MathGroup Archive 2003

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Re: Re: ricatti & set of ODE solution.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg41737] Re: [mg41716] Re: [mg41692] Re: [mg41676] ricatti & set of ODE solution.
  • From: Arda Kutlu <e130559 at metu.edu.tr>
  • Date: Tue, 3 Jun 2003 07:13:19 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

> I'm still not understanding the nature of your system. It sounds as
if 
> you have a system of 1st order differential equations with initial 
> values at t=0 (?) and final values at t=2. That kind of problem is 
> simply not well posed. Or do you have second order equations?

allright. here is the question. ricatti part only.

R=r*IdentityMatrix[4] 
r is a value to be found or chosen.

Q=q*IdentityMatrix[4]
q is also a value to be chosen.

ricatti equation.
M(K) --> matrix of K 4x4 
Mprime(K) is the time derivative of K.

Mprime(K)= -M(K).Transpose[A].M(K)-Q+M(K).B.R.Transpose[B].M(K)
where 
A={{0,1,0,0},
      {0,0,0,0},
      {0,0,0,1},
      {0,0,0,0}}

B={{0,0},
      {0.116, (-0.116)},
      {0, 0}, 
      {(-0.116), 1.366}}

first order nonlinear differential set.
and boundary .

K(2)=H
value of K at 2 seconds when the proceses ends. 

H=h*IdentityMatrix[4]
again h is a value to be chosen.

As you can see here i only know/chose the final value of K. And I need
to find K. Possible numerical solution to this problem is shooting
method, but due to the last term in ricatti the ode is non-linear and
the method doesn't work.
I am supposed to find values of K in 0 2 seconds interval with a small
increment. Or better K(t).

it is well possed. Just the problem is i don't know the initial values
but final values.

These were for ricatti solution.
If u are interested in optimization or this problem i can send you the
problem and my solution (my solution using the other way - set of odes
-with semi-numerical solution, symbolic solution looks like not
possible with today's pc).


  • Prev by Date: Re: Low pass filtering
  • Next by Date: RE: Re: help converting mathtype to mathematica
  • Previous by thread: Re: Re: ricatti & set of ODE solution.
  • Next by thread: Re: Re: Re: ricatti & set of ODE solution.