  Optimal quantum control theory carries a huge promise for quantum technology.
Its experimental application, however, is often hindered by imprecise knowledge
of the its input variables, the quantum system's parameters. We show how to
overcome this by Adaptive Hybrid Optimal Control (Ad-HOC). This protocol
combines open- and closed-loop optimal by first performing a gradient search
towards a near-optimal control pulse and then an experimental fidelity measure
with a gradient-free method. For typical settings in solid-state quantum
information processing, Ad-Hoc enhances gate fidelities by an order of
magnitude hence making optimal control theory applicable and useful.
