  In this paper, a model of a pair of Dubins vehicles is considered. The
vehicles move from an initial position and orientation to final position and
orientation. A long the motion, the two vehicles are not allowed to collide
however the two vehicles cant to far each other. The optimal control of the
vehicle is found using the Pontryagins Maximum Principle (PMP). This PMP leads
to a Hamiltonian system consisting of a system of differential equation and its
adjoint. The originally differential equation has initial and final condition
but the adjoint system doesn't have one. The classical difficulty is solved
numerically by the greatest gradient descent method. Some simulation results
are presented in this paper.
