A solid mount resonator sensor has a substrate. An anti-reflector stack is disposed proximate the substrate. The anti-reflector stack includes one or more acoustic interference layers. A first electrode is disposed proximate the anti-reflector stack. A second electrode having a first surface facing towards the first electrode and an opposing second surface facing away from the first electrode. A substantially quarter-wave piezoelectric material layer is disposed between the first and second electrodes.

The invention relates to a toilet cleaning tool comprising: a handle; a vibration member attached at a free end of the handle, wherein said vibration member includes an emitting surface for emitting vibrational waves;
wherein the toilet cleaning tool further includes one or more spacers arranged around the vibration member to keep the vibration member free of the toilet bowl during cleaning.

Methods and systems for calibrating a haptic system in an electronic device are provided. The calibration of the haptic system may be performed in a facility prior to a shipment to a user. The calibration may also be performed by a user prior to or after his/her use of the haptic system in the electronic device over time. A method for performing a calibration process in an electronic device includes generating a drive signal from a haptic driver in a haptic system disposed in an electronic device, transmitting the drive signal to an actuator in the haptic system, detecting a back Electromotive Force (bEMF) signal from the actuator in the haptic system, analyzing an output waveform from the bEMF signal, and adjusting a scale of the drive signal generated from the haptic driver.

A method for controlling at least two mechanical oscillators, more particularly in a motor vehicle, where each oscillator oscillates at a frequency during operation and where the frequency can be controlled by the power applied to the oscillators, includes arranging a single sound transducer at a distance from the oscillators and capturing an electrical signal, where the electrical signal is subjected to a Fourier transform and thus a Fourier spectrum is determined. The frequency of each oscillator is determined from extreme values of the Fourier spectrum.

The present invention is a piezoelectric actuator drive method, a piezoelectric actuator drive circuit, and a piezoelectric actuator drive system capable of causing a piezoelectric element to vibrate in a maximum amplitude state. The piezoelectric actuator drive circuit includes: an obtainment unit that obtains operation information pertaining to operation of the piezoelectric element in a period that is a part of one cycle of a drive cycle in which the piezoelectric element is driven; and a control unit that performs feedback control of a drive parameter for driving the piezoelectric element based on the operation information.

A system and method for detecting an anomaly in a structure using an adaptive filter to compensate for variations in piezoelectric transducer performance due to environmental factors such as temperature. A first voltage signal having a first amplitude is sent to a reference piezoelectric actuator. Thereafter, a first reference voltage signal is received from a reference piezoelectric receiver which is acoustically coupled to detect the guided wave generated by the reference piezoelectric actuator. A second amplitude is determined using an optimization algorithm of an adaptive filter to compensate for nonlinear behavior of the reference piezoelectric actuator and receiver based on the first reference voltage signal. Then the adaptive filter sends a second voltage signal having the second amplitude to the reference and test piezoelectric actuators. Reference and test voltage signals are received from the reference and test piezoelectric receivers in response to the second voltage signal. A difference voltage signal representing differences between the reference and test voltage signals received is then recorded.

The present invention proposes a parameter that appropriately characterizes non-Gaussianity in a random vibration test and realizes vibration control using the parameter. A vibration control system calculates a KRS of a response waveform. The system compares a reference KRS as a target and the response KRS, and controls a characteristic of a phase used to generate a waveform for control such that the response KRS becomes equal to the reference KRS. Upon generation of the waveform for control, the waveform for control is generated by applying an appropriate random phase to each frequency component of an amplitude corresponding to PSD for control. The system controls a characteristic of this random phase (for example, standard deviation of phase distribution, or the like) per frequency, and controls the KRS of the waveform for control. The system deforms the waveform for control on the basis of an equalization characteristic, for which a transfer function of the system is taken into consideration, and calculates a drive waveform. The system sequentially updates the equalization characteristic on the basis of the response waveform and the drive waveform. The calculated drive waveform is converted into a drive signal by a D/A convertor 26, is amplified by an amplifier 28, and is provided to a vibration generator 2.

Methods and systems for calibrating a haptic system in an electronic device are provided. The calibration of the haptic system may be performed in a facility prior to a shipment to a user. The calibration may also be performed by a user prior to or after his/her use of the haptic system in the electronic device over time. A method for performing a calibration process in an electronic device includes generating a drive signal from a haptic driver in a haptic system disposed in an electronic device, transmitting the drive signal to an actuator in the haptic system, detecting a back Electromotive Force (bEMF) signal from the actuator in the haptic system, analyzing an output waveform from the bEMF signal, and adjusting a scale of the drive signal generated from the haptic driver.

An ultrasonic motion generator includes a non-resonant inverter, an ultrasonic transducer, and a comparator. The non-resonant inverter inverts direct current (DC) to alternating current (AC) having a first frequency. The ultrasonic transducer is electrically coupled with the non-resonant inverter and generates an ultrasonic motion based on the inverted AC. The comparator automatically detects a deviation of the first frequency from a resonant frequency of the ultrasonic transducer based on motion current passing through the ultrasonic transducer and generates an output signal based on the deviation to drive the non-resonant inverter.

Circuitry for estimating a displacement of a piezoelectric transducer in response to a drive signal applied to the piezoelectric transducer, the circuitry comprising: monitoring circuitry configured to be coupled to the piezoelectric transducer and to output a sense signal indicative of an electrical signal associated with the piezoelectric transducer as a result of the drive signal; wherein the circuitry is configured to generate a difference signal based on the drive signal and the sense signal; and wherein the circuitry further comprises processing circuitry configured to apply at least one transfer function to the difference signal to generate a signal indicative of the displacement of the piezoelectric transducer.