  Cloud cavitation causes nontrivial energy concentration and acoustic
shielding in liquid, and its control is a long-standing challenge due to
complex dynamics of bubble clouds. We present a new framework to study
closed-loop control of cavitation through acoustic feedback. While previous
approaches used empirical thresholding, we employ model-based state estimation
of coherent bubble dynamics based on theory and high-performance computing.
Using a pulsed ultrasound setup, we demonstrate set-point control of the pulse
repetition frequency (PRF) to modulate acoustic cavitation near a solid target
over $O(100)$ s. We identify a quasi-equilibrium correlation between PRF and
the bubble dynamics, and an optimal PRF to minimize acoustic shielding of the
target. This framework can be readily scaled up by enhanced acoustic sensing
and computational power.
