Optimal vibration isolation and alignment over non-rigid bases with the CRO-SL ensemble

This work proposes the design of both Single-Input–Single-Output (SISO) and Multiple-Input–Multiple-Output (MIMO) isolation controllers, when the interaction between the isolator system and the base structure is considered. The problem to be addressed is based on the reduction of the vibration of every platform, and also on the alignment between the different isolators. Both techniques, SISO and MIMO, are optimally tuned by the recently-proposed Coral Reefs Optimisation with Substrate Layers (CRO-SL), a multi-method ensemble evolutionary approach. In the proposed design, the stability of both systems (the isolators and the supporting structure) is verified. Also, the importance of considering the supporting structure dynamic is shown, by comparing the results with those obtained when the base structure is assumed to be rigid and infinitely heavy. This work shows considerable and not obvious improvements when the interaction between the isolator system and the base frame is considered. Numerical examples are included to illustrate the significant differences between using SISO and MIMO cases, and to motivate the use of CRO-SL. In addition, a real application example is analysed based on experimental data. Verified practical guidelines to be followed in experimental tests are finally shown.