Casas, EduardoTröltzsch, Fredi2021-12-172021-12-172002-02-012197-8085https://depositonce.tu-berlin.de/handle/11303/15459http://dx.doi.org/10.14279/depositonce-14232We consider the finite-element approximation of a distributed optimal control problem governed by a semilinear elliptic partial differential equation, where pointwise constraints on the control are given. We prove the existence of local approximate solutions converging to a given local reference solution. Moreover, we derive error estimates for local solutions in the maximum norm.en510 Mathematikoptimal control problems involving partial differential equationsproblems involving partial differential equationsmethods based on necessary conditionsoptimization and variational techniquesResearch Paper