The present disclosure provides a vibration sensor. The vibration sensor may include a vibration receiver and an acoustic transducer. The vibration receiver may include a housing, a limiter and a vibration unit. The housing and the acoustic transducer may form an acoustic cavity. The vibration unit may be located in the acoustic cavity to separate the acoustic cavity into a first acoustic cavity and a second acoustic cavity. The acoustic transducer may be acoustically connected to the first acoustic cavity. The housing may be configured to generate a vibration based on an external vibration signal. The vibration unit may change an acoustic pressure within the first acoustic cavity in response to the vibration of the housing, such that the acoustic transducer generates an electrical signal. The vibration unit may include a mass element and an elastic element. A first side of the elastic element may be connected around a side wall of the mass element. A second side of the elastic element may be connected with the limiter.

An alternate venting path can be employed in a sensor device for pressure equalization. A sensor component of the device can comprise a diaphragm component and/or backplate component disposed over an acoustic port of the device. The diaphragm component can be formed with no holes to prevent liquid or particles from entering a back cavity of the device, or gap between the diaphragm component and backplate component. A venting port can be formed in the device to create an alternate venting path to the back cavity for pressure equalization for the diaphragm component. A venting component, comprising a filter, membrane, and/or hydrophobic coating, can be associated with the venting port to inhibit liquid and particles from entering the back cavity via the venting port, without degrading performance of the device. The venting component can be designed to achieve a desired low frequency corner of the sensor frequency response.

A vibration sensor/accelerometer includes, in various implementations, a MEMS die that includes a plate having an aperture, an anchor disposed within the aperture, a plurality of arms (e.g., rigid arms) extending from the anchor, and a plurality of resilient members (e.g., looped or folded springs with a carefully designed spring stiffness), each resilient member connecting the plate to an arm of the plurality of arms. The plate may be made from a solid layer in which the resilient members are etched from the same layer. The MEMS die may also include top and bottom wafers, and travel stoppers extending from the top and bottom wafers as well as through the plate.

A vibration sensor/accelerometer includes, in various implementations, a MEMS die that includes a plate having an aperture, an anchor disposed within the aperture, a plurality of arms (e.g., rigid arms) extending from the anchor, and a plurality of resilient members (e.g., looped or folded springs with a carefully designed spring stiffness), each resilient member connecting the plate to an arm of the plurality of arms. The plate may be made from a solid layer in which the resilient members are etched from the same layer. The MEMS die may also include top and bottom wafers, and travel stoppers extending from the top and bottom wafers as well as through the plate.

A static electricity distribution measuring apparatus (1) according to the present disclosure measures the static electricity distribution on a measurement surface of a measurement target (200), and is provided with: an array antenna (2) that receives electric fields generated from each of a plurality of areas (211) on the measurement surface through vibration; a vibrator (3) that vibrates the measurement target (200) or the array antenna (2); a measurer (4) that measures at least one from among intensity, frequency and phase of the electric fields in each of the plurality of areas (211) received by the array antenna (2); a calculator (5) that calculates an amount of static electricity for each of the plurality of areas (211) based on measurement results by the measurer (4); and a drawer (6) that draws the static electricity distribution on the measurement surface based on the amount of static electricity in each of the plurality of areas (211). The array antenna (2) has a plurality of antenna elements (21) respectively corresponding to the plurality of areas (211).

An identification method of nonlinear system of loudspeaker includes the following steps: providing an amplified pumping signal to the loudspeaker; measuring a voltage signal and a current signal; obtaining linear parameters of the loudspeaker system; obtaining the nonlinear parameters of the loudspeaker system: inputting the measured current signal into a lumped parameter model of the loudspeaker system to calculate the estimated voltage signal; comparing the estimated voltage signal with the measured voltage signal to calculate a voltage error signal between the two; conducting decoherence with the voltage error signal to get rid of a linear component of the voltage error signal, obtaining then, according to the voltage error signal after decoherence, the nonlinear parameters by using an adaptive iterative algorithm.

An identification method of nonlinear system of loudspeaker includes the following steps: providing an amplified pumping signal to the loudspeaker; measuring a voltage signal and a current signal; obtaining linear parameters of the loudspeaker system; obtaining the nonlinear parameters of the loudspeaker system: inputting the measured current signal into a lumped parameter model of the loudspeaker system to calculate the estimated voltage signal; comparing the estimated voltage signal with the measured voltage signal to calculate a voltage error signal between the two; conducting decoherence with the voltage error signal to get rid of a linear component of the voltage error signal, obtaining then, according to the voltage error signal after decoherence, the nonlinear parameters by using an adaptive iterative algorithm.

A vibronic sensor for determining and/or monitoring at least one process variable of a medium in a container. The sensor at least comprising: a unit which can oscillate mechanically; a driving/receiving unit; and an electronic unit. The driving/receiving unit is designed to excite, by means of an electrical excitation signal, mechanical oscillations in the unit which can oscillate mechanically and is designed to receive the mechanical oscillations of the unit which can oscillate mechanically, and to convert them into an electrical receiving signal. The electronic unit is designed to generate the excitation signal on the basis of the receiving signal and to determine the at least one process variable from the receiving signal; The electronic unit comprises at least one adaptive filter; and the electronic unit is designed to set the filter characteristic of the adaptive filter in such a way that there is a target phase shift between the excitation signal and the receiving signal.

A vibronic sensor for determining and/or monitoring at least one process variable of a medium in a container. The sensor at least comprising: a unit which can oscillate mechanically; a driving/receiving unit; and an electronic unit. The driving/receiving unit is designed to excite, by means of an electrical excitation signal, mechanical oscillations in the unit which can oscillate mechanically and is designed to receive the mechanical oscillations of the unit which can oscillate mechanically, and to convert them into an electrical receiving signal. The electronic unit is designed to generate the excitation signal on the basis of the receiving signal and to determine the at least one process variable from the receiving signal; The electronic unit comprises at least one adaptive filter; and the electronic unit is designed to set the filter characteristic of the adaptive filter in such a way that there is a target phase shift between the excitation signal and the receiving signal.

A vibration detection apparatus is disclosed. The vibration detection apparatus comprises a body configured to have internal space, and a vibration sensor formed on the body and configured to sense vibration from a measuring object. Here, a space exists between the vibration sensor and a surface opposed to the vibration sensor of the body.