mpt_prepareDU

MPT_PREPAREDU Extends system and problem matrices to deal with deltaU constraints

 [sysStruct, probStruct] = mpt_prepareDU(sysStruct, probStruct)

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 DESCRIPTION
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 Extends system and problem matrices to deal with deltaU constraints in
 closed-loop

 Introduce new state vector z(k) = [x(k) u(k-1)]
 The new input is now delta u, i.e., du(k)=u(k)-u(k-1).
 Therefore the state update equation can now be written as:

         [A B]         [B] 
 z(k+1)= [0 I] z(k) +  [I] du(k)

 internal function

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 INPUT
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 sysStruct   - system definition
 probStruct  - problem definition

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 OUTPUT                                                                                                    
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 sysStruct   - system definition with tracking
 probStruct  - problem definition with tracking
      .Rdu   - additional field in probStruct; weight on the delta u; 
               by default, this is identical to the weight on u;