The disclosure provides a method, system, device and medium for online monitoring of a plane stress field without baseline data based on a piezoelectric transducer array. Since Lamb waves have complex multi-mode characteristics, a suitable excitation frequency needs to be selected according to geometric dimensions of the structure to be measured, and then, only low-order mode Lamb waves are excited inside the measured structure to avoid serious waveform aliasing. For isotropic measured objects, anisotropic characteristics will be generated under the action of pre-stresses, that is, the propagation velocities of ultrasonic waves in all directions are different, but there is a linear relationship between velocity changes in different propagation directions and stresses. Therefore, there is still a linear relationship between the difference of velocity changes in different propagation directions and the stress. According to this characteristic, a characterization method of an absolute stress field without baseline data can be implemented. The method of the disclosure can make full use of the low attenuation characteristics of the Lamb waves to realize online monitoring of the plane stress field with a large coverage area.

A control device that controls an electronic device including a top panel having an operation surface, a position detector that detects a position of operational input performed on the operation surface, and a first vibrating element that generates vibration in the top panel, the control device includes a first processor that outputs a first drive signal to the first vibrating element to drive the first vibrating element; a first capacitor inserted in series between the first vibrating element and the first processor; and a first differential amplifier that detects a first voltage of the first capacitor or the first vibrating element, wherein the first processor is configured to determine whether pressing operation to the top panel has been performed based on the first voltage detected by the first differential amplifier.

In a driver for a piezo-electric transducer, when a converter circuit and a sensing circuit are the same circuit, many limitations exist on the accuracy of the sensing, due to multiple parasitic effects arising from the interconnection of the power devices. These limitations may limit viability of the sensing for many applications, in particular an accurate determination of when the force on the piezo-electric transducer is fully removed. Providing an additional switch in the sensing circuit configured to repeatedly zero the sensed voltage across the piezo-electric transducer each time the sensed voltage reaches a threshold voltage generates a plurality of voltage segments between zero and the threshold voltage. Accordingly, a controller may then be configured to generate a digital reconstruction of the sensed voltage across the piezo-electric transducer by adding the plurality of voltage segments.

In a driver for a piezo-electric transducer, when a converter circuit and a sensing circuit are the same circuit, many limitations exist on the accuracy of the sensing, due to multiple parasitic effects arising from the interconnection of the power devices. These limitations may limit viability of the sensing for many applications, in particular an accurate determination of when the force on the piezo-electric transducer is fully removed. Providing an additional switch in the sensing circuit configured to repeatedly zero the sensed voltage across the piezo-electric transducer each time the sensed voltage reaches a threshold voltage generates a plurality of voltage segments between zero and the threshold voltage. Accordingly, a controller may then be configured to generate a digital reconstruction of the sensed voltage across the piezo-electric transducer by adding the plurality of voltage segments.

A sensor assembly adapted to be embedded in a concrete structure comprising a body, and at least one sensor configured to determine parameters related to the durability of a concrete structure, wherein the sensor is arranged at least partially within the body, wherein the body comprises a shell covering the outer surface of the body and consisting of or comprising a mineral material, and wherein the sensor assembly has a rounded shape, particularly an ellipsoid or spherical shape, and a first extension extending along a first axis being 90 mm or less. A concrete structure is also provided having at least one sensor assembly.

A sensor assembly adapted to be embedded in a concrete structure comprising a body, and at least one sensor configured to determine parameters related to the durability of a concrete structure, wherein the sensor is arranged at least partially within the body, wherein the body comprises a shell covering the outer surface of the body and consisting of or comprising a mineral material, and wherein the sensor assembly has a rounded shape, particularly an ellipsoid or spherical shape, and a first extension extending along a first axis being 90 mm or less. A concrete structure is also provided having at least one sensor assembly.

Systems and methods are provided for monitoring the structural integrity of a vehicle. In particular, systems and methods are provided for using transducers positioned at various location in and on a vehicle to measure parameters related vehicle structural health. In various implementations, the integrity of the vehicle frame and the integrity of the vehicle body are monitored using a multi-axis accelerometer and/or microphone. The use of transducers for monitoring can replace time-consuming and expensive manual inspections.

Systems and methods are provided for monitoring the structural integrity of a vehicle. In particular, systems and methods are provided for using transducers positioned at various location in and on a vehicle to measure parameters related vehicle structural health. In various implementations, the integrity of the vehicle frame and the integrity of the vehicle body are monitored using a multi-axis accelerometer and/or microphone. The use of transducers for monitoring can replace time-consuming and expensive manual inspections.

A foldable device includes a housing and a foldable display device coupled to the housing. The foldable display device includes a foldable display layer, a foldable glass layer on a first side of the foldable display layer, and a sensing device on a second side of the foldable display layer. The sensing device includes a strain gauge layer. The strain gauge layer includes an array of resistors arranged on a piezoresistive substrate. Changes in resistance levels measured by the array of resistors are used to detect faults such as scratches, punctures, cracks and the like in the foldable glass layer. The foldable device may output an alert in response to detection of a fault in the foldable glass layer.

A foldable device includes a housing and a foldable display device coupled to the housing. The foldable display device includes a foldable display layer, a foldable glass layer on a first side of the foldable display layer, and a sensing device on a second side of the foldable display layer. The sensing device includes a strain gauge layer. The strain gauge layer includes an array of resistors arranged on a piezoresistive substrate. Changes in resistance levels measured by the array of resistors are used to detect faults such as scratches, punctures, cracks and the like in the foldable glass layer. The foldable device may output an alert in response to detection of a fault in the foldable glass layer.