Abstract: Provided is a pressure-resistant underwater acoustic coating structure with a mesh structure interlayer, including an outer coating, a mesh structure interlayer, an inner coating, and a metal backing; wherein the outer coating is used for inputting acoustic waves, the mesh structure interlayer and the inner coating are used for consuming acoustic wave energy, and the metal backing is used for enriching a sound absorption mode; and the outer coating, the mesh structure interlayer, the inner coating and the metal backing are attached in sequence.

Abstract: The present disclosure is an electromagnetic force control method of a magnetic disk type negative stiffness electromagnetic actuator. The present disclosure relates to the technical field of vibration control. According to the actually required static bearing capacity, the present disclosure determines the positive stiffness k of a mechanical spring required for a magnetic disk type quasi-zero stiffness vibration isolator; and establishes an electromagnetic force mathematical model of a single electromagnet under a condition of magnetic unsaturation.

Abstract: An active control method for filtered reference affine projection sign algorithm based on variable step size includes: S1, acquiring impulse noise signals and transmitting the signals to control filters; S2, transmitting the impulse noise signals by the control filters to post filters; S3, generating cancellation signals of the impulse noise signals by the post filters according to the impulse noise signals and internal active control algorithms, and transmitting the cancellation signals to a speaker; S4, sending out the cancellation signal by the speaker to superimpose with the impulse noise signals to cancel the impulse noise signal.

Abstract: The disclosure provides a magnetic suspension type quasi-zero stiffness electromagnetic vibration isolator with active negative stiffness. The disclosure relates to the technical field of vibration control. The disclosure can selectively realize passive negative stiffness and active negative stiffness by adjusting the control mode of a controller. By adopting an amplifying mechanism and DIESOLE type electromagnets, the bearing capacity of the vibration isolator is further increased, and the disclosure is suitable for the field of ultra-low frequency heavy load vibration reduction and isolation. The displacement state of a negative stiffness mechanism can be measured in real time according to a sensor, and by means of cooperation of the controller and a driver, active negative stiffness is realized, real-time linear negative stiffness is realized, the multi-stable phenomenon is avoided, and complex dynamic phenomena such as jumping during working of the vibration isolator are prevented.

Abstract: An active control method for filtered reference affine projection sign algorithm based on variable step size includes: S1, acquiring impulse noise signals and transmitting the signals to control filters; S2, transmitting the impulse noise signals by the control filters to post filters; S3, generating cancellation signals of the impulse noise signals by the post filters according to the impulse noise signals and internal active control algorithms, and transmitting the cancellation signals to a speaker; S4, sending out the cancellation signal by the speaker to superimpose with the impulse noise signals to cancel the impulse noise signal.

Abstract: A quasi-zero stiffness electromagnetic vibration isolator for ultra-low frequency vibration reduction and isolation is provided. When the vibration isolator is in a static equilibrium position, upper and lower air gaps are equal, and electromagnetic attraction forces of upper and lower stator assemblies to a mover assembly are equal. When the load tends to move upwards, the mover assembly is subjected to an upward resultant force, when the load tends to move downwards, the mover assembly is subjected to a downward resultant force, showing the characteristic of negative stiffness. A negative stiffness mechanism composed of the upper stator assembly, the lower stator assembly and the mover assembly is connected in parallel with the positive stiffness springs to achieve a quasi-zero stiffness.

Abstract: The present disclosure is an electromagnetic force control method of a magnetic disk type negative stiffness electromagnetic actuator. The present disclosure relates to the technical field of vibration control. According to the actually required static bearing capacity, the present disclosure determines the positive stiffness k of a mechanical spring required for a magnetic disk type quasi-zero stiffness vibration isolator; and establishes an electromagnetic force mathematical model of a single electromagnet under a condition of magnetic unsaturation.

Abstract: The disclosure provides a magnetic suspension type quasi-zero stiffness electromagnetic vibration isolator with active negative stiffness. The disclosure relates to the technical field of vibration control. The disclosure can selectively realize passive negative stiffness and active negative stiffness by adjusting the control mode of a controller. By adopting an amplifying mechanism and DIESOLE type electromagnets, the bearing capacity of the vibration isolator is further increased, and the disclosure is suitable for the field of ultra-low frequency heavy load vibration reduction and isolation. The displacement state of a negative stiffness mechanism can be measured in real time according to a sensor, and by means of cooperation of the controller and a driver, active negative stiffness is realized, real-time linear negative stiffness is realized, the multi-stable phenomenon is avoided, and complex dynamic phenomena such as jumping during working of the vibration isolator are prevented.