Multiple-Input/Multiple-Output Random Vibration Control for Simulating a Horizontal Direction Launch Environment

Abstract

A vibration test system (VTS) consisting of a single shaker and a slip table is the most widely used for a horizontal direction launch environment test. When the single shaker is controlled according to the average of absolute responses at interface points, the payload will have a quite different vibration response, depending on the installation position on its slip table. This paper first discusses the limitation of the conventional VTS. To improve the uniformity of the payload response for each test configuration, an additional shaker can be installed on the opposite side of the slip table. Currently, a multiple-shaker VTS is used for the single-axial launch environment test, where each shaker is controlled by a single drive signal. This approach is effective in increasing the force capability, but it cannot sufficiently reduce the difference of the payload response. Conventional multiple-input/multiple-output control methods have limitations when controlling several interface responses within the tolerance. This study proposes a new control method for the random vibration test; the combination of interface responses is controlled for the high-frequency band and only a single shaker is controlled for the low-frequency band. The proposed method can increase the reliability of the random vibration verification tests for simulation launch environment.