A new set of necessary conditions are presented for solutions to optimal programming problems with a state variable inequality constraint (SVIC). On a constrained arc, the dimension of the state space is reduced, and the influence functions associated with this reduced state space are shown to be unique and continuous across junctures with unconstrained arcs. It is also shown that unconstrained arcs must satisfy certain constraints at both ends of a constrained arc and that explicit use of this fact must be made if the SVIC is adjoined directly to the performance index. ^EVERAL investigators have discussed necessary condi^ tions for solutions to optimal programming problems with a state variable inequality constraint.15 Most of these investigators recognized that, at a point where the system enters onto a constrained arc (an entry point), all feasible unconstrained arcs passing through this point must satisfy certain tangency constraints, namely, these arcs must have zero values of the state variable constraint function and all of its time derivatives that do not involve the control variable (say p-1 of them). Since control of the constraint function is realized only by changing its pth time derivative, no finite control will keep the system on the constraint boundary if the path reaching the constraint boundary does not meet these tangency constraints. In this paper, we point out that the tangency constraints also apply to the unconstrained arc at a point where the system leaves a constrained arc (an exit point). These exitpoint tangency constraints are satisfied automatically if the necessary conditions of Ref. 3 are used. However, if one uses the direct adjoining approach of Ref. 4, we shall show that explicit use must be made of the tangency constraints at both ends.
Read full abstract