these disciplines. Those with expertise in one particular area, such as electrical engineering, may end up doing on-the-job training in other aspects of mechatronics, or trying to learn how to incorporate components from an unfamiliar manufacturer.

One effective approach is to use the services of an integrator who specializes in mechatronics and is experienced in blending mechanics and electronics. Cross-disciplinary integrators are becoming more common as mechatronics applications expand, and the trend toward cross-disciplinary integration skill is consistent with the current industry focus on accomplishing more with fewer people.

Integration can act as a “force multiplier,” extending the capabilities of existing technology to create quantum leaps in production efficiency, reduced downtime, and cost savings. For example, an automotive production line can be made many times more productive by substituting different control commands for retooling, and an outboard support axis added to a 3-axis Cartesian robot creates a gantry device. Many similar solutions are possible for designers who adopt a multidisciplinary, full-system approach.

Use of 3D simulation during the design phase of the project can prevent the need for reconfiguring system elements later in the project.

After integration, the final step is implementation. But the final step should be well planned early in the process, or the result can be significant delays and added machine or production line costs. Avoid potential problems by clearly defining the roles and responsibilities of integrator and customer. This task can be a challenge in a process that blends a number of different engineering disciplines to create an integrated solution. The key is communication, right from the beginning — including detailed questions. For example, regarding system adjustments or changes, what is the responsibility of the integrator and what can be done by on-site personnel? The answers should be carefully documented to head off potential problems before they start. Of course, no one can foresee the future. But good implementation envisions the context in which a mechatronics system will operate.

Cross-disciplinary integrators are becoming more common as mechatronics applications expand.

As a cross-disciplinary process, mechatronics demands integrated thinking to go with integrated engineering. Part of this thinking involves the ability to envision the day-to-day operation of assembly line functions, including the working environment and the blending of electronic protocols, to anticipate and head off potential disciplines. Be prepared for the reality of cross-disciplinary requirements that may call for an integration specialist to get all the components working together. Finally, to implement the system, clearly communicate with everyone involved about their roles and responsibilities. For mechatronics to be truly successful, the development process must involve not only mechanical and electronic elements, but process elements as well: the key phases of design, integration, and implementation.

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Software tools speed integration

Proper design begins with determining mathematical factors such as payload, travel distance, desired speed, and sizing of axes. Bosch Rexroth developed “LOSTPED”—a multi-step analysis process to help designers gather information for specifications.

To help answer mechatronic questions, Bosch Rexroth developed “LOSTPED”—a multi-step analysis process for gathering information for specifications. LOSTPED stands for Load (the weight or force applied), Orientation (direction each axis is mounted), Speed (and acceleration), Travel (distance and range of motion), Precision (repeatability or positioning accuracy), Environment (operating conditions), and Duty cycle (duration the machine will run; example: 24 hr/day, 5 days per week). In an automotive assembly application, for example, duty cycle and assembly line speed are crucial to determine insertion arm size, motor size and logic control, along with many other key factors.

Bosch Rexroth
www.boschrexroth-us.com

Supporting Mechatronics across Design Lines

By Ralph Raiola, Editor
Electronic Products

When it comes to mechatronics design, getting everyone on the same page is apparently more difficult than one might think. A recent Webcast sponsored by IBM titled “System Design: New Product Development for Mechatronics,” presented research about the challenges and pressures faced when designing in a mechatronics environment.

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Energy Stimulus Debate

As “We the People” wait for Congress to do something to stimulate the economy we are flooded with information about “Green Initiatives” as part of the stimulus strategy.  And its really easy to get dragged along with the tide of enthusiasm.  After all, the electric car has languished in the shadows for over 70 years since the Baker company closed its doors.  So the idea of re-inventing even a small part of the automotive industry in the US is very appealing during a difficult period in our history.

We all share the concern that unemployment is up and many areas of the economy are slow.  But let’s be sure that when the government says its going to spend our money, that the decisions are based on sound strategy.  Maybe government spending money that it doesn’t currently have isn’t such a great idea. Read more

Robots and Actuators

A couple of important nuances of the robotics field came to my attention recently.  The relationship of the actuators themselves to the robot design, and of course, the kinematic framework of the robot itself.  I have some history in both areas but am regularly surprised by the way innovation continues to take place. Despite the appearance that we have reached some plateau of performance based on the existing solutions, and that further progress is marginal, man continues to change, and improve, his relationships with machines.

Actuators are a combination of mechatronic components that achieve linear or rotary motion.  This isn’t always apparent because we purchase many actuators as finished products.  The integration process is not easy and involves a number of technical disciplines.  For many factory floor applications, it is more cost effective to purchase the actuator as a product.

But aspects of actuators such as power density and accuracy become the building blocks of more complex systems, like robots. It turns out that robots which use parallel actuators have greater power density and accuracy due to the elimination of parasitic losses that result from the way that robots are organized.  This is a subtlety I missed.

On the topic of broad organization of the robot, the kinematics, there are two major families that have been defined.   The robots that have been around for a while doing welding, painting and material handling tasks are generally referred to as Serial robots. They are serial in the sense that the load and forces of each axis are dependent on the axis that follows in a series, regardless of whether the axes are rotary or linear.   The more axes, the more loads and error that must be compensated for in each preceding axis.

This is especially true for machining applications.  Most CNC’s are serial in their framework.  Its great from the control system standpoint since the axes can all be treated independently.  But when the cumulative error or each axis can be measures, with an orthogonal laser system, things can be pretty well out of hand.  The latest solution is a 3D compensation model added to the coordinate system of the machine.  Siemens has pioneered the development of such as system and it works.

So the alternative to serial robots is parallel kinematic machines.  PKM.  And you can find a few really interesting examples.  The now classic Delta robot available from Lenze, Siemens and others.  The Lenze version recently added a rotary axis in the center line of the machine making it more versatile.  Check out www.pkmtricept.com for  some insights from one of the pre-eminent suppiers of parallel kinematic machines.  There are also some excellent notes and applications from Physik Instrumente (www.hexapods.net).  In general the hexapod topic is now dominated by 6 legged robots, which is an interesting side note, but not really the core of the technology we’re looking at, but again, it is fun to see how people continue to apply robotics in unique and interesting ways.