.FeedDriveLibrary.HelpBlocks.TimeTable_Periodic

Information

This block generates an output signal by linear interpolation in a table. The time points and function values are stored in a matrix table[i,j], where the first column table[:,1] contains the time points and the second column contains the data to be interpolated. The table interpolation has the following proporties:

• The time points need to be monotonically increasing.
• Discontinuities are allowed, by providing the same time point twice in the table.
• Values outside of the table range, are computed by extrapolation through the last or first two points of the table.
• If the table has only one row, no interpolation is performed and the function value is just returned independently of the actual time instant.
• Via parameters startTime and offset the curve defined by the table can be shifted both in time and in the ordinate value.
• The table is implemented in a numerically sound way by generating time events at interval boundaries, in order to not integrate over a discontinuous or not differentiable points.

Example:

   table = [0  0
            1  0
            1  1
            2  4
            3  9
            4 16]
If, e.g., time = 1.0, the output y =  0.0 (before event), 1.0 (after event)
    e.g., time = 1.5, the output y =  2.5,
    e.g., time = 2.0, the output y =  4.0,
    e.g., time = 5.0, the output y = 23.0 (i.e., extrapolation).

Revisions

Release Notes:

• Oct. 21, 2002 by Christian Schweiger:
  Corrected interface from

      parameter Real table[:, :]=[0, 0; 1, 1; 2, 4];
  

  to

      parameter Real table[:, 2]=[0, 0; 1, 1; 2, 4];
  

• Nov. 7, 1999 by Martin Otter:
  Realized.