March 12, 2019 Volume 15 Issue 10

Motion Control News & Products

Designfax weekly eMagazine

Subscribe Today!
image of Designfax newsletter

Buyers Guide

Archives

View Archives

Partners

Manufacturing Center
Product Spotlight

Modern Applications News
Metalworking Ideas For
Today's Job Shops

Tooling and Production
Strategies for large
metalworking plants

Cobot is 'golden arm' for new pipe welding system

ARC Specialties has solved the challenge of creating repeatable, full-penetration pipe welds by combining artificial intelligence (AI), advanced sensors, and the UR5 collaborative robot from Universal Robots. The unique Artificial Intelligence Pipe Welding System debuted at the Offshore Technology Conference in Houston at the beginning of May.
Read the full article.


Piezo motor technology: Questions answered

There's a new kind of piezo motor in town, and it's got legs. The Piezo LEGS rotational motor is a direct-friction drive that provides precise motion without any mechanical play or backlash. There are no gears or transmission, so changing the direction of the motion will introduce no error. The simple Piezo LEGS motor is also extremely stiff. Find out the answers to frequently asked questions about this exciting motor technology available from the FAULHABER Group.
Read the full article.


Get a linear shafting sample on the house

Lee Linear has produced world-class, linear motion components and linear shafting for over 40 years. With the ability to manufacture custom shafting -- threading, diameter reduction, keyways, flats, plating, and more -- to required standards in a short amount of time, Lee Linear is able to fulfill orders on time, eliminating downtime and increasing profits for its customers.
Request your sample.


Real-World Application: Actuator linkage for diverter valve in hybrid vehicles

Cablecraft Motion Controls was contacted by a large exhaust gas management system supplier to develop a special actuator linkage to control a diverter valve in the exhaust gas stream of hybrid passenger vehicles. The application presented quite a number of challenges, including meeting cost, temperature, and PPAP timing requirements.
Read the full article.


Next-gen permanent magnet AC motor with integrated encoder

Designed for today's demanding machine drive applications, the new VFsync synchronous AC motors from Bison Gear and Engineering run at high efficiency with advanced variable frequency drives. These IP66/IP54 platform motors were optimized with FEA software and then tooled with highly efficient internal permanent magnet-style rotors. VFsync provides a compact footprint that is 56 percent smaller and 63 percent lighter than common 3-phase induction motors. Power range is .25 to 1.5 hp. They are supplied with swivel connectors and shielded cables to make installation trouble-free. Popular frame sizes available. The product line includes the new motors, quick-connect cables, and a programmable and networked VFD.
Learn more.


Largest autonomous mobile robot can lift 1 metric ton

At the Automate 2019 Show and Conference, Mobile Industrial Robots launched the MiR1000, the company's largest autonomous mobile robot (AMR). This mobile platform can automatically pick up, transport, and deliver pallets and other heavy loads up to 1,000 kg (2,200 lb) through dynamic environments. Like the MiR500 introduced in 2018, the MiR1000 is a collaborative, safe, and flexible alternative to potentially dangerous and expensive forklifts on the factory floor. MiR also released another industry first -- artificial intelligence (AI) capabilities across all of its AMRs for improved navigation.
Learn more.


Top Roller conveyor for mobile industrial robots

Real efficiency in logistics automation is achieved when the entire workflow is handled by robotics solutions that communicate smoothly with each other. That's the vision behind ROEQ's new TR500 Top Roller unit that automates load and unload operations of the MiR500, the largest and most powerful autonomous mobile robot from Mobile Industrial Robots (MiR). Danish company ROEQ is launching the Top Roller at the Automate 2019 show in Chicago this week, along with a host of other add-ons for MiR. The TR500 accommodates U.S. pallets and can be delivered with a fully automated lifter functionality for pick-up and delivery of goods.
Learn more.


Top Tech Tip: Specifying self-lubricating bearings for linear motion systems

Self-lubricating ball bushing bearings have experienced an increase in use among motion system designers thanks to their ability to significantly reduce cost of ownership, improve performance, and deliver virtually maintenance-free operation. However, these bearings may not reach their full potential without being properly specified, installed, and evaluated for compatibility with their intended environment. Learn how to specify them for long-lasting use in your motion system applications.
Read this informative Thomson article.


New long-travel linear motor stage

The new V-417.336025E1 linear translation stage from PI is engineered for industrial applications with high demands on dynamics, precision, smooth scan motion, short settling times, and low tracking error. It provides 32 in. of travel (813 mm). The stage achieves high velocities to 79 in./sec (2 m/sec) based on a direct-drive ironless linear servo motor. High accuracy, repeatability, and functionality are guaranteed by an integrated absolute-measuring linear position encoder featuring 1-nm sensor resolution. Applications include: pick and place, optics, semiconductor test and inspection, bio-tech, DNA sequencing, 3D printing, and laser processing and machining.
Learn more.


More stopping power for servo motors -- using less space

Miki Pulley's BXR-LE spring-applied Electro-Magnetic brake series safely holds a static position, without the need for external power. When the stator is energized, the brake is disengaged allowing free rotation. When no current is applied, compression springs halt the brake rotor, thereby stopping the input shaft rotation. This is an ideal feature to prevent rotation during power failure events. There are six total size configurations in the BXR-LE series to choose from. Of particular importance: These brakes have a slim design and high holding torque in a very compact package. Great for robotics.
Learn more.


Variable frequency drives benefit constant speed applications

Using a variable frequency drive (VFD) can be beneficial in many constant speed applications driven by electric motors, such as those that require controlled starting and have been historically served by a reduced-voltage soft-starter (RVSS). While an RVSS and a VFD can both provide a controlled start, let's examine the benefits of each technology and when it makes sense to use one over the other.
Read this informative Parker Hannifin blog.


How a Seventh Axis adaptation aims to move cobot technology into more factories

Advances in technology and software are expanding the scope of potential cobot work environments to include small and mid-size operations. That's why Rollon Corporation has created a Seventh Axis system for collaborative industrial robots from Universal Robots (UR). This shuttle system is designed to extend the operating area of UR's cobots to enhance their performance in automated processes for various industries without sacrificing their simplicity.
Read the Rollon article.


New 200-W high-torque brushless servo motor

The new EC-i 52XL 200W Brushless Servo Motor from maxon is a powerhouse. When space is limited but high torque and dynamics are required, the maxon EC-i 52XL motor is the ideal motor choice. With its extended length (80 mm to 110 mm), this motor with flux collector rotor provides outstanding torque performance compared to the existing EC-i 52 180W High Torque that is often needed, especially on the industrial automation front. Its extra power can be even more significant at relatively low speed, which makes it a solid fit for a variety of industrial applications including material handling and transport systems.
Learn more.


ABB launches IEC food-safe motors

ABB has launched a full range of IEC Food Safe motors designed for applications in the food and beverage industry that need frequent sanitation. The new IEC Food Safe motors are part of ABB's Food Safe family that includes stainless steel NEMA motors, mounted ball bearings, and gearing. Motors are available in the power range 0.18 to 7.5 kW, in 2- to 6-pole versions for 230- to 690-V at 50 or 60 hertz. They feature IE3 premium efficiency to reduce energy consumption and emissions. Flexible mounting arrangements ensure they will fit almost any application. Frame sizes are 71 to 132.
Learn more.


New Sinamics G120X drive series specializes in infrastructure pump, fan, and compressor applications

Siemens has introduced the new Sinamics G120X drive, a simple, seamless, and easy-to-use drive designed for use in pump, fan, and compressor applications in industries such as water/wastewater, HVAC/R, irrigation/agriculture, and in industrial environments. Sinamics G120X has a power range of 1 to 700 hp (0.75 to 630 kW) and can operate in temps from -4 to 140 F (-20 to 60 C) with any standard motor, including synchronous reluctance motors (SRM). It has an integral DC choke that improves harmonics and EMC performance. Sinamics G120X meets all the latest and upcoming UL, NEMA, and EN/IEC standards for 2019 and beyond and offers up to 100-kA short-circuit current rating (SCCR), ensuring enhanced product safety and energy efficiency.
Learn more.


Computer vision challenger: RFID tags provide new way for robots to track moving objects with unprecedented precision

By Rob Matheson, MIT

A novel system developed at MIT uses RFID tags to help robots home in on moving objects with unprecedented speed and accuracy. The system could enable greater collaboration and precision by robots working on packaging and assembly, and by swarms of drones carrying out search-and-rescue missions.

In a paper presented at the USENIX Symposium on Networked Systems Design and Implementation in February 2019, the researchers show that robots using the system can locate tagged objects within 7.5 msec, on average, and with an error of less than a centimeter.

In the system, called TurboTrack, an RFID (radio-frequency identification) tag can be applied to any object. A reader sends a wireless signal that reflects off the RFID tag and other nearby objects, and rebounds to the reader. An algorithm sifts through all the reflected signals to find the RFID tag's response. Final computations then leverage the RFID tag's movement -- even though this usually decreases precision -- to improve its localization accuracy.

MIT Media Lab researchers are using RFID tags to help robots home in on moving objects with unprecedented speed and accuracy, potentially enabling greater collaboration in robotic packaging and assembly and among swarms of drones. [Photo courtesy of the researchers]

 

 

 

 

The researchers say the system could replace computer vision for some robotic tasks. As with its human counterpart, computer vision is limited by what it can see, and it can fail to notice objects in cluttered environments. Radio frequency signals have no such restrictions: They can identify targets without visualization, within clutter, and through walls.

To validate the system, the researchers attached one RFID tag to a cap and another to a bottle. A robotic arm located the cap and placed it onto the bottle, held by another robotic arm. In another demonstration, the researchers tracked RFID-equipped nanodrones during docking, maneuvering, and flying. In both tasks, the system was as accurate and fast as traditional computer-vision systems, while working in scenarios where computer vision fails, the researchers report.

"If you use RF signals for tasks typically done using computer vision, not only do you enable robots to do human things, but you can also enable them to do superhuman things," says Fadel Adib, an assistant professor and principal investigator in the MIT Media Lab, and founding director of the Signal Kinetics Research Group. "And you can do it in a scalable way, because these RFID tags are only 3 cents each."

In manufacturing, the system could enable robot arms to be more precise and versatile in, say, picking up, assembling, and packaging items along an assembly line. Another promising application is using handheld "nanodrones" for search-and-rescue missions. Nanodrones currently use computer vision and methods to stitch together captured images for localization purposes. These drones often get confused in chaotic areas, lose each other behind walls, and can't uniquely identify each other. This all limits their ability to, say, spread out over an area and collaborate to search for a missing person. Using the researchers' system, nanodrones in swarms could better locate each other, for greater control and collaboration.

"You could enable a swarm of nanodrones to form in certain ways, fly into cluttered environments and even environments hidden from sight, with great precision," says first author Zhihong Luo, a graduate student in the Signal Kinetics Research Group.

The other Media Lab co-authors on the paper are visiting student Qiping Zhang, postdoc Yunfei Ma, and Research Assistant Manish Singh.

Super resolution
Adib's group has been working for years on using radio signals for tracking and identification purposes, such as detecting contamination in bottled foods, communicating with devices inside the body, and managing warehouse inventory.

Similar systems have attempted to use RFID tags for localization tasks. But these come with tradeoffs in either accuracy or speed. To be accurate, it may take them several seconds to find a moving object; to increase speed, they lose accuracy.

The challenge was achieving both speed and accuracy simultaneously. To do so, the researchers drew inspiration from an imaging technique called "super-resolution imaging." These systems stitch together images from multiple angles to achieve a finer-resolution image.

"The idea was to apply these super-resolution systems to radio signals," Adib says. "As something moves, you get more perspectives in tracking it, so you can exploit the movement for accuracy."

The system combines a standard RFID reader with a "helper" component that's used to localize radio frequency signals. The helper shoots out a wideband signal comprising multiple frequencies, building on a modulation scheme used in wireless communication, called orthogonal frequency-division multiplexing.

The system captures all the signals rebounding off objects in the environment, including the RFID tag. One of those signals carries a signal that's specific to the specific RFID tag, because RFID signals reflect and absorb an incoming signal in a certain pattern, corresponding to bits of 0s and 1s, that the system can recognize.

Because these signals travel at the speed of light, the system can compute a "time of flight" -- measuring distance by calculating the time it takes a signal to travel between a transmitter and receiver -- to gauge the location of the tag, as well as the other objects in the environment. But this provides only a ballpark localization figure, not subcentimeter precision.

Leveraging movement
To zoom in on the tag's location, the researchers developed what they call a "space-time super-resolution" algorithm.

The algorithm combines the location estimations for all rebounding signals, including the RFID signal, which it determined using time of flight. Using some probability calculations, it narrows down that group to a handful of potential locations for the RFID tag.

As the tag moves, its signal angle slightly alters -- a change that also corresponds to a certain location. The algorithm then can use that angle change to track the tag's distance as it moves. By constantly comparing that changing distance measurement to all other distance measurements from other signals, it can find the tag in a three-dimensional space. This all happens in a fraction of a second.

"The high-level idea is that, by combining these measurements over time and over space, you get a better reconstruction of the tag's position," Adib says.

"The work reports sub-centimeter accuracy, which is very impressive for RFID," says Lili Qiu, a professor of computer science at the University of Texas at Austin whose research focuses on wireless networking and communications. "The paper proposes an interesting idea that lets a 'helper' transmit a wideband signal compatible with RFID protocol to achieve high tracking accuracy [and] develops a ... framework for RF localization that fuses measurements across time and across multiple antennas. The system has potential to support [the researchers'] target applications, such as robotic assembly and nanodrones. ... It would be very interesting to see the field test results in the future."

The work was sponsored, in part, by the National Science Foundation.

Published March 2019

Rate this article

[Computer vision challenger: RFID tags provide new way for robots to track moving objects with unprecedented precision]

Very interesting, with information I can use
Interesting, with information I may use
Interesting, but not applicable to my operation
Not interesting or inaccurate

E-mail Address (required):

Comments:

Copyright © 2019 by Nelson Publishing, Inc. All rights reserved. Reproduction Prohibited.
View our terms of use and privacy policy