122 results about "Free oscillation" patented technology

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.

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.

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 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.

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 All Digital PLL (ADPLL) and oscillation signal generation method using the ADPLL is provided for generating a spur-free oscillation signal by improving the frequency resolution of the ADPLL. An all digital phase-locked loop of the present invention includes a digitally controlled oscillator for generating an oscillation signal having a frequency corresponding to an inputted control signal, a re-timer for retiming a reference clock based on the oscillation signal, a feedback circuit for accumulating a number of clocks of the oscillation signal within a time period and generating a phase information of the oscillation signal in synchronization with the retimed reference clock, a sigma-delta modulator for sigma-delta modulating a frequency command signal into a modulation signal having a less number of bits than a number of bits of the frequency command signal, a reference phase accumulator for accumulating phases corresponding to the modulation signal, a phase difference detector for generating a phase difference information between an output signal of the reference phase accumulator and the phase information, and a digital loop filter for filtering the phase difference information to generate the control signal.

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.

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.

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 relates to a method for operating a vibrating gyroscope and to a sensor arrangement comprising such a vibrating gyroscope. Said vibrating gyroscope is used as a resonator and is part of at least one control circuit that excites the vibration gyroscope by feeding an excitation signal with its natural frequency. An output signal can be tapped from the vibrating gyroscope from which the excitation signal can be derived by filtering and amplification. The invention is characterized in that, once the sensor arrangement is switched on, the frequency of the excitation signal is adjusted by exciting the vibrating gyroscope, before the excitation signal is fed, to oscillate freely, measuring the frequency of the free oscillation and feeding the excitation signal to the vibrating gyroscope with the measured frequency.

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.