Drives + Supplies - Motion Control Tips

Drives and controls for robotics: See them at the 2019 Robotics Summit

May 16, 2019 By Lisa Eitel Leave a Comment

In a couple weeks, the 2019 Robotics Summit (focused on the design, development, manufacture, and delivery of commercial robotics) will take place in Boston. It will be co-located with the DeviceTalks event at the Seaport World Trade Center. One display will be an array of precision processing and powering technologies for robotics.

Elmo Motion Control • Booth #118 — This is a top visit if you’re interested in drives and controls for on-robot (distributed) control. We recently touched on some multi-axis solutions for these setups in a visit at Automate:

In fact, you will get to see Brian Mason (who gives the booth tour in the above video) on Wednesday, June 5th at 2:00 at the Robotics Summit, when he will present on motion control in robots. You’ll also get to ask him questions about miniature network-based servo drives and novel ways to power and control robot joints for less cabling.

Infranor • Booth #139 — Look for servo drives and servomotors here, and give us a shoutout on LinkedIn if you end up having a conversation with this company about new robotics applications for semiconductor, packaging, or aerospace industries (and are at liberty to divulge a vague detail or two).

Performance Motion Devices • Booth #145 — Little-known fact about PMD … this company is well-versed in sharing motion fundamentals with the industry. So if your primary engineering focus is in fact not motion control and you attend the Summit, say hello to the team here to get answers to questions you’ve always wanted to ask but felt were elementary. Performance Motion Devices sells multi-axis motion products (and ICs, digital drives, and amplifiers, and machine boards) and provides technical support on these technologies.

PI • Booth #151 — Physik Instrumente makes regular appearances in our editorial for its precision subsystems. Piezomotors feature large in a lot of miniature designs — see what we did there? — although this company integrates a whole host of other actuator and motor types as well as various kinematics iterations. Check out this FAQ for more on the kinematic possibilities for some robotics: What’s the difference between serial kinematics and parallel kinematics in multi-axis motion design?

This is a piezo motor from Physik Instrumente (PI) that moves to 200 mm/sec. It has an integrated driver.

Kollmorgen • Booth #202 — Catch up on the features and case studies we’ve done (listed below) on how to size and apply servomotors, frameless motors, and stepper motors to robotics and other applications. Then go see the engineers from Kollmorgen at the Summit to see what new robotics applications they observe on the horizon for these technologies — especially for collaborative robots, industrial articulated robots, and medical robots … and particularly those employing frameless motors (a huge trend in the industry) as well as harmonic gearing for high torque density and smaller and faster robots.

Trends in electric motors Part II — Scott Evans sets record straight on motion design

Difference between continuous ratings and holding continuous loads (an ac servo-motor terminology primer)

Thermal time constants and managing PMAC servo motor overloads

Frameless motors and gearmotors for robot design at XPONENTIAL 2019

JF Shaw • Booth #212 — You’d be hard pressed to think of a component used in automaton and robotics that this company doesn’t supply, as they include sensors, connectivity equipment, motors, and drives; mechanical offerings relevant to the application of robots include spur gears, industrial belts, pulleys, and couplings … as well as whole assemblies and end-of-arm tooling including electrical and pneumatic grippers. We editors at motioncontroltips.com are just learning of the capabilities from this supplier ourselves, so stay tuned in coming months to get more on its engineers’ expertise in the design and integration of various industrial applications.

ADVANCED Motion Controls debuts family of compact FlexPro digital servo drives

May 14, 2019 By Miles Budimir Leave a Comment

The FE060-25-EM is the first servo drive of the new FlexPro digital drive family from ADVANCED Motion Controls (AMC). Designed with compact form and power density in mind, the micro-sized FE060-25-EM can outperform larger-sized digital servo drives and still be integrated into tight spaces.

At just 1.5 x 1 x 0.6 in. (38 x 25 x 16 mm) in size, the footprint of the drive is approximately the same as two standard postage stamps. In other words, four of these drives can fit on a standard business card. Even with its small size, the FE060-25-EM can supply brushed, brushless, stepper, and linear servo motors with up to 25 A continuous current and 50 A peak current.

AMC_Image_FE060-25-EM features include:

10 to 55 Vdc supply voltage
Highest power density servo drive from ADVANCED Motion Controls to date
EtherCAT Communication
Incremental encoder and BISS C-mode feedback
Torque, velocity, and position operating modes
Configuration and full loop tuning
IMPACT architecture

IMPACT (Integrated Motion Platform And Control Technology) is the architecture that makes AMC’s FlexPro drives possible. The stacking of circuit boards with creative selection and placement of high-power components allows for much higher power density than previously produced servo drives.

A developer version is available for proof-of-concept and testing purposes – part number FD060-25-EM. It comes with an FE060-25-EM soldered to a larger board equipped with various connectors for simplified interfacing.

The small size of the FE060-25-EM makes it perfect for cobots (collaborative robots), AGVs, portable devices, lab and warehouse automation, military equipment, and any other integrated design.

For more information, visit www.a-m-c.com.

Robotics Summit in June: Attend for technology insights (and hero Tyler Shultz)

May 6, 2019 By Lisa Eitel Leave a Comment

In a few short weeks, the 2019 Robotics Summit (focused on the design, development, manufacture, and delivery of commercial robotics) will take place in Boston. It will be co-located with the DeviceTalks event at the Seaport World Trade Center.

Side note — and yes, we at Design World are quite excited about this one: DeviceTalks is featuring a truly remarkable keynote speaker in Tyler Shultz, the entrepreneur and Theranos whistleblower who brought to light many of the revelations detailed in Bad Blood, which we cover here on designworldonline.com.

Shultz is the closing keynote in the afternoon June 6th and goes later than the Robotics Summit closing keynote from Dev Singh of Qualcomm Technologies on the application of 5G in robotics. That means if you register for the Robotics Summit, you’ll get to see and ask questions of both Singh and Shultz.

On the technologies themselves, we of course know that motion control and power-transmission technologies are at the heart of all robot designs. Following is a smattering of some such components you’ll see at the Summit.

Robot degrees of freedom — tracked with feedback

Sensing and feedback allow for monitoring of robot axes (to track position in space as well as speed, acceleration, and torque) for the correction of motion … to deliver on preprogrammed moves and adjust to external factors. In most cases, sensing and feedback components in robotics take the form of encoders (on electric-motor-driven axes) and other sensors for end-of-axis tracking or mapping. Some suppliers showing such technologies at the 2019 Robotics Summit include the following.

ifm • Booth #104 — Information to glean from these folks includes that on position and fluid sensors as well as diagnostic, networking, and connectivity solutions (which are increasingly pre-engineered, as we cover here and here). ifm manufactures industrial sensors and other control products to support an array of robotics applications — and those for assembly too.

Renishaw • Booth #130 — If you attend the Summit, get this team to summarize for you how to choose between and apply optical, laser interferometer, and magnetic encoder technologies. Renishaw sells (among other things) components for measurement and motion control, though the supplier is probably best known for its encoders for OEM positioning applications.

Motors propel, rotate, actuate robotic axes

Electric motors are far and away the most common technology imparting motion to robotics. On the rise today are PMDC motors, stepper and servo motors, PMAC and brushless motors, and frameless iterations of various motor subtypes. That latter can include direct-drive motors and (often when referring to motors that drive AGVs and similar autonomous robotics) torque motors.

Nidec • Booth #110 — As we outline in more detail in this article (Motion Trends: New motor breeds are smart, connected, and compact) Nidec founder Shigenobu Nagamori identifies these trends in industries employing electric motors:

• Home appliances traditionally employing brushed motors are increasingly using brushless dc motors
• Rising electrification of automobiles relies on electric motors
• There’s significant replacement of manual tasks in logistics and agriculture with automated designs — and the potential for drones in these markets is especially high
• Proliferating robots (including collaborative robots) are almost all equipped with electric motors and speed reducers. These robots are expensive, but use will rise as prices decrease, said Nagamori.

Visit Nidec at the summit to see its lineup of precision motors suitable to impart motion to robotic designs.

maxon precision motors • Booth #114 — If you missed the recent Automate show in Chicago, you didn’t get the chance to see the tabletop robotics display maxon had at its booth … a KINOVA arm:

The company’s Jaco2 Robotic Arm provides a lightweight, quiet and easily controlled device to the service industry; it actuates in six degrees of freedom using six flat motors.

You’re likely to see this or comparable application examples (as well as maxon motor and drive offerings to satisfy robotic designs with parameters as demanding as those for Mars rovers) in Boston — so go say hello.

Bodine Electric Co. • Booth #122 — This is a stop for stock and custom gearmotors and drives as well as fixed and variable speed ac, brushless dc, and permanent magnet dc motors and motion controls. Again, tag us on LinkedIn if you visit Bodine and want us to share your conversation online.

Electrocraft • Booth #226 — Here get a unique take on application-engineered motors and motion products for inspection and agricultural robots, robotic mowers, surgical robots, domestic-service robots, and end effectors. This motor maker also sells gearboxes, gearmotors, linear actuators, and integrated motor drives for such applications.

MICROMO • Booth #248 — One reason attend the Summit in Boston is to see this manufacturer’s micro dc motors firsthand — especially if you’re an engineer or OEM aiming to boost design quality. Besides brush and brushless dc motors, stepper motors, and linear dc servomotors, MICROMO also supplies gearheads, encoders, and micro linear actuators. As the North American supplier of FAULHABER micro-motion products, MICROMO also provides value-add design and engineering services.

Precision power-transmission for robotics

Harmonic Drive • Booth #119 — Strain-wave gearing sets are core to so many robotics applications. One company supporting this technology’s application is Harmonic Drive — which designs and sells an array of precision servo actuators, gearheads, and gear component sets. Solutions are standard or (in most cases) custom.

Note that on Wednesday at the Summit (11:45 to 12:30 pm) president and CEO of Harmonic Drive Doug Olson will present on these technologies for robotic actuators.

Intech • Booth #124 — Here you’ll get to see various robotic applications for self-lubricating plastic rollers, gears, and cam followers of non-hygroscopic Power-Core material (and supplied with durability calculations). Fast as well as lubrication (and maintenance) free, these motion components also have low inertia and deliver smooth motion so critical to automated designs.

See you in Boston.

Automate 2019 closes last show in Chicago with record attendance and leads

April 30, 2019 By Lisa Eitel Leave a Comment

Automate, North America’s largest showcase devoted to automation industry trends, leading-edge technology and business innovation, ended its eight-year run in Chicago with record numbers. According to preliminary figures, more than 20,000 walked the show floor at the biennial event – an increase of 25% over 2017 – to see the advancements in robotics, vision, motion and advanced automation technology from over 500 exhibitors from around the world.

President of the Association for Advancing Automation (A3) Jeff Burnstein reports that the majority of the largest exhibitors have already reserved their spots for 2021 in Detroit, all citing the strong connections they were able to make at this year’s show.

The Association for Advancing Automation is the global advocate for the benefits of automating. A3 promotes automation technologies and ideas that transform the way business is done. A3 is the umbrella group for Robotic Industries Association (RIA), AIA – Advancing Vision + Imaging, Motion Control & Motor Association (MCMA) and A3 Mexico. RIA, AIA, MCMA and A3 Mexico combined represent over 1,200 automation manufacturers, component suppliers, system integrators, end users, research groups and consulting firms from throughout the world that drive automation forward.

Automate has proven once again to be a suitable venue for manufacturers to find the latest innovations in automation — from collaborative and mobile robots to artificial intelligence, machine vision and motion control, Burnstein said. “From what we’ve heard from exhibitors and attendees alike, the show was a great success, generating thousands of valuable leads as business leaders learned how the various innovations can help their companies thrive in today’s highly competitive global environment. We can’t wait to do it all again in 2021, this time in Detroit.”

Mobile Industrial Robots (MiR) is one exhibitor planning a return to Automate in 2021. According to Ed Mullen, MiR’s vice president of sales for the Americas, the company received more than 1600 leads over the week, the most the Danish manufacturer of autonomous mobile robots has received at any trade show to date.

“Automate attracts thousands of companies from across the United States, which makes it an suitable venue for us,” Mullen said. “The massive amount of highly qualified leads we received at Automate this year compared to when we first launched in North America in 2017 completely validates the decision to exhibit at the show. We’re looking forward to 2021.”

Another company at Automate was Innovative Mechatronic Systems B.V., which was the 2019 winner of the $10,000 Launch Pad Startup competition for its Archimedes Drive. This toothless gearbox with speed reducer technology brings groundbreaking improvements in performance compared to current drive solutions. Founder Thibaud Verschoor and six other finalists had five minutes to present their innovations before the judges chose the winner. Judge Oliver Mitchell of Autonomy Ventures wrote that IM Systems universally stood out for its important contribution … with potential to generate a billion-dollar valuation with its promise of bringing down the cost of adoption and quickening the speed of deployment.

At Automate, A3 also announced the date and location for Automate 2021. It takes place May 17-20 at Detroit’s Cobo Center. Exhibitors, participants and attendees can find more information about Automate 2021 at www.automateshow.com.

New supply module from Beckhoff accommodates cabinet-free servo drive installation

April 26, 2019 By Miles Budimir Leave a Comment

To reduce cabinet and enclosure requirements for machine builders and manufacturers, Beckhoff Automation has announced the new AMP8620 supply module. The AMP8000 Distributed Servo Drive system provides optimal support for the implementation of modular machine concepts. With the AMP8620 supply module’s IP 65 protection rating and consistent decentralization, the entire motion system can now be mounted directly on the machine. This means drive technology can now be implemented entirely without control cabinets, resulting in maximum possible savings in terms of cost, materials, space and installation work.

While coupling modules already reduced the requirements for connecting distributed AMP8000 drives to the control cabinet to just one cable, the cabinets can now be completely eliminated when using the AMP8620 supply module. Eliminating the need for a control cabinet further reduces the footprint and cabling requirements for the entire machine. Costly air conditioning equipment, which would otherwise be necessary to cool control cabinets, can also be eliminated.

The AMP8620 module connects directly to the mains supply. It contains all circuitry required for that purpose, such as mains filters, rectifiers and charging circuits for the integrated DC link capacitors. The supply module enables the optional connection of additional distribution modules or distributed AMP8000 Servo Drives. It is also equipped with two EtherCAT P outputs, which can either supply EtherCAT P modules or connect to additional supply modules that may be required for motion system expansions. The safe 24-V power supply unit integrated in the supply module ensures that the logic power supply does not exceed the permissible level. The DC link capacitors integrated in the supply module store the regenerative energy of the entire system and then make it available again for acceleration processes. This ensures the most efficient usage of the energy supply.

For more information, visit www.beckhoffautomation.com.

What is droop control in the context of AC motors and drives?

April 17, 2019 By Danielle Collins Leave a Comment

One of the fundamental characteristics of an AC induction motor is that the rotor spins at a slower rate than that of the stator’s rotating magnetic field. This difference in speed between the rotor and the stator’s magnetic field is known as slip.

Slip allows the motor to produce torque — the higher the slip, the higher the torque production, but also, the lower the motor’s efficiency (in most cases). But in load-sharing applications, motor slip can be used to prevent one motor from taking a disproportionate share of the load.

N_s = synchronous speed (rpm)

N = rotor speed (rpm)

Load-sharing, in this context, refers to two or more AC motors connected to and driving the same load. Theoretically, each motor in a load-sharing set-up would experience an equal percentage of the load. But in real-world applications, numerous factors, such as variations in load along the length of a conveyor, or inconsistencies in the driven process, can cause the load to be distributed unevenly among the motors.

“Natural” load balancing

Because slip is inherent in AC motors, when two or more motors are connected to one drive, their natural slip will work to achieve balanced load sharing. As one motor experiences increased load, its speed (i.e. rotor speed) slows down, increasing slip between the rotor and stator. The second (and subsequent) motors, which are connected to the same drive, will also slow, allowing them to take on the additional load. While using the motors’ natural slip is a simple method of load-sharing, it is very imprecise and not reliable at high loads.

Droop control

For applications where load-sharing needs to be precise and controllable, some AC drives include a function — typically referred to as droop control — that manipulates motor slip to better ensure equal load-sharing. Here’s how it works:

Droop control effectively shifts the motor’s torque vs frequency curve so that an increase in torque causes a decrease in the drive’s output frequency.
Image credit: Schneider Electric

The drive monitors the motor torque (via current draw), and if the torque increases beyond a set value (indicating that the motor is taking on too much load), the droop control function decreases the output frequency of the drive.

The rotor speed has slowed due to the increased load, and the decreased output frequency from the drive causes the stator magnetic field to also decrease in speed. Hence, there’s a smaller difference between stator speed and rotor speed. In other words, slip is reduced, which reduces the motor’s torque production, allowing other motors to take more of the load.

Droop control can work both ways — reducing the output frequency of the drive when the load increases (to decrease the amount of load on an overloaded motor), or increasing the output frequency of the driven when the load decreases (to increase the amount of load on a non-drooping motor). This two-way method of controlling load sharing is sometimes referred to as “bipolar” droop control.

Droop control is often used to increase slip in an overloaded motor, allowing other motors connected to the same load to take a higher share of the load. One application where droop control is useful is a conveyor with multiple driven rolls. If one section of the conveyor (and, therefore, one motor) sees an increase in load, droop control prevents the motor from sustaining this disproportionate share of the load, preventing damage to the motor and, potentially, to the system.
Image credit: Rockwell International Corporation

The Automate show moves to Detroit in 2021

April 10, 2019 By Lisa Eitel Leave a Comment

Automate, North America’s largest showcase devoted to automation industry trends, leading-edge technology and business innovation, is moving to Detroit. The biennial Automate Show and Conference, colocated with Promat in Chicago since 2011, has grown to more than 500 exhibitors, over 20,000 attendees and 1,000 paid conference registrants. The move for the next event, which will take place May 17-20, 2021 at Cobo Center, was announced last night at the Automate 2019 “Moving to Motown” networking party in Chicago.

“To continue our rapid growth, and better meet the needs of our exhibitors who look to Automate to reach new potential customers, we’ve decided that now is the right time to move Automate to its own location – and Detroit is an ideal fit,” said Jeff Burnstein, president of the Association for Advancing Automation (A3), the show’s organizer. “Detroit is turning into the next major technology hub in the United States. This is an exciting change for us and our exhibitors, allowing Automate to expand in size and technology scope as the automation industry continues its steady growth.”

Named one of Lonely Planet’s top cities to visit in 2018, Detroit is transforming. Over the last few years, studies from the Brookings Institution have rated Detroit No. 4 on a list of the country’s hubs for advanced technology employment, with nearly 15 percent of the workforce in the Detroit-Warren-Dearborn area working in areas such as research and development and engineering. Though known as a traditional automotive hub, the region is growing in other industries such as aerospace, logistics and advanced mobility.

“We’re very excited that Automate will be moving to Detroit in 2021,” said Mike Cicco, president and CEO of FANUC America, a leading supplier of robotics and automation based in Rochester Hills, Mich. “It’s evident that Michigan is quickly regaining its strength as a manufacturing and technology powerhouse, and we’re proud that our headquarters has been in the Detroit Metro area since 1982.”

“Detroit is so pleased to be welcoming Automate to our destination next year because it makes sense for a region whose future success, particularly in the automotive sector, is dependent on new technology improvements and automation for the making and delivering of products and services,” said Larry Alexander, president and CEO of the Detroit Metro Convention & Visitors Bureau. “Our hospitality community will roll out the welcome mat in our vibrant city for the nearly 20,000+ attendees of Automate.”

Companies at Automate 2019 this week in Chicago can reserve space now by visiting the A3 sales office (booth #9667), or by contacting Jim Hamilton (734) 994-6088 for exhibiting information.

Automate 2019 April 8 through 11: See Elmo Motion Control + future of motion control

April 5, 2019 By Lisa Eitel Leave a Comment

Elmo Motion Control a leading provider of motion control technology, will be showcasing its latest innovation during the 2019 Automate tradeshow from April 8-11, 2019 in Chicago … booth #7729. Amongst Elmo’s state-of-the-art products, visitors will find the award-winning Double Gold Twitter servo drive, the Platinum Maestro multi-axis motion controller, and for the first time the 4-in-1 fully integrated motion control system.

With an insightful look to the future, Elmo has been creating products and solutions for more than 30 years, aiming to answer the ever-growing requirements and demanding applications of Industry 4.0.

The Double Gold Twitter stands out as one of the smallest STO-certified (SIL-3) servo drives in the market, delivering over 10kW of qualitative power, and providing continuous current of up to 160A (80V) and 140A (100V). Thanks to its compact size, this miniature drive can be placed on a moving load, within a motor, or in-between robotic joints, helping engineers to save space, improve machine performance, reduce the amount of cables, and eliminate electrical cabinets, while still delivering unprecedented power capabilities.

The 4-in-1 complete motion control solution is Elmo’s latest innovation to answer the market requirement for a highly integrated all in one solution taking care of both high-power servo capability as well as advanced multi-axis control.

The ultimate servo technology with the best of safety

As safety takes the forefront of many operations, Elmo ensures products comply with the highest possible standards (IEC 61800-5-2 SIL-3, Cat4 PL-e), by integrating safety over EhterCAT – FSoE (Fail/Safe over EtherCAT), and advanced functional safety. Elmo equips manufacturers with top of the line foolproof products that increase their operation’s productivity, lowers operational expenses, and improves safety methods to create truly smart and efficient operations.

Elmo Motion Control (Elmo) designs, produces and implements comprehensive, field-proven motion control solutions that helps clients discover their machine’s potential. The company’s R&D department combines intelligent motion control technologies, real-time programming and control algorithms with advanced digital hardware to enable leaner, more flexible machines. Controlled by the Elmo application studio (EAS)—a software environment that cuts integration time and maintenance costs—Elmo’s servo drives and multi-axes motion controllers minimize a machine’s footprint and cabling, improve throughput, and give original equipment manufacturers (OEMs) a competitive edge. Founded in 1988, the company is headquartered in Israel, employs more than 300 staff worldwide, and has a dedicated presence in the United States, China, Germany, Italy, Switzerland, Korea, Poland and the United Kingdom. For more information, visit www.elmomc.com.

What’s the difference between PL and SIL machine safety standards?

April 5, 2019 By Danielle Collins Leave a Comment

Machine safety is governed by two standards: EN/ISO 13849-1 and EN/IEC 62061. Both standards are harmonized to the EU Machinery Directive 2006/42/EC, which defines the Essential Health and Safety Requirements (EHSR) for machinery. Although their methods for performing risk assessment are different, both standards — EN ISO 13849-1 and EN 62061 — when correctly applied, achieve the same result.

The EU Machinery Directive requires that machine manufacturers eliminate or minimize hazards as much as reasonable, apply necessary protective measures against hazards that cannot be eliminated, and inform users of the risks that remain and requirements for training or personal protective equipment. Although this directive is specific to the European Union (EU), it is recognized and followed in other regions around the world, to better facilitate equipment shipments outside the EU.

The EN/ISO 13849-1 machine safety standard uses a qualitative risk graph, or flow chart, to assign a performance level (PL), based on three criteria:

severity of injury
frequency and/or exposure time to the hazard
possibility of avoiding the hazard or limiting the harm

The performance level (PL) is designated by an alphabetic character, a thru e, with PLe being the highest risk level.

EN/ISO 13849-1 assigns a performance level (PL) rating from a to e, with PLe being the highest risk.
Image credit: TUV

Once the performance level has been determined, the architecture that facilitates the defined performance level is classified into one of six categories (“B” and 1 thru 5, with B being the least safe and 5 being the most safe). The architecture category is determined by combining the performance level (PL) with quantitative measures of diagnostic coverage (DC) and mean time to dangerous failure (MTTF_d).

This chart shows the relationship between Category, Diagnostic Coverage, and Mean Time to Dangerous Failure for PL levels under EN/ISO 13849-1. Note also the correlation with probability of dangerous failure per hour (PFH_d) rates.
Image credit: ABB

The EN/IEC 62061 machine safety standard (often written as just EN 62061) assigns a safety integrity level (SIL) to each function based on the severity of the potential harm (Se) and the probability of the harm occurring.

The severity of potential harm is given a score from 1 to 4, with 4 being the most severe. The probability of harm occurring is broken down into three parameters:

frequency and duration of exposure (Fr)
probability of an event occurring (Pr)
probability of avoiding or limiting the harm (Av)

EN 62061 assigns a safety integrity level (SIL) from 1 to 3 based on the severity of potential harm and the probability of the harm occurring.
Image credit: TUV

Each of these parameters is scored from 1 to 5, with 5 being the “worst,” or least safe situation, and their scores are summed to determine a class (Cl). The SIL rating is then chosen from a matrix that plots the severity scores (Se) and classes (Cl).

SIL ratings are determined by a matrix that ranks the severity of injury and the injury classification.

Once the safety integrity level (SIL) has been assigned, the system is broken into subsystems, whose architectures are classified as A, B, C, or D, with D being the “highest,” or safest. Each architecture is associated with a formula to determine the probability of dangerous failure per hour (PFH_d) of the subsystem.

Note that performance level (PL) ratings under EN/ISO 13849-1 are also correlated with probability of dangerous failures per hour (PFH_d) values, so direct comparisons can be made between EN/ISO 13849-1 performance levels and EN 62061 safety integrity levels.

There is no strict guideline regarding the use of machine safety standards for particular applications, but the choice may be influenced by:

Prior experience with one standard or risk assessment methodology
The use of safety-related controls that are not based on electrical, electronic, or programmable electronic systems (use EN/ISO 13849-1)
A requirement to use SIL ratings to demonstrate safety integrity (use IEC 62061)
Use of equipment in process industries where other safety-related systems are characterized in terms of SIL (use IEC 62061)

Single-axis PWM drive for brushless/brush dc, voice coil, and stepper motors

April 4, 2019 By Miles Budimir Leave a Comment

The new XC4e PWM digital drive from Aerotech is a high-performance single-axis motor drive to control brushless dc, brush dc, voice coil, or stepper motors at up to 340 Vdc operating voltage and 30 A peak current capability. All versions are compatible with the Automation 3200 motion platform utilizing the HyperWire motion bus.

The digitally closed current loop and servo loop ensure the highest level of positioning accuracy and rate stability. This allows loop closure rates up to 20 kHz as well as digital and analog I/O processing, data collection, process control, and encoder multiplication tasks in real time.

Standard features include Safe Torque Off (STO), a data array consisting of over 16 million 32-bit elements, digital and analog I/O, one-axis Position Synchronized Output (PSO), dedicated home and end-of-travel limit inputs, and an enhanced current sense device. Encoder support includes square-wave, sine-wave, and absolute encoders.

The standard XC4e accepts square-wave encoder feedback at rates of up to 40 million counts-per-second. Sine-wave encoders can be multiplied by up to 65,536 with the optional encoder multiplier feature. Dual-multiplied encoder feedback is also supported.

Each single-axis XC4e PWM digital drive can be ordered with the MX2 high-performance single encoder multiplier or the MX3 high-performance dual-loop encoder multiplier, enabling higher levels of position and velocity control. Also available are a wide variety of extensions to the base PSO functionality. Track up to three encoders in real time with three-axis PSO or extend PSO’s functionality to kinematic arrangements through the use of Aerotech’s Part-Speed PSO feature.

Each drive has an optional I/O expansion board to greatly increase the number of I/O points. The board includes a dedicated PSO output and a PSO synchronization input, often used to synchronize process control with an external mode-locked frequency input.

For more information, visit www.aerotech.com.