Avoid StateSpaceModel SystemsModelDelay time delay problem in MMA 10.0.2.0?

Questions
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1

hi,
I was trying to run the example in SystemsModelDelay->Basic Examples:
“A time-delay state-space model created from delay differential equations:”

In[1]:= StateSpaceModel[{x'[t] == x[t] - 2 x[t - T] + u[t]},
 {x[t]}, {u[t]}, {3 x[t - T]}, t]

And I’m getting errors preventing evaluation (see below). My platform is Mac OSX x86 (32-bit, 64 bit kernel) and the Version Number is 10.0.2.0. I’ve tried running similar equations and get similar errors. Is there a bug in this release, and how can I upgrade/fix it?

During evaluation of In[1]:= Set::shape: Lists {Control`RecastDEquationsDump`additionalStateEqns,Control`RecastDEquationsDump`outputsNew,Control`RecastDEquationsDump`states} and Control`RecastDEquationsDump`accommodateOutputDynamics[If[-2 T==0,Continuous,DelayedContinuous],t,{},{u},t] are not the same shape. >>

During evaluation of In[1]:= $RecursionLimit::reclim: Recursion depth of 1024 exceeded. >>

During evaluation of In[1]:= $RecursionLimit::reclim: Recursion depth of 1024 exceeded. >>

During evaluation of In[1]:= Set::shape: Lists {Control`RecastDEquationsDump`inputsNew,Control`RecastDEquationsDump`controlDTerms} and Control`RecastDEquationsDump`siftedControlTerms[If[-2 T==0,Continuous,DelayedContinuous],{u},{},t] are not the same shape. >>

During evaluation of In[1]:= Flatten::normal: Nonatomic expression expected at position 1 in Flatten[0]. >>

During evaluation of In[1]:= StateSpaceModel::invrlzn: Cannot construct a state-space realization for the system of equations {(x^\[Prime])[t]==u[t]+x[t]-2 x[t-T]} with variables {{x[t],0}}, inputs {{u[t],0}}, and outputs {3 x[t-T]}. >>

Out[1]= StateSpaceModel[{Derivative[1][x][t] == 
   u[t] + x[t] - 2 x[t - T]}, {x[t]}, {u[t]}, {3 x[t - T]}, t]
2

This appears to be an old issue which was fixed sometime around version 10.3.

What you should do depends on how you get your license. If your license is from a university or a company, I would contact whoever is in charge of software purchasing or maintaining the license. They probably have an answer for you.

If this is a personal license, I would contact Wolfram Technical Support by email (support@wolfram.com) asking if there is a workaround that can be done for the problem.

3

Great, thank you. I will see if I can get upgraded to 10.3+.