.Modelica_LinearSystems2.UsersGuide.ReleaseNotes.Version_2_3

Information

This release is backward compatible to the previous version 2.2. It contains the following main improvements (and several minor ones):

• New package "Modelica_LinearSystems2.ModelAnalysis" that contains several functions to linearize a model and perform a selected linear analysis operation, like plotting of poles, zeros or transfer functions. This allows a user to conveniently utilize the analysis functions by basically only providing the name of a Modelica model.
  
• New plot functions in package "Modelica_LinearSystems2.Utilities.Plot" to plot parameterized curvces, as well as to plot a root locus of a model, by linearizing a model for a set of selected parameter values.
  
• A new function "Modelica_LinearSystems2.Utilities.Import.linearize2" to (a) set parameters of a model, (b) linearize the model and (c) return a StateSpace object (the existing Import.linearize function does only allow to linearize around the default parameter settings and the function returns the A,B,C,D matrices and therefore it is not possible to utilize directly the many functions operating on StateSpace objects).
  
• The layout of the output of function Modelica_LinearSystems2.StateSpace.Analysis.analysis has been improved.
  
• The analysis functions have been corrected, so that they do not trigger an error, if inputs or outputs are not present. Instead, analysis operations that require inputs and/or outputs are not executed.

For versionBuild=4 (March 25, 2013), several bug fixes have been performed. In particular:

• Several issues with limiting cases (no states and/or no inputs and/or no outputs) have been fixed for the analysis functions (#1050, #1051, #1052).
• Some wrong Modelica constructs regarding the "operator" language keyword have been fixed (#908, #909).
• Improved and corrected the algorithm to compute invariant zeros, so that large zeros are treated as "infinite" (and are therefore removed). Hereby also corrected an error that set infinite zeros to "zero" (and not to "infinite"), resulting in a wrong system description. As a result the conversion from a StateSpace to a ZerosAndPoles object is corrected/improved, in case large zeros are present.
• Improved efficiency of some analysis functions so that unnecessary translations of models are removed (and the previous translated model is utilized again).
• Fixed error in Modelica_LinearSystems2.Examples.StateSpace.designKalmanFilter since design matrices Q and R had been declared with fixed dimensions that run only for the default example case.
• Improved numerical efficiency and reliability for StateSpace.Plot.BodeMIMO (originally, the state space system was transformed to a zeros and poles object then to a transfer function and then the Bode plot of the transfer function was generated. This was changed to only transform to a zeros and poles object and plot the Bode plot of this object).
• Corrected minor bug in Modelica_LinearSystems2.ZerosAndPoles.Analysis.evaluate that resulted in some cases in a wrong division by zero.
• Fixed bug in isControllableSISO and isDetectableSISO (if all eigenvalues are controllable or observable, the eigenvalue LAPACK function was called with a (0,0) matrix resulting in an error).