Lotka Volterra fishing problem

This problem was set up as a simple benchmark problem. Despite of its simple structure, the optimal solution contains a singular arcs, making the Lotka Volterra fishing problem an ideal candidate for benchmarking of algorithms.

Model dimensions and properties

The model has the following dimensions:

$\begin{array}{rcl} n_x &=& 3\\ n_z &=& 0\\ n_u &=& 1\\ n_p &=& 0\\ n_c &=& 0\\ n_{r^\mathrm{i}} &=& 0\\ n_{r^\mathrm{e}} &=& 3 \end{array}$

It is thus an ODE model. The interior point equality conditions fix the initial values of the differential states.