Abstract: Multi Input Multi Output (MIMO) random vibration test is of utter importance in product validation. As a type of time domain method, inverse system methods are capable of generating drive signals directly from reference ones (i.e., the desired response signals). However, in practice, these methods are prone to produce unstable results. To address this issue, an inverse multi-step prediction model is induced from the finite difference model of the system, and a MIMO random vibration test control scheme utilizing both the inverse multi-step prediction model and matrix power algorithm are proposed. First, a simulation of double-input-double-output-random-vibration test on a cantilever beam is conducted to show that the inverse multi-step prediction model can generate drive signals needed to satisfy the control requirement. After that, the capability of the proposed MIMO random vibration test control scheme is further validated in a test performed on a three-axis shaker.

Key words: inverse system, multi-step prediction model, MIMO, random vibration, environmental test