Abstract: In the environmental vibration test of a structural part, it is necessary to use several sensors to control the excitation applied to the test sample, so that the power spectrum input to the test sample would be basically consistent with the reference spectrum. However, the power spectrum measured by each of the control sensors may be very different, and result in a noticeable inconsistency between the magnitudes of vibration forces transferred to the test sample by fixture. In some cases, the control spectrum may even go out-of-tolerance to interrupt the test. In order to deal with such a problem, this paper carries out the research on the optimization design of the control sensors’ positions for a vibration test. Firstly, according to the multi-point control strategy of the random vibration test on the vibration table, the mathematical model of the position optimization of the control sensors is established. By using the feature mapping method, the frequency response function of a control sensor is obtained by the weighted sum of the frequency response function at the nodes around the control point. In this way, the control sensor can move continuously during the optimal design process. Then, by using the gradient-based optimization algorithm, the optimal position design of the control sensors can be founded readily, and the difference between the root-mean-square value of the response spectra measured by the control sensors is obviously reduced. The optimization method proposed in this paper can provide a theoretical guidance for the position design of control sensors in the environmental vibration test of a structural part.

Key words: Sensor layout optimization, Feature mapping, power spectral density, Sensitivity optimization, Excitation function fidelity