TIME-DELAY EFFECTS ON ACTIVELY DAMPED STRUCTURES

This paper shows the time-delay effect on the distributed parameters structures controlled using direct velocity feedback. It is shown how the stability of the structure could be lost due to time delay. Two ways of time-delay compensation are suggested. The first way is to redesign the gain matirx considering the presence of the time delay. In this case, however, the structure could remain unstable when using control moments as control actions. The other way is to use low-pass filters to filter the velocity measurements from the frequency components of the high order modes. In this case, one can control and compensate for time delay a number of vibrational modes equivalent to the number of control actions. However, the higher order modes remain uncontrolled.