The paper deals with an optimal control problem, namely a bond graph approach, from the problem definition up to the simulation stage. The main role of this article is to supply an alternative approach for solving optimal control problems, both at the representation level and the numerical resolution level. The work presented in this paper, although it concerns optimal control, applies this effort at different levels. The framework of this research belongs to a more general task of dimensioning mechatronic systems. The optimal control implementation constitutes one of the phases that has to be overcome, in order to advance in the direction of the virtual prototyping of these systems. The class of the problem concerns linear time invariant single input single output systems, where the performance index corresponds to dissipative energy. The control variable is taken into account as dissipative loss also, using a weighting factor.