A dynamic disturbance force measurement system based on array sensor for large moving device in spacecrafts

Abstract

The control of micro-vibrations is an increasingly significant aspect of the research related to high-precision equipment in spacecraft. As the scale and mass of these vibration sources become larger, the control precision required also increases, and the requirements for the vibration source ground test equipment are thus becoming more demanding. This paper therefore proposes a generalized disturbance force measurement system for large device vibration sources. The use of a redundant array of piezoelectric sensors can significantly increase the size, load capacity and stiffness of the platform. In addition, the D-optimal designs used by the system overcomes the redundant measurement errors introduced by array-based measurements. Based on the above, a more accurate 3D force decoupling expression is obtained using the linear decoupling algorithm of the full regression method. A system prototype is then designed and tested based on the results of this approach. Experimental results show that the system guarantees high load capacity (416 kN) and stiffness, the dynamic relative error within the 8–800 Hz frequency range is less than 3% for a 3D generalized force in the force hammer test, and the relative error of the test system under sinusoidal excitation is within 5%; additionally, the linearity for generalized forces over the full range is within 0.1% full scale and the results are not affected by the characteristics of the measured object.