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FirstOpNet DCS system for Cold Rolling Mills with adaptive control

FirstOpNet DCS system for Cold Rolling Mills with adaptive control

The DCS control system designed by First Control is based on modern control technology with self-tuning control to achieve maximal production performance. Experience from several installations shows that the self-tuning regulator reduces the thickness deviations by 50-75% compared to conventional


Control package includes the following functions

  • Self-tuning thickness FB control
  • Self-tuning feedforward control
  • Self-tuning mass flow control
  • Automatic AGC start-up
  • Thick end disturbance reduction
  • Adaptive control of hydraulics
  • Mill safety protection
  • Mill setup
  • Thickness gauge setup
  • Thickness profile measurement
  • FirstOpNet operator interface
  • OPC system communication
  • Production quality supervision
  • Rolling statistics
  • General automation

Production result in an old mill

The diagram shows the improvements in strip thickness using First Control’s self-tuning regulator in an old Sendzimir Mill at Outokumpu Stainless in Långshyttan Sweden.

Each point in the diagram shows the average standard deviation in strip thickness during one month of production.
The upgrading of the mill was done in steps during about 3 years. The improvment after each new self-tuning function is seen as jumps in the performance curve above. In the end, the strip accuracy achieved (0.0005 mm) was better than most new mills.
The large improvement in strip quality meant that the company could increase their sales and the owner invested in two completely new mills which are also controlled by First Control’s self-tuning regulators.

Production result in a new mill

The table shows the production results in a recent Mitsubushi-Hitachi mill at Outokumpu stainless in Långshyttan, Sweden

The table shows the average standard deviation (s) for all production during. The quality measures are computed from unfiltered data during the whole rolling, from start to stop of the pass.
The operator is free to select the control strategy in each pass:

  • Self-tuning FB and FF control
  • Self-tuning mass flow control with FF
  • Self-tuning FB without FF control
  • Self-tuning Massflow without FF control