Abstract: A resonator includes a support frame, a rectangular vibrating plate that performs contour vibration in a predetermined direction, and two pairs of support arms. The vibrating plate includes four vibration regions arranged in a row in the lengthwise direction and electrodes disposed in the vibration regions. Each of the vibration regions vibrate with a phase opposite to phases with which the adjacent vibration regions vibrate upon excitation. A center line of a pair of the electrodes in the lengthwise direction is offset from a center line, in the lengthwise direction, of a corresponding vibration region that includes the electrode disposed thereon.

Abstract: An ultrasonic detection circuit includes a transmitter circuit that provides excitation signals to an ultrasonic transducer during an excitation interval. A control circuit includes a port to receive a command. The control circuit controls the frequency and the duty cycle of the excitation signals of the transmitter circuit during the excitation interval. The control circuit generates a first excitation signal sequence of the excitation interval followed by a first monitoring period to receive a first echo signal in response to the command. The control circuit generates a second excitation signal sequence of the excitation interval followed by a second monitoring period to receive a second echo signal in response to the command. The control circuit outputs results via the port based on at least one of the first or second echo signals received.

Abstract: An actuator device is provided having a controllable stiffness profile, wherein an actuator member (12) comprises an electroactive polymer material (16) having light absorbing filler elements (20) embedded therein. The filler elements are adapted to absorb and convert incident light (26) to heat energy to therefore heat surrounding sections of the electroactive material. By selectively controlling an intensity level or spectral composition of a light source (24) directed at the actuator member, a specific degree and spread of heating can be achieved across the member and, as a result, a specific desired stiffness or flexibility profile can be realised across the actuator member.

Abstract: An ultrasonic detection circuit includes a transmitter circuit that provides excitation signals to a terminal of an ultrasonic transducer to drive the ultrasonic transducer during an excitation interval. The excitation signals provided during the excitation interval include a first excitation signal at a first resonant frequency of the ultrasonic transducer followed by a second excitation signal at a second resonant frequency of the ultrasonic transducer. The first resonant frequency is different from the second resonant frequency.

Abstract: An acoustic impedance transformation circuit and related apparatus are provided. In aspects discussed herein, the acoustic impedance transformation circuit can be configured to transform an input impedance into an output impedance higher than the input impedance. In this regard, the acoustic impedance transformation circuit can be provided in an apparatus to enable impedance matching between two electrical circuits. As a result, it may be possible to reduce signal reflection resulting from impedance mismatch between the two circuits, thus helping to improve performance of the apparatus.

Abstract: The disclosure relates to a circuit arrangement that includes a first DC-DC converter that is connected on the output side to a capacitor. A first terminal of the capacitor is a supply voltage terminal and a second terminal of the capacitor is a reference potential terminal. The circuit arrangement also includes a second DC-DC converter, which is connected on the input side with the capacitor and on the output side to a first terminal of a piezo actuator. The second terminal of the piezo actuator is connected to the first terminal of the capacitor.

Abstract: An ultrasonic vibrator driving apparatus applies a sine-waveform alternating voltage as a drive voltage via a conversion circuit to an ultrasonic vibrator that has a unique resonance frequency. A first current detector that detects a first current that flows from the drive voltage generator to the conversion circuit and a second current detector that detects a second current that flows from the conversion circuit to the ultrasonic vibrator are included. A frequency controller performs control on the drive voltage generator to change the frequency of a square-waveform alternating voltage so that the difference between the first current and the second current is reduced or approaches a minimum.

Abstract: A shaft being, e.g., flexible, that includes an elongated outer sheath, at least one drive shaft disposed within the outer sheath and a ring non-rotatably mounted on the at least one rotatable drive shaft and at least one light source mounted within the shaft, such that, upon rotation of the at least one rotatable drive shaft, the ring alternately blocks and allows light from the light source to be detected. The shaft may also include a moisture sensor disposed within the outer sheath of the shaft and configured to detect moisture within the outer sheath. The shaft may include couplings that connect a distal end of the outer sheath to a surgical attachment and a proximal end of the outer sheath to a remote power console.

Abstract: A contactless power supply has a dynamically configurable tank circuit powered by an inverter. The contactless power supply is inductively coupled to one or more loads. The inverter is connected to a DC power source. When loads are added or removed from the system, the contactless power supply is capable of modifying the resonant frequency of the tank circuit, the inverter frequency, the inverter duty cycle or the rail voltage of the DC power source.

Abstract: An acoustic biometric touch scanner device and method is disclosed. In one aspect, an acoustic fingerprint sensing device includes an array of ultrasonic transducers configured to transmit an ultrasound signal having a frequency in a range from 50 megahertz (MHz) to 500 MHz. The acoustic fingerprint ultrasonic transducers include a piezoelectric film. The acoustic fingerprint sensing device further includes a receiving surface configured to receive a finger. The acoustic fingerprint sensing device further includes a processor configured to generate an image of at least a portion of a fingerprint of the finger based on a reflection of the ultrasound signal from the finger.

Abstract: An imaging apparatus can mount a lens device, which is an external device, on the main body thereof. The main body includes a shake detection unit that detects a shake amount and a power supply fluctuation detection unit that detects a fluctuation in power supply supplied from a power supply unit to the lens device. A frequency calculation unit calculates a driving frequency of the lens device based on the fluctuation in power supply during lens driving. If the driving frequency of the lens device interferes with the driving frequency of the shake detection unit, the system control unit inhibits or restricts a function using the shake detection unit.

Abstract: There is provided a liquid discharge apparatus including: a discharge unit which discharges a liquid by applying a driving signal to a piezoelectric element; and a driving circuit which outputs the driving signal based on an original driving signal, in which the driving circuit includes a transistor pair for outputting the driving signal, a first gate driver which generates a first control signal, and a linear amplifier which amplifies a voltage of the original driving signal, in which a first output terminal from which the first control signal is output, a first input terminal to which a first feedback signal, and a second input terminal to which a second feedback signal, and in which the shortest distance between the first output terminal and the first input terminal is longer than the shortest distance between the first output terminal and the second input terminal.

Abstract: An oscillation circuits that provides stable oscillations even when the amount of phase rotation of a piezoelectric resonator is small or fluctuates. The oscillation circuit includes a first amplifier having an input and an output, and a piezoelectric resonator connected between the input and the output of the first amplifier. Moreover, the oscillation circuit feeds, back to the input, a current flowing from the output of the first amplifier to the piezoelectric resonator. The oscillation circuit further includes an alternating-voltage waveform shaping circuit that applies, to the piezoelectric resonator, an alternating-voltage waveform having rising portions sharper than those of a sine wave.

Abstract: There is provided a liquid discharge apparatus including: a discharge unit which discharges a liquid by a piezoelectric element; and a driving circuit which drives the piezoelectric element, in which the driving circuit includes a first transistor pair which is driven by a first power source voltage and a second power source voltage, a second transistor pair which is driven by the second power source voltage and a third power source voltage, and a first control circuit which controls on a first input signal, and in which, the shortest distance between the first power source voltage and the first input terminal is shorter than the shortest distance between the second power source voltage and the first input terminal, and the shortest distance between the second power source terminal and the first input terminal is shorter than the shortest distance between the third power source voltage and the first input terminal.

Abstract: An ultrasound imaging device includes an exterior housing including a panel, a processor positioned within the exterior housing, and an acoustic exciter attached to the panel and electrically connected to the processor. The processor is configured to drive the acoustic exciter in order to vibrate the panel and transmit audible sounds. A method of providing audible sounds from an ultrasound device includes attaching an acoustic exciter to a panel, electrically connecting the acoustic exciter to a processor, providing signals to the acoustic exciter from the processor, vibrating the acoustic exciter in response to the signals, and transmitting audible sounds from the panel connected to the acoustic exciter.

Abstract: A surgical apparatus includes an end effector configured to interact with a tissue and a surgical instrument. The surgical instrument includes at least one drive mechanism operable to effect at least one motion in the end effector. The surgical instrument further includes one or more vibration sensors configured to record vibrations generated by the at least one drive mechanism, wherein the one or more vibration sensors are configured to generate an output signal based on the sensed vibrations, and wherein the output signal is employed to select between an acceptable status, a marginal status, and a critical status of the surgical instrument.

Abstract: A control console for a powered surgical tool. The console includes a transformer that supplies the drive signal to the surgical tool. A linear amplifier with active resistors selectively ties the ends of the transformer primary winding between ground and the open circuit state. Feedback voltages from the transformer windings regulate the resistances of the active resistors.

Abstract: An ultrasonic surgical instrument comprises a cylindrical shaft and a blade at a distal or free end of the shaft, the blade being unitary and continuous with the shaft, without an intervening joint. The shaft has a longitudinal axis and the blade includes a flat or planar blade body with a proximal end eccentrically disposed relative to the shaft axis. Thus, the blade body or at least a proximal end portion thereof is disposed eccentrically relative to the shaft. The blade in its entirely may be inclined relative to the shaft axis or extend parallel thereto.

Abstract: Disclosed examples include ultrasonic cleaning systems, driver integrated circuits and methods for cleaning a lens, in which an oscillating drive signal is provided to an ultrasonic transducer and the driver controls the frequency of the drive signal according to a current sense signal representing a drive current flowing in the transducer. The driver sweeps the drive signal frequency and compares the sensed current values with predetermined profiles corresponding to a clean lens and a lens with one or more known contaminants, and generates the drive signal at one or more frequencies corresponding to peaks or valleys of the sensed current values or predetermined frequencies to promote cleaning of the lens.

Abstract: An electrical voltage-generating piezoelectric device comprising at least a first blade (1) with a curved portion (10) defining a first arm (11) and a second arm (12) of the blade, the first arm (11) being intended to be fastened to a fixed support, the second arm (12) being substantially flat and having a free end (120) designed to oscillate around its resting position under the effect of mechanical force, at least one piezoelectric element (31) resting upon one of the main surfaces (14) of the second arm (12) of the first blade. The device also includes a second blade (2) identical in structure to the first blade (1), the first arms (11, 21) of the first and second blades (1, 2) being fastened together on all or part of their surfaces and being fixed relative to each other.

Abstract: Methods and apparatus for ultrasonic lens cleaner using configurable filter banks are disclosed. In certain described examples, the methods and apparatus can expel fluid from a droplet on an optical surface using an ultrasonic transducer mechanically coupled to the optical surface and having first and second resonant frequency bands.

Abstract: A system and method are disclosed for conserving power during navigation, e.g., user device pointer/cursor navigation, using a fingerprint image sensor, that may comprise processing, via a computing device, fingerprint image sensor data indicative of finger position and movement with respect to a fingerprint image sensor surface in a finger navigation mode to determine if the finger is in a first finger navigation mode; processing, via the computing device, fingerprint image sensor data indicative of finger position and movement with respect to a fingerprint image sensor surface in a finger navigation mode to determine if the finger is in a second finger navigation mode; and transitioning, via the computing device, the fingerprint image sensor from a first power consumption mode to a second power consumption mode, based on detecting a transition from the first finger navigation mode to the second finger navigation mode.

Abstract: Computer-implemented techniques include receiving, at a first mobile computing device having one or more processors, a first input signal from a first set of pressure sensors associated with the first mobile computing device, the first input signal having been generated by the first set of pressure sensors in response to a first force applied by a first user. The techniques also include transmitting, from the first mobile computing device to a second mobile computing device, the first input signal, wherein receipt of the first input signal causes the second mobile computing device to generate and output a first output signal based on the first input signal, and wherein the output of the first output signal causes a first set of haptic actuators associated with the second mobile computing device to generate a second force to be felt by a second user.

Abstract: A method for performing vibration detection on a feed system of a machine tool is implemented by a detecting device, and includes: calculating a target frequency range associated with a rotation speed of the machine tool; detecting vibration of the feed system in a static state; calculating a smoothed signal according to detected result, the smoothed signal including a plurality of noise amplitude values distributed across the target frequency range; identifying a measurement frequency that corresponds with a smallest one of the noise amplitude values; calculating a suggested rotation speed based on the measurement frequency; and detecting vibration of the feed system rotating at the suggested rotation speed.

Abstract: A piezoelectric device includes a piezoelectric element including a first electrode, a second electrode, and a piezoelectric layer provided between the first electrode and the second electrode, and a driving system that drives the piezoelectric element by applying voltage to the first electrode and the second electrode, in which the driving system drives the piezoelectric element at a maximum voltage that is lower than a voltage at which a tunnel current or a Poole-Frenkel current starts to be generated in the piezoelectric element.

Abstract: A vibration suppressing apparatus and a vibration suppressing method thereof are provided. The vibration amplitude, vibration frequency, and vibration phase of a vibration suppressing unit are adjusted in real-time according to the vibration amplitude, vibration frequency and vibration phase of a vibration source.

Abstract: According to one embodiment, a power supply device includes a voltage conversion circuit configured to convert a voltage of power generated by a power generation element; a plurality of power storage elements connected in parallel with respective load circuits; a switch circuit configured to switch an electrical connection between the voltage conversion circuit and each of the plurality of power storage elements; and a control circuit configured to measure voltages of the plurality of power storage elements and to control the switch circuit based on the measured voltages.

Abstract: An ultrasonic transducer that can include a driver side and a bias voltage side. A higher voltage source can be electrically connected to the bias voltage side through a first resistor. A lower voltage source can be electrically connected to the driver side of through a second resistor. A field effect transistor or other suitable switch can be included, having a source, a gate and a drain. The source can be electrically connected to ground and the gate can be electrically connected to a control signal source. The drain can be electrically connected to the lower voltage source through a second resistor and be electrically connected to the driver side of the ultrasonic transducer. The gate can be electrically connected to a signal source through a third resistor.

Abstract: A method and apparatus for delivering energy during a surgical procedure such as phacoemulsification is provided. The method and apparatus include applying energy during at least one pulsed energy on period, comprising applying energy during a series of short burst periods, the short burst periods interspersed by short rest periods. The method and apparatus further comprise delivering minimal energy during a long off period, the long off period comprising a relatively long period when minimal energy is applied, wherein one long off period follows each pulsed energy on period. The short burst periods and the short rest periods are relatively brief in duration as compared with the long off period.

Abstract: This disclosure provides systems and methods for sensing coupling of an ultrasound source to a target and for providing a constant average output of power from an ultrasound source. The systems and methods can include a frequency sweep function. The systems and methods can also include receiving reflected energy from an acoustic window and determining a feedback using the reflected energy. The systems and methods can also include comparing the feedback with a threshold level and using the comparison to determine if the ultrasound source is coupled with a target.

Abstract: In an approach for providing simulation results of an interaction between a transducer head and a magnetic medium, a computer identifies a first raster scan of a sample via a scanning probe microscope. The computer generates a topography image based on the first raster scan of the sample. The computer identifies one or more reference features within the created topography image. The computer calculates an average height based on the one or more reference features. The computer determines a lift distance associated with a probe of the scanning probe microscope. The computer defines a uniform plane based on the calculated average height and the determined lift distance. The computer performs a second raster scan of the sample based on the defined uniform plane. The computer generates a fly-height image based on the second raster scan. The computer provides simulation results based at least in part on the second raster scan.

Abstract: The present disclosure provides a device having a circuit. The circuit includes at least one boost converter receiving power from an energy source, a square wave driver in series with the boost converter, an inductor in series with the square wave driver for converting a square wave to a sinusoidal wave, and a piezoelectric transducer in series with the inductor, the piezoelectric transducer connectable to a load. The device further includes a phase-locked loop coupled to the circuit to determine a resonance frequency of the piezoelectric transducer when the piezoelectric transducer is connected to the load.

Abstract: In an approach for providing simulation results of an interaction between a transducer head and a magnetic medium, a computer identifies a first raster scan of a sample via a scanning probe microscope. The computer generates a topography image based on the first raster scan of the sample. The computer identifies one or more reference features within the created topography image. The computer calculates an average height based on the one or more reference features. The computer determines a lift distance associated with a probe of the scanning probe microscope. The computer defines a uniform plane based on the calculated average height and the determined lift distance. The computer performs a second raster scan of the sample based on the defined uniform plane. The computer generates a fly-height image based on the second raster scan. The computer provides simulation results based at least in part on the second raster scan.

Abstract: Disclosed is a method of generating electrical signal waveforms by a generator. The generator includes a digital processing circuit, a memory circuit in communication with the digital processing circuit, the memory circuit defining a lookup table, a digital synthesis circuit in communication with the digital processing circuit and the memory circuit, and a digital-to-analog converter (DAC) circuit. The method includes storing, by the digital processing circuit, phase points of a digital electrical signal waveform in the lookup table defined by the memory circuit, wherein the digital electrical signal waveform is represented by a predetermined number of phase points, wherein the predetermined number phase points define a predetermined wave shape. Receiving a clock signal by the digital synthesis circuit. Retrieving, by the digital processing circuit, a phase point from the lookup table. Converting, by the digital processing circuit, the retrieved phase point to an analog signal.

Abstract: A control apparatus of a vibration actuator performs control of the vibration actuator using a control amount calculated using both of a first deviation which is a difference between a command value and a relative position, and a gain changed in accordance with a second deviation which is a difference between a target position and the relative position, so as to reduce the gain in accordance with reduction of the second deviation.

Abstract: A variable inductor includes a three-limbed core first section having an inductor winding wound about a medial limb. An air gap is disposed in the medial limb. The inductor includes a second section having a control limb in which a first end of the control limb is connected to a first outer limb of the three-limbed core, and a second end of the control limb is connected to a second outer limb of the three-limbed core. A control winding is wound about the control limb. The inductor may be used in a control circuit to control a power signal driving a transducer. The inductor may be controlled by a signal derived from a comparison of a voltage phase of a power signal to the transducer and a phase of the current traversing the transducer. A system may include the control circuit, including the variable inductor, and the transducer.

Abstract: A pressure-detecting sensor that includes a piezoelectric sensor, a rectangular plate member, and an attaching member. The piezoelectric sensor is attached to the plate member via the attaching member so that the piezoelectric sensor is located in the vicinity of an end of the plate member in the longitudinal direction of the plate member, and such that the longitudinal direction of the piezoelectric sensor is parallel to the transverse direction of the plate member. The attaching member is composed of a sticky agent having an elastic constant of 106 Pa or lower. The piezoelectric sensor has a shape having aspect ratio of 2.5 or higher.

Abstract: A method may include: (i) based on an error between a setpoint value and a measured process value, determining an integrated error indicative of a time-based integral of the error; (ii) based on the error, determining a differential error indicative of a time-based derivative of the error; (iii) based on the integrated error and the error, generating a proportional-integral output driving signal; (iv) based on the differential error and the error, generating a proportional-differential output driving signal; (v) determining whether the differential error is stable; (vi) responsive to determining that the differential error is stable, generating a driving signal for controlling a plant based on the proportional-differential output driving signal and independent of the proportional-integral output driving signal; (vii) responsive to determining that the differential error is unstable, generating the driving signal for controlling the plant based on the proportional-differential output driving signal and the pro

Abstract: A method for identifying an overcurrent when charging a piezo actuator, by periodically connecting and disconnecting the piezo actuator to and from an energy source via a charging coil. A connection is followed by a disconnection when the charging current has reached a prescribed maximum current value and a minimum switched-on time has elapsed, and a connection is effected again when either a prescribed minimum current value has been reached or a maximum switched-off time has elapsed. An overcurrent is identified when a disconnection is effected when the minimum switched-on time has elapsed and the charging current has previously reached or exceeded a prescribed maximum current value. An overcurrent is also identified when, after a disconnection on account of the prescribed maximum current value having been reached, a connection is effected again when the maximum switched-off time has elapsed without the minimum current value having been reached.

Abstract: A motor driving apparatus including an inverter having a plurality of switching devices, wherein the inverter converts a direct current (DC) power into an alternating current (AC) power according to switching of the switching devices and supplies the AC power to a motor, and a controller to control the inverter, wherein the controller performs a control operation such that a switching frequency of the respective switching devices of the inverter remains constant in a first mode corresponding to a motor operation mode and performs a control operation to change the switching frequency of the respective switching devices of the inverter in a second mode corresponding to a sound output mode for fault diagnosis to output sound corresponding to the changed switching frequency.

Abstract: A method is directed to tuning a haptic actuator that includes a housing having a ferromagnetic mass, a coil carried by the housing, and a field member movable within the housing responsive to the coil. The haptic actuator is operative as a resonator and has an initial quality (Q) factor. The method may include determining whether the initial Q factor is within a desired Q factor range, and when the initial Q factor is not within the desired Q factor range, performing ferromagnetic mass change iterations until an updated Q factor is within the desired Q factor range. Each ferromagnetic mass change iteration may include changing the ferromagnetic mass of the housing, determining the updated Q factor based upon changing the ferromagnetic mass of the housing, and determining whether the updated Q factor is within the desired Q factor range. Another embodiment changes the ferromagnetic mass of the field member.

Abstract: A piezoelectric motor assembly for producing rotary motion, according to the present invention, has a motor frame and a circular body rotatably mounted on the motor frame having a diameter, a thickness, and a circumferential outer surface. At least two piezoelectric motors are mounted on the motor frame in tangential engagement with the outer surface of the circular body. The at least two piezoelectric motors are biased against the outer surface, resulting in an unbalanced net force on the circular body.

Abstract: A power generation apparatus and a touch apparatus with grain materials are provided. The power generation apparatus includes a grain material layer, a first electrode, an electric material layer, a second electrode and a conductive wire. The first electrode is electrically connected to the grain material layer. The electric material layer corresponds to the grain material layer, and a gap is formed between the grain material layer and the electric material layer. The second electrode is electrically connected to the electric material layer. The conductive wire is electrically connected to the first electrode and the second electrode. The grain material layer and the electric material layer interact with each other to generate a current or a voltage. Thereby, the present invention can generate power by utilizing a grain material.

Abstract: An ultrasonic transducer that can include a driver side and a bias voltage side. A higher voltage source can be electrically connected to the bias voltage side through a first resistor. A lower voltage source can be electrically connected to the driver side of through a second resistor. A field effect transistor or other suitable switch can be included, having a source, a gate and a drain. The source can be electrically connected to ground and the gate can be electrically connected to a control signal source. The drain can be electrically connected to the lower voltage source through a second resistor and be electrically connected to the driver side of the ultrasonic transducer. The gate can be electrically connected to a signal source through a third resistor.

Abstract: An impedance matching circuit is provided for use with a piezotransducer that includes a parasitic capacitor comprising: an inductor coupled in parallel with the parasitic capacitor; a peak and valley detection circuit configured to detect output voltage waveform peaks and valleys; a first switch circuit configured to bias flip the output voltage waveform at a selectable first time relative to a detected peak and at a selectable first time relative to a detected valley; a second switch circuit configured to couple the inductor to the energy storage circuit at a selectable second time following each output voltage bias flip; an energy monitoring circuit to provide an indication of energy flow from the inductor to the energy storage circuit following each output voltage bias flip; and a maximum power point tracking (MPPT) circuit configured to select the first time and the second time based at least in part upon the indicated energy flow.

Abstract: A method, system, and/or computer program product mitigate sympathetic resonance in a structure that is physically proximate to a machine. One or more processors, based on readings from a sound sensor associated with a machine, detect a sound generated by a machine component of the machine. One or more processors, based on readings from a resonance sensor, detect vibration caused by sympathetic resonance in a structure that is physically proximate to the machine, where the sympathetic resonance is caused by the sound generated by the machine component. One or more processors then direct a machine component controller to adjust the machine component in order to mitigate the sympathetic resonance in the structure that is physically proximate to the machine.

Abstract: A scanning endoscope apparatus is provided that includes: an endoscope having a light guide portion configured to guide and emit an illuminating light for illuminating a subject, and an actuator configured to oscillate the light guide portion; a storage portion configured to store a resonance frequency at a time when the light guide portion is caused to oscillate in a resonant state; an application portion configured to sequentially apply a plurality of signals having different frequencies to the actuator; a signal monitoring portion configured to monitor signals that are applied to the actuator; and a determination portion configured to compare a frequency of a signal which is smallest in a case where the actuator is taken as a load with the resonance frequency stored in the storage portion to determine whether or not the endoscope is abnormal.

Abstract: The present invention relates to an apparatus and method for attenuation of vibration in a machine tool, and more particularly, to an apparatus and method for attenuation of vibration in a machine tool in which a vibration of a machine tool is measured, and generates an identical frequency with a piezoelectric actuator as well as changes a phase for making dissipative interference of a generated vibration wave form.

Abstract: An electricity generator including a first converter suitable for converting a variation of an energy to be harvested into a corresponding excess of electrical charges. The generator includes a circuit for collecting the excess of electrical charges, the circuit has a first controllable mechanical switch, and a control device for the first switch designed to control the switching of the switch to its closed position when the excess of electrical charges exceeds a first predetermined threshold. The switch is a magnetic switch and the control device comprises a variable magnetic field source which controls the switching of the first switch to its closed position only at the time when the excess of electrical charges exceeds the first predetermined threshold.

Abstract: A system for searching for a resonant frequency of a transducer, comprising: an initializing unit (11), a phase determining unit (12), an interval hopping control unit (13), a hopping interval generating unit (15), a frequency output control unit (17), a phase acquiring unit (16), and a resonant frequency obtaining unit (14). The search range of the interval for the last search can be narrowed by at least half thereof in each frequency hopping, thus allowing for reduced amount of searches.