1077results about How to "Improve sampling accuracy" patented technology

The invention relates to a device and a method for detecting and positioning small current earthing fault. The device comprises a slave computer and a host computer composed of a CPU module, a DSP, a pre-loop unit module, a A/D conversion module, a memory module, a display and keyboard operation module as well as a communication module; wherein, the pre-loop unit module, the A/D conversion module, the CPU module and the DSP are connected in sequence; the memory module, the display and keyboard operation unit module and the communication module are respectively connected with the CPU; the host computer is connected with the communication module. The CPU module collects the analog signal of the zero-sequence voltage of the bus and the zero-sequence current of each line, and adjusts the value in proportion to the amplitude range so that the device can deal with. The analog signal is turned into digital signal recognized by the computer module, and analyzed by the DSP to judge whether the fault occurs or not. If the fault occurs, then the DSP gives the line selection result, saves the fault information and transfers the line selection result to the host computer for fault alarm.

A method of measuring the surface flux of a component of a soil gas comprises placing a chamber for collecting said gas sealably in contact with a soil the chamber initially containing atmospheric gas. Then, the chamber is connected to a purging apparatus to purge the chamber of all measurable traces of the component. Then the soil is permitted to enter the chamber. The method uses a system for measuring the surface flux of the component. The system comprises a chamber having an open bottom for collecting soil gas, a venting port, an exhaust port having a valve and means to purge the chamber of the component.

The invention discloses an on-line positioning method of a section with low-current ground faults and a system based on the positioning method. The method and the system are suitable for a neutral ungrounded power grid of 3-60kV. Under the operation condition of a line with single-phase ground faults, the phasor information of a zero-sequence voltage and the amplitude and phasor information of a zero-sequence current of the line are measured, and the section position of a fault point is determined according to the amplitude and phase information. The accuracy and rapidity of positioning are fully ensured, and the on-line positioning problem of single-phase ground faults of the neutral ineffectively grounded power grid and the monitoring problem of short-circuit faults between lines are effectively solved.

The invention relates to a method for vertically processing a cooling passage of a liquid rocket engine thrust jet, which belongs to the processing method field of liquid rocket engine thrust jet. In the invention, the thrust jet adopts a vertical clamp; a single-point laser sensor scans bus bars strip by strip to acquire the actual profile of the thrust jet and a sampled data set to reconstruct the bus bars of the thrust jet strip by strip; the buses of the sampled data set are smoothed strip by strip to acquire a thrust jet smoothed data set; the data set of all the bus bars are compressed to acquire a compressed data set; and a cubic spline is used for performing interpolation to approximate the actual bus bars of the thrust jet. The milling tool position is calculated by dual milling head for symmetrical milling and high speed back chipping. The method realizes the integration of measurement and processing, finishes the treatments of profile measurement, milling groove and back chipping by one clamping, can satisfy the processing requirements on different physical dimensions and different bus bar linetypes, has high processing efficiency and good consistency, and realizes the digital processing with high efficiency and high precision of the cooling passage of the liquid rocket engine thrust jet.

The invention discloses a localizable ultrahigh-frequency cable partial discharge detection method and device. The invention is characterized in that a data synchronous acquisition module comprises two high-speed acquisition channels and one low-speed acquisition channel, two ultrahigh-frequency sensors and one power-frequency signal sensor are externally connected for synchronous acquisition of ultrahigh-frequency partial discharge signals, environment signals and power-frequency voltage signals below 1GHz, and the ultrahigh-frequency sensors are directly arranged on a cable; an analyzing and processing module compressively analyzes the acquired synchronous data by the five combined method, effectively identifies cable partial discharge signals and external noise interference and further realizes partial discharge positioning; a power denoising module is used to prevent introduction of noise interference by a portable power source during outdoor use; and a user control terminal has the functions of data acquisition display, result analysis, historical data review and real-time report printing. The invention makes it possible to detect and position partial discharge of power cables, improves the reliability of partial discharge detection and realizes accurate judgment on partial discharge.

The invention discloses a multi-path data acquiring system based on FPGA, which mainly solves the problems of small signal acquiring range and poor acquiring precision of the prior multi-path acquiring system. The multi-path data acquiring system comprises a multi-path selector, a programmable-gain amplifier, an AD converter and an FPGA data processing module, wherein the FPGA data processing module sends an address signal to the multi-path selector and also sends a magnification signal to the programmable-gain amplifier; the multi-path selector selects an external analog signal according to the address signal to enter the programmable-gain amplifier; after amplifying the input analog signal, the programmable-gain amplifier outputs the analog signal to the AD converter; the AD converter samples the input analog signal, quantifies the analog signal to form a digital signal and transmits the digital signal to the FPGA data processing module; and the FPGA data processing module transmits the input data to a host computer after sequencing, wave filtering and table searching. The invention has the advantages of wide signal acquisition range, high precision can convenient acquisition path expansion, thereby being suitable for the signal acquisition of an industrial monitoring and sensing network.

The detecting device comprises of the reagent strip, the reagent plate, the scanner, the data processing device, the output device and IC card. The reagent strip with the quality control strip and the detection strip being coated is stuck on the reagent plate fixedly. The density and the scanning time are stored on the IC card. With the parameters on the IC card being read out, the data processing device control the scanner to scan the reagent strip and the signals collected are transferred back to the data processing device. After the optical density value of the quality control strip and the detection strip being recognized, calculated and analyzed, the result is transferred to the output device. The invented detecting device provides the quantified detection with the precision and the accuracy accorded with the requirement.

The invention provides an intelligent battery cycle charge-discharge testing device. The device is a secondary battery automatic charge-discharge testing device with low price, high precision and good stability. The device can test main parameters of a secondary battery, has safe and reliable performance and has wide application prospect. The device comprises a power supply module, an electronic load, an acquisition control module, a PC machine and a charge-discharge module, wherein an output of the power supply module is connected with the electronic load and the charge-discharge module; a battery to be tested is connected with the electronic load by the charge-discharge module; a signal acquisition end of the acquisition control module is connected with the battery to be tested, while a control end thereof is connected with the charge-discharge module; and the acquisition control module is on-line with the PC machine by a USB data wire.

The invention provides a frequency calibration circuit and a method thereof. The frequency calibration circuit comprises a phase lock loop circuit, an M-dividing divider for generating a plurality of phase signals, a sampling circuit for sampling on the rising edges of the phase signals, a first counter for counting reference frequency signals, a second counter counting first phase signals, a logical control circuit for comparing a count value with a target count value to obtain a minimum difference value, and looking up a control bit of a voltage-controlled oscillator through the difference value, and a comparison circuit for judging whether the control voltage of the voltage-controlled oscillator is in a set range or not. The method comprises the following steps: sampling the reference frequency signals to obtain a total count value; comparing the total count value with a target count value; selecting a next resonance line according to a binary lookup flow till binary lookup ends; and outputting a resonance line corresponding to a minimum error in order that the output frequency of the voltage-controlled oscillator reaches a required value. Through adoption of the frequency calibration circuit and the method thereof, the speed and accuracy are increased, and the requirement on the working frequency of a digital circuit is lowered, so that a design method is simplified.

The invention relates to the field of data acquisition and processing, in particular to a multichannel data acquisition instrument based on time synchronization. In order to solve the problems in the prior art, the multichannel data acquisition instrument based on time synchronization is provided. The multichannel data acquisition instrument is used for data acquisition after being subjected to time correction through a VCO adjusting module, an FPGA and a processor are in parallel connection to conduct data transmission, data collected by a sensor are stored in a memory, data of a data storage chip are read to conduct subsequent data processing, or data interaction is conducted through an internet access and an upper computer, and upper computer data processing is conducted. According to the multichannel data acquisition instrument based on time synchronization, the processor, an FPGA control circuit, an analog-digital conversion and conditioning circuit and a sensor circuit are in mutual connection, and the design of the multichannel data acquisition instrument is achieved. The data acquisition instrument based on time synchronization is applied to the field of high-speed data acquisition.

The invention provides a multichannel temperature acquisition system, which comprises a sensing unit, a current source, a multichannel scan switch unit, an analog-to-digital converter, a controller, and the like, wherein the sensing unit comprises a group of temperature sensors for acquiring temperature of the environment surrounding the multichannel temperature acquisition system; the current source is used for providing exciting current for the sensing unit; the multichannel scan switch unit is used for selecting the temperature sensors of the sensing unit and sending temperature data acquired by the selected temperature sensors to the analog-to-digital converter; the analog-to-digital converter is used for converting an analog signal selected by the multichannel scan switch unit into a digital signal and providing the digital signal to the controller; and the controller is used for processing a switch selection signal provided by the multichannel scan switch unit, a selection signal provided by the current source and the digital signal of the analog-to-digital converter and providing the signals to a storage. The multichannel temperature acquisition system has simple structure and improves the acquisition precision.

A quantitative sampler of pathogens in exhaled air is provided. The quantitative sampler includes an air inputting pipe for a sampled individual to blow exhaled air; a check valve unit for preventing the exhaled air from reversely flowing; an aerosol filtering unit having an aerosol filtering material for collecting aerosol particles in the exhaled air; and an air flow meter for measuring if total accumulated volume of the exhaled air reaches a predetermined sampling volume defined as a concentration denominator of exhaled pathogens. The quantitative sampler can be used to collect the aerosol particles, and then moves the aerosol filtering material out of the aerosol filtering unit followed by separating genetic substances in the aerosol particles from the aerosol filter, so that a real-time qPCR can be reacted by using the genetic substances for obtaining a quantitative concentration of the exhaled pathogens.

The invention discloses a multichannel voltage collecting device and method. The device of the invention comprises filtering discharge units, multichannel switching units, logic control units and processor units, wherein the number of the filtering discharge units is the same as that of voltage modules to be detected, and the filtering discharge units are respectively connected with the voltage modules to be detected; the multichannel switching units are connected with the filtering discharge units; the logic control units are respectively connected with the multichannel switching units and is used for generating channel switching control signals for the multichannel switching units to carry out voltage collecting channel switching control; and the processor units are respectively connected with the multichannel switching units and the logic control units and is used for processing the collected voltage and controlling the logic control units to generate the channel switching control signals. In the invention, by filtering the output voltage of a power supply module to be detected, when in in transmission, space common mode interference and line transmission interference born by the output voltage of the power supply module to be detected are eliminated; and by switching on and switching off an optical coupler relay control channel, the invention has the characteristics of fast velocity response, short stabilization time, good linearity and long service life.

The invention discloses a soil measuring device for land planning, and relates to the technical field of land planning equipment. A driving motor is fixedly arranged on the upper part of a lifting plate through a motor bracket, a rotating shaft is fixedly arranged at the output end of the driving motor, the upper end of the rotating shaft is rotatably arranged on the middle part of the lifting plate through a bearing, and a drill bit is fixedly connected to the bottom end of the rotating shaft; a fixing plate is arranged on the lower side of the lifting plate, two electric lifting rods are symmetrically and fixedly arranged on the left side and the right side between the lifting plate and the fixing plate, the upper ends of the electric lifting rods are fixedly connected with the bottom ofthe lifting plate, and the bottom ends of the electric lifting rods are fixedly connected with the upper part of the fixing plate; leg supporting mechanisms are vertically and fixedly arranged on four corners of the bottom of the fixing plate; and a detection mechanism fixedly sleeves the outer side wall of the rotating shaft on the upper side of the drill bit. Technicians can conveniently sampledeep-level soil, the sampled depth can be effectively controlled, the humidity of a hard soil layer can be effectively measured, and soil humidity sensors are damaged.

The invention discloses a timed passive air sampler, which comprises an air sampler main body, wherein the air sampler main body comprises a packaging barrel with an opening at the top, an adsorbent cage which is sheathed in the packaging barrel, a blocking pillar, an electromagnet and a timing driving circuit; a timing beginning sensor and a mounting bracket are arranged on the side wall of the packaging barrel; a rubber plug matched with the top of the packaging barrel is arranged at the top end of the adsorbent cage; a return spring is arranged between the bottom of the adsorbent cage and the bottom of the packaging barrel; a bayonet which can be pulled out to expose the packaging barrel and a sensing body corresponding to the timing beginning sensor are arranged on the adsorbent barrel; the blocking pillar is arranged on the mounting bracket and can move in the radial direction of the packaging barrel and be matched with the bayonet; the electromagnet is arranged on the outer wall of the bracket of the packaging barrel and can control the blocking pillar to be departed from the bayonet; and the timing driving circuit is connected with the timing beginning sensor and the electromagnet. The timed passive air sampler can implement the accurate automatic control of the sampling time, automatic packaging, and effectively improve the sampling accuracy of the passive air sampler.

The invention discloses a sampling holding circuit applied to a high-speed high-precision circuit. The sampling holding circuit comprises a full-differential type operational amplifier, two sampling capacitors Cs, two sampling switches S1 and five selective switches and a low-pass filter circuit formed by a resistor R1 and a capacitor C1. The full-differential type operational amplifier is a gain enhancement folding cascade full-differential type operational amplifier, a sampling switch S1 is a grid voltage bootstrap switch, connected structures of the positive end and the negative end of the full-differential type operational amplifier are completely same, and a signal input end passes through the low-pass filter circuit to be connected with a lower pole plate of the sampling capacitors Cs through the sampling switches S1. A selective switch S3 is connected with the lower pole plate of the sampling capacitors Cs and the output end of the full-differential type operational amplifier. An upper pole plate of the sampling capacitors Cs is connected with the input end of the full-differential type operational amplifier, a selective switch S4 is connected with upper pole plates of the two sampling capacitors Cs, and a selective switch S2 is connected with the input end and the output end of the full-differential type operational amplifier. The sampling holding circuit can achieve sampling holding of the input signals in the high-speed high-precision circuit.

A method of cycle sampling for detecting electric energy quality includes using a fixed sampling frequency for sampling and using waveform fitting technique to restore it to be waveform, finding out zero ¿C crossover point of the waveform with least square method to obtain a complete cycle, carrying out secondary sampling on fitted waveform and analyzing electric energy quality index in system according to these points.

The invention discloses an underground fluid laminated sampling device based on a U-shaped pipe technology. The underground fluid laminated sampling device comprises an underground fluid sample injection subsystem, a packer subsystem, a chaining subsystem, a ground sampling subsystem and a soil gas sampling subsystem, wherein the underground fluid sample injection subsystem comprises a driving pipe, a sample discharging pipe, a fluid storage container, a liquid phase check valve and a filtering element; the soil gas sampling subsystem comprises a gas phase check valve arranged at a set position; the gas phase check valve is connected with a manual pump through a pneumatic ball valve and a gas sampling bag. The invention further discloses an underground fluid laminated sampling method based on the U-shaped pipe technology. The underground fluid laminated sampling device is novel in structural design; multiple technical difficulties are overcome; compared with a product of the original technology, the underground fluid laminated sampling device has the advantages that the working performance, the application range and the system stability are greatly improved, has higher competitiveness and industrial leading superiority, can be widely applied, is good in engineering demand, and has good application prospect and commercial value.

The present invention provides a method, system and detection machine for detecting the atmospheric waveguide environment, wherein the method includes: emitting laser light into a simulated atmospheric environment; acquiring the laser light to irradiate aerosol particles with different radii in the simulated atmospheric environment, generating The laser detection backscattered light signal; the scattered light signal after the laser detection is analyzed to obtain the backscattering characteristics of the laser detection of the aerosol particles with different radii; The characteristic parameters of the atmospheric waveguide are obtained based on the backscattering characteristics and the change of the atmospheric refractive index. The solution of the invention utilizes the laser to detect the atmospheric waveguide environment, and the detection has high real-time performance.

The invention relates to a voltage collecting circuit for monomer batteries of a battery pack. After voltages of the monomer batteries of the power battery pack are isolated and sampled by employing a solid-state relay, a signal conditioning and isolating circuit and a microcontroller in a matching manner, the voltages are fed into an A/D (Analog-to-Digital) passage of the microcontroller for analog-to-digital conversion; the microcontroller is used for rapidly controlling two paths of solid-state relays connected with two electrodes of any monomer battery to operate at the same moment, thus, a terminal voltage of the corresponding monomer battery can be obtained on a sampling bus; simultaneously, as for electrical security, a terminal voltage signal, obtained from the battery pack, of the monomer battery needs to be isolated by an isolation amplifier, then can be input to the A/D passage of the microcontroller; and the process above is suitable for the voltage collecting circuit for the monomer batteries of the power battery pack. The circuit is low in cost, simple and practical, as well as safe and reliable.

The invention provides an automatic test system and method of an oscilloscope, and belongs to the technical field of measuring instruments. The automatic test method of an oscilloscope includes the steps: based on a LabVIEW platform, self-manufacturing a set of oscilloscope automatic test software being able to control a digital oscilloscope to automatically set measurement parameters; automatically releasing the acquisition stopping state after single time of triggering, and realizing continuous automatic acquisition of signals; and automatically storing acquired data in a PC, thus solving the problem that the digital oscilloscope is not enough in the storage depth, and realizing long time of measurement and recording of signals in an unattended operation condition; according to a test demand, realizing automatic measurement of the preset test sequence; and according to the change of the signal, automatically adjusting the measurement shift (horizontal time base and vertical shift), and realizing adaptive measurement of unknown signals.

The invention discloses a human energy metabolism detection device and a human energy metabolism detection method. The human energy metabolism detection device comprises a gas collecting and mixing part, a gas concentration analyzing part, a control unit and human-computer interaction equipment, wherein the gas collecting and mixing part comprises a breathing mask, a flow sensor, a pulse solenoid valve (1) and a micro mixing chamber, and the breathing mask, the flow sensor, the pulse solenoid valve (1) and the micro mixing chamber are connected in sequence through connecting pipes; the gas concentration analyzing part comprises a gas cylinder, a three-way solenoid valve, a pulse solenoid valve (2), an oxygen sensor, a carbon dioxide sensor, a throttle valve and a gas sucking pump (2), the gas cylinder, the three-way solenoid valve, the pulse solenoid valve (2), the oxygen sensor, the carbon dioxide sensor, the throttle valve and the gas sucking pump (2) are connected by connecting pipes in sequence, and the upper end opening and the right end opening of the three-way solenoid valve are respectively connected with the gas cylinder and the pulse solenoid valve (2). The human energy metabolism detection device and the human energy metabolism detection method have the advantages of high equal proportional sampling precision of human exhaled gas and discontinuity of a sampling process.

The invention relates to a static reactive power compensation device based on an energy method and a control method thereof, belonging to the technical field of power transmission and distribution. The invention comprises a mutual inductor group, a filtering and signal conditioning module, an A/D conversion module, a computing module, a memory module, a phase-locked loop circuit module, a communication module and a display and keyboard operation module. The invention can evaluate and analyze possibly potential dangers of a power grid by adopting energy function method, predict the influence on the stable operation of the power grid possibly resulted from faults by establishing an anticipated accident list, carry out scientific, effective and real-time analysis and evaluation on the power grid state and carrying out integral cognition on the power grid performance as complete as possible, thereby quantitatively evaluating the operation state level of the power grid; and the invention effectively avoids an algorithm from falling to local optimum by adopting an improved particle intelligent swarm algorithm based on a fuzzy control theory.

The invention discloses a micro-flushing groundwater automatic sampling system. Groundwater is pumped in a micro-flushing mode by using a preset groundwater pumping strategy, real time acquisition and quality index analysis are carried out on the pumped groundwater to automatically and intelligently determine the micro-flushing process and optimize the pumping speed of the groundwater in order to obtain stable water quality indexes within a shortest time and to obtain an aquifer representative water sample by beginning the water sample acquisition at a most reasonable time, so the problems of labor waste, slow sampling speed and no representative water sample obtaining caused by the adjustment of the pumping speed of the groundwater and the determination of the water quality index stability time point in a manual mode are solved, and the problem of data processing inaccuracy caused by large error of data after-processing due to wrong manual recording is avoided. The real time acquisition and water quality index analysis of the pumped groundwater are carried out to realize corresponding water quality monitoring and predicating functions.