  Atom-interferometric quantum sensors could revolutionize navigation, civil
engineering, and Earth observation. However, operation in real-world
environments is challenging due to external interference, platform noise, and
constraints on size, weight, and power. Here we experimentally demonstrate that
tailored light pulses designed using robust control techniques mitigate
significant error sources in an atom-interferometric accelerometer. To mimic
the effect of unpredictable lateral platform motion, we apply laser-intensity
noise that varies up to 20$\%$ from pulse-to-pulse. Our robust control solution
maintains performant sensing, while the utility of conventional pulses
collapses. By measuring local gravity, we show that our robust pulses preserve
interferometer scale factor and improve measurement precision by 10$\times$ in
the presence of this noise. We further validate these enhancements by measuring
applied accelerations over a 200 $\mu g$ range up to 21$\times$ more precisely
at the highest applied noise level. Our demonstration provides a pathway to
improved atom-interferometric inertial sensing in real-world settings.
