Fast and accurate modeling and sensitivity analysis of an acquisition system for very low-g accelerations to be used in spacecraft testing and environmental noise measurements

The paper presents a low-g acceleration acquisition system, realized at the Test Centre Division, Europeans Space and Technology Centre of the European Space Agency. The system has been developed in the frame of an investigation on MEMS based sensors for the detection of very low g accelerations. A possible use of this type of technology is in the field of environmental noise measurement or in specific spacecraft testing where the effects of micro-vibrations induced by the activations of actuators need to be monitored. A Simulink-based approach is proposed for fast, accurate and reconfigurable modeling of the measuring system (sensor plus acquisition chain). The paper shows how such models are essentials to exactly predict the distortion and noise sources, to allow for fast set-up of the experiments, and to manage the signal conditioning process. The validity of the proposed technique is assessed by comparing the predicted results with tests on the real implemented system.