Robotics - Motion Control Tips

New RH-N gearbox kits from Nabtesco Motion Control are pre-engineered offering

January 28, 2019 By Lisa Eitel Leave a Comment

Nabtesco Motion Control now offers pre-engineered RH-N gearbox kits. RH-N kits use the manufacturer’s newest RV-N series of gearboxes … to 20% smaller and 30% lighter than the original RV-E series. RH-N gearbox kits make for turnkey motion solutions that trim lead, engineering, and installation times. The RH-N directly bolts onto servomotors without the need of additional components, as the gearbox kits eliminate the need to manufacture and machine motor plates and housings.

More specifically, RH-N kits include an RV-N-series gearbox; oil seals and O rings; RH-N middle flange and RH-N motor flange; all necessary fasteners; and input pinion. In fact, the input pinion requires no machining … so installers can simply bolt the design together.

Suitable applications for the RH-N include and array of servomotor-driven designs … and in fact, Nabtesco’s value-added gearbox-kit solution works on all RV-N series gear reducers with standard ratios.

RH-N Kits are designed and manufactured in the U.S. with a two-week lead time on all non-stocked items … though one Nabtesco Motion Control objective for 2019 is to increase stock levels to allow for JIT delivery.

Nabtesco Motion Control can design and manufacture various configurations from the RV-N gearbox body. Fully assembled RH-N variations (in the form of fully completed assemblies of the kit and gearbox excluding grease) are available. Oil seals are properly installed and all bolts torqued to the proper specs.

Note: Nabtesco Motion Control RD2-S and RD2-R use legacy RV-E series gearboxes. The newer RV-N series comes in sizes that are far larger (for much higher maximum rated torques). The manufacturer anticipates a migration to the RV-N Series (and the RH-N kits) for two reasons:

RV-N series gearboxes are smaller, lighter and more powerful than the traditional RV-E series
Pre-engineered solutions help design engineers as detailed above

For more information on RH-N Kits (and to provide feedback or submit requests) visit this deep link on nabtescomotioncontrol.com.

Chip-level connectivity and design sees synergies for motion and robotics

November 2, 2018 By Lisa Eitel Leave a Comment

In a recent interview with Brendan O’Dowd, general manager for industrial automation at Analog Devices, we got the chance to hear about new devices — even to the chip level — that allow better integration of robotics into motion designs and machines for automation.

Eitel • Design World: We cover motion control as it relates to motors, power transmission, and automation. What new developments in these areas do you consider most significant?

O’Dowd • Analog Devices: Our company has been around for 50 years. For some time, we’ve investigated the systems into which our parts go … to create better solutions for these designs. For example, sometimes engineers asked us to reduce power consumption. Usually there was something specific prompting the question — such as thermal dissipation being an issue. We learned that it’s not always the posed question needing addressing — but something related to it. So we began using technology and our silicon experience to solve problems in new ways.

On connected motion and servos and drives, several parts are involved in the sequencing. There’s the processor — the system brains — and the PWMs driving the signal … as well as the isolated gate drivers (IGBTs) … and the measurement of the currents returning — for a complete control-loop algorithm. We’ve worked to optimize many of these.

But from a system point of view, communications have become more critical — and deterministic Ethernet is increasingly a part of these communications. Even in factory control and process automation where 4-to-20 mA and fieldbuses have reigned for a long time, Industrial Ethernet is coming to the floor … in an array of standards.

Eitel • Design World: Our industry sees a lot of proprietary standards — all good for certain things — but not always able to work together.

O’Dowd • Analog Devices: They’ve been successful … but now as we need higher speeds, there’s migration towards unified standards — with the TSN collection of standards currently leading. In fact, nine or 10 different IEEE standards are part of that TSN bundle. They cover things such as ingress policing (for the prevention of traffic overload conditions on a network) and other network functions. We expect TSN standards to supersede most existing industrial Ethernet protocols.

Eitel • Design World: But it’s unlikely that those invested in existing industrial Ethernet networks will abandon what they use … and those networks’ unique benefits — especially for real-time functionality.

O’Dowd • Analog Devices: Yes — and with the growing tide of robots and especially cobots, real-time functionality is absolutely critical. So we’ve invested in multi-protocol solutions … because it’s okay if you’re Siemens, Rockwell, or Beckhoff with all your equipment the one standard you sponsored — but many smaller players must deal with these different standards. For them, it means unless they’re designing for an all-Siemens factory or an all-Beckhoff factory, they must support multiple standards.

Eitel • Design World: What kinds of products support all major protocols?

O’Dowd • Analog Devices: Some of our Ethernet switch ICs have built-in TSN features to support several IEEE TSN standards. We aim to offer compatible updates to next-generation TSN as those standards are finalized. As any latency-controlled Ethernet standard, TSN standards allow synchronization of the Media Access Control (MAC) physical interface on different boards at different parts of the system.

For a drive, motor, or robot, actual motion is controlled by PWM output. The time synchronization then has to make its way through the communications stack and through the motion-control stack and out to the PWM output — to drive the actual gate drivers to time the motor. So many view TSN from the Ethernet point of view — and focus on getting that synchronization down to the boards … a significant problem itself. But they leave the rest of the problem to individual designers.

That’s why we bring motor-control and motion-control signal-change domain expertise to our Ethernet work. We aim to deliver system solutions, and not just pieces of silicon.

The key point is when a semiconductor supplier can apply domain expertise to silicon design, it is possible to solve wider system-level problems.

Eitel • Design World: How does that relate to robots and the new wave of cobots in automation?

O’Dowd • Analog Devices: The latter are about sensing and understanding the environment … with many offerings today being very much in the analog domain. But using technologies borrowed from other fields — such as radar and LiDAR from automotive, for example— will come to expand the array of system-level domains in robotics. People often ask why we’re acting more as system suppliers and not acting as a traditional component supplier. Well, it’s because we’re working to be relevant at higher levels — by leveraging our domain-level expertise and newer expertise in robots, motor control, condition monitoring, and Ethernet.

Eitel • Design World: Just to be clear for engineers who don’t usually think of design work at the chip level — would you explain what you mean by domain in this context?

O’Dowd • Analog Devices: Sure. There are IC technology silos — for A-to-D converters, performance amplifiers, processors, and power supplies, for example. We also have experience silos for automotive, motor control, and process control. Some we developed internally from work with customers on applications. Some we’ve hired into the team — for example, in robotics and motor control design — to get views that are different from a silicon designer’s view.

The challenge is that silicon designers think in terms of what they know — transistors and fab processes and so forth — whereas motor-control designers think in terms of PWMs, and current feedback, and control loops. So having them work together for weeks, months, and years spurs richer conversations and solutions that wouldn’t have been created otherwise. That’s what constitutes domain-level design.

The fido5200 REM switch (one version of the fido5000 series) supports industrial Ethernet protocols such as EtherCAT.

Eitel • Design World: You’ve been gracious in not mentioning specific Analog Devices products for such flexible functionality. But may I ask what those are?

O’Dowd • Analog Devices: Our single piece of silicon — the fido5000 REM Switch IC — is configurable with a binary download we supply.

That means engineers can setup for an EtherCAT version of a field instrument … or a PROFINET version … or Ethernet IP version … and it’s the same hardware, just with a different binary download. With less designing and debugging, that in turn reduces time to market and models in inventory … and boosts assurance that what gets shipped to the end user will be the right version, as it’s just a software image.

In this way, the fido5000 REM Switch IC is a flexible part — with TSN protocols ready to go and pin-for-pin replacement compatibility.

Eitel • Design World: Many proprietary offerings provide real-time functionality. Does your new offering adhere to IEEE standards for that?

O’Dowd • Analog Devices: Our Deterministic Ethernet Technology Group (DET) director Jordan Woods also represents us on the standards bodies — so we can sell standards-ready silicon from day one. Even when standards aren’t finalized, we have customers evaluating our ICs’ functionalities to deliver on what’s coming.

Eitel • Design World: What in the motion and robotics markets are driving innovation?

O’Dowd • Analog Devices: Motor control and robotics are driving the need for higher bandwidth. Some in factory automation resist the idea of needing GbE — accepting 100 Mb as enough. But they’ll need higher bandwidth in the future. Even in residential homes, the number of Internet-connected things has risen dramatically. Factories are no different — and high-bandwidth items such as cameras and radar (for time-of-flight measurement and positioning, for example) are leading the charge. Such technologies are key to knowing where people are around a robot, for example. Having a work cell’s cameras execute auto recognition on workpieces … or artificial intelligence — these too demand big bandwidth.

What’s more, some design engineers are frustrated with accommodating lots of standards.

These two things are driving the trend towards standard TSN. So I predict the big players will continue to support legacy equipment with proprietary standards — even while next-generation standards are still being worked out. Rest assured we’ll be there to support the latest solutions.

Eitel • Design World: Do you offer software for configuring your chips?

O’Dowd • Analog Devices: We sell preconfigured chips — and supply the binary … already certified with the standards body — so the chips are ultimately pre-certified to EtherCAT or PROFINET or to the applicable standard. That minimizes work for the engineer. But higher-level software — that lets engineers configure networks — that’s not something we offer yet. At the moment these offerings are tied to more integrated designs.

Eitel • Design World: On the topic of more connectivity between motor-driven machine axes and robotics — what’s particularly innovative here?

O’Dowd • Analog Devices: We’ve supplied lots of I/O for PLC-based control … analog out and in … digital out and in. We see such controls moving to higher data rates as well — and I think TSN standards will become very prevalent here. But at Ethernet IP becomes standard in the factory everywhere — and not just in parts — it will replace some 4-to-20 mA and fieldbus connections. So while motor controls and drives will spur higher bandwidth, maybe not factory automation but certainly process control — including oil and gas and pharmaceutical industries — will increase use of lower bandwidth over longer distances.

Eitel • Design World: Another area of interest is network security.

O’Dowd • Analog Devices: Standard approaches to using PCs and IT infrastructure with firewalls and certificates doesn’t work well at the factory level. After all, firewalls between machines could quickly bring down production. So configuration and setup must be well engineered. Our security company subsidiary Sypris Solutions works on this for us.

Eitel • Design World: How does this relate to another connectivity-enabled function — that of condition-based machine health monitoring?

O’Dowd • Analog Devices: We’ve been doing MEMs vibration sensors for 25 or 30 years … with most airbags in the world controlled with our MEM sensors, for example … and first-generation Nintendo Wii consoles as well. With our motion and vibration-sensing expertise, now we’ve begun exploring ways to use MEM sensors in motor control … as a lot of information can be gained from monitoring motors over time to understand their states — as bearings wear or loads begin to have issues, for example. We’ve all heard stories of that one guy who can hear problems or lay his hands on a machine to detect issues — or skillfully use probes for measuring various characteristics.

In short, there is now a way to have this level of monitoring using technology rather than a highly skilled “machine whisperer” …

Schneider Electric’s PacDrive 3: Smart machine drive for safe and flexible machines

September 25, 2017 By Lisa Eitel Leave a Comment

Schneider Electric, global specialist in energy management and automation, is showcasing its smart machine setups for packaging at Pack Expo 2017. Schneider Electric’s smart machine setups are built on its IIoT-enabled open and interoperable EcoStruxure system architecture and platform, which delivers “Innovation At Every Level” as the manufacturer touts — from connected products to edge control to applications, analytics, and services.

Enhances controller-to-controller communication and OPC Unified Architecture via Sercos
SoMachine with new functions brings smart engineering to the forefront
Lexium 62 ILD servo drives form basis for the most flexible drive systems on the market

Using open technology platforms, Schneider Electric helps original equipment manufacturers (OEMs) and machine builders create smarter, future-proof machines that are safe, connected, efficient and reliable. To improve profitability, speed and agility, Schneider Electric continues to make strong advances in its PacDrive 3 technology … which unifies PLC, motion and robotics control functionality on a single hardware platform. A centralized architecture makes PacDrive 3 the market-leading setup for controlling a broad range of servo-driven production and packaging machines, as well as material handling equipment and robotics.

“Today, PacDrive 3 controls more than 80,000 machines across the world, reinforcing stronger time to market and maximum reliability,” said Ashish Patwardhan, Packaging and Material Handling Segment Marketing Manager, Schneider Electric. “Customers today need their machines to be smarter and better connected. PacDrive 3 makes that a reality by integratingsynchronized multi axis motion, PLC functionality and robotic control on a single hardware platform. PacDrive 3 brings machine control and motion control together to help the customers reduce complexities and improve efficiency.”

Enhancing controller-to-controller communication and OPC UA via Sercos

With controller-to-controller communication (C2C), a master controller within a Sercos network can communicate at the production line level with up to 20 slave-controllers, in parallel to Sercos communication at the field level to improve operational communication. This introduces deterministic real-time communication at the level of the production line, meaning PacDrive 3 synchronizes with up to 130 servo axes and can run up to 2,600 axes fully synchronized.

In addition, C2C provides a communication channel for “standard” non-real-time communication, which is used for OPC UA communication on the same Sercos cable. OPC UA delivers benefits to automation like data browsing and encrypted communication, and is accepted by multiple automation and IT vendors, qualifying OPC UA as a standard for vertical integration. By combining C2C and OPC UA on the PacDrive 3 controllers, the basis for machine-to-machine communication is set.

Innovative motion setups and robotics optimize packaging

With the new Lexium 62 ILD integrated servo drives, the PacDrive 3 automation setup reinforces its market leadership. The Lexium 62 ILD triple and single drive units are detached servo drives in a solidly built housing, suited for installation directly at the machine frame. They fit within the network setup for Lexium 62 ILM integrated servo drives, and enable the use of Schneider Electric’s standard servo motors — another substantial step forward for cabinet-less automation — making all types of packaging machines smarter and more compact. Additional functionalities include:

Plug-and-play technology with pre-assembled hybrid cables
Up to 90% less wiring time; up to 70% less cabling
Up to 90% less wiring and cabling requirements in the control cabinet
Automatic network configuration; diagnostic functions

The Lexium 62 ILD is fully software compatible with the Lexium 52 standalone servo drives, as well as with all drives and integrated drives in the Lexium 62 multi-axis servo system. Together, they form the basis for one of the most flexible servo drive setups available on the market.

SoMachine with new functions brings smart engineering to a new level

PacDrive 3 brings the tool chain known for common programming environments into the automation world. Simulation, semantic code analysis, automated test and subversion support the application life cycle management in a modular machine design. With the latest version, SoMachine V4.4, PacDrive 3 offers an integrated dependency viewer that enables analysis of the dependencies between machine modules. If a machine has an infeed conveyor, for example, the developer can easily identify all other machine parts relying on this conveyor. In addition, code conventions can be defined, helping software development teams to enforce the same coding style independent of individual developers.

SoMachine can now generate several metrics describing the complexity of the code, allowing users to identify weaknesses in the application and easily address them. Lastly, SoMachine – ETest, the integrated test automation tool, is improved with parameterized tests so more opportunities to define the tests can be carried out.

Expanded robotics options is enabled by fully integrated robots

On PacDrive’s robotics side, Delta 2 robots (PacDrive T3 and T5), and Delta 3 robots (P2, P4, and P6), gives Schneider Electric a comprehensive range of stainless steel kinematics with different work spaces and for different product weights. Additional highlights include:

The fifth axis on Tool Center Point provides new° of freedom for Delta 3 kinematics
Faster commissioning with Smart Template

PacDrive, Lexium, and SoMachine are all part of EcoStruxure Machine, the company’s machine-centric automation architecture that enables machine builders to design safe, better connected, more flexible, and more efficient machines through advanced digital technologies and open standards. For complete information on these offers, please visit http://www.schneider-electric.com/b2b/en/campaign/innovation/industries.jsp.

For more information on PacDrive 3 and Schneider Electric’s work with smart machines, please visit booth S-6167 at Pack Expo.

Technologies from Bosch Rexroth you missed at MD&M West

February 18, 2017 By Lisa Eitel Leave a Comment

MD&M West is known for its unwavering usefulness to attendees and exhibitors alike, and this year’s event delivered as usual. Here’s what we saw at the Bosch Rexroth booth (within the colocated ATX West) during our visit at the show.

A main focus at the Bosch Rexroth booth was connected automation technology — also called the Internet of Things, IIoT, and Industry 4.0 — depending on the context and who you ask. Showcasing Bosch Rexroth offerings here was an Open Core Engineering demonstration — in the form of spreadsheet-based networked control of a multi-axis Cartesian system. Read more about the related offering — Rexroth Open Mechatronics — and the demonstration at ATX West here. There’s an explanatory video at the link.

Here, Richard Vaughn of Bosch Rexroth explains how (thanks to the Open Core suite of products) he is controlling the multi-axis setup in the background through a custom program on his tablet.

In short, Open Core Mechatronics is multi-axis motion control and programming that lets engineers access the core of Rexroth’s motion-logic drive and control platforms … so they can use familiar IT languages (MATLAB, LabVIEW and even Visual Basic for Applications or VBA and Java) to write automation functions and applications.

Software engineers can also streamline HMI programming through Rexroth’s Open Core Interface.

Leveraging predefined software functions, machine builders can create custom interfaces in the form of mobile apps or HMI screens — to let users perform machine functions and collect data from virtually anywhere.

Other items Bosch Rexroth had on display at ATX West were their second-generation electromechanical cylinder with a hygienic design; details on their new microsite for resource kits; details on their Factory Automation Road Show traveling truck of technology; and their TSplus and VarioFlow plus conveyors:

Prototype in 2015 — and now the product is here to replace factory whiteboards

Bosch Rexroth also showed the new release of something I saw as a prototype with my colleague Mary Gannon back in 2015 — a digital iteration on the old-school whiteboard so common on factory floors for tracking production data.

Here’s a little tweet from that 2015 visit with Bosch Rexroth with Morrell Group graciously hosting … 3D-printing and other technologies were on display:

Precision #3Dprinting from #voxeljet at #RexrothI40 event at @morrellgroup | Prints of sand for direct #moldmaking pic.twitter.com/AW3Y2bjA6f

— Elisabeth Eitel (@EitelonDesign) September 15, 2015

Called the Manual Production Systems & Active Cockpit, this digital communication station lets workers and managers access production data.

Manual assembly will always be part of manufacturing. So to serve this portion of the factory floor in a modern way, Rexroth’s Active Cockpit connects to data-sensing manual and automated processes to give plant personnel a realtime view of production data, work instructions, meeting minutes — whatever information is needed for instant access to boost production.

Paring this technology with Rexroth’s Manual Production Systems (MPS) makes manual jobs even more efficient. (With Rexroth’s reconfigurable aluminum framing, MPS makes lean manufacturing easy and lets manufacturers adapt quickly to changing demands.) As literature we got on the product explains, Active Cockpit is an interactive web-based communications platform that detects all relevant data for a production line, updates it in a dynamic manner, and visualizes it clearly in realtime, directly on the line:

ActiveCockpit software from Bosch Rexroth delivers Industry 4.0 technology straight into users’ hands as it records, processes and visualizes manufacturing data in real time. So IT applications such as production planning, quality data management and e-mail dispatch connect with software functions from machines and systems. Key metrics clearly display in realtime in the most appropriate format — so on a large touchscreen directly at the manufacturing line or on an interactive tablet onsite, for example.

Personnel can immediately see production problems to initiate corrections based on all relevant data. For more information, visit boschrexroth.com/en/us/activecockpit.

Smattering of other items at the Bosch Rexroth booth

Below are details on a few other items Bosch Rexroth displayed at ATX West — enjoy. Also note that Bosch Rexroth will be showing at CONEXPO-CON/AGG 2017 in Las Vegas March 7 through 11. Catch them at IFPE – South Hall 3 – S80214 if you’re attending.

Right turn for higher energy efficiency: Frequency converters from Rexroth

Rexroth IndraControl XM series programmable logic controllers integrate I/O for speed and flexibility

VarioFlow plus expands application range for conveyors

Rexroth ball-screw assemblies increase service life by 80%

Heavy duty oil rig robot takes top prize

June 8, 2016 By Lisa Eitel Leave a Comment

The project from Norwegian company Robotic Drilling Systems has been awarded the most creative Energy Chain application system in biennial awards.

Every two years, igus presents its “vector awards,” celebrating unique and creative uses of Energy Chain cable carrier systems. This year, the gold vector was awarded to Norwegian company Robotic Drilling Systems, for their “Drill-floor Robot DFR1500,” a central robot for a fully automated oil drilling system. While in typical oil drilling operations work requires the carrying of individual drilling elements and the manual fixing of bolts, the company is working to develop the oil platform of the future, where drilling and preparation are carried out entirely by robots.

The DFR-1500 uses individual drilling elements, moving them into the correct position for drilling operation using a reverse-bend-radius (RBR) Energy Chain cable carrier in the articulated joints of the system. This sophisticated and unique design won over the vector jury, consisting of representatives of business, research, and specialized media platforms. The award, including a $5690.75 prize, was accepted by Robotic Drilling Systems’ CEO, Jimmy Bostrøm at Hannover Messe 2016.

Fast rotational movements take the silver

The silver vector was awarded to Italian company Fidia, which utilized a pre-harnessed multi-rotational module (MRM), which allows for rotational movements up to 720º atop one of the company’s machine tools. The MRM Energy Chain offers high speeds and accelerations or extremely fast changes in direction and rotation in the machine tool’s Z-axis.

Production plant for concrete elements wins bronze

German company Ebawe Anlagentechnik GmbH’s project took home third prize in the 2016 awards. A concrete distributor, which is used for the industrial production of a large variety of concrete elements, must be moved to a cleaning area multiple times each day to maintain smooth production. To compensate, two Energy Chains in a trough are used, one longer, and one shorter. In regular production travels, the chain is locked, and moves together with the trough on wheels until fully extended. When moving to the cleaning area, the remaining distance is covered by the longer chain in a fully automated process.

Special award for truly unique yacht concept

The large width of catamaran boats typically required two berths in port to handle their large width, which is expensive and often not available in busy harbors. Craning of these boats can also be problematic, as few facilities offer the width required. To resolve these problems, Futura Yachtsystems Entwicklungs GmbH developed the first width variable catamaran, which took home a special vector award. The variable width application enables the hulls to extend and retract, reducing the width using seawater resistant Energy Chains, along with DryLin self-lubricating linear sliders, both from igus.

igus
http://www.igus.com

Robots and end effectors: from heavy duty to human scale

April 6, 2016 By Miles Budimir Leave a Comment

Miles Budimir

Senior Editor

Robotics is hot. Manufacturers in the business know this, and others are catching on. From investors to companies using more robots on the manufacturing floor, to consumers snapping up robots to do mundane house chores, robots are here to stay.

Industrial robots in particular are finding their way into new applications. And these aren’t the robots of yesterday, but nimbler and thus better able to handle some of the assembly tasks that were once the job of human workers.

While industries like automotive manufacturing continue to be far and away the largest users of robots and robotic end effectors, other industries are catching on as well, noted Robert Little, CEO of ATI Industrial Automation. “A fast rising industry for robotic end effectors is consumer electronic assembly, such as mobile phone and computer manufacturing,” he said. “This type of manufacturing has been done by hand with cheap labor out of China. The volume is extremely high, but the parts are inexpensive so this is driving lower-cost end effectors.” In robotics and material handling, end effectors are tools or devices connected to the end of a robot arm that accomplish some task. End effectors can be a range of types, including cutting tools and drills, welding tools, brushes, screwdrivers, vacuum cups and grippers.

Robotic tool changers can range in size from the small and lightweight, such as ATI’s QC-001, weighing less than 60 g (center), to heavy-duty devices like ATI’s QC-1510 designed to handle payloads of up to 9,000 lb.

End effectors are one area where there has been much development over the past decade or so. As Little pointed out: “The sheer volume of robotic end effectors has quintupled from 10 years ago. Now we have a tool changer that can change out tools on very small spider robots and another tool changer that can assist with changing out multi-ton rockets.” The overall effect is more and better end effectors for a broader range of applications. “End effectors have increased their reliability and can be used in extreme environments like underwater, clean room, food handling and in space such as the Mars Rover,” he added. Another visible trend in robotics is the increase in robots designed to work closely with humans. Traditional factory-floor robots were often large pieces of moving metal that had to be enclosed in special cages with a plethora of safety features to keep human workers safe. Nowadays, robots are slimmer, nimbler and designed to work alongside humans. More robots in the workplace allow humans “to be moved from dull, dirty, delicate and dangerous tasks, into more stimulating jobs with far more potential for satisfaction and advancement, such as production management or robot programming,” said John Bubnikovich, VP, sales and marketing, ABB Robotics North America.

Collaborative robots designed to work with humans, such as ABB’s YuMi, are the next wave of robots for industry. This collaborative, dual arm, small parts assembly robot features flexible hands, parts feeding systems, camera-based part location and advanced robot control.

This trend toward more collaborative robots means that robots will become more commonplace in manufacturing settings. “Collaborative robotics and innovations that allow humans and robots to safely work side-by-side, like vision and advanced software technologies, can be deployed and programmed far more easily and rapidly than ever before,” added Bubnikovich.

And while some analysts have raised concerns about the effects on employment as more robots enter the workspace, ABB sees the opposite effect. As Bubnikovich noted: “A study by Metra Martech concluded that the one million industrial robots currently in operation are directly responsible for the creation of close to three million jobs. The study further concluded that growth in robot use over the next five years will result in the creation of one million high-quality jobs around the world in prominent industries such as consumer electronics, food and beverage, alternative energy and advanced battery manufacturing.”

The bar graph shows robot shipments in the U.S. versus non-farm employment from 1996 to 2014.

Five key electrical design concepts for mechanical engineers

March 11, 2016 By MCTips Staff Leave a Comment

Edited by: Paul J. Heney, Editorial Director

Mechanical engineers often overlook important electrical issues when specifying their respective parts of an electromechanical system. This targeted advice will help you design your next electromechanical system.

Mechatronic systems are the state-of-the-art technology in automation systems, intelligently integrating 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. Electrical engineers involved in helping design and build mechatronic systems often see how inefficiencies and unnecessary complexity can be unintentionally designed into machines.

Better mechatronic systems can be created when mechanical engineers consider five crucial concepts when 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 can’t 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 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.

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

Place motors on the machine in the best location so that operators aren’t accidentally stepping on cables and connectors 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 helps reduce mass, provides more energy-efficient motion, and makes it easier to size-up smaller motor/drive components for the machine. We’ve seen a lot of 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.

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

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.

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 solution (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 needs to be compensated for during machine commissioning and 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.

direct-drive-direct-motors-linear-motors

Using direct drive, direct motors and linear motors versus mechanical couplings allows machine designers to run higher gains and improve machine performance.

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

Electromechanical design architecture (top) versus an older mechanical line shaft design (bottom).

3. Use electronic gearing and camming
Today’s electronic drives and motion control platforms give the mechanical engineer 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 1/16 or 1/32 in. typical with mechanical line shafts, down to motion precision closer to hundredths or even thousandths of an inch with electronic line shafting.

Using electronic gearing and camming allows for better machine synchronization while eliminating the mechanical line shaft.

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. Using FlexProfile technology, with the touch of a button on the HMI screen, you can load a machine recipe, and the changes are made in the control and servo system to run the next product.

This new FlexProfile camming technology makes it possible to build multi-segmented cam profiles based on position, velocity or time-based motion profiles. When you change a section of the electronic cam through 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.

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 on the machine, and 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 (regenerating 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 resistor, power is shared, so the machine’s power consumption is significantly reduced.

Regenerative power supplies feed power back through a shared bus to re-use on the machine rather than dissipating excess power as heat.

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.

5. Use HMIs for better troubleshooting
The computer revolution has spread to today’s machine control panel, replacing knobs and pushbuttons with sophisticated PC-based and embedded HMIs with advanced programming and Windows-based operating systems.

Consider your typical office copier: when there’s a paper jam, a touchscreen control indicates where the jam is, what door to open, how to correct the problem, and prompts you what to do next once you’ve cleared the jam. The same user-friendly intelligence is now available to machine designers through today’s touchscreen HMIs featuring the latest graphical user interfaces. 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 ease. Drawings and interactive instructional tools can not only show the precise point where a problem is—they can also show how to open enclosures and what steps an operator can take to put the machine in safe mode for initial maintenance, and other support resources to resolve a problem and step the operator back through the tasks to restart production.

HMI-intelligent-predictive-maintenance-alerts

Intelligent predictive maintenance alerts can be displayed via the HMI to the operator, along with next steps necessary to correct the issue.

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. Called predictive maintenance, this capability lets machine designers set fault tolerance bands in drives and then monitor drive performance. Electric drives and motors, such as IndraDrive systems, 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 and 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 over 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.

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 manufacturing 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 simplify certain mechanical design and engineering challenges and provide new resources for driving innovation and creativity in machine design.

Reprint info >>

Bosch Rexroth
www.boschrexroth-us.com

Get ready for National Engineers Week

February 19, 2016 By Miles Budimir Leave a Comment

A woman adjusts a prosthetic foot for a boy, while a female mentee leans in to observe and learn. Photo by Lisa Abitbol for DiscoverE.

This year, National Engineers Week runs from February 21st through the 27th. The annual celebration focuses on introducing kids to engineering through a variety of activities. Its aim is to raise awareness of what engineering is, what engineers do, and how kids can get active and involved in engineering.

This year, National Engineers Week celebrates is 65th anniversary with the theme ‘Engineers Make a World of Difference.’ Beginning in 1951, when the National Society of Professional Engineers (NSPE) initiated the celebration, the event has become embedded in hundreds of organizations around the world, exposing the general public as well as children to the possibilities of engineering.

Some of the highlights for the week include:

Global Day: A truly global event, this aims to “celebrate the accomplishments of engineers, give students around the world a chance to experience engineering, and share the amazing innovations engineers create every day.”

Introduce a Girl to Engineering Day: One of the best programs associated with National Engineers week, this program aims to introduce girls to engineering showing how creative it can be and how engineers can change the world.

Discover Engineering Family Day: The drawback to this event is that it takes place in Washington D.C., so not everybody can attend (unless you happen to live close to the D.C. metro area.) And it’s only one day. But what a day it promises to be. It takes place at the National Building Museum, with thousands of children learning about engineering through hands-on activities.

A comprehensive list of events and happenings can be found on the NSPE web site here.

You can track Engineers Week activities by checking the Twitter hashtag #eweek2016.

And speaking of kids and engineering, here’s a recent video of Design World editor Paul Heney’s son Josh tackling a robotics kit from Modern Robotics:

Two positioning components speed OEM product development

February 8, 2016 By Motion Control Tips Editor Leave a Comment

by Robert Gloeckner, Advanced Engineering Group, MICROMO

Innovative components help OEMs revolutionize designs. In fact, some original equipment can now benefit from zero-backlash actuators and integrated gearhead encoders. These give designers multiple options for demanding applications.

Performance, cost and size requirements for motion applications vary widely. In some cases, performance trumps all and the budget must simply tolerate the result. In others, the application demands performance but at reasonable price. As we’ll explore, if an application requires absolute accuracy, a gearhead encoder is an economical and compact solution. For applications that cannot tolerate any backlash, zero-backlash actuators remove it mechanically.

This tiny FDM0620 series FAULHABER stepper motor from MICROMO delivers high performance. All of its components (including connections) are in a housing that measures 9.7 x 6 mm in diameter. It’s an expansion of a stepper-motor family in the 6 to 22 mm diameter range.

Consider a perfect motion system in which the controller sends a signal, and then the hardware delivers the load to the commanded position. In reality, error sources such as mechanical hysteresis and backlash compromise performance. With enough design time, effort and money, it’s possible to minimize these effects. However, motion is an enabling technology rather than an end in itself—which means OEMs generally aim to focus on their product’s unique value proposition, and not on matching gear teeth and damping vibration, for example.

Now, new technology simplifies performance optimization and makes it cheaper, too.

Preventing lost motion with tandem gearing
As mentioned, some zero-backlash actuators ensure stable performance for applications that cannot tolerate lost motion. To remove error caused by vibration, compliance and shock load, the gearhead encoder drives deviation to zero. That frees OEMs to focus on the development of innovative products of their own.

Even the best gearheads have small gaps between the teeth to let them mesh and maintain lubricant between contacting surfaces. The downside is that this space introduces a bit of lost motion called backlash. This shows up as positioning error, especially in precision applications with frequent reversals. Even for high-accuracy or precision gearheads, backlash still amounts to a few degrees of arc-min, and normal wear over the lifetime of the machine only worsens it. This is not a problem for a case packer or palletizer, but even that small amount of error is too much for applications such as robotics, optical positioning and gantries.

Over the years, motion vendors introduced designs to mitigate backlash using plastic spacers, split gears and springs to apply a preload that maintains contact between the gear teeth. But none are ideal, because they still exhibit a few arc minutes of error, and the preload needs adjusting for wear and environmental changes to maintain performance.

To address the problem, some zero-backlash actuators use an integrated assembly. These deliver fast and accurate positioning without backlash, which in turn delivers loads to commanded locations with minimal error. Compact and robust, the plug-and-play actuators also speed assembly and eliminate scrap.

Consider one specific setup with two motors. This design uses a gear flanked by two motor-driven pinions. One pinion positions the axis, and the other engages the opposite tooth flank and takes up backlash. During normal motion, the motors drive the load with combined torque. At the end of the move, the first pinion holds the position while the second pinion reverses to apply the counterforce. This effectively removes backlash mechanically. Such actuator gearheads perform equally well during acceleration, deceleration and reversals. They’re flexible in that the servo controller can adjust the preload to be softer or stiffer. Plus, it’s a scalable design.

In addition to two-motor setups, this design concept also implements with four or even six motors to increase torque while adding redundancy, especially in high-reliability applications.

Zero-backlash actuator options
Design engineers can choose from rotary and linear actuator configurations with myriad performance levels and form factors. For example, through-hole versions are useful for optical systems that operate in space-constrained applications. More specifically, through-hole zero-backlash actuators can position optical components while a laser beam shines through the aperture. The result is precise performance in a compact system. The aperture also lets users run cables through the center as a way to save space and reduce cable fatigue.

Zero-backlash actuators can have a central gear flanked by two pinions. Consider this generic CAD rendering: During normal operation, the pinions (green) drive the motor shaft. When the move completes, one pinion drives forward while the other reverses to introduce a counter force to mechanically remove backlash. Applications for such actuators are optics, photonics, medical devices and small robotics.

Such actuators also excel in gantries for pick-and-place operations, where backlash can cause binding (and compromise performance while making the system wear prematurely). Here, zero-backlash actuators ensure symmetrical motion so carriages can travel faster while handling heavier loads.

Just consider how the position of a solar cell on a satellite can mean the difference between a functioning device and a useless lump of space junk. In one real-world setup, the reliability and functionality of a zero-backlash actuator lets engineers optimize solar cell positioning. The actuator has also maintained solid performance, even under launch and orbital conditions.

Another approach: Driving error toward zero
In standard servo systems, an encoder mounted to the motor shaft monitors the number of rotations to estimate the position of the load. However, compliance, hysteresis and backlash all introduce error between predicted and actual load positions. This error can be as much as 2 to 3° in some cases. While that’s acceptable in many standard designs, demanding OEM applications can’t tolerate such error.

Kessler-Optics-and-Photonics-Solutions-microscope

Shown here is a dual-band fluorescent microscope from Kessler Optics and Photonics Solutions. Actuators with a through-hole design can be useful in similar applications to position optical components while beams shine through an aperture. The result is precise performance in a tight system, and an aperture that lets cables run through the center to save space and reduce cable fatigue.

Precision OEM machines need an encoder mounted to the output shaft of the gearhead, not just the motor shaft. Such systems can operate on a dual control loop. They first close the loop around the motor encoder and then around the gearhead encoder. This configuration lets the controller measure the difference between predicted and actual location of the load (and compensate for the error). This process introduces a small amount of latency, but makes for highly accurate and precise output. It’s particularly effective for ultra-demanding applications such as micro-robotics.

3D printing and aerospace
Dual-control-loop techniques can be challenging, though. Space can be a factor. After all, adding an encoder to the gearhead won’t do much good if the assembly won’t fit. Mounting an encoder to a gearhead shaft involves mechanical, electrical and controls interfaces. That’s a non-trivial task that consumes time that would be better spent working on the actual product being designed.

The new MICROMO MCST 3601 motion controller for steppers fits the FDM 0620 motor.

As one solution, some motion vendors offer magnetic gearhead encoders. These integrated packages are assembled in the factory and fine-tuned to optimize performance. Based on a Hall-effect sensor, they deliver 0.022° resolution—and excel in applications subject to vibration or shock loads, and those that can’t tolerate settling times. It can work as stand-alone feedback for configurations that lack the space around the motor to install a conventional shaft encoder. Coupled with a stainless-steel housing, the encoder makes the gearhead encoder robust enough to handle tough contamination and vibration conditions. It’s also compact—just 15 mm in diameter—so it fits in tight spots.

Such encoder setups work in myriad applications. In robot-guided surgery, even a millimeter of error can drastically impact patient outcome. Using the gearhead encoder in a robot end effector lets surgeons position their equipment with absolute accuracy. 3D printing demands the same level of performance to fabricate parts with fine detail.

In robot-guided surgery, even a
millimeter of error can drastically impact patient outcome. Here, zero-backlash actuators with encoder-equipped gearheads at the robot end effectors let surgeons accurately position equipment.

Consider another example: In electronics assembly, accurate positioning of components during pick-and-place operations can mean the difference between a finished circuit board and expensive pieces of scrap. The gearhead encoder’s accuracy and small size make it suitable for these uses.

Reprint info >>

MICROMO
www.micromo.com

SCHUNK PWG-plus two-finger angular gripper

December 3, 2015 By Lisa Eitel Leave a Comment

The PWG-plus is compact and robust due to the oval piston drive, the strong aluminum housing, and the almost wear-free T-bar drive. Depending on the application, it can also be equipped with an ID/OD spring safety device. Numerous accessories are available, including inductive proximity sensors and magnetic sensors.

The PWG-plus gripper jaws and gripper mounting holes are capable of mounting directly to certain SCHUNK compensation units, attachment valves, and quick-change jaw systems.

There are many advantages to using the PWG-plus gripper, including the design of outrigger workpiece supports due to threaded connections and centering sleeve options. There are also a variety of gripper sizes and gripping torques.

SCHUNK is the worldwide competence leader for clamping technology and gripping systems. Totaling more than 60 years of experience, SCHUNK is a family owned operation and a global player in one. For more information, visit www.schunk.com