Optimalswitchingandimpulsecontrolsforadistributedparametersystemsareconsidered.Weprovethatthevaluefunctionsu_u(·)ofapproximatingproblemsapproachtothevaluefunctionu(·)oftheoriginalproblem,whileu_u(·)istheuniqueviscositysolutionofthecorrespondingHamilton-Jacobi-Bellmansystem.Wealsoconstructanoptimalcontrolfortheoriginalproblemviathevaluefunctionu(·).
