Using the Constraint Satisfaction Function  

This task explains how to solve a set of constraints using operators, functions and measures. This scenario can be run from any document. 
  • The syntax of this feature is the same as the one of the set of equations. 
  • Note that the constraint satisfaction capabilities require the PEO product.

  1. Create a pad with a rectangular base.

  2. Use the Formula editor to create a Volume parameter.

  3. From the Start > Knowledgeware menu, access the Product Engineering Optimizer workbench.

  4. Click the Constraint Satisfaction icon (). In the first dialog box which is displayed, enter the name of the relation, and a comment (optional). Click OK.

  5. Enter the set of equations below into the edition box:

    Volume==smartVolume (PartBody\Pad.1 );
    PartBody\Pad.1\FirstLimit\Length >= 1mm;
    PartBody\Pad.1\FirstLimit\Length <= 1000mm

Now, your editor looks like this:

 
  1. Click the Parse arrow (). At this step the editor identifies the variables of the set of constraints and puts them as Unknown parameters.

     
  • Before solving, select the parameters that will be considered as input (constant) and the parameters that will be considered as variables by the solver.
  • The value of the input parameters must be set to the desired values.
  1. Select the Volume parameter and use the arrow to move it to the Constant parameters column.

  2. Change the value of the Volume parameter. To do so, click twice (slowly ) inside the Value cell and set the value to 0.003 M3. Click Solve. A message is displayed indicating that the solving operation was successful.

The pad height is modified by the constraints satisfaction solver to match the given volume (0.003 M3).
  1. This process can be reversed: The input parameters can be transferred to outputs and vice-versa using the Switch input/output arrow ().

It is now possible to change the value of the Pad height and obtain the volume as a result.

 
  • A constraint satisfaction feature is not a conventional relation feature (like rules, checks, and formulas). It is an asynchronous feature (as the optimization.) Although input and output parameters are defined, changing an input outside the Constraint satisfaction editor does not trigger the solving process.
  • Like sets of equations and unlike optimization, constraint satisfaction issues an "unresolved system" warning if the solver is unable to satisfy all the equations and inequations. 
  • If a set of constraints cannot be satisfied, you can relax the equality constraints by using a double inequality.

Volume+epsilon<=smartVolume (PartBody\Pad.1 );
Volume-epsilon>=smartVolume (PartBody\Pad.1 );
PartBody\Pad.1\FirstLimit\Length >= 1mm;
PartBody\Pad.1\FirstLimit\Length <= 1000mm;

Using the Constraint Satisfaction Editor