Adaptive techniques

The diagram shows the improvement in an old cold rolling mill when First Control introduced the adaptive techniques. Each point in the diagram shows the average value of max strip thickness deviations during one month. The final result is considerably better than what can be achieved today in completely new mills with conventional  model based control.

The self-tuning regulators are based on techniques developed by researchers at Lund Institute of Technology under the leadership of the legendary Professor Karl Johan Åström. The role of First Control has been to make the general self-tuning regulators robust enough for industrial use and understandable for normal engineers not familiar with adaptive control.

The improvements First Control has achieved in metallurgical processes are remarkable and has been in the area of 50-75% less variations in controlled variables compared to conventional non-adaptive techniques. The same improvements can be expected in other areas.  To this date there are more than 500 self-tuning controllers installed in various processes.

Real-time simulation with MODELICA

In the example above we are using a dynamical system of second order with a time delay which is controled by a simple PID regulator. To make it more realistic, a measurement noise is added to the measurement value. The sytem creates a graphical object ”Modelica” with inputs and outputs, see in the middle above, The signal values are shown in curves selectable on-line, as the step response displayed above,

Any process model created with the Modelica language can be loaded to the XC05 unit for real-time simulation.  The model may run at the same time as the unit is controlling a physical process. The user can thus  verify his control strategy with the model before he applies it to the real process.  He can also construct his own control object as long as it is expressed  in the Modelica language.

For instance a  Boiler model with about 100 internal states could be run without any problems.

Graphical programming on-line

All programming and configuration is controlled by a project tree which describes all running data.

First Control introduces a new principle of programming control systems that will heavily reduce engineering time. The principle is based on a target system where you immediately see the effects of what you are doing. The target system may be a physical target as an  XC05 or an emulated version installed on your PC.

At the same moment you open an application program or a configuration page, it is updated from the target system. The programming you make will be directly alive in the target and the documentation is updated automatically.  Every change you make will in principle be alive momentarily in the target without disturbing  the running functions.

Automatic code generation

In the example above, which describes a page with an adaptive regulator, the objects are sorted and will be executed from left to right in the order decided by the sequencing algorithm.

XC05 is programmed graphically in a way that is much simpler than conventional PLC programming –  and much safer. You select objects from the local function library and connect them together with the mouse pointer into a control scheme. All objects are then automatically sorted in a correct execution  order depending how they are connected to each other.

Logical connection errors and impossible (non-causal) solutions are automatically blocked by the automatic sequencer.