ABB IndustrialIT

Interstand Dimension Control, IDCABB IndustrialIT

Interstand Dimension Control, IDC

- takes your profile mill into a new dimension

ABB Automation TechnologiesHot Rolling MillsSE-721 67 Västerås, SWEDENTel +46-21 34 00 00Fax: +46 21 18 17 24www.abb.com/metals

AC800M AC800

Ethernet TCP/IP / UDP

AC450

MP200 Alien

Operate ITUG tool

TouchPanel

U Pad

WLANGateway

Web server

U Gauge

HPC / VIPProfiBus / Discret I/OMB300

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Traditional rolling methods in rod andbar mills are based on minimum tensioncontrol and loop control. These methodsare not sufficient to meet the increasingmarket demands on quality and tolerance.

Minimum Tension Control, derived from tor-que measurements, freezes the speed relation-ships to the front end demands by assuming a constant dimension and temperature profilealong the bar. The dimensional tolerances ofbillets normally lie in the range of ± 2 %. Thetemperature fluctuations from head to tail canbe as much as 20 to 50 °C, depending on thefurnace condition and the temperature dropbetween the furnace and the first mill stand,which results in a colder tail end. In reality,these kinds of variations require Loop Controlto take care of the mass flow variation. However, Loop Control cannot control thespread in the roll gap that causes variations in the dimensions, thus affecting the final tolerances.

IDC provides a tool for the continuousimprovement and control of the rollingprocess and especially the tolerancesfrom head to tail of round long products.

The IDC concept is based on the latest deve-lopments in process control and wireless com-munication and consists of:- The U Gauge sensor for on-line measure-

ments from head to tail.- The TCP/IP gateway with web server and

interface for external log.- The UG Tool, a PC-based operator and

maintenance interface.- The U Pads, specially developed user inter-

face for Pocket and Tablet PCs working with WLAN.

- The AC800M controller for communication and process control.

ABB IndustrialIT

Interstand Dimension Control- a concept for dimension control in profile mills• Closer tolerances• Higher yield and availability• Simplified operation

IDC concept

IDC is applicable to both old and new profilemills. It is easy to integrate IDC into an existingautomation system via a network or digital/analog I/O and it can be configured as a control or measuring system. Installation andcommissioning can take place during normalproduction.

IDC benefits

- Tighter tolerances head to tail.- Improved

Product qualityYieldAvailability

- Fast product and dimension changes- Early indication of abnormal mill

conditions- Operator tool to facilitate process

understanding- More consistent mill setup- Improved pass schedules

AC800M AC800

WLAN

U Pad

TouchPanel

Ethernet TCP/IP / UDP

AC450

MP200 Alien

Operate ITUG tool

TouchPanel

U Pad

WLAN

Gateway Web server

U Gauge

HPC / VIPProfiBus / Discret I/OMB300

U Gauge Sensor

The U Gauge is based on ABB’s patentedPulsed Eddy Current Technology and does nothave the limitations and drawbacks associatedwith conventional eddy current technology. Itensures that measurements are performedwith exceptionally high accuracy, also undervery difficult environmental conditions.

Key dimensions like height, width, area, resis-tivity, temperature and position are measuredin less than one millisecond. Height, width,position, temperature and gauge status arecommunicated via a TCP/IP gateway. Thegateway also includes a web server for dataand maintenance access via standard webbrowsers.

IDC Control

IDC controls the mass flow with the help ofwidth, height and speed control of the rolledmaterial. The width is controlled from head totail by means of interstand speed changes,while the height is compensated for roll wearbetween bars.

An Automatic Dimension Control package,ADC, is available as an option to the IDC con-cept. The ADC system is used after the finalmill stand to control the diameter and ovality.

Operator Interface

By observing the graphical displays, the rollersget early warnings of abnormalities in the rol-ling and can make the necessary adjustments.

It is essential that the human system interface,HSI, is designed with the user in mind andtherefore the IDC operator interfaces are divi-ded into two categories, one for the controlroom and main operator and the other for themill crew on the floor.

The main operator interface includes schedu-le, setup, analysis and maintenance displays.The mill crew interface can be mounted inlocal pulpits or be incorporated in hand-held Pocket and Tablet PC working with theWLAN.

Installed U Gauges Final U Gauge control configuration

Mill Configuration

A good strategy to implement IDC is first toinstall as many sensors as possible in the millin order to identify and find problems relatedto dimension, temperature and pass design.Experience has shown that problems arefound and can be addressed, resulting in areduced need for sensors after each stand.

The first step to investigate the mill could bedone by the customer himself by just installinga stand-alone Measuring system.

Later on, this system can be upgraded to aStand-alone Control system or an IntegratedControl System with the addition of the IDCcontrol system based on AC800M controllers.

Result

The final IDC control configuration can beoptimized to a few strategic positions in themill. With an optimized IDC control configura-tion as described above, a 20 mm round barcan be rolled to tolerances as below.