  We present a method for determining optimal modes of operation for
autonomously oscillating systems with uncertain parameters. In a typical
application of the method, a nonlinear dynamical system is optimized with
respect to an economic objective function with nonlinear programming methods,
and stability is guaranteed for all points in a robustness region around the
optimal point. The stability constraints are implemented by imposing a lower
bound on the distance between the optimal point and all stability boundaries in
its vicinity, where stability boundaries are described with notions from
bifurcation theory. We derive the required constraints for a general class of
periodically operated processes and show how these bounds can be integrated
into standard nonlinear programming methods. We present results of the
optimization of two chemical reaction systems for illustration.
