Novel method for measuring non-stationary pitch and roll angles with a pendulous accelerometer in the presence of vibrations

We developed a novel universal method to solve an important mechanics problem arising during wind tunnel tests of aircraft models: the measurement of non-stationary pitch and roll angles of aircraft models and straingauge balances using a pendulous accelerometer. The method is based on a physical model in which the accelerometer pendulum is replaced by a proof mass and its hinge is replaced by a spring with damping. This model makes it possible to measure non-stationary pitch and roll angles in a wide range of vibration frequencies, including the accelerometer's eigenfrequency. We propose a method for determining the accelerometer's natural frequency in the absence of damping (resonance frequency) as well as the ratio of the damping coefficient to the pendulum's mass. We also conducted experimental studies in which an acceleration similar in form to the Heaviside function was applied to the accelerometer; the results verify the proposed method.