123 results about "Free oscillation" patented technology

A data emission / reception device by inductive coupling includes an inductive antenna circuit in which an antenna signal appears, a mechanism configured to for extracting a first periodic signal from the antenna signal, a synchronous oscillator receiving the first periodic signal and supplying a second periodic signal, and an active load modulation circuit configured to apply bursts of the second periodic signal to the antenna circuit. The device is configured to place the oscillator in the synchronous oscillation mode before each application of a burst of the second periodic signal to the antenna circuit, then place the oscillator in the free oscillation mode.

A method for sending data by inductive coupling includes: extracting an antenna signal from an antenna circuit, extracting from the antenna signal a first periodic signal, producing a second periodic signal by way of a synchronous oscillator, placing the oscillator in a free oscillation mode and applying to the antenna circuit the second periodic signal, modifying the impedance of the antenna circuit, restoring the amplitude of the antenna signal, then resynchronizing the oscillator on the first periodic signal.

A shock absorbing tool for use in pipelines and oil wells, particularly in combination with perforation guns comprises a central mass supported on two springs between the end terminal members. The shock wave is absorbed in the free oscillation of the mass. The mass is constituted by a piston assembly. A steel rope permits the shock absorbing tool to be maneuvered within the bore hole without damage to the springs.

Various embodiments of the present invention relate to an actuator driver in a camera module, and more particularly to methods, systems and devices of employing self-calibrated ringing compensation to improve the autofocus rate of the camera module that is driven by an actuator. Oscillation characteristics of the actuator are calibrated to control a sink current that drives the actuator during an autofocus. The actuator driver comprises a digital-to-analog converter (DAC), a filter, a current sink and a self calibration module. The self calibration module calibrates the free-oscillation frequency and damping coefficient, and accordingly, the DAC generates a voltage that may be subsequently bypassed, filtered or shaped by the filter. This voltage is further converted to the sink current by the current sink. Such self-calibrated ringing compensation allows close tracking of free oscillation, and may efficiently enhance the settling time of the lens and autofocus rate of the camera module.

PCT No. PCT / JP95 / 01044 Sec. 371 Date Dec. 13, 1996 Sec. 102(e) Date Dec. 13, 1996 PCT Filed May 30, 1995 PCT Pub. No. WO95 / 34427 PCT Pub. Date Dec. 21, 1995A piezoelectric actuator is deformed from an initial condition for a time (T1) in a direction, in which an inner volume of an ink chamber is increased, to supply ink to the ink chamber. Subsequently, the piezoelectric actuator is deformed for a time (T2) at a considerably slow speed as compared with the time (T1) for the preceding supply of ink to gradually increase the inner volume of the ink chamber to supply ink to the ink chamber. During the time (T2), free oscillation having generated in ink in the piezoelectric actuator and the ink chamber attenuates. Subsequently, the piezoelectric actuator is rapidly deformed to compress the ink chamber, thereby jetting ink in the ink chamber via nozzle holes.

A power supply unit comprises a series regulator and a switching DC-DC converter controlled by a PWM signal and connected in parallel with the series regulator, which are switchably enabled by a mode instruction signal depending on the magnitude of a load current. In switching the series regulator and the DC-DC converter, they are simultaneously enabled for a predetermined overlapping time. Further, in changing the operating condition of the DC-DC converter, the width of the PWM signal is shortened to extend the dead time of the DC-DC converter by a predetermined period, thereby suppressing free oscillations and accompanying overshoots that could take place in the power supply unit during switching.

Provided is a self-adaptive line selection method for a single-phase earth fault of a resonant earthed system. The self-adaptive line selection method for the single-phase earth fault of the resonant earthed system comprises the steps that when zero-sequence voltage of the system is greater than setting voltage, a fault line selection device is started and records bus zero-sequence voltage and zero-sequence currents of circuits before the fault and after the fault; atomic decomposition improved based on a PSO is carried out on the bus zero-sequence voltage, time of occurrence of the fault is determined, preprocessing is carried out on the collected zero-sequence currents of the circuits based on the time of occurrence of the fault to obtain transient state zero-sequence currents of two power frequency cycles, then the atomic decomposition improved based on the PSO is carried out on the transient state zero-sequence currents, and an optimal matched atom representing a transient state free oscillation component and a decaying direct current component of the transient state zero-sequence current of each circuit is obtained; corresponding characteristic information of the optimal matched atoms is extracted; according to the size of an energy entropy scaling factor, a single-phase earth fault occurrence mode is determined, and self-adaptive fault line selection is carried out according to the mode.

A power supply unit comprises a series regulator and a switching DC-DC converter controlled by a PWM signal and connected in parallel with the series regulator, which are switchably enabled by a mode instruction signal depending on the magnitude of a load current. In switching the series regulator and the DC-DC converter, they are simultaneously enabled for a predetermined overlapping time. Further, in changing the operating condition of the DC-DC converter, the width of the PWM signal is shortened to extend the dead time of the DC-DC converter by a predetermined period, thereby suppressing free oscillations and accompanying overshoots that could take place in the power supply unit during switching.

The invention discloses an active radio frequency identification tag and an implementation method thereof. According to the frequency and phase information of a carrier tracked and received by a phase-locked loop, the tag generates a local oscillation signal with the same frequency and phase of the carrier, and data to be sent is modulated onto the local oscillation signal and transmitted to a reader after power amplification. No crystal oscillator needs to be circumscribed to the tag to be used as a reference datum and the reference datum of the tag comes from the carrier received by tag antenna. A power management circuit is arranged in the tag and controls the on-off of the tag, switches sender-receiver modes and manages power consumption. When the tag is in receiving mode, the phase-locked loop tracks the carrier and when the tag is in sending mode, the local oscillation signal maintains the free oscillation of the state of the moment before.

A two vacuum actuated switch mechanism is provided within an engine or hydromount. First and second ports are provided along a peripheral portion of an inertia track assembly. A decoupler or vacuum diaphragm is selectively exposed to vacuum through a first port. Under the influence of the vacuum, the decoupler can no longer oscillate. If vacuum is applied only to the decoupler, and not and idle diaphragm, the fluid is forced through a low frequency inertia track which creates high levels of damping and low frequencies. If vacuum is also applied to the decoupler and the idle diaphragm, the high frequency inertia track is opened and causes the fluid to flow therethrough. This creates a high frequency dynamic rate dip. Alternatively, if no vacuum is applied to either the decoupler or the idle diaphragm, the decoupler is allowed to freely oscillate creating a decoupled state for low input displacements. Higher input displacements results in fluids being forced through the low frequency inertia track. An integrated accumulator is disposed between the port and the decoupler to reduce or eliminate air resonance response, buffering the pumping effect of the decoupler in a decoupled state.

The invention discloses a low frequency oscillation distinguishing method based on response ingredient and oscillation characteristic identification. The low frequency oscillation distinguishing method mainly comprises the following steps: selecting to-be-analyzed oscillation data; identifying response ingredients and oscillation characteristics; first distinguishing negative damping oscillation, ending if the oscillation is negative damping oscillation, or else performing distinguishing of resonance oscillation; if the oscillation is distinguished to be resonance oscillation in the distinguishing process of the resonance oscillation, and transferring to distinguishing of positive damping resonance and zero damping resonance; otherwise, transferring to distinguishing of positive damping free oscillation, performing distinguishing of zero damping equiamplitude free oscillation if the oscillation is not positive damping free oscillation, performing distinguishing of zero damping beat frequency oscillation if the oscillation is not distinguished to be zero damping equiamplitude free oscillation, performing distinguishing of positive damping beat frequency oscillation if the oscillation is not distinguished to be zero damping beat frequency oscillation, and ending. The low frequency oscillation distinguishing method has the advantages of being simple and clear in principle, distinguishing finely and being complete in criterion.

The invention discloses a PRCE-based low-frequency oscillation mode on-line identification method and belongs to the power system low-frequency oscillation field. The method includes the following steps that: the angular velocity measurement signals of a plurality of generators after the disturbance of a section of a power system are read; a Hankel matrix is constructed through free oscillation signals, and a column vector is solved by using the least squares method; and a matrix polynomial is constructed so as to solve an eigenvalue matrix and a right eigenvector matrix, and therefore, the oscillation frequency, damping ratio and oscillation mode of the system can be obtained. The method of the invention, based on multi-channel signals, can identify oscillation modes and can obtain more stable identification results. Compared with a TLS-ESPRIT method and an SSI (stochastic subspace identification) method, the method of the invention is advantageous in more stable identification results, higher identification accuracy and higher identification efficiency.

This power generation switch (100) is provided with: parallel beams (11a, 11b) that include at least one magnetostrictive rod that is a magnetostrictive material formed into a beam shape; coils (12a, 12b) wound around the magnetostrictive rod; a first joining member (10a) that, at the first end of the parallel beams, is a member that joins two beams that configure the parallel beams; a second joining member (10b) that, at the second end, is a member that joins the two beams that configure the parallel beams; field magnet units (14a, 14b) that cause the generation of magnetic flux penetrating each of the two beams in the same orientation; and an operation member (50) that a user operates. The first joining member forms an affixed end that is not displaced, and the second joining member forms a free end that can oscillate freely. The operation member applies external force to the second joining member in a manner so that a free oscillation wherein positive axial force arises at one of the two beams and negative axial force arises at the other of the two beams arises at the parallel beams.

The invention relates to an actuator driver in a camera module, more specifically, to a method, a system and a device utilizing the self-calibration ring compensation to improve the self focus rate of the camera module driven by the actuator. The oscillating characteristic of the actuator is calibrated, thereby controlling the sink current driving the actuator in the automatic focus period. The actuator driver includes a digital-analog converter (DAC), a filter, a current absorber and a self-calibration module. The self-calibration module calibrates free oscillation frequency and damping coefficient. Correspondingly, the DAC generates voltage that can be filtered or reshaped by a bypass of the filter later. The voltage is converted into the sink current further by the current absorber. Therefore, the self-calibration ring compensation can trace free oscillation closely and can improve the stable period of lens and improve the automatic focus rate of the camera module efficiently.

The invention discloses an electric system low frequency oscillation mode identification method based on correlation functions. The method includes the following steps that firstly, a section of an active power signal of a circuit having high observability for a low frequency oscillation mode under the circumstance that no large disturbance exists in an electric system is read and serves as a signal to be analyzed, and a sampling time interval Ts is determined; secondly, the read active power signal is preprocessed to obtain a corresponding power fluctuation signal; thirdly, a self-correlation function of the power fluctuation signal is solved, and a system free oscillation signal is obtained; fourthly, based on an extended Prony method, mode identification is carried out on the free oscillation signal to obtain a low frequency oscillation mode frequency and a damping ratio. The electric system low frequency oscillation mode identification method has the advantages that the method is only based on random response signals, operation is simple, the calculation amount is small, and identification accuracy is good.

An inductive displacement sensor having a displaceable or rotatable, magnetically permeable measuring head, at least one measuring loop whose geometric shape varies in response to the longitudinal / rotary displacement of the measuring head, and at least one excitation loop by which a magnetic flux can be generated in the measuring head. The flux penetrates the at least one measuring loop at any point of the longitudinal / rotary displacement, essentially in the region of the measuring head, and inducing an electric measuring signal (i2). A resonant circuit, which is electrically decoupled from the outside, is arranged on the measuring head and is excited in correct phase relation by a short voltage pulse after a number of, preferably, 10 to 20 free oscillations.

The invention discloses a method for discriminating the type of a low frequency oscillation mechanism based on envelope fitting. The technical scheme comprises the steps of: first, acquiring an envelope of a dominant oscillation mode curve through oscillation data to be analyzed; then, carrying out discrimination on the periodicity of the envelope, thereby coming into different fitting determinations according to discrimination results; and finally, realizing discrimination of negative damping free oscillation, zero damping free oscillation, positive damping resonance and zero damping resonance according to fitting results. Compared with a technical scheme in the prior art, the method disclosed by the invention utilizes WAMS measured data, makes full use of envelope characteristics of various types of low frequency oscillations after extracting dominant mode signals through a digital signal processing method, and discriminates the type of the low frequency oscillation in a mode of fitting, the discrimination process is clear, the discrimination is precise and reliable, and the discrimination speed is high, thereby well meeting requirements for discrimination of the type of the low frequency oscillation, and having good engineering application values.

An impact test apparatus allows a retaining member to retain a test object. The retaining member is attached to an elastic member. When a weight is made to collide against the test object, impact is applied to the test object. The test object is subjected to free oscillation in response to the impact. The elasticity of the elastic member accepts the movement of the retaining member. Damping of the free oscillation of the test object is minimized. The impact test sufficiently reflects the influence of the free oscillation.

An electromagnetically driven valve includes a driven valve having a stem and carrying out reciprocating motion along a direction in which the stem extends, a disc support base having an abutment surface, a disc extending from one end coupled to the stem toward the other end supported by the disc support base so as to allow free oscillation of the disc, and an electromagnet applying electromagnetic force to the disc. The disc has a root portion formed at the other end, and an arm portion formed from the root portion to one end. The electromagnet has a surface facing the arm portion. When the disc is attracted to the electromagnet the abutment surface abuts on the root portion and a gap is created between the surface and the arm portion. With such a structure, excellent quietness and durability can be achieved and energy loss can be reduced.

The invention discloses a method and a device for promoting output characteristics of a Nd:YAG laser device and belongs to the field of laser device manufacturing. The device comprises a trapezoid lath laser gain medium, a pumping source, a total reflective mirror, a cylindrical mirror, a diaphragm and an output lens; a Nd:YAG crystal lath bonded with sapphire is arranged as the trapezoid lath laser gain medium; a bonding technique of different materials is utilized to reduce the heat effect of a heat lath laser device and promote the output power and the light beam quality. The excellent heat conduction of the sapphire is utilized to realize the laser output in high output power and high light beam quality in the free oscillation running process of the grazing incidence lath laser device.

The invention discloses a device for testing a stable platform, which comprises a measurement bench unit and a rotary base unit. The measurement bench unit is made of a non-magnetic or weak magnetic material, which can effectively reduce the interference on the stable platform so as to ensure the accuracy of a test result; the measurement bench provides the stable platform with a required rotation speed of a generator, a rotation speed of a drill collar and a load torque, and can simulate underground working conditions; and a measurement system can obtain parameters of a rotation angle and a rotation speed of the stable platform, the rotation angle, the rotation speed and an output torque of an output shaft, an inclined angle of a test bed and the like, thereby verifying whether the performance parameters of the stable platform are correct. The rotary base unit can realize free oscillation of a platform in a spatial vertical plane and free rotation of the platform around the central axis of the base, thereby simulating well deviation and the change of an orientation parameter, and verifying whether the stable platform works stably and accurately.

An impact test apparatus allows a retaining member to retain a test object. The retaining member is attached to an elastic member. When a weight is made to collide against the test object, impact is applied to the test object. The test object is subjected to free oscillation in response to the impact. The elasticity of the elastic member accepts the movement of the retaining member. Damping of the free oscillation of the test object is minimized. The impact test sufficiently reflects the influence of the free oscillation.

The invention discloses an electric power system low frequency oscillation mode online identification method comprising the steps that firstly generator angular velocity signals recorded by an electric power system wide area measurement system under the normal operation situation are read firstly; then de-mean processing is performed on the read generator angular velocity signals; then zero mean signals are inputted to a signal processing module based on the random decrement technology so that free oscillation signals are acquired; and finally model identification is performed on the free oscillation signals based on a least square complex exponential method so that the frequency and the damping ratio of the electric power system low frequency oscillation mode can be identified. According to the method, the electric power system low frequency oscillation mode can be identified in a wider range of time and the method has great identification accuracy and anti-noise performance so that a brand-new approach and method can be provided for electric power system low frequency oscillation analysis.

The invention discloses a detecting method based on a multi-frequency stimulation Duffing chaotic oscillator weak signal detection system. The method comprises the following steps that 1) the multi-frequency stimulation Duffing chaotic oscillator weak signal detection system is established, namely a free-oscillation Duffing chaotic oscillator mathematic model is selected; detected signals which do not contain noise are decomposed in a different-frequency-harmonic-wave-superposition mode; the detected signals which do not contain noise are used as Duffing chaotic oscillator stimulation item factors, the multi-frequency stimulation Duffing chaotic oscillator weak signal detection system is established; an equation set form is rewritten, an equation set is solved, F0 corresponding to a phase transformation critical state which is sensitive to driving force and is good in identifiability is used as initial driving force of the detection system; 2) the detected signals are introduced into the multi-frequency stimulation Duffing chaotic oscillator weak signal detection system, and detection is carried out according to the phase transformation law. According to the method, when multi-frequency signals are detected, the uncertain influence of the detected signals on the phase transformation law of a single-frequency stimulation chaotic oscillator detection system can be removed or lowered.

A target detection system may include a power supply and an inductor capacitor (LC) tank circuit. The LC tank circuit may include a sensing coil, a first tank capacitor, and a second tank capacitor. Further, the LC tank circuit may alternate between the first tank capacitor and the second tank capacitor, and the power supply may power the LC tank circuit. The target detection system may further include measurement circuitry to measure a first decay characteristic of a first set of free oscillations from the first tank capacitor and a second decay characteristic of a second set of free oscillations from the second tank capacitor. Additionally, the target detection system may also include processing circuitry to compare the first decay characteristic to the second decay characteristic to determine a presence and a distance of a target.

An adaptive sliding-frequency triggering ignition method for electronic ballast of high pressure gas discharge lamp includes the steps of: measuring an accurate value of free oscillation frequency of the ballast load loop by using a single-chip before sliding-frequency triggering ignition, implementing safe and reliable sliding-frequency triggering ignition after calculating the initial frequency and ending frequency of sliding-frequency triggering ignition according to the accurate value. The method can safely and reliably finish sliding-frequency triggering ignition course, thus improving the parameters such as the quality, life of the high pressure gas discharge lamp electronic ballast.

The invention discloses a method for distinguishing free oscillation and forced oscillation of an electric power system, and belongs to the technical field of electric power system analysis. The method includes the steps: monitoring active power amplitudes of a generator, a transformer and a circuit and analyzing active power data with the maximum amplitude after the system starts oscillation; solving the maximum value and the minimum value of the active power in each oscillation cycle, subtracting the minimum value from the maximum value to obtain an oscillation peak-to-peak value and analyzing a few or a dozen of oscillation cycles with peak-to-peak values increased with time from oscillation starting time; subtracting a previous peak-to-peak value from each peak-to-peak value to obtain the increment of each peak-to-peak value and solving natural logarithms for the increment; and linearly fitting the natural logarithms for the increment of the peak-to-peak values, calculating a slope index and judging that oscillation is free oscillation when the slope index is larger than zero and the oscillation is forced oscillation when the slope index is smaller than zero. By the method, oscillation types are distinguished according to waveform features at an oscillation starting stage, oscillation type distinguishing speed and accuracy are improved, a power grid operator can be helped to timely and accurately distinguish the oscillation types, and targeted measures are taken to calm down oscillation.