Stochastic Vibration Responses of the Bistable Electromagnetic Actuator with Elastic Boundary Controlled by the Random Signals

This paper comprehensively investigates the stochastic vibration responses of a bistable electromagnetic actuator with elastic boundary (EB-bistable actuator) controlled by Gaussian white noise and low-pass filtered stochastic noise. The EB-bistable actuator uses an oblique spring and another linear spring to realize the bistability and the elastic boundary, respectively. The elastic boundary can dynamically vary the bistability to enhance the vibration outputs of the EB-bistable actuator under the stochastic control signals. The paper firstly presents the governing equations and numerical integration method of the EB-bistable actuator controlled by the Gaussian white noise and low-pass filtered stochastic noise, respectively. Secondly, experiments are performed to verify the numerical predictions. Thirdly, the performance improvement of the EB-bistable actuator is validated, by comparing its stochastic responses with a bistable actuator with a fixed boundary (the FB-bistable actuator) and a linear actuator. Compared with the FB-bistable actuator for some appropriate parameters, the displacement variance of the EB-bistable actuator can be increased by 27.1% under Gaussian white noise signal and by 26.2% under low-pass filtered stochastic noise owing to the enhancement of the stochastic inter-well response, respectively. Moreover, the displacement variance of the EB-bistable actuator can be 109 times and 1138 times higher than that of the linear actuator controlled by Gaussian white noise and low-pass filtered stochastic noise, respectively. Finally, this paper uncovers the influence of the actuator structure parameters and control signal features, which presents the useful guidelines of the EB-bistable actuator for stochastic vibration application.