classic | mobile
 

Search...

SA Instrumentation & Control Buyers' Guide

Technews Industry Guide - IIoT 2018

Technews Industry Guide - Maintenance, Reliability & Asset Optimisation

 

Matching linear measurement performance to application needs
January 2019, Motion Control & Drives


Almost all modern automated machines and systems require precise, reliable and cost-effective linear measurement. And although this need increases in line with demands for greater efficiency, speed and quality, in reality, most common industrial applications do not require micron accuracy.

The problem here is that most engineers seeking a reliable and sufficiently accurate linear measurement system, typically have few viable options. Most of today’s solutions are considered too expensive, too complex or are overly specified, while low-cost alternatives quickly reach their limits when longer measuring lengths are required. Factors like these apply to systems such as scales, potentiometers and magnetostrictive systems, among others.

Over-specified solutions

Many optical systems, while offering high levels of accuracy, are often over specified and too costly for the task in question. Most common industrial applications do not demand accuracies of a thousandth or even hundredth of a millimetre. Also, in terms of environmental performance, the susceptibility of optical systems to the ingress of contaminants can be an issue.

With potentiometers, factors such as extreme temperatures, vibration, wear and susceptibility to foreign matter are all well documented issues, while magnetostrictive systems also suffer from temperature effects, as well as sensitivity to shock and potential inaccuracy over distances of less than 100 mm.

A new era of linear measurement

With the shortcomings of existing solutions sometimes precluding them from use in particular applications, there is a need for alternatives. One such measuring system, which has emerged more recently, is Sensoflex SFI-plus from Parker Hannifin. Simple in design and able to provide a resolution of 0,1 mm, this new technology can match the requirements of many common positioning operations. The possible objection, that this measurement accuracy is insufficient, overlooks the fact that in most cases no higher accuracy is required.

Typical applications to benefit include conveyor and storage technology, lining work on wood or plastic machines, automatic cut-to-length machines, and worktables and transportation carts. Designed for both linear and rotary motion, Sensoflex SFI-plus operates reliably within pneumatic, hydraulic and electrical systems.

Two principal components make up this contactless magnetic length-measuring system: a 10 mm wide, self-adhesive magnetic scale and a reading/sensing head with connection to an external control unit.

Contactless and wear free, scanning is carried out magnetically. In terms of operation, the read head converts the magnetic poles into electrical signals that are processed by downstream counter inputs, using a PLC, PC or digital counter. Two pulsating, 90° out-of-phase counter signals (phase A/B) are provided with a 0,1 mm resolution. Signal integrity is maintained even at travel speeds of up to 10 m/s.

Cost considerations

The cost-effective nature of such a solution stems from the fact that the scale itself is little more than a magnetised strip of tape stuck to the mounting surface. Further economies are achieved through quick assembly and minimal time required for wiring.

This new concept in linear measurement also meets many other common application demands. For instance, the system is compact as it can be mounted directly on the actuator profile, while flexibility is derived through straightforward integration in existing systems.

Universal application is facilitated through a choice of drive technologies and the fact that the system is suitable for almost any control or display unit with a counter input. User friendliness is enhanced via variable measuring lengths up to 32 m, the only requirement being that the scanning head is also able to cover the entire travel distance. Lastly, the system is resistant to both vibration and impact, and offers a degree of protection to IP67.

High-accuracy solutions are not only expensive, but often require careful installation. Additionally, the adoption of such systems might not be possible in many applications because of factors such as vibration or differential thermal expansion. Here, the lack of robustness of high-accuracy solutions can lead to failure or malfunction. Ultimately, the best strategy is to specify an approach that accurately reflects the needs of the application – performance beyond that is unnecessary.

For more information contact Lisa de Beer, Parker Hannifin SA, +27 11 961 0700, lisa.debeer@parker.com, www.parker.com/za


Credit(s)
Supplied By: Parker Hannifin Sales Company South
Tel: +27 11 961 0700
Fax: +27 11 392 7213
Email: parker.southafrica@parker.com
www: www.parker.com/za
Share via email     Share via LinkedIn   Print this page

Further reading:

  • Case History 164: More on valves that do not control properly.
    January 2019, Michael Brown Control Engineering, Motion Control & Drives
    I often publish articles showing valve problems. One of the reasons is that I do not think many people understand that valves are generally responsible for 75-80% of all control loop problems. When it ...
  • Global partnerships for automotive support
    January 2019, Parker Hannifin Sales Company South, Motion Control & Drives
    Parker Hannifin is a global leader in motion control components and system solutions serving industrial, mobile and automotive markets. Specialising in hydraulics, pneumatics, electromechanics, fluid ...
  • Case History 163: Control limitations on mineral processing plants
    November 2018, Michael Brown Control Engineering, Motion Control & Drives
    I was recently asked to conduct a control loop audit on a mineral extraction processing plant which was fairly old and had been acquired by new owners. A new and very modern control system had been installed ...
  • PC-based control ­ increases throughput in additive ­manufacturing
    November 2018, Beckhoff Automation, Motion Control & Drives
    Automated post-print processing puts the finishing touches on 3D printed parts.
  • SEW supplies industrial gear units for West African mine
    November 2018, SEW-Eurodrive , Motion Control & Drives
    Having an in-house projects department to focus on the specific requirements of project houses, OEMs and other tender-related project activity is starting to bear fruit for drive and automation specialist ...
  • Motion analyser software shortens design time
    November 2018, Rockwell Automation, Motion Control & Drives
    Rockwell Automation has released an updated version of the Allen-Bradley Motion Analyser software tool, which offers an optimised user experience with intuitive navigation and in-workflow product selection. ...
  • Edge applications for machine tools
    November 2018, Siemens Digital Factory & Process Indust. & Drives, Motion Control & Drives
    As part of Siemens Industrial Edge, the company is launching applications for Sinumerik Edge, the machine-level platform specially designed for the machine tool industry, at AMB 2018 in Stuttgart. This ...
  • Nord drives for wash-down ­applications
    November 2018, Bearing Man Group t/a BMG, Motion Control & Drives
    BMG’s range of Nord aluminium drives is available with the nsd tupH (sealed surface conversion system) anti-corrosion treatment, which has been developed for improved process reliability in extreme environmental ...
  • Eaton motor control for easy installation
    November 2018, Magnet , Motion Control & Drives
    Magnet’s portfolio of space saving Eaton motor control and protection devices offer motor starting and protection solutions in diverse industries, including mining, oil and gas, pulp and paper, the automotive ...
  • Linear modules with one-point lubrication simplify assembly
    November 2018, Tectra Automation, Motion Control & Drives
    The third generation of MKK and MKR linear modules from Tectra Automation expands the range of equipment options for the company’s linear module series. In the corrosion resistant versions, hard chrome ...
  • Using IIoT analytics to build customer solutions
    October 2018, Parker Hannifin Sales Company South, IT in Manufacturing
    Parker’s Voice of the Machine platform contextualises the data collected from machines.
  • How drives help in papermaking
    October 2018, Nidec, Motion Control & Drives
    Papermaking machinery, from tissue winders through to suction rolls, embossers, print units and conveyors, must utilise the latest drive technologies to meet modern paper mill production schedules and ...

 
 
         
Contact:
Technews Publishing (Pty) Ltd
1st Floor, Stabilitas House
265 Kent Ave, Randburg, 2194
South Africa
Publications by Technews
Dataweek Electronics & Communications Technology
Electronic Buyers Guide (EBG)

Hi-Tech Security Solutions
Hi-Tech Security Business Directory

Motion Control in Southern Africa
Motion Control Buyers’ Guide (MCBG)

South African Instrumentation & Control
South African Instrumentation & Control Buyers’ Guide (IBG)
Other
Terms & conditions of use, including privacy policy
PAIA Manual





 

         
    classic | mobile

Copyright © Technews Publishing (Pty) Ltd. All rights reserved.