46results about How to "Meet error requirements" patented technology

The invention provides a device and method for detecting the interior initial stress of a steel structural member based on the ultrasonic method. According to the method for detecting the interior initial stress of the steel structural member based on the ultrasonic method, the interior initial stress sigma of the steel structural member is solved by firstly calibrating the acoustic elasticity coefficient B of the fixed sonic path distance of a replica of the steel structural member in service and then detecting the change of the acoustic time t of ultrasonic waves in the steel structural member in service. An existing method for nondestructive detection of the stress of a steel structural member mainly has the disadvantages that only the change of the stress can be detected, and the intensity of the stress in the current state can not be detected; only the stress of the positions located on the surface of the steel structural member and the stress of the positions at most dozens of microns below the surface of the steel structural member can be detected, and the intensity of the stress of positions with depths of several millimeters can not be detected. The method for detecting the interior initial stress of the steel structural member based on the ultrasonic method can overcome the defects of the existing method and can be used for nondestructive detection of the interior initial stress of various steel structural members. Detections results are verified, the precision is high, the error requirement of practical engineering can be met, and the structural member can not be damaged during detection.

The invention discloses a measuring device and method for direct current supply output impedance. The measured direct current supply output impedance is defined at a specific operating point and a specific test cross section, the presented equivalent impedance is seen in the direction of the test cross section facing a power supply, and system deviation in the measuring process, caused by load input impedance, is avoided. The measuring device comprises a test frequency point voltage phasor extraction module, a test frequency point current phasor extraction module, a low-current excitation load module, a sweep frequency phasor analysis module and a control computer, wherein the test frequency point voltage phasor extraction module and the test frequency point current phasor extraction module are respectively connected with a voltage input end and a current input end of the sweep frequency phasor analysis module; the signal output end of the sweep frequency phasor analysis module is connected with the low-current excitation load module; and the sweep frequency phasor analysis module is further connected with the control computer.

The invention discloses a load characteristics comprehensive classification method based on Markov Monte Carlo. The method includes the following steps: finding the voltage drop time point, carrying out load dynamic characteristics extraction and classification at the disturbance moment corresponding to the voltage drop time point; judging whether the change between the load classifications has a Markov property or not; dividing all data into uniform segments by time; establishing Markov chain's probability transfer matrix based on the maximum likelihood thought for each data segment; judging whether the numerical characteristics are changed or not: if no, go to step V; if yes, carrying out clustering on the load data in the time segment according to the numerical characteristics corresponding to the matrix, and obtaining the probability transfer matrix of the load data with changed numerical characteristics in each time segment ; carrying out Markov Monte Carlo simulation and describing the load change situation; processing the sequence reflecting the load classification conversion using the Hidden Markov Model (HMM). The method provided by the invention improves the Markov chain Monte Carlo simulation and effectively reduces the possibility of the matrix entering the stable state after iteration.

The present invention relates to a method for improving precision of external reference calibration of a multi-ocular camera based on multiple identification plate images, in order to solve the problem that the modeling error is large caused by that the positional relationship between the multi-phase cameras in the existing three-dimensional modeling is not accurate. The method for using the high precision calibration to calibrate the low precision provided by the present invention, the direction error of the axial direction is calibrated through the single point displacement error so as to reduce the overall calibration error; according to the method provided by the present invention, more spatial calibration information is constantly collected, and the spatial calibration information is taken to calibrate coordinate origin information and compensate the direction axis error, so that the effect that the characteristic with the large error degree is compensated by the information with small error degree; by virtue of the method provided by the present invention, the calibration error of the two-phase camera is reduced from that the original error level of the direction axis can be determined by multi-point measurement to the error level that the origin position can be determined by single-point measurement; and the method of the present invention is applied to the field of camera calibration.

The invention discloses a method of measuring component contents in fluorite by applying an X fluorescence powder tablet pressing method. The method comprises the following steps of: (1) pressing a fluorite standard sample and an adhesive into a group of standard sample pressed tablets with proper CaF2 gradient contents; (2) preparing a sample to be tested and the adhesive into a sample pressed tablet to be tested; (3) analyzing the standard sample pressed tablet by using an X fluorescence spectrometer and acquiring a linear regression analysis curve by enhancing absorption and deducting spectral line overlapping interference after the analysis is finished, then selecting and using the working curve to measure the sample pressed tablet to be tested, and calculating the contents of various components of the fluorite according to correspondence of analyzed spectral line intensity and concentration; and (4) pressing the standard sample pressed tablet and the sample pressed tablet to be tested by uniformly mixing and grinding the fluorite standard sample as well as the fluorite sample to be tested and the adhesive respectively, sieving through a 300-mesh screen and finally pressing into tablets in a tablet press. The method is quick and accurate, the check cost is reduced, and the check efficiency is greatly increased.

The invention provides a device and a method for nondestructively testing an axial stress of a concrete member based on a nonlinear ultrasonic harmonic wave method. The method comprises the steps of through calibrating an initial nonlinear coefficient beta 0 and coefficients m and n of the concrete member, detecting an acoustic parameter nonlinear coefficient beta of an ultrasonic wave in the concrete member, and solving an inner axial stress sigma of a concrete structure. The concrete stress detection method provided by the invention has special sensitivity on disclosing concrete early-stagecrack and stress evolutionary characteristics, and solves the problem that a traditional ultrasonic wave method is insensitive to an early-stage stress. A detected result is verified, the accuracy ishigher, an error requirement in actual engineering can be met, and the structure member cannot be damaged during a detection process.

At present, a steel member stress nondestructive detecting method mainly has the following defects that only variable quantity of stress can be detected, and absolute stress can not be detected; detected stress is located on the surface of a member and on the portion in the depth range of dozens of microns to the maximum below the surface, and the stress in the deeper depth range can not be detected; one-way absolute stress can be detected, the distribution of the absolute stress along the depth can not be detected. In order to overcome the defects in the prior art, the invention provides a method for detecting distribution of the steel member absolute stress along the depth on the basis of a critical refraction longitudinal wave method. Due to the fact that the propagation depth in the steel member and the sonoelastic coefficient B in a fixed sonic path distance of the Lcr waves with different frequencies are calibrated, a self-made caliper probe is adopted to detect propagation sound-timing t of the Lcr waves with the different frequencies in the steel member to solve the distribution of steel member absolute stress sigma along the depth. According to the method for detecting the distribution of the steel member absolute stress along the depth on the basis of the critical refraction longitudinal wave method, the accuracy of the detection result is high, error requirements in actual engineering can be met, and damage can not be caused to the structural member in the detection process.

The invention relates to a short-term power load prediction method based on a twin support vector machine. The method comprises the following steps of 1) creating a sample data set according to a format of a model input vector; 2) classifying data of the sample data set, wherein one type of the data is used for parameter optimization, and the other type of the data is used for testing; performingnormalization preprocessing on the type of the data for the parameter optimization; 3) optimizing DW-TSVR parameters for the sample data subjected to the normalization preprocessing by using LBSA; and4) by adopting a DW-TSRVR algorithm based on LBSA parameter optimization, and in combination with the other type of the sample data used for testing, performing verification of a DW-TSVR model, and calculating a prediction result of short-term power load. According to the method, Levy flight is introduced into a flight behavior of a BSA algorithm; the LBSA algorithm is provided; the optimizationperformance of the algorithm is obviously improved, and meanwhile, the convergence speed of the algorithm is also improved to a certain extent; and therefore, a Levy flight-based bird flock algorithmprovided in the method has better performance.

The invention discloses a phasor amplitude measurement method of a power system. The method comprises the following steps: the low-pass filtration is firstly carried out on an original sinusoidal input signal, namely a voltage simulation quantity signal by a low-pass filter module; the original sinusoidal input signal respectively enters a hardware zero-crossing detection frequency module for measuring the frequency f of the signal and a hardware fixed time interval discrete sampling module for measuring the amplitude Fm and the initial phase angle phi after the filtration treatment by the low-pass filter module; and the signal respectively enters a module for calculating the offset Delta lambda of the frequency and an amplitude gain GAIN module at the current frequency after obtaining the frequency f. When the phasor frequencies which access to the same A / D multi-channel power system are inconsistent, the method can obtain the offset Delta lambda of the frequency by greatly reducing or even having no need of complicated calculation, thereby not only being easy to realize on a frequency voltage emergency control device of the power system, but also meeting the error requirements on a project and solving the contradiction between calculating the cost and the precision.

An ultrasonic wave residual stress test device provided by the invention comprises an ultrasonic transducer set, a multichannel ultrasonic card, a signal processing board card and a control terminal. The ultrasonic transducer set includes a critical refraction longitudinal wave excitation probe and a critical refraction longitudinal wave reception probe, and also comprises a longitudinal wave flat probe capable of emitting ultrasonic wave longitudinal wave signals to a test area of a weldment to be tested and receiving longitudinal wave echo signals; the multichannel ultrasonic card includes an ultrasonic wave signal excitation module and an ultrasonic wave signal acquisition module; the signal processing board card includes a longitudinal wave attenuation degree calculation module, a database module and a residual stress calculation module; and the control terminal is configured to perform instruction control of each module in the multichannel ultrasonic card and the signal processing board card. The ultrasonic wave residual stress test device is able to correct the influence of the microscopic organization differences of welding area, the heat effect area and the base material area of a weldment to be tested on an ultrasonic wave residual stress test, so that the ultrasonic wave test precision of the welded joint residual stress is substantially improved.

The invention discloses a speed compensation method of one-dimensional distance images of a moving object. The method comprises the steps of: caching one-dimensional distance images continuously obtained by a radar in preset time intervals to a buffer; carrying out pre-processing on the one-dimensional distance images cached in the buffer, obtaining an analysis window of the one-dimensional distance images, and removing noises; then carrying out cross-correlation processing on all the one-dimensional distance images, arranged in the analysis window, of the buffer; estimating an object envelopment moving amount, adding a reference signal time-delay corresponding position, and obtaining the practical position of the object; obtaining a speed estimation value of the one-dimensional distance images by a primary curve fitting method; according to the speed estimation value of the one-dimensional distance images, carrying out speed compensation on the one-dimensional distance images; and carrying out variance estimation on each one-dimensional distance image after the speed compensation, and determining whether a pulse number used for the speed compensation meets error requirements. By adopting the method provided by the invention, unfavorable influences caused by high-speed movement can be effectively eliminated.

The invention discloses a positioning method based on multi-mark fingerprint positioning. The method comprises the steps of drawing a wifi deployment map, and marking the position of a wireless AP (Access Point) on the map; then coordinating the map during offline sampling, marking each coordinate point as a training tuple, dividing the training tuples by using signal strength RSSI (Received Signal Strength Indicator) information of the wireless AP acquired by a mobile terminal at each coordinate point in a WiFi network, and establishing an offline database after filtering, wherein the offline database comprises the training tuples as well as marks and coordinates corresponding to the training tuples; and finally, calculating Manhattan distances between the raining tuples and tested tuples by traversing a training tuple set in the offline database during online positioning, updating a priority queue according to the Manhattan distances, and collecting statistics on the frequency of occurrence of each training tuple in the priority queue, wherein the coordinate point corresponding to the training tuple occurring most frequently is the coordinate point of the mobile terminal to be positioned.

The invention discloses a photovoltaic power supply power prediction method based on positive and negative error variable weights. The method specifically includes the following implementation steps that firstly, n optical power prediction models are set, N prediction time points exist, and y(t) is a true value of photovoltaic power generation power at the tth moment; then, a prediction result is subtracted with the true value, and the weight of the tth moment of the ith model is calculated; finally, a final prediction result is obtained through n prediction values. The method solves the problems that prediction precision of a prediction method in the prior art can not meet requirements, and the prediction effect is poor.

The invention relates to the technical field of electric power measurement, and especially to a protective Rogowski coil current transformer based on the combined integral. The protective Rogowski coil current transformer based on the combined integral includes a current wire, a Rogowski coil, a first conditioning circuit, a second conditioning circuit, a first converting circuit, a second converting circuit and a digital processor. The first conditioning circuit and the first converting circuit are connected in series to form a digital integral circuit. The second conditioning circuit and the second converting circuit are connected in series to form a hardware analog integral circuit. The digital integral circuit and the hardware analog integral circuit are connected in parallel and are connected to two ends of an output lead of the Rogowski coil. The digital integral circuit is connected to the digital processor. The hardware analog integral circuit is connected to the digital processor. The protective Rogowski coil current transformer based on the combined integral has good measurement accuracy during a steady-state current, well meets the error requirements during a steady-state primary rated current, has good transient characteristics during a transient current, and restores a primary measured current without distortion.

The invention relates to a direct-current even-order harmonic error calibration method and an electric energy meter, and the method comprises the steps that the fitting of direct-current even-order harmonic errors corresponding to different power factors and different current value ranges of the electric energy meter is carried out, and fitting formulas are obtained; primary current waveform data of the electric energy meter are collected for FFT conversion and judgment, and when direct-current even-order harmonics exist, the fitting formula corresponding to a current current effective value and a power factor is adopted to calculate a metering error, and the metering value of the electric energy meter is compensated. On the premise that hardware cost is not increased, the precision of the electric energy meter is greatly improved in a compensation mode, direct-current even-order harmonics can be resisted, and the error requirement is met. The cost of electric energy meter transformation is greatly reduced, and most electric energy meters can meet standard requirements only by software upgrading. Different power factors and different current ranges are reasonably divided, error curves are fitted respectively, compensation curves are changed according to actual conditions, and compensation precision is improved.

The invention discloses a high-fidelity chaotic polynomial correction method suitable for CFD uncertainty quantification, and the method is characterized in that the method comprises the steps of obtaining a low-fidelity model at a low-fidelity model level through calculation, and building a rough chaotic polynomial expansion; performing a small amount of calculation on a high fidelity model level; and correcting the low-fidelity model to obtain a final high-fidelity correction model. According to the invention, the statistical information of the obtained high fidelity correction model is slightly different from that of the original high fidelity model; the mean value difference is smaller than three ten thousandths and can be ignored, the error requirement of engineering application is completely met, the calculation time needed by the high-fidelity model established through the method is about 40% of that of an original method, and the calculation cost is greatly saved.

The invention discloses an extraction method for extracting the key frames of virtual human motion data. The method comprises the steps of quantizing the original multi-dimensional joint motion data of a virtual human body into a one-dimensional data sequence; determining the set of initial key frames based on the motion activity information contained in the one-dimensional data sequence; and optimizing key frames in the set of initial key frames as optimal key frames. According to the technical scheme of the extraction method for extracting the key frames of virtual human motion data, the analysis of motion data and the optimization of motion data are combined, so that key frames, as few as possible, are quickly and reasonably extracted out of original motion data. In the animation of the virtual human body, a reconstructed motion sequence, obtained through the motion synthesizing and editing of key frames or the data interpolation at the key frames, is relatively good in performance.

The embodiment of the invention provides a three-dimensional warning fence manufacturing method, an air route planning method and a flight adjusting method. The three-dimensional warning fence manufacturing method comprises the following steps: acquiring position information and base station parameter information of at least one base station in a manufacturing area; within a preset height range, according to the position information and the base station parameter information of each base station, determining signal coverage information of a horizontal layer of at least one preset height; determining a level signal warning fence corresponding to each horizontal layer in the signal coverage information of each horizontal layer according to a preset signal quality level; and determining a three-dimensional warning fence of the manufacturing area according to the signal warning fence in the signal coverage information of each horizontal layer. According to the embodiment of the invention, by making the three-dimensional warning fence, the signal blind area in the flight area can be accurately and timely obtained, the unmanned aerial vehicle is effectively prevented from entering the signal blind area, and the flight safety of the unmanned aerial vehicle is guaranteed.

The invention discloses a computing method for a phasor angle of an electric system. The computing method comprises the following steps of: designing an enquiry form according to a tangent value or a cotangent value, increasing the tangent value from 0 to 1 according to the same step length, wherein the results, which are obtained by anti-tangent computation, of step length values form an element of the enquiry form in sequence, the decimal place of the practical value of the element is designed according to precision to be computed for outputting; computing the tangent value according to the real part and the imaginary part of the phasor, computing the cotangent value and taking the absolute value of the cotangent value to obtain a computed result if the tangent value is bigger than 1; and calling the data of the enquiry form and obtaining a practical angle or radian result according to characteristics of eight zones which are obtained by dividing the angle or the corresponding radian value on a complex number plane. The computing method disclosed by the invention can be used for solving contradictions between expense computation and precision computation; when the algorithm is used in the same CPU (Central Processing Unit), the computation time is better than that of a system calling function, and the precision can satisfy the application needs according to the design of the enquiry form.

The invention discloses an intelligent control system of a foam concrete preparation machine. The intelligent control system comprises a human-computer interface component, a central controller component, a raw material metering component, a raw material power control component, a raw material flow monitoring component and a fluid power output control component. The human-computer interface component is connected with the central controller component. The central controller component is in signal connection with the raw material metering component, the raw material power control component, theraw material flow monitoring component and the fluid power output control component. An automatic control manner of intelligent information processing, intelligent information feedback and intelligent control decision making is adopted, only technical parameters such as the foam concrete wet density, the foam density, the mix proportion and the yield need to be input during use, after equipment is started, a control system automatically controls feeding, metering and stirring of raw materials, the output quantities of neat paste, a foaming agent, foaming agent dilution water and compressed gas are dynamically adjusted, and electronic metering, automatic control and intelligent adjustment are fully realized.

The invention discloses a measuring device and method for direct current supply output impedance. The measured direct current supply output impedance is defined at a specific operating point and a specific test cross section, the presented equivalent impedance is seen in the direction of the test cross section facing a power supply, and system deviation in the measuring process, caused by load input impedance, is avoided. The measuring device comprises a test frequency point voltage phasor extraction module, a test frequency point current phasor extraction module, a low-current excitation load module, a sweep frequency phasor analysis module and a control computer, wherein the test frequency point voltage phasor extraction module and the test frequency point current phasor extraction module are respectively connected with a voltage input end and a current input end of the sweep frequency phasor analysis module; the signal output end of the sweep frequency phasor analysis module is connected with the low-current excitation load module; and the sweep frequency phasor analysis module is further connected with the control computer.

The invention provides a toxic gas experimental device for mice, and relates to the field of medical experimental instruments.The toxic gas experimental device comprises an experimental box used for containing the mice, the experimental box comprises an experimental box body, a first control box with a first control cavity and a second control box with a second control cavity, and the experimental box body comprises an experimental cabin and a recycling cabin which are arranged up and down; the circumferential side wall of the experiment module is connected with an annular shell which is coaxially arranged, an annular channel communicated with a poison gas supply source is formed between the annular shell and the side wall of the experiment module, and the annular shell is arranged on the outer ring of the experiment module, so that poison gas is fed from the top originally and diffused from the periphery to the middle; the annular shell is matched with the gas conveying end, poison gas at the input end can be diffused in advance and fully shunted, all annular spaces are covered, the poison gas can be evenly released into the cabin body and evenly distributed in the cabin body, a disturbance structure does not need to be arranged in the cabin body, it is effectively guaranteed that the detected concentration is close to the actual concentration in the cabin body, and the error requirement is met.

The invention provides a device and method for non-destructive detection of initial stress inside a steel structural member based on the ultrasonic method, which includes firstly calibrating the acoustic elastic coefficient B of the fixed sound path of the replica of the in-service steel structural member, and detecting the ultrasonic in-service steel structural member The method of solving the internal initial stress σ of the steel structure member by the change of the acoustic time t. The current non-destructive testing method for stress of steel structure members mainly has the following disadvantages: one is that it can only detect the change of stress, but not the magnitude of stress in the current state; The depth range of microns cannot detect the magnitude of stress at a depth of several millimeters. The method proposed by the invention can overcome the above-mentioned difficulties, and can be applied to the non-destructive detection of the internal initial stress of various steel structure components. The detection results have been verified, with high precision, which can meet the error requirements in actual engineering, and will not cause damage to structural components during the detection process.

The invention relates to a large antique city wall structure and a construction method thereof. The city wall structure comprises a steel frame structure, a first outer mesh sheet, a second outer mesh sheet, a mortar structure and grooves, wherein the first outer mesh sheet is laid on the outer side face of the steel frame structure, the second outer mesh sheet is arranged on the outer side of the first outer mesh sheet, a gap is reserved between the second outer mesh sheet and the first outer mesh sheet, and the second outer mesh sheet is connected with the steel frame structure through connecting ribs, the mortar structure formed on the second outer mesh sheet is sprayed, the steel frame structure, the first outer mesh sheet and the second outer mesh sheet are covered with the mortar structure, the gap between the second outer mesh sheet and the first outer mesh sheet is partially filled with the mortar structure, and the grooves formed in the outer side face of the mortar structure are chiseled, and the outer side face of the mortar structure forms an antique city wall style through the groove. The steel frame structure can ensure the perpendicularity and the deformation amount of the city wall, the deformation amount can meet the error requirement, the mortar structure belongs to light materials, the influence on deformation of the steel frame structure is small, and it can be ensured that cracking cannot be generated.

The invention discloses a method for determining the iron soap content in an emulsion. The method comprises the following steps: weighing an emulsion sample having a weight Ws, adding into a round-bottom flask having a weight W1, and performing vacuum dewatering to obtain a dewatered sample in the round-bottom flask, wherein the total weight after dewatering is W2; adsorbing iron powder in the dewatered sample by means of a magnet; taking a test sample having a weight W3 from the top of the dewatered sample, preparing a test sample trichloromethane solution, passing the solution through a normal solid-phase extraction column at a rate of 1-2 ml / min, and sequentially eluting the normal solid-phase extraction column with trichloromethane and isopropanol; passing a 2-10wt.% hydrochloric acid isopropanol solution through the normal solid-phase extraction column at a rate of 1 ml / min or below to obtain a separation eluate, collecting the obtained separation eluate by means of a beaker having a weight W4, evaporating the solvent of the separation eluate, and cooling to obtain a collection; removing impurities in the collection, wherein the total weight of the impurity-removed collection and the beaker is W5; and determining the iron soap content W% according to a computing formula shown in the specification.

The invention relates to a method to definite-time list item process in communication device. It uses time label counter parameter when taking definite-time process to the item on list. Thus, the precision of definite-time process is improved. Moreover, it can adjust the precision by adjusting the number of counter of the time label. The invention could satisfy the request of precision of different people. And it is especially suited for ageing treatment for communication device. For example, the invention is used to take ageing treatment for MAC address list, even if the ageing refresh granularity precision request of MAC address is not very high during process, the maximum error may caused is only half of threshold value of ageing time, when the width of the chosen time label is one.

The structural system comprises a fast-assembly adjustable frame body system and a precast concrete panel fixedly connected to the fast-assembly adjustable frame body system, and the fast-assembly adjustable frame body system comprises a set of bottom coarse adjustment devices, a supporting steel frame body and a set of top fine adjustment devices; the supporting steel frame body comprises a set of steel stand columns, a set of steel cross beams, a set of steel distribution beams and a set of steel frame body supports, the bottom of the top fine adjustment device is arranged on the upper top faces of the steel distribution beams, and the steel frame body supports comprise connecting steel supports and inclined steel supports. A two-stage regulation and control scheme combining coarse adjustment and fine adjustment is adopted, the elevation of the whole frame body of the steel structure can be macroscopically and greatly adjusted through the coarse adjustment device at the bottom, local fine adjustment can be conducted on the precast concrete panel through the fine adjustment device at the top, local fine adjustment of the precast concrete panel can be achieved, and the construction efficiency is improved. And the fine adjustment devices are relatively independent, so that the additional influence caused by the adjustment of the coarse adjustment device is avoided.

The invention discloses a method for continuously processing wheel-track force of a track vehicle by means of a ground test, which comprises the steps of: A, acquiring wheel-track force test data and corresponding time data of a wheel pair passing through a track test area by means of a track ground test, removing the data smaller than a threshold value to form waveform data which is mutually separated, and then picking out the maximal value in each waveform data to obtain discrete wheel-track force data and time data thereof; B, training a radial group neutral network of a single hidden layer by using the discrete wheel-track force data and the time data thereof to ensure that the radial group neutral network reaches a set precision; and C, with the time ranging from 0.0005 to 0.001 seconds as the step length, inputting the time data and performing simulative calculation by the neutral network to obtain the continuous wheel-track force data to further obtain the continuous wheel-track force of the track vehicle passing through the track test area by means of a test. The method can be used for obtaining the continuous wheel-track force by means of the test, acquiring the wheel-track forces at all positions, and detecting the safe operation state of the wheel pair more effectively in order to evaluate the traveling safety of the vehicle more reliably.

The invention provides a method for monitoring the two-dimensional displacement and the strain of a structure based on the digital image processing technology. The method is characterized in that a circular pattern is adopted as a target, wherein the target is a shooting object used for being shot to acquire a digital image, the displacement or the strain of a corresponding point, to be monitored, of the structure can be determined by processing the digital image, the circular pattern guarantees the non-directional feature of the cross section of the target, namely, the target does not need to be strictly adjusted to be right during monitoring of physical quantities of the structure, in common words, the situation that due to inclination of the target, the circular pattern becomes rhombic from being square like a square pattern is avoided, and the circular pattern can be kept circular all the time; a square pattern with the known side length is adopted as a calibration plate, wherein the calibration plate is a shooting object for calibration of a current vision monitoring system; a circular circle center is selected as the feature of the image of the target to be extracted, wherein the feature is a monitoring calculation point selected for determining the corresponding displacement or strain of the structure from the shot digital image of the target.

The invention belongs to the technical field of power system relay protection, and particularly relates to a light-weight three-phase voltage and current generator. The light-weight three-phase voltage and current generator provided by the invention is small in size and light in weight, and is applied to a relay protection secondary loop. The light-weight three-phase voltage and current generator comprises a three-phase AC voltage forming circuit and a three-phase AC current forming circuit, and is characterized in that the three-phase AC voltage forming circuit comprises a switch K1, one end of the switch K1 is connected with a power supply input terminal, the other end of the switch K1 is connected with an input end of a self-coupling voltage regulator T2, an output end of the self-coupling voltage regulator T2 is connected with an input end of an isolation transformer T3, one end of an output end of the isolation transformer T3 is connected with one end of a resistor R5, the other end of the resistor R5 is connected with one end of an adjustable resistor R6, one end of a resistor R11 and a voltage output terminal UA, and the other end of the adjustable resistor R6 is connected with one end of a resistor R7.