added: xs_0 and as_0 args in NonLinModelDAE constructor for initial guesses - #445
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It allows providing an initial guess (or warm-start) for the algebraic variable when simulating in open-loop. I will use the value of this argument for the upcoming closed-loop functionalities. This is particularly important for DAEs, I experienced it myself by playing with some famous DAE models.
franckgaga
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as_0 argument in NonLinModelDAE constructor as_0 argument in NonLinModelDAE constructor for initial guess
franckgaga
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as_0 argument in NonLinModelDAE constructor for initial guessxs_0 and as_0 argument in NonLinModelDAE constructor for initial guesses
franckgaga
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xs_0 and as_0 argument in NonLinModelDAE constructor for initial guessesxs_0 and as_0 args in NonLinModelDAE constructor for initial guesses
This is needed to reset the warm-starting strategy for `NonLinModelDAE` simulations. It's also now possible to send `x_0=nothing` to `sim!`. It will automatically compute the steady-state for the `LinModel` case.
It will reset the warm-start strategy before starting the loop for simulations of `NonLinModelDAE` plant models. Note that it also compute the steady-state for the `LinModel` case, but the results is overwritten by the next `setstate!(plant, x_0)` line.
It allows call like `setstate!(model, 0)`, or `sim!` with arguments `x_0=0` or `x̂_0=0`.
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## main #445 +/- ##
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+ Coverage 96.87% 96.92% +0.04%
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Files 28 28
Lines 6628 6656 +28
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+ Hits 6421 6451 +30
+ Misses 207 205 -2
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Warm-starting states and algebraic variable for DAEs
This PR introduces two new keyword arguments in
NonLinModelDAEconstructor:xs_0=zeros(nx): initial guess (optimization warm-start) for the states.as_0=zeros(na): initial guess (optimization warm-start) for the algebraic variables.It currently allows providing an initial guess for the the state and the algebraic variable when simulating in open-loop. These guesses are only used at the discrete time$k=0$ , that is, just after construction of $k=0$ , the values computed at the previous time steps are used since it is assumed that they represent better guesses. I will use the value of these two arguments for the upcoming closed-loop functionalities.
NonLinModelDAEor afterinitstate!(model::NonLinModelDAE, u, d)is called. AfterThis is particularly important for the algebraic variables of DAEs. I experienced it myself by playing with some famous DAE models. This PR covers the suggestion of @baggepinnen here.
The function
setstate!(obj, x)now supports scalarxIt allows call like
setstate!(model, 0), and alsosim!with arguments likex_0=0orx̂_0=0.