An acceleration detection device includes a board including first and second surfaces, an acceleration detector on the first surface of the board, first circuit components on the second surface of the board, a seal including a first sealing portion covering the acceleration detector on the first surface of the board and a second sealing portion covering the first circuit components on the second surface of the board, the second sealing portion including an inner surface facing the board and an outer surface on a side opposite to the inner surface, the seal being made of a resin, and a high-rigidity body extending in a direction in which the outer surface and the second surface of the board are connected to each other within the second sealing portion, the high-rigidity body having higher rigidity than the seal.

An acceleration detection device includes a board including first and second surfaces, an acceleration detector on the first surface of the board, first circuit components on the second surface of the board, a seal including a first sealing portion covering the acceleration detector on the first surface of the board and a second sealing portion covering the first circuit components on the second surface of the board, the second sealing portion including an inner surface facing the board and an outer surface on a side opposite to the inner surface, the seal being made of a resin, and a high-rigidity body extending in a direction in which the outer surface and the second surface of the board are connected to each other within the second sealing portion, the high-rigidity body having higher rigidity than the seal.

An athletic parameter measurement device worn by an athlete during an athletic activity session includes a housing which attaches to the athlete, a display, a processor associated with the display, and an athletic parameter measurement sensor. During the athletic activity, the device detects, using the sensor, a vertical jump height of the athlete, and displays, during the performance of the athletic activity session, a representation of the vertical jump height on the display.

An athletic parameter measurement device worn by an athlete during an athletic activity session includes a housing which attaches to the athlete, a display, a processor associated with the display, and an athletic parameter measurement sensor. During the athletic activity, the device detects, using the sensor, a vertical jump height of the athlete, and displays, during the performance of the athletic activity session, a representation of the vertical jump height on the display.

A process for producing a piezoelectric sensor includes the following steps: a step of providing a housing made of stainless steel; a step of producing a solution of a compound comprising a metal or metalloid element; a step of depositing a layer of the solution over at least one inner surface of the housing; a step of oxidizing the deposited layer of solution; a step of placing a piezoelectric element inside the housing; a step of closing the housing. A piezoelectric sensor obtained by such a process and comprising a closed steel housing, a piezoelectric element arranged inside the housing and a layer of a solution of a compound comprising a metal or metalloid element that is arranged over at least one inner surface of the housing.

A process for producing a piezoelectric sensor includes the following steps: a step of providing a housing made of stainless steel; a step of producing a solution of a compound comprising a metal or metalloid element; a step of depositing a layer of the solution over at least one inner surface of the housing; a step of oxidizing the deposited layer of solution; a step of placing a piezoelectric element inside the housing; a step of closing the housing. A piezoelectric sensor obtained by such a process and comprising a closed steel housing, a piezoelectric element arranged inside the housing and a layer of a solution of a compound comprising a metal or metalloid element that is arranged over at least one inner surface of the housing.

A system includes a microphone unit coupled to a roof of an autonomous vehicle. The microphone unit includes a microphone board having a first opening. The microphone unit also includes a first microphone positioned over the first opening and coupled to the microphone board. The microphone unit further includes an accelerometer. The system also includes a processor coupled to the microphone unit.

An accelerometer including: a housing having an internal cavity; a piezoelectric material disposed in the internal cavity; a mass movable disposed in the internal cavity; and a spring disposed between the piezoelectric material and a portion of the housing, the spring being compressively preloaded against the piezoelectric material; wherein the mass is movable when the housing experiences an acceleration such that the mass acts upon the spring and the spring acts against the piezoelectric material, the piezoelectric material outputting a signal corresponding to a magnitude of the acceleration.

A MEMS vibration sensor includes a piezoelectric membrane including a segmented electrode affixed to a holder; and an inertial mass affixed to the piezoelectric membrane, wherein the segmented electrode includes four segmentation zones, wherein, in an X-direction, a signal from a first segmentation zone is equal to a signal from a third segmentation zone, a signal from a second segmentation zone is equal to a signal from a fourth segmentation zone, and the signal from the first segmentation zone and the signal from the second segmentation zone have opposite signs, and wherein, in a Y-direction, a signal from the first segmentation zone is equal to the signal from the second segmentation zone, the signal from the third segmentation zone is equal to the signal from the fourth segmentation zone, and the signal from first segmentation zone and the signal from the third segmentation zone have opposite signs.

A MEMS vibration sensor includes a piezoelectric membrane including a segmented electrode affixed to a holder; and an inertial mass affixed to the piezoelectric membrane, wherein the segmented electrode includes four segmentation zones, wherein, in an X-direction, a signal from a first segmentation zone is equal to a signal from a third segmentation zone, a signal from a second segmentation zone is equal to a signal from a fourth segmentation zone, and the signal from the first segmentation zone and the signal from the second segmentation zone have opposite signs, and wherein, in a Y-direction, a signal from the first segmentation zone is equal to the signal from the second segmentation zone, the signal from the third segmentation zone is equal to the signal from the fourth segmentation zone, and the signal from first segmentation zone and the signal from the third segmentation zone have opposite signs.