Control accuracy and sensitivity of a double rhombic-strut adaptive beam string structure

The control accuracy and sensitivity of active struts in traditional adaptive beam string structures (ABSS) pose significant challenges to meeting the control requirements in different working states, which will seriously limit its adaptability to various external environments. To address this issue, a double rhombic active strut adaptive beam string structure (DRSABSS) was developed. To analyze the working mechanism of the double rhombic active strut and its feasibility in structural active control, its geometric deformation model was established, and the design formula was derived. The experiments and numerical simulations were conducted on a scaled model of the DRSABSS under different load cases. A control strategy that minimizes displacement considering control accuracy and sensitivity was proposed based on a genetic algorithm (GA). The test and simulation results showed that the initial angle of the double rhombic active strut was a crucial factor in determining its control function, and the accuracy of its design formula was verified. Additionally, the structural responses were significantly reduced after active control, and the double rhombic active struts can improve the structural control accuracy and sensitivity simultaneously, and the flexible switching of control modes under different requirements in real-time can be achieved. The test results were in good agreement with the simulation results. The rhombic amplification mechanism of DRSABSS proposed in this paper provides a new approach to improve the control accuracy and sensitivity of adaptive structures, and it can be applicable to the control requirements under different loads.