Semi-active Vibration Control of a Composite Beam using an Adaptive SSDV Approach

In this paper, an improved semi-active control method is proposed and applied to the vibration control of a composite beam. This method is an improved version of the previously developed SSDV (synchronized switch damping on voltage) approach. In SSDV, a voltage source is connected to the shunting branch, in series with the inductor, which can magnify the inverted voltage and hence improve the control performance. Optimization of the voltage source is an important issue in all SSDV techniques. In the proposed approach, called adaptive SSDV, the voltage coefficient that controls the damping effectiveness is adjusted adaptively. An improved switching algorithm, which prevents the switch from over-frequently switching on-and-off and accordingly improves the control performance, is also proposed. Compared with previous SSDV techniques, this adaptive SSDV is the most stable, is independent of the excitation level, and is more flexible because the voltage coefficient is adjusted adaptively to achieve optimal control performances. The adaptive SSDV has been applied to the vibration control of a composite beam and its control results were compared with those of previously developed SSDV techniques. The effectiveness of the new switching algorithm was also verified by comparing it with the conventional switch. An experimental setup of a semi-active control system for the cantilever composite beam was established, and control experiments were carried out using different SSDV methods.