  The ability to prepare non-classical states in a robust manner is essential
for quantum sensors beyond the standard quantum limit. We demonstrate that
Bayesian optimal control is capable of finding control pulses that drive
trapped Rydberg atoms into highly entangled GHZ states. The control sequences
have a physically intuitive functionality based on the quasi-integrability of
the Ising dynamics. They can be constructed in laboratory experiments resulting
in preparation times that scale very favourably with the system size.
