  This paper proposes a new time-scaling approach for computational optimal
control of a distributed parameter system governed by the Saint-Venant PDEs. We
propose the time-scaling approach, which can change a uniform time partition to
a nonuniform one. We also derive the gradient formulas by using the variational
method. Then the method of lines (MOL) is applied to compute the Saint-Venant
PDEs after implementing the time-scaling transformation and the associate
costate PDEs. Finally, we compare the optimization results using the proposed
time-scaling approach with the one not using it. The simulation result
demonstrates the effectiveness of the proposed time-scaling method.
