(An) improved control of vibration test system for simulating a horizontal direction launch environment

Abstract

Vibration test system 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 test article will have a quite different vibration response depending on the installation position of its slip table. To improve the uniformity of the test article responses for each test configuration, an additional shaker can be installed to the opposite side of the slip table. Currently a multiple-shaker vibration test system is used for the single axial launch environment test. However, 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. Independent control of multiple shakers is required. However, conventional Multiple-Input Multiple-Output (MIMO) control methods have limitations when controlling several interface responses within the tolerance and have problems of control the responses for low frequency band. This study proposes a new control method for simulating a horizontal direction launch environment

the combination of interface responses is controlled for the high frequency band and only a single shaker is controlled for low frequency band. The validity of the proposed method is presented through an analysis of the finite element model and experimental results.