Product category:
Industrial Drives/Controls
News Release from: Control Techniques | Subject: Unidrive UD70 soft logic module
Edited by the Engineeringtalk Editorial
Team on 12 June 2000
Modern drive updates yarn winding
machine
A retrofit drive package, comprising Control Techniques' Unidrive, UD70 soft logic module and a flux vector motor, is achieving 20% more output from a 25 year old yarn winding machine.
A retrofit drive package, comprising Control Techniques' Unidrive, UD70 soft logic module and a flux vector motor, is achieving 20% more output from a 25 year old yarn winding machine for Incotex, a Portuguese textile company The constant tension control provided by the drive system is also ensuring that Incotex benefits from improved quality of its finished yarn
This article was originally published on Engineeringtalk on 30 Jan 2001 at 8.00am (UK)
Related stories
Plan how to offset the Climate Change Levy now
The Climate Change Levy is viewed by industry as an imposition, but it is also a stimulus to action, to be more energy efficient ...and with good reason
Unidrive with DeviceNet simplifies cable winder
A despatch-winding machine, recently installed at BICC General UK Cables in Wrexham, features a new approach to the design of the drive control system.
Based approximately 50 kms from Porto, in northern Portugal, Incotex has been producing cloth for use in the manufacture of household textiles since it was founded in 1970.
The company is successful in its markets and operates a demanding 24 hour production schedule.
Recently, this schedule was threatened by a problem with a 25 year old Sclafhorst yarn winding machine.
The machine was supposed to wind 29,950 metres of yarn (over three times height of Mount Everest) onto a 7ft wide roll at a constant speed of 600 metres/min.
Unfortunately the speed control system on the machine, consisting of an electric motor and a hydraulic speed variator, was unable to maintain the linear speed of the roll constant from its minimum diameter to its maximum (when, incidentally, it would weigh some 415 Kgs).
Further reading
Big savings on fan running costs with zero outlay!
Owens Corning is achieving annual energy savings of over £150,000 on the operation of three large fans, with zero capital outlay, thanks to Control Techniques and Hyder Energy Services
Ski innovation helped by versatile digital drives
Mantec in Italy has developed a form-grinder which uses Control Techniques Unidrives and Unimotors to drive 4 servo axes that combine to grind tiny profiles into skis.
Form-grinder which uses Control Techniques drives
Mantec, a high tech company near Milan, has developed a form-grinder which uses Control Techniques Unidrives and Unimotors to drive 4 servo axes that combine to grind tiny profiles into skis
The winding operation would commence at 600 metres/min but, as the roll diameter grew, its speed would increase also.
Sometimes the linear speed would reach 700 metres/min, a point at which point the operator would have to intervene and slow the machine to prevent physical damage.
The outcome of this was lost production.
Moreover, even when the speed did not reach a critical physical point, the fact that it was not constant meant that the tension of the yarn was affected and this impacted negatively on the final quality of the process.
Joaquim Alves, Incotex's Technical Support Manager, was aware that he could replace the existing electric motor/hydraulic variator drive system with a similar, but more up-to date one.
However, the cost was very high and he was not totally convinced that this method of control was now the appropriate one for the machine.
He called in Harker Sumner, a specialist automation and control company which has been Control Techniques' distributor in Portugal for 16 years.
After surveying the machine and studying it in actual operation, Harker Sumner formulated a modern, state-of the art, closed loop control system for the winder.
This was immediately attractive to Incotex, not least because its cost was just one third of that required to replace the original drive system.
The closed loop system is based around a Control Techniques Unidrive, with a UD70 soft logic options module and a flux vector motor.
Other elements include a 500ppr encoder on the jockey roller, over which the yarn passes on its way to the main roll, and a 1024ppr encoder on the flux vector motor.
The Unidrive is directly interfaced to the powerful, 32-bit floating-point, UD70 co-processor which runs application specific software, written off-line by Harker Sumner.
The software was developed using Control Techniques Drive Programming Language (DPL).
This is a high level language that allows the programmer access to all the drive firmware parameters, all communications functions and the full range of mathematical, control and logic functions normally available in a high level language.
The ability to employ this language and combine it with a 32 bit architecture are the reasons why the UD70 is ideally suited to undertaking the mathematically complex drive related functions (such as calculating roll diameters and associated linear speeds) which are routinely encountered in winding operations.
While software engineers were preparing the UD70 control program the physical elements of the drive system were being installed on the machine.
When this was complete the program was brought to site and downloaded into the UD70 via a portable computer.
The whole process of downloading and then getting the machine to work with the software took just two hours.
The benefits of fitting the new drive system were immediately obvious.
The operation of the machine is now totally consistent and transparent to the operator, with the linear winding speed of the yarn remaining at 600 metres/min irrespective of the roll diameter.
As the yarn is wound onto the roll and its diameter increases the rotational speed is reduced accordingly.
This is accomplished by the UD70 software: it calculates the required motor RPM based upon the linear speed set point and stored data giving roll diameter and the gear box ratio.
The operator is able to observe this process as it happens via the visual display on the front of the Unidrive.
Previously, in any 24 hour period, Incotex was able to produce 15 rolls of fully wound yarn.
The greater flexibility and consistency provided by the Control Techniques control system has meant that the company can now produce 3 extra rolls during the same period, an increase in output of 20%.
An added benefit is that, with the force on the roll now held constant, the yarn is more tightly wound and this has positive implications for the manufacturing process further down the line.
Joaquim Alves is delighted with the outcome of the project.
He calculates that with the increased output the pay-back period for the drive system will be 18 months.
"Any future drive applications undertaken in this company will be with Control Techniques," he says.
"Our working time is now optimised, and there have been no problems, whatsoever, with the new equipment. Request a free brochure from Control Techniques ...
We are also pleased because the new Control Techniques drive system has made our working environment quieter.".
• Control Techniques: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
