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How to convert back to transfer function in Maple?


using DiffEquation can transform to diff sys, but if convert back to transfer function, How is it?

with(DynamicSystems):
sys2 := DiffEquation(sqrt(1-a^2)/(1-a/s));
PrintSystem(sys2);

de := [Diff(x1(t),t) = a*x1(t)+a*u1(t), y1(t) = sqrt(1-a^2)*x1(t)+sqrt(1-a^2)*u1(t)];

Solution

  • I'm not sure that I understand the phrasing of your question. Is this the sort of thing that you want?

    with(DynamicSystems):
    
    sys2 := DiffEquation(sqrt(1-a^2)/(1-a/s)):
    
    sys2:-de;
    
            [                               
            [ d                             
            [--- x1(t) = a x1(t) + a u1(t), 
            [ dt                            
    
                              (1/2)                 (1/2)      ]
                      /     2\              /     2\           ]
              y1(t) = \1 - a /      x1(t) + \1 - a /      u1(t)]
                                                               ]
    
    K:=TransferFunction(sys2):
    
    K:-tf;
    
                      [         (1/2)         (1/2)  ]
                      [  (a + 1)      (-a + 1)      s]
                      [- ----------------------------]
                      [             -s + a           ]
    
    expand(combine(K:-tf[1,1])) assuming a>0;
    
                                        (1/2)  
                                /     2\       
                                \1 - a /      s
                              - ---------------
                                    -s + a