42results about How to "The calculation method is simple and fast" patented technology

The invention discloses a calculation method of power supply capability of a power distribution system. The calculation method is characterized in that the 'N-1' safety criterion is adopted as the premise, the interconnection relation of a main transformer is adopted as the basis, the upper-lower level coordination relation of the power distribution system is fully considered, the influence of load transfer limit of medium-voltage connection and short-time overload of the high-voltage main transformer are considered, and the power supply capability of the power distribution system can be accurately estimated, so that the deficiency of the load supply capability estimation on quantity when the single voltage level is only considered is avoided; the limit of the whole load supply capability of the power distribution system can be accurately mastered, so that the planning and the construction of the power distribution system is guided; and when the regional load increases in certain degree, the requirement for load increase is met by discovering the power supply capability of the existing power supply facilities. According to the method, the limit utilization ratio of the power distribution equipment can be determined on the premise of meeting the safety of the system and reference for a supply transferring scheme can be provided when the equipment fails, thus the operation scheduling of the power distribution system is guided and the method is beneficial to the effective use of the power distribution system facilities in power supply enterprises.

The invention discloses an indoor distance measuring method. By use of a direction sensor arranged on an AR (augmented reality) device, a horizontal distance between a pick-up head and an object and a height of the object are obtained and are superposed to a scene of a real world displayed by the AR device. According to the invention, the horizontal distance between the pick-up head and the object and the height of the object can be calculated by use of the Pythagoras theorem simply through obtaining an included angle between a connecting line from the pick-up head to an intersection point of an object bottom and the ground and a ground vertical direction, or an included angle between a connecting line from the pick-up head to an intersection point of an object extension line and the ground and the ground vertical direction, an included angle between a connecting line from the pick-up head to the object top and the ground vertical direction and an included angle between a connecting line from the pick-up head to the object bottom and the ground vertical direction according to a vertical distance between the pick-up head and the ground. The calculation method is simple and fast, the computation quantity is small, and the cost is quite low.

The invention discloses a method for predicting an inbound and outbound passenger flow of an urban rail transit station. The method comprises the steps of firstly, counting an average inbound and outbound passenger flow of an existing rail transit station on weekdays according to an automatic ticketing system; then, respectively obtaining built environmental elements within the range of 500 m at peripheries of the existing rail transit station and new rail transit station; establishing a regression model of the average inbound and outbound passenger flow data of the existing rail transit station on weekdays and the built environmental elements within the range of 500 m at the periphery of the existing rail transit station, and substituting the built environmental elements within the rangeof 500 m at the periphery of the new rail transit station into the regression model to obtain an average inbound and outbound passenger flow prediction value of the new rail transit station on weekdays. By use of the method for predicting the inbound and outbound passenger flow of the urban rail transit station, an influence of built environments at the periphery of the station on inbound and outbound passenger flows can be effectively analyzed, and further the passenger flow of the new rail transit station is predicted based on the influence.

The invention relates to a method for inverting transverse isotropic rock mass ground stress. Through rock mass displacement in a roadway, transverse isotropic rock mass ground stress is inverted. The method comprises the following steps: establishing a transverse isotropic rock mass model in an x-y-z coordinate system, a roadway cross section being parallel to an isotropic plane; determining the direction of ground stress in the transverse isotropic rock mass; taking a rock mass sample in the roadway, measuring transverse isotropic rock mass parameters of the rock mass sample; measuring deformation displacement of the rock mass in the roadway; and according to a roadway displacement analytic formula, obtaining a ground stress expression. The method can obtain a set of specific formulas to calculate transverse isotropic rock mass ground stress just by substituting the rock mass parameter measured values and a displacement measured value into the displacement analytic formula. The method prevents problems of complex equipment arrangement, large errors, and limited application range caused by measuring ground stress on site. The calculation method is simple and fast, and the method is mainly used for calculating transverse isotropic rock mass ground stress.

A galloping start control method of a frequency converter comprises the steps that the line voltage of the frequency converter is sampled, processed correspondingly and then output to a digital signal processor, and then a sampling software hysteresis method is used for shaping positive voltage to obtain square-wave voltage signals. The frequency of the square-wave voltage signals is calculated, and the start method of the frequency converter is controlled according to the frequency of the square-wave voltage signals. Particularly, when the frequency of the square-wave voltage signals is larger than or equal to 1 Hz, the frequency converter is in a rotation state, and therefore the frequency converter is controlled to start at the current frequency, and damage to the frequency converter or a load caused by reverse rotation of the frequency converter or inconsistence of the current rotation frequency is avoided. The calculation method of the galloping start control method of the frequency converter is simple, convenient and rapid to operate, and galloping start control over the frequency converter can be finished without a complex algorithm.

The invention discloses a measuring method for a toe angle of a car, which establishes a new measuring device for the toe angle of the car, and uses the device to perform measurement. The method comprises the following steps of: during measuring, separately emitting line lasers from two sides to the opposite side, collecting the data by the opposite cameras, and sending the data to a measuring unit for measurement and calculation; starting the working of the cameras; acquiring the current images of the cameras for processing; acquiring the images once from the cameras for processing after theprocessing is completed, and so on; calculating the threshold value of the monochromatic light component of each image by extracting a maximum monochromatic light component of the acquired image everytime; selecting N rows of pixel points on a projection surface, sequentially dividing the pixel points of each row according to the threshold value, and obtaining the divided effective pixel points in each row; calculating the center position of the effective pixel points by using the effective pixel points; and calculating the offset distance of the line laser projections by using the central position, so as to calculate the offset angle. The calculation method is rapid and simple, and has high precision.

The invention relates to a dynamic password intelligent unlocking system, which comprises a user terminal, an intelligent lock and a dynamic password server. The user terminal comprises a display module, a processing module I, a communication module I and a storage module 1, the intelligent lock comprises a processing module II, a communication module II and a storage module II, the dynamic password server comprises a processing module III, a communication module III and a storage module III. The invention also relates to a dynamic password intelligent unlocking method, and the method respectively generates password corresponding to the user terminal and the intelligent lock. By using the generated dynamic password method and the corresponding dynamic password of the invention, the password does not need to be replaced frequently, the calculation method for updating the password is simple and convenient, and if the dynamic password is stolen in the transmission process, the real dynamic password content cannot be obtained because the calculation and conversion rules cannot be obtained, so that the security of authentication and transmission is improved.

The invention discloses an abrasion test method for determining rational hardness pairing of a friction pair; the abrasion test method comprises: the material A and the material B which form the rational hardness pairing of the friction pair are determined, and then an upper sample A and a lower sample B, and an upper sample B and a lower sample A are respectively tested to obtain abrasion loss, and then the abrasion loss is compared, the relative abrasion performance is calculated, and then the rational hardness pairing of the friction pair is determined. The test method takes the factors of the friction pair such as material pairing, hardness pairing, contact type, motion mode, speed, contact stress, lubrication state, operation environment and the like into account, the disadvantages that the existing method does not take the material pairing and the hardness pairing into account are overcome, and the test method can be directly applied to the research and selection of the rational hardness pairing of the friction pair; the operation is convenient, the calculating method is simple and the method for determining the rational hardness pairing of material is feasible and effective.

The invention provides a simple intracranial hematoma puncture orientation instrument. The bottom end of a support is fixedly connected to the top of a bottom plate, and the top of a first sliding block is sleeved with the surface of the support; the surface of a transverse rod penetrates through the bottom of the first sliding block, and the back surface of the first sliding block is slidably connected to the surface of the transverse rod. The simple intracranial hematoma puncture orientation instrument is fixed with the sagittal line as a reference plane and is not interfered with the thickness of scalp, and intracranial and extracranial projections are consistent; meanwhile, the parallel line principle is used and the principle that corresponding angles are equal is used, so that the direction of needle feeding is accurately fixed; a protractor is provided with a pointer, so that it is guaranteed that puncture needle feeding is free of deviation at any moment in an operation; multi-point puncture fixation is not needed, repeated CT scanning is not needed, and unnecessary injury of a patient is reduced; a measuring and calculating method is simple and rapid, and measuring and calculating errors are greatly reduced, so that the operation time is saved; complicated equipment is not needed, the treatment cost of the patient is reduced, mounting and dismounting are convenient, and the instrument is convenient to transport.

The invention relates to a rapid calculation method for the reconstruction volume of a compact oil reservoir volume fractured horizontal well, which comprises the following steps: step 1, collecting production data and calculating required basic parameters, the production data comprising a pressure history and a flow history, wherein the basic parameters comprise the original pressure, the comprehensive compression coefficient, the porosity and the fluid volume coefficient of the stratum; 2, drawing a relation curve of the regularized yield and the material balance time; and 3, calculating the transformation volume by using a depletion flow stage pressure change formula. Linear regression is carried out by utilizing production data in a linear flow stage, and the permeability is determined by combining a linear flow equation. According to the invention, the relation curve is drawn by directly utilizing the existing production dynamic data, the transformation volume is determined in combination with the depletion flow stage pressure change formula, well shut-in and curve fitting are not needed, and the calculation method is simple and rapid.

The invention discloses a photoelectric speed measuring chip. The chip comprises a first photosensitive detection module, a second photosensitive detection module, a third photosensitive detection module and a fourth photosensitive detection module, wherein the four photosensitive detection modules are identical in shape and size, the chip further comprises a first comparator, a second comparator,a sequential control module and a voltage controlled oscillator, an output end of the voltage controlled oscillator is connected with the sequential control module, output ends of the first photosensitive detection module and the third photosensitive detection module are connected with positive and negative input ends of the first comparator, output ends of the second photosensitive detection module and the fourth photosensitive detection module are connected with positive and negative input ends of the second comparator, and output ends of the first comparator and the second comparator respectively output a first output signal and a second output signal. The chip is advantaged in that the chip is simple in structure and has relatively small land occupation area, and the rotation speed ofa code disc can be determined accurately according to the output of the comparators.

The invention discloses a calculation method of an energy dissipation coefficient of subgrade filling under the uplift action of a foundation. The energy dissipation coefficient of the subgrade filling under the uplift action of the foundation is determined scientifically and rationally, and the needs of practical engineering design and construction are met. The calculation method comprises the following steps that (1), a trenching sand filling method or a trenching irrigation method or a nuclear densimeter method is used for determining the subgrade filling dry density [rho]d, indoor compaction experiments are used for determining the largest subgrade filling dry density [rho]dmax, and the compaction coefficient K of the subgrade filling is determined; (2), the reciprocal beta of a limitvalue of the 'compression effect' coefficient of the subgrade filling is determined; (3), the reciprocal alpha of the 'compression effect' coefficient of an initial tangent line of the subgrade filling is determined; and (4), the energy dissipation coefficient kappa of the subgrade filling under the uplift action of the foundation is determined.

The invention discloses an object tracking device. A lens and a reflector are arranged on a seat stand; by means of the reflection effect of the reflector, images are formed in the lens by surrounding scenes, the camera shooting equipment moves and completes alignment tracking through the movable base table, visual angle limitation does not exist, and if multiple lenses are adopted, the multiple lenses do not need to work at the same time, and the requirement for hardware models and parameters is lowered. The invention discloses an object tracking method. The reflection effect of the reflector is utilized to make the peripheral scene form an image sequence in the lens; images in an image sequence are compared; through juding the threshold value, the image of the to-be-tracked object is acquired, the positioning of the tracked object is completed through coordinate calculation, the motion instruction is sent to the seat stand, the camera of the camera shooting equipment is aligned with the tracked object, and calculation and superposition of data of a plurality of lenses are not needed due to reflector matching and lenses.

The invention discloses a special-shaped plate part hot precision forging forming mould cavity correction method. According to the method, a mathematic model, the profile of which deforms in the hot precision forging process on the basis of a force piece and a mould, is established; and the mathematic model comprises mould heat expansion td, force piece cold deflation tw, mould stress elastic expansion ed and force piece mould-out springback ew. The established mathematic model gives full consideration to various deformation factors in the hot precision forging process, so that the factors influencing the precision of the hot precision forging are well revealed; a mathematic functional expression is used for calculating mould cavity correction and the calculation method is simple, rapid and convenient for engineering application; and the correction method is high in correctness, and can be used for effectively improving the hot precision forging forming precision so as to decrease the subsequent precision machining margin and even satisfy the requirement for direct use.

The invention discloses a device for measuring the deformation strain gradient of a component, which resolves the problems of the prior art that measurement equipment is complex in installation, highin cost and large in measurement result error when the deformation strain gradient of the component is measured. The system comprises a bending machine and a detection system, wherein the detection system comprises a strain gradient measuring unit, a data acquisition and sending unit and a back-end server. The gradient analysis software and background display BS framework software are written in the back-end server, and the rear-end server performs online implementation on receiving, storage, processing, analysis, alarm and visual displaying and the like of deformation strain gradient monitoring data of the component. The invention further discloses a method for measuring the deformation strain gradient of the component. According to the invention, only a simple grating material parametermeasurement test and spectral data analysis before and after component deformation are needed, so that more accurate structural member strain gradient data can be obtained through calculation, the calculation method is simple and rapid, and the method is mainly used for measuring the strain gradient of isotropic material components such as concrete and steel.

The invention discloses a method for calculating the ignition temperature of mixed pulverized coal airflow after blending combustion of two single coal types, and the method comprises the following steps: firstly, providing the ignition temperature and blending combustion ratio of the pulverized coal airflow of a blending combustion coal type 1 and a blending combustion coal type 2; then calculating the blending combustion coal type proportion, the blending combustion coal type ignition performance and the nonlinear influence of the blending combustion coal type ignition performance deviationon the blended coal ignition temperature; and finally, predicting the pulverized coal airflow ignition temperature IT of the mixed coal. According to the method, through a large number of laboratory mixed coal combustion performance test results, the correlation between the mixed coal ignition performance and the blending combustion coal type is found through research, and then the nonlinear influence relation of the mixed coal ignition performance is quantitatively given. The calculation method is simple, rapid and high in precision, in the coal blending combustion process, real-time ignitionperformance analysis and evaluation can be conducted according to existing coal quality data, coal blending combustion and operation optimization of a power plant can be guided in time, and the method is convenient to apply and popularize in daily coal blending combustion and intelligent coal blending combustion of the power plant.

The invention discloses series voltage equalization method of support insulators of a high-voltage flexible direct-current converter valve. The method belongs to the field of electric field algorithms of the converter valve, and includes two steps of selecting a waterway clamp point, and calculating an optimization effect by circuit equivalence. A waterway and metal parts connected with an insulator string are mutually clamped, a phenomenon of uneven electric potential distribution caused by uneven stray capacitance distribution is directly and quickly ameliorated through characteristics that potential distribution of the waterway is even and a waterway resistance value is low than a capacitance reactance value, the principle is simple and easy to understand, structure features of the converter valve are utilized very well, an extra structure is not needed to be added, engineering requirements can be well satisfied, installation costs are small, and engineering implementation is convenient. In order to more conveniently calculate an optimization result, a circuit equivalence calculation method is used for calculation, and repeatedly modifying a clamp point position and finding the best optimization scheme are facilitated. Circuit parameter calculation is carried out through equivalent resistance and capacitance values, the calculation is simple, calculation time is short, and engineering costs and time can be greatly saved.

The invention discloses a device for measuring the deformation strain gradient of a component, which resolves the problems of the prior art that measurement equipment is complex in installation, highin cost and large in measurement result error when the deformation strain gradient of the component is measured. The system comprises a bending machine and a detection system, wherein the detection system comprises a strain gradient measuring unit, a data acquisition and sending unit and a back-end server. The gradient analysis software and background display BS framework software are written in the back-end server, and the rear-end server performs online implementation on receiving, storage, processing, analysis, alarm and visual displaying and the like of deformation strain gradient monitoring data of the component. The invention further discloses a method for measuring the deformation strain gradient of the component. According to the invention, only a simple grating material parametermeasurement test and spectral data analysis before and after component deformation are needed, so that more accurate structural member strain gradient data can be obtained through calculation, the calculation method is simple and rapid, and the method is mainly used for measuring the strain gradient of isotropic material components such as concrete and steel.

The invention discloses a method for predicting an inbound and outbound passenger flow of an urban rail transit station. The method comprises the steps of firstly, counting an average inbound and outbound passenger flow of an existing rail transit station on weekdays according to an automatic ticketing system; then, respectively obtaining built environmental elements within the range of 500 m at peripheries of the existing rail transit station and new rail transit station; establishing a regression model of the average inbound and outbound passenger flow data of the existing rail transit station on weekdays and the built environmental elements within the range of 500 m at the periphery of the existing rail transit station, and substituting the built environmental elements within the rangeof 500 m at the periphery of the new rail transit station into the regression model to obtain an average inbound and outbound passenger flow prediction value of the new rail transit station on weekdays. By use of the method for predicting the inbound and outbound passenger flow of the urban rail transit station, an influence of built environments at the periphery of the station on inbound and outbound passenger flows can be effectively analyzed, and further the passenger flow of the new rail transit station is predicted based on the influence.

The invention discloses a photoelectric speed measuring chip. The chip comprises a first photosensitive detection module, a second photosensitive detection module, a third photosensitive detection module and a fourth photosensitive detection module, wherein the four photosensitive detection modules are identical in shape and size, the chip further comprises a first comparator, a second comparator,a sequential control module and a voltage controlled oscillator, an output end of the voltage controlled oscillator is connected with the sequential control module, output ends of the first photosensitive detection module and the third photosensitive detection module are connected with positive and negative input ends of the first comparator, output ends of the second photosensitive detection module and the fourth photosensitive detection module are connected with positive and negative input ends of the second comparator, and output ends of the first comparator and the second comparator respectively output a first output signal and a second output signal. The chip is advantaged in that the chip is simple in structure and has relatively small land occupation area, and the rotation speed ofa code disc can be determined accurately according to the output of the comparators.

The invention relates to a fast calculation method for volume fracturing of a tight oil reservoir for horizontal well stimulation, which includes: step 1: collecting production data and basic parameters required for calculation. Including the original pressure, comprehensive compressibility, porosity, and fluid volume coefficient of the formation; step 2, draw the relationship between normalized production and material balance time; step 3, use the pressure change formula in the depletion flow stage to calculate the reformed volume. The invention utilizes the linear flow stage production data to perform linear regression, and combines the linear flow flow equation to determine the permeability. The present invention directly uses the existing production performance data to draw the relation curve, and determines the reformed volume in combination with the pressure change formula in the depleted flow stage, without shut-in or curve fitting, and the calculation method is simple and fast.

The invention discloses a method for quantitatively evaluating the coverage rate of a zinc phosphating film of cold-rolled automobile steel. The method comprises the following steps: (1) determining the phase composition of the phosphating film on the surface of a cold-rolled automobile steel sample by adopting the phase quantitative function of an X-ray diffractometer; and (2) according to the detection result of the step (1), the coverage rate of the phosphating film is calculated, and the coverage rate of the phosphating film is equal to (zinc triphosphate Zn3 (PO4) 2.4 H2O + zinc iron phosphate Fe2Zn (PO4) 2.4 H2O) percentage / zinc triphosphate Zn3 (PO4) 2.4 H2O + zinc iron phosphate Fe2Zn (PO4) 2.4 H2O + Fe) percentage. According to the method, the coverage rate of the phosphating film in the target phosphating area can be directly calculated, measurement with a ruler is not needed, and a benchmarking map and a calculation method are simple, convenient and rapid.

The invention discloses a calculation method of an energy dissipation coefficient of subgrade filling under the uplift action of a foundation. The energy dissipation coefficient of the subgrade filling under the uplift action of the foundation is determined scientifically and rationally, and the needs of practical engineering design and construction are met. The calculation method comprises the following steps that (1), a trenching sand filling method or a trenching irrigation method or a nuclear densimeter method is used for determining the subgrade filling dry density [rho]d, indoor compaction experiments are used for determining the largest subgrade filling dry density [rho]dmax, and the compaction coefficient K of the subgrade filling is determined; (2), the reciprocal beta of a limitvalue of the 'compression effect' coefficient of the subgrade filling is determined; (3), the reciprocal alpha of the 'compression effect' coefficient of an initial tangent line of the subgrade filling is determined; and (4), the energy dissipation coefficient kappa of the subgrade filling under the uplift action of the foundation is determined.

The invention discloses a calculation method of power supply capability of a power distribution system. The calculation method is characterized in that the 'N-1' safety criterion is adopted as the premise, the interconnection relation of a main transformer is adopted as the basis, the upper-lower level coordination relation of the power distribution system is fully considered, the influence of load transfer limit of medium-voltage connection and short-time overload of the high-voltage main transformer are considered, and the power supply capability of the power distribution system can be accurately estimated, so that the deficiency of the load supply capability estimation on quantity when the single voltage level is only considered is avoided; the limit of the whole load supply capability of the power distribution system can be accurately mastered, so that the planning and the construction of the power distribution system is guided; and when the regional load increases in certain degree, the requirement for load increase is met by discovering the power supply capability of the existing power supply facilities. According to the method, the limit utilization ratio of the power distribution equipment can be determined on the premise of meeting the safety of the system and reference for a supply transferring scheme can be provided when the equipment fails, thus the operation scheduling of the power distribution system is guided and the method is beneficial to the effective use of the power distribution system facilities in power supply enterprises.

A method and system for color image segmentation are provided. The method comprises: calculating distances between pixel points of the color image based on pixel values of three channels of RGB of each pixel point of the color image and abscissa and ordinate values; Constructing a fused k-nearest neighbor graph fusing k-nearest neighbor graph and inter k neighborhood graph based on the calculateddistances between pixels of the color image; Performing clustering analysis on each pixel of the color image based on the constructed fused k-nearest neighbor graph; The color image is segmented according to the result of the clustering analysis. The color image segmentation method and system according to the invention can increase the computational complexity and obtain a better clustering effectof a non-linear data set, thereby achieving a better color image segmentation effect.

The invention discloses a method for calculating the burn-off rate of a one-dimensional flame furnace of mixed coal. The method comprises the following steps: 1, obtaining the burn-off rate Bp value and the blending combustion ratio of the one-dimensional flame furnace of two single coal types; 2, calculating the weighted average burn-off rate Bpc of the mixed coal according to the blending combustion proportion; 3, calculating the influence degree delta Bpc of the burnout performance of the blended coal according to the burnout performance of the blended coal and the blended combustion proportion; and 4, finally calculating the burn-off rate Bph of the mixed coal according to Bpc and delta Bpc. According to the method, non-linear influence on the burn-off rate of the mixed coal by the burn-off performance of the mixed coal, the burn-off performance deviation, the mixed burning proportion, wind grabbing of the easy-to-burn coal and the like are fully considered, and finally the method capable of predicting the burn-off rate of the mixed coal one-dimensional flame furnace with high precision is obtained. The method is reliable in data source, wide in coal type application range and suitable for power coal such as anthracite, meagre coal, bituminous coal and lignite. The deviation between the predicted value and the measured value of the mixed coal Bph is within 1%, and the model precision can meet the engineering requirements.

The invention relates to the technical field of power plant thermoelectric cost apportionment calculation, in particular to a heat supply unit thermoelectric cost apportionment method. According to the power supply and heat supply cost allocation method provided by the invention, factors influencing coal consumption calculation, such as heat supply meter metering errors and fire coal heat value test errors, are comprehensively considered, reasonable allocation is carried out in heat supply and power generation links, and auxiliary power, heat supply and power generation cost and the like can be allocated by utilizing a heat supply ratio; various methods for calculating the heat supply cost of the current domestic heat supply unit are fully combined, and the cost allocation calculation method is perfected and corrected; the result meets the actual conditions of various types of units, and the method is extremely high in universality and has good expansibility.

The invention discloses an indoor ranging method, which uses a direction sensor set on an AR device to obtain the horizontal distance between its camera and a target object and the height of the target object, and superimposes it on the scene in the real world displayed by the augmented reality device. . The present invention only acquires the angle between the line connecting the camera to the bottom of the target and the intersection point of the ground and the vertical direction of the ground or the angle between the line connecting the camera to the intersection of the extension line of the target and the ground and the vertical direction of the ground, and the angle between the camera and the top of the target. The angle between the connection line and the vertical direction of the ground, the angle between the line connecting the camera to the bottom of the target and the vertical direction of the ground, and then according to the vertical distance between the camera and the ground, the Pythagorean theorem can be used to calculate the distance between the camera and the target The calculation method of the horizontal distance and the height of the target object is simple and fast, with a small amount of calculation and low cost.

The invention discloses a measuring method for a toe angle of a car, which establishes a new measuring device for the toe angle of the car, and uses the device to perform measurement. The method comprises the following steps of: during measuring, separately emitting line lasers from two sides to the opposite side, collecting the data by the opposite cameras, and sending the data to a measuring unit for measurement and calculation; starting the working of the cameras; acquiring the current images of the cameras for processing; acquiring the images once from the cameras for processing after theprocessing is completed, and so on; calculating the threshold value of the monochromatic light component of each image by extracting a maximum monochromatic light component of the acquired image everytime; selecting N rows of pixel points on a projection surface, sequentially dividing the pixel points of each row according to the threshold value, and obtaining the divided effective pixel points in each row; calculating the center position of the effective pixel points by using the effective pixel points; and calculating the offset distance of the line laser projections by using the central position, so as to calculate the offset angle. The calculation method is rapid and simple, and has high precision.

The invention provides a grid harmonic detection method and a grid harmonic detection device. The grid harmonic detection method includes: step S11, obtaining an analog signal of AC power in the power grid to be tested, and performing discrete processing on the analog signal to obtain discrete data x(t); step S13, obtaining discrete data x(t) On the basis of superimposing multiple sets of different Gaussian white noise signals ωi(t), multiple sets of original signals Xi(t) are obtained, and multiple sets of original signals Xi(t) are subjected to empirical mode decomposition to obtain natural modes of each order function component; step S15, perform mean value operation on the intrinsic mode function components obtained by decomposing multiple groups of original signals Xi(t), and obtain the nth intrinsic mode function component cn(t); step S17, divide the nth intrinsic mode function The state function component cn(t) is substituted into a group of original signals X(t), and the harmonic decomposition result of the group X(t) is obtained. The calculation method of the invention is simple and quick, and the harmonic detection precision is high.