Simulating Existing Circuit Diagrams

Included with the FluidSIM installation disks are a number of working circuit diagrams.

Among others, these are circuit diagrams as part of the learning material and will be discussed in the following workbooks “Hydraulics Basic Level TP 501”, “Hydraulics Advanced Level TP 502”, “Electrohydraulics Basic Level TP 601” and “Electrohydraulics Advanced Level TP 602”.

The circuit library of the FluidSIM student version contains only circuits of the basic levels.

These circuit diagrams can be opened and simulated with FluidSIM as follows:

            Click on  or choose Circuit Preview in the File menu.

Preview windows containing overviews of existing circuit diagrams should appear:

A preview window displays the circuit diagrams of a specific directory in alphabetical order accompanied by a miniature representation. The name of the current directory is shown in the title bar of the preview window; the files of the FluidSIM circuit diagrams contain the extension ct.

By double clicking a directory icon you go down to the respective subdirectory.

  In the ct subdirectory of the fl_sim_h installation additional subdirectories for diagrams can be created. These subdirectories are automatically found by FluidSIM, and extra directory icons are created for them.

            Open the circuit diagram demo1.ct by double clicking on its miniature representation.

Circuit diagrams can also be opened using the File Selector dialog box. By clicking on  or choosing Open... under the File menu, the File Selector dialog box will appear, in which a circuit diagram can be opened by double clicking on its filename.

In either case the circuit diagram is opened and displayed in a new window:

            Click on  or on Execute- Start, or press the key F9.

FluidSIM switches to the simulation mode and starts the simulation of the circuit diagram. When in the simulation mode, the mouse cursor changes to a hand .

During the simulation FluidSIM first calculates all electrical parameters. pressure is calculated.

This step is followed by formulating a model of the hydraulic circuit and, based on this model, a continuous distribution for flow and pressure will be calculated for the circuit.

Formulating models is demanding. Depending on a circuit's complexity and the computer's power, a circuit's simulation may take considerable time. Likewise, the real-time completion of the following dynamic simulation cannot always be guaranteed. The percentage of real-time achieved is shown in FluidSIM in the status bar at the lower edge of the main window.

As soon as the results are available, the connection lines will be shown in color and the cylinders extend in sequence:

The colors of the connection lines have the following meaning:

Colors of the electrical and hydraulic lines

You can define your own mapping between colors and state values under Options- Simulation.... The varying thicknesses of the dark red connection lines corresponds to the pressure as related to the maximum pressure. FluidSIM distinguishes between three thicknesses of line:

Thickness of the dark red hydraulic connection lines

The exact numeric values for pressures, flow rates, voltages, and currents are displayed on the attached measuring instruments. Section Displaying Quantity Values describes how you may go about getting values for all or only selected variables on the circuit diagram, even when measuring instruments are not present.

  Simulation in FluidSIM is based on physical models whose components match those components found in the Festo Didactic GmbH & Co. KG equipment set. Therefore, calculated values should closely match measured values. When comparing results, please acknowledge the fact that in practice, measurements can be subject to large fluctuations. The reasons for differences range from component tolerances to oil temperature.

The calculation of variables forms the basis for an exact, real-time proportional animation of the cylinder.

Real-time-proportionality guarantees the following property: If in reality a cylinder moves twice as fast as another one, the relationship between these two components is shown in the animation. In other words, the real-time relationship remains unaltered.

Manually operated valves and switches, found in the circuit diagram, can be switched by clicking on them with the mouse:

            Move the mouse cursor to the left switch.

The mouse cursor becomes a hand with index finger  and indicates that the switch may be flipped.

            Click on the switch.

When you click on a manually operated switch, its real behavior is simulated. In this example the clicked switch becomes closed and recalculation begins automatically. Following the calculation, the new pressure and flow values are indicated and the cylinders retract.

  The switching of a component is only possible when a simulation is running () or when a simulation has been set to pause ().

In the event that you would like to simulate another circuit diagram, it is not necessary to close the open one. FluidSIM allows you to have several circuits open at one time. Furthermore, FluidSIM is able to simulate multiple circuits simultaneously.

            Click on  or Execute- Stop to switch the current circuit from Simulation Mode to Edit Mode.

  By switching a circuit from Simulation Mode to Edit Mode, all components will automatically be set back to their “normal status”. In particular, switches are set to their original position, valves switch to their normal position, cylinder pistons are set to their previous position, and all values calculated are deleted.

  By clicking on  (alternative: Execute- Pause or F8) you can switch from Edit Mode to Simulation Mode without starting the simulation. This feature is useful, if components shall be set before the simulation is started.

Related Topic

Additional Simulation Functions