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<math>
<math>
\begin{array}{llcl}
\begin{array}{llcl}
  \displaystyle \min_{x, u} &x_2(t_f)  \\[1.5ex]
  \displaystyle \min_{x, u} & x_2(t_f)  \\[1.5ex]
  \mbox{s.t.} & \dot{x}_1 & = &  u, \\
  \mbox{s.t.} & \dot{x}_1 & = &  u, \\
  & \dot{x}_2 & = & x_1 (1+u^2)^{1/2},  \\
  & \dot{x}_2 & = & x_1 (1+u^2)^{1/2},  \\
& \dot{x}_3 & = & (1+u^2)^{1/2), \\
& \dot{x}_3 & = & (1+u^2)^{1/2), \\
  & x(t_0) &=& (a,0,0)^T, \\
  & x(t_0) &=& (a,0,0)^T, \\
& x_1(t_f) &=& b, \\
& x_3(t_f) &=& Lp, \\
& x(t) &\in& [0,10], \\
& u(t) &\in&  [-10,20].
\end{array}  
\end{array}  
</math>
</math>

Revision as of 17:41, 5 May 2016

Hanging chain problem
State dimension: 1
Differential states: 2
Discrete control functions: 1
Interior point equalities: 2

The Hanging chain problem is concerned with finding a chain (of uniform density) of length L suspendend between two points a,b with minimal potential energy. (Problem taken from the COPS library)


Mathematical formulation

The problem is given by

Failed to parse (unknown function "\begin{array}"): {\displaystyle \begin{array}{llcl} \displaystyle \min_{x, u} & x_2(t_f) \\[1.5ex] \mbox{s.t.} & \dot{x}_1 & = & u, \\ & \dot{x}_2 & = & x_1 (1+u^2)^{1/2}, \\ & \dot{x}_3 & = & (1+u^2)^{1/2), \\ & x(t_0) &=& (a,0,0)^T, \\ \end{array} }

Parameters

In this model the parameters used are \begin{array}{rcl} [t_0, t_f] &=& [0, 1],\\ (a,b) &=& (0.4, 0.2),\\ Lp &=& 4. \end{array}

Source Code

Model descriptions are available in