Aluminum Mill Finishing Mill Control Replacement

IPACT received an order to replace the finishing mill control system on a three stand aluminum hot rolling mill in South Korea.  The control system consisted of

• high speed hydraulic cylinder control
• screwdown control
• inter-stand tension control
• positive and negative roll bending
• automatic gauge control
• adaptive threading
• metal-in-stand
• mill zeroing
• mill setup
• modulus curve generation
• process data collection
• tailout and threading control. 

The system had to be fully tested with simulation, including the integration with the mill level 2 computer and existing PLCs and HMIs.  The new control was to be installed during a planned 6 day outage.   

The system was developed and 100 percent simulated at IPACT’s facility in Valparaiso, Indiana.  Because of the simulation methodology used by IPACT, we were able to successfully commission the new system during the six day outage, allowing the facility to start up as planned.  Complete commissioning with fine tuning and field requested changes totaled three weeks, during which time the hot mill moved up the planned learning curve and back to 100 percent production level.  Due to cabinet and wiring considerations, the old system hardware was completely demolished during the outage, hence doing a shadowed "phase-in" approach was not an option.  The simulation allowed the software to work successfully on the first coil through the mill.

The project went in on time and on budget, and after the outage the system came up as planned, with no major delays or problems.  It has been functioning within its specifications since that time,and has achieved and outstanding 30 percent increase in productivity.  The project is acknowledged by all who were involved as a success.  And it was accomplished with the implementation being done many thousands of miles away, and commissioned on a single mill outage.  IPACT had only one opportunity and had to “get it right the first time”.

The system was tested using a variety of simulation techniques.  Some parts of the simulation run at extremely high speed in order to simulate such things as cylinder positions and roll forces.  Others run more slowly to simulate mill sequencing.  Because of IPACT’s hardware resources, we were able to stage the VME Control target, the GE 90/70 sequencing PLC, and the supervisory OpenVMS Alpha system as part of the simulation and testing.  Running the integrated system against a simulation provides a level of testing that is unsurpassed and our commissioning record for these systems bears that out.

The actual control system was implemented using VMICs I/OWorks with two target VME processors.  Changes were made in the GE 90/70 mill sequencing to accommodate the new control system.  The VME, GE 90/70, and the OpenVMS Alpha were all integrated using VMIC’s reflective memory ring.  An IPACT finishing mill setup model running in the OpenVMS supervisory system provided the mill setup using the reflective memory ring to the GE 90/70 and the AGC system.  Feedback data received through the reflective memory from the AGC system was used to train the finishing mill setup model.  It was also used to create a gauge report (gauge average and standard deviation per meter of strip).

Products

GE FANUC Reflective memory

GE 90/70 PLC

Alpha OpenVMS

VMIC IOWorks

Integrated Process Automation & Control Technologies