Adaptive control of propellant slosh for launch vehicles

This paper investigates the use of an adaptive system to stabilize a launch vehicle with sloshable fuel. The adaptive system utilizes a laser sensor to measure fluid displacement in the tank, a recursive-least-squares estimator to estimate the natural frequency of the sloshing fuel, and a linear filter which stabilizes the unstable fuel slosh using the frequency estimate. The method was successful for a single slosh-pendulum model and requires no tank baffles or partitions.