A method of determining the center of loading of a rolling element includes providing a rolling element body and at least three load sensors. The sensors are each positioned within a bore of the rolling element body at a separate distance from a reference position. Load measurements are taken with each one of the sensors at various positions about the circumference of the bearing and the center of loading is calculated at each one of the positions to determine the variation in axial loading about the bearing circumference.

A deformation detection sensor that includes a conductive member, a plurality of thermoplastic resin layers, and a piezoelectric film. At least one of the thermoplastic resin layers has a main surface, and the conductive member is formed on the main surface thereof. The plurality of thermoplastic resin layers are laminated and integrally formed by hot pressing into a laminated body. A transmission line is formed form a first portion of the conductive member and the thermoplastic resin in the laminated body. The piezoelectric film is attached to the laminated body to form a piezoelectric element made of a second portion of the conductive member, the thermoplastic resin in the laminated body, and the piezoelectric film.

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 wearable device can include a wearable band configured to contact a user of the wearable device, an actuator, a sensor, and one or more processors in communication with the actuator and the sensor. The processors can be configured to measure a back electromotive force (“EMF”) of the actuator; determine, based on the measured back EMF, data that describes a contact force between the wearable band and the user; and determine, based on the data that describes the contact force, a quality metric describing a data quality of sensor data collected by the sensor. In some embodiments, the processor(s) can determine, generate sensor output data based on the sensor data and based at least in part on the data describing the contact force between the wearable band and the user. For example, one or more machine-learned models maybe leveraged to generate sensor output data that is compensated for the wearable band being too tight or too loose.

A method for manufacturing a deformation detection sensor that includes: preparing a plurality of thermoplastic resin layers, at least one of which has a main surface on which a conductive member is formed; laminating the plurality of thermoplastic resin layers; after lamination, integrally forming the plurality of thermoplastic resin layers by hot pressing to obtain a laminated body configured so that a transmission line is formed from a first portion of the conductive member and the laminated body; and attaching a piezoelectric film to the laminated body so that a piezoelectric element is formed from a second portion of the conductive member, the laminated body, and the piezoelectric film.

A force sensing device is mounted on a tool to sense force, particularly quasi-static and static forces. The force sensing device includes at least one a sensor. A piezoelectric element in the sensor includes a driving portion and a sensing portion. A first voltage is input to the driving portion to generate a vibration in the piezoelectric element and a second voltage in response to the vibration is output from the sensing portion. The second voltage output from the sensing portion is changed as the vibration in the piezoelectric element is suppressed by an external force acting on the force sensing device so variation of the second voltage can be used to measure the external force.

An ultrasound time-of-flight (TOF) sensor module includes an ultrasonic transducer device, a cover layer, an elastic member, and a signal processor electronically coupled to the ultrasonic transducer. The ultrasonic transducer device includes at least one ultrasonic transducer, which is configured as an ultrasonic transmitter and/or an ultrasonic receiver. The elastic member is interposed between the ultrasonic transducer device and the cover layer. The elastic member undergoes reversible compression in response to an external object impacting and/or contacting the cover layer. An ultrasound propagation distance between the ultrasonic transducer and the cover layer varies in accordance with the compression. The ultrasonic transmitter(s) transmit ultrasound signals. The cover layer reflects a fraction f of the ultrasound signals incident thereon. The signal processor obtains TOF data which indicate time differences between times of transmission of transmitted ultrasound signals by the ultrasonic transmitter(s) and times of receipt of reflected ultrasound signals by the ultrasonic receiver(s). The time differences vary in accordance with the ultrasound propagation distance.

Provided are a resonator, a method of manufacturing the resonator, and a strain sensor and a sensor array including the resonator. The resonator is provided to extend in a lengthwise direction from a support. The resonator includes a single crystal material and is provided to extend in a crystal orientation that satisfies at least one from among a Young's modulus and a Poisson's ratio, from among crystal orientations of the single crystal material.

A vibration sensor according to an embodiment includes a laminated body. The laminated body includes a support layer a first end of which is fixed; a piezoelectric layer on the support layer; an insulating layer disposed between the support layer and the piezoelectric layer; a common electrode disposed on a first principal surface of the piezoelectric layer; a first sensing electrode disposed in a first area on a second principal surface of the piezoelectric layer on the side opposite to the first principal surface; and a drive electrode disposed in a second area different from the first area on the second principal surface of the piezoelectric layer. The first area is located near the first end of the support layer.

A resonant sensor comprises a proof body subjected to a torque of forces produced by an external mechanical structure, the body comprising: a first and a second interface that can each come into contact with the structure; at least two sensitive zones arranged between these two interfaces; a sensitive zone formed by a plate embedded in a frame secured mechanically to the interfaces, the plate able to resonate under the effect of local mechanical excitations produced at particular points by excitation transducers bearing the plate at several resonant frequencies, sensors picking up the resonant signals produced at the particular points, measurement means measuring the resonant frequency shifts of signals which are linear combinations of the resonant signals picked up, the shifts being a function of mechanical stresses induced by the forces and transmitted to the plate by the frame, the components of the torque of forces being determined from the resonant frequency shifts measured on the plates of the sensitive zones.