| Because vibration test can reproduce the real vibration environment through the repetition of a given power spectrum or vibration waveform, it is often used for assessing performance of different kinds of equipment working in vibration environment. Due to its function, it’s widely used in aerospace, machinery, vehicle and ship, bridges and buildings, and structure damping. With the complication and diversification of product structure, multi-axis multipoint excitation vibration test can more truly simulate the actual vibration environment than single-point excitation vibration test. Based on the existing research results of multi-axis vibration system, this paper made a further research on the multi-axis system, including the following three aspects:1) Complete the multi-axis system composition and feature analysis. By analysis summary the existing single and multi-axis system platform, it designed the scheme of the multi-axis vibration test system, and put forward the system technical index.2) Complete the multi-axis system mesa design. It made theoretical analysis on single and triaxial mesa structure scheme and optimization, and simulated the two mesa modal using the ANSYS software. Form the simulation results, we obtained the required frequency.3) Realize the control algorithm design. Vibration control technology is a key technology of vibration system. Considering there is noise in the input and output signals, it analyzed multi-axis vibration test system modeling methods, and applied Hv estimation method of system frequency response function for system identification. Due to the system coupling, the transfer function appears singular in some frequency points. In order to settle the difficulty of the matrix inversion, it proposed decoupling control algorithm on the basis of the generalized inverse theory. It used the singular value truncation to assure the stability of the control algorithm, and applied iterative control algorithm to increase the control precision.Finally, in order to verify the control algorithm precision, triaxial vibration test system hardware platform was established to do the sine sweep repetition and power spectrum repetition tests. The tests results showed that the antiresonance peak of the system transfer function was very small and the system response spectrum was controlled within the range of ±3dB. The results verified the multi-axis vibration table had great control precision. |
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