109 results about "Vector decomposition" patented technology

The invention belongs to the field of exploration geophysics and particularly relates to an elastic seismic wave field forward modeling method. The seismic forward modeling method includes the steps of firstly, according to the principle of wave field vector decomposition, decomposing a seismic wave field into a longitudinal wave field and a transverse wave field and respectively calculating corresponding propagation matrixes of the longitudinal wave field and the transverse wave field; secondly, according to the principle of low-rank decomposition, decomposing the propagation matrixes to obtain propagators of vector longitudinal wave and vector transverse wave so as to reduce calculation amount of numerical simulation to improve calculation efficiency; and thirdly, coupling updated records of the vector longitudinal wave and the vector transverse wave acquired after the numerical simulation so as to obtain a forward modeling result of the seismic wave field. The calculation precision is high due to the fact that the propagation matrixes include compensations to medium parameter and numerical simulation parameter. Numerical dispersion of seismic wave field records acquired by the forward modeling method is nearly eliminated and stability of the numerical simulation is high; accordingly, the forward modeling method is a high-precision elastic wave field numerical simulation method.

The invention discloses a bionic hair sensor for being sensitive to flow velocity and accelerated velocity vectors and a detection method thereof; the bionic hair sensor includes a top polymer hair, a middle annular silicon micro-sensor structure, and a bottom signal wire prepared on a glass substrate. When acted by an external accelerated velocity or fluid, the top hair drives a round mass block and an annular mass block in the annular silicon micro-sensor structure to swing; with use of a negative stiffness effect principle of an electrostatic force, and through swinging of the round mass block and the annular mass block in the annular silicon micro-sensor structure, resonant frequencies of resonators arranged around the round mass block and the annular mass block are caused to be changed, and values of the flow velocity and the accelerated velocity are detected; with use of a coupling structure of the mass block and the annular mass block, the swinging direction of the top hair is subjected to vector decomposition, and the vector direction of the accelerated velocity or the fluid velocity is detected.

The invention discloses a controllable dynamic shape interpolation method with physical third dimension. According to the method, a rotation-strain space definition is provided, and a set of conversion mode from a three-dimensional model to a rotation-strain space coordinate is established, so that the primary nonlinear deformation can be expressed by linear operation of the coordinate in the rotation-strain space; and the method greatly reduces the algorithm complexity and improves the solving efficiency by combining the traditional mode shape decomposition to perform dimension reduction. The method comprises the following steps of: decomposing a base vector acquired by the traditional mode shape decomposition into rotation and strain parts, and constructing a deformation subspace by using rotation-strain corresponding to the main component bases; obtaining a rich dynamic deformation effect by editing and regulating mode shape coordinate motion interpolation curve parameters in the subspace; and finally, obtaining a new model pose sequence through a reconstruction process according to the interpolated mode shape coordinate.

The invention discloses a detection method and device for side rollover and collision of a vehicle, as well as applications of the detection method and device. The detection method comprises the following specific steps of: 1) collecting acceleration values of an X-axis, a Y-axis and a Z-axis, performing vector synthesis on the acceleration values of two of the axes, and then respectively going on a step 2) to perform collision judgment and a step 3) to perform side rollover judgment; 2) judging whether a synthesized acceleration value is greater than a collision acceleration threshold, if yes, determining that a collision occurs, and if not, determining that no collision occurs, and returning to the step 1); and 3) performing a trigonometric function calculation by using the synthesized acceleration value, a gravitational acceleration value and the acceleration value of another axis to obtain at least three inclination angles, taking an average inclination angle, and judging whether side rollover occurs. According to the detection method and device as well as the applications thereof disclosed by the invention, vehicle collision strength is calculated through a vector synthesis method, a vehicle side rollover angle is calculated through a vector decomposition method, omni-directional accurate detection of vehicle collision and side rollover events is realized, the precision is high, no blind spots exists, and the phenomena of false alarm and omitted alarm are avoided.

The invention discloses an activity recommendation method based on user interest degree and geographic position. The method comprises the following steps: firstly obtaining the corresponding right on a Meetup API open platform and extracting the corresponding group data information, activity data information and member data information through a group interface, an activity interface and a member interface; then primarily screening an activity dataset interested by the user by using a vector decomposition model according to the extracted dataset information; then combining the social relationship of the user and further screening the activity dataset interested by the user by using Pearson correlation coefficients; subsequently dividing the activity generating geographic position into regions by considering the influence of the activity generating geographic position on the problem whether the user takes part in one activity, and determining the activity dataset which is finally interested and attended by the user by using an optimization method; and finally recommending the activity information to related users. The method can be used for efficiently recommending suitable activities to the users from a large amount of activity data.

The invention relates to a P and S wave combined quick positioning method and system for microseism in a well, and the method comprises the steps: a, obtaining the microseism data of the same event, carrying out the vector decomposition of the microseism data of the same event, and obtaining two vertical azimuth angles of a three-component detector; b, building the function relation, which takes the three-component detector as the start point, between a vertical depth H and a horizontal distance L according to the snell law; c, building a P&S wave depth target function related with the position of a seismic focus, enabling the target function to be minimized through depth scanning, calculating the vertical depth and horizontal distance of the seismic focus relative to the three-component detector, and achieving the P and S wave combined quick positioning. The method just employs two vertical azimuth angles of the three-component detector, builds the P&S wave depth target function related with the position of the seismic focus according to the snell law, enables the target function to be minimized through depth scanning, and can achieve the P and S wave combined quick positioning.

The invention discloses a multi-rotor unmanned aerial vehicle spraying control method and system based on speed detection. The method comprises the following steps of detecting the flight speed and the flight direction of an unmanned aerial vehicle; performing vectorial orthogonal decomposition on the flight speed and the flight direction according to the orientation of a vehicle head, and determining a velocity component V1 of the orientation of the vehicle head and a transverse velocity component V2; according to the velocity component V1 of the orientation of the vehicle head and the transverse velocity component V2, controlling some water pumps to be turned on, and the other water pumps to be turned off. The method has the advantages that plant protection objects are drifted down behind the unmanned aerial vehicle and cannot drift down on the unmanned aerial vehicle, the service life of the unmanned aerial vehicle cannot be shortened, crops cannot be damaged, and plant protection objects are saved. The system comprises a flight data detection unit, a vector decomposition unit and a control unit. The system has the advantages that the plant protection object atomization degree is controlled, and the purpose of not damaging crops can be achieved by adjusting different mist particles according to different crops.

The invention discloses a vehicle classification method for double-row vertical radar waves. A microwave vehicle detector is installed on the side of the road. The microwave vehicle detector adopts an array type double microwave radar. The microwave vehicle detector is composed of a vector decomposition module and a frequency analysis module. and a microprocessor. The method of the present invention is a comprehensive identification and analysis of the echo characteristics, analyzing the characteristic value of the echo to obtain a group of typing results, analyzing the frequency of the echo, and then obtaining a group of typing results; finally, the The two classification results are weighted to obtain the final vehicle classification result. Because this product adopts the two-level small network classification method in the neural network, it can greatly improve the classification speed, solve the real-time problem of vehicle classification, and improve the accuracy and stability of classification.

The invention relates to the field of image understanding in computer vision, and discloses a retro-gradation detection method based on a video and a system thereof. In the invention, an angular point is extracted in a frame difference image, angular point optical flow tracking is performed in an original image, and generation of retro-gradation is judged according to an optical flow characteristic vector decomposition motion mode so that robustness of retro-gradation detection is enhanced, and probability of omission report and false report in the retro-gradation detection in a complex scene is effectively reduced. Different motion modes are obtained by aiming at motion areas in the video via an iteration clustering algorithm so that the motion modes corresponding to different moving objects in the complex scene can be effectively extracted and analysis of the retro-gradation detection is facilitated. Movement of image blocks in a larger range can be dealt with by adopting an idea of pyramid hierarchy so that the method is applicable to application scenes of the retro-gradation detection.

The invention relates to the technical field of information security and optical information processing, and aims to greatly reduce the complexity of an encryption system. The security of the system is improved, and common cryptography attacks can be effectively resisted. Therefore, the single-channel color image encryption method based on vector decomposition and phase encoding comprises the following steps: (1) an image encryption part: firstly decomposing a color image to be encrypted into three color channels, namely red R, green G and blue B; Carrying out first three-dimensional chaotic random phase mask modulation on the synthesized grayscale image, carrying out first Gyrator transformation on the modulated image, and then carrying out second Gyrator transformation on the modulated image, so that the transformed image is a final encrypted image; And (2) an image decryption part: firstly, carrying out inverse transformation of Gyrator transformation for the second time on the encrypted image, and integrating the three color channels together to obtain a decrypted color image. The method is mainly applied to an optical information encryption and decryption processing occasion.

The invention provides a method for determining duty ratio of universal pulse width for control of a three-phase AD motor PWM (pulse width modulation). The method comprises the following steps: determining normalization three-phase current set values Ia, Ib and Ic of the three-phase AD motor; calculating each two-phase current difference Iab, Ibc and Iac according to the normalization three-phase current set values Ia, Ib and Ic; calculating the maximum value max{|Iab|, |Ibc| and |Iac|} of absolute values of each two-phase current difference; determining the duty ratios ka, kb and kc according to three conditions of the max{|Iab|, |Ibc| and |Iac|} through four arithmetic operations. Compared with the conventional six sector vector decomposition method for determining the duty ratio of three-phase pulse, the method has the same result; but because of simple process and prevention of complicated vector determination and trigonometric function operation, the method has less realized code amount, small occupied hardware resources and high operation efficiency, can realize multiple PWM control modes including control modes of SPWM (sine pulse width modulation) and SVPWM (space vector pulse width modulation), and is particularly applicable to high-precision SVPWM control of the three-phase AD motor.

The invention discloses an efficiency optimizing control method for a permanent magnet motor. The efficiency optimizing control method comprises the following steps of (A) collecting a hall position signal of a motor rotor by an MCU through a capturing port; (B) working out a motor rotational speed <omega> and a rotor angle <theta> according to the hall position signal; (C) generating a sine wave modulation ratio M by performing calculation on a difference between a set speed <omega> <ref> and a real-time rotational speed <omega> of the motor through a speed PI ring; (D) obtaining a voltage vector advance angle which is as shown in the specification after current vector lagging; (E) adding the rotor real-time angle <theta> on the advance angle which is as shown in the specification, and then performing SVM (space vector modulation) with the sine wave modulation ratio M to generate sine wave driving signals U, U and U<c> required by the motor; and (F) loading the sine wave driving signals U, U and U<c> to the motor winding to enable the motor to rotate. By adoption of the efficiency optimizing control method, hardware circuit cost of the driver collecting phase current and vector decomposition parts is lowered, and product competitiveness is improved.

An early warning method for abnormity of the whole lateral load resistance performance of a large-span bridge structure comprises the following steps that (1), data acquisition is carried out on the three-dimensional wind field and the GPS displacement effect of the midspan position of a main beam; (2), vector decomposition and mean processing are carried out on the collected data, and static wind speed sequences and static displacement sequences in the transverse direction of the bridge are obtained; (3), the static wind speed sequences and the static displacement sequences are divided according to months, and a main correlation sequence of the static wind speed sequences and the static displacement sequences on the same month is determined by the utilization of wavelet packet cross correlation coefficients; (4), Fourier series fitting is carried out on the main correlation sequences on all the months in sequence, and the abnormity of the whole lateral load resistance performance of the large-span bridge structure is warned easily by the utilization of the month change characteristics of the fitted parameter values. The early warning method for abnormity of the whole lateral load resistance performance of the large-span bridge structure based on the measured wind load effect makes up for the blank in the research on the aspect of the early warning of the abnormity of the whole lateral load resistance performance of the large-span bridge structure and can provide important reference for monitoring and analyzing the whole lateral load resistance performance of the large-span bridge structure.

The invention discloses an ultrasonic modulation discharge-electrolysis high-efficiency milling system, and belongs to the technical field of special machining. The ultrasonic modulation discharge-electrolysis high-efficiency milling system consists of an ultrasonic vibration control system, a multi-axis machine tool control system, a composite machining power supply control system and an electrolyte circulation system, wherein corresponding machining tracks are matched according to the profile characteristics of an anode workpiece; the machining tracks can be subjected to vector decomposition; the machining tracks are converted into control input quantity of the ultrasonic vibration control system and the multi-axis machine tool control system, the accurate synchronization of the millingprocess and the ultrasonic vibration is achieved; the ultrasonic vibration amplitude is detected in real time through a displacement sensor; the control input quantity serving as the composite machining power supply control system is processed through the programmable controller, the coupling effect of a variable voltage process and the ultrasonic vibration process is achieved, and the removal efficiency of the anode material and the stability of the machining process can be improved; and high-speed high-pressure electrolyte fluid provided by the electrolyte circulation system is directly conveyed into a machining gap through a rotary joint, so that the mass transfer efficiency of the fluid in the gap is enhanced, and the efficient composite machining with a smaller gap is achieved.

The invention belongs to the technical field of radar imaging and discloses a related motion error compensation method based on BiSAR echoing, a system and application. Through BiSAR signal modeling and wave number vector decomposition, image spectrum analytical expression under polar coordinates is obtained, and a correlation between a phase error caused by a motion error and non-systematic distance unit migration is found; and a phase error is roughly estimated by methods of combined estimation and compensation. FFBP imaging treatment is conducted on an echoing signal, so that an SAR image under the polar coordinates before error compensation is obtained; the image is converted to a distance compression-orientation frequency domain, and rough estimation of a phase error thereof is conducted, so that the rough phase error is obtained; and NsRCM is compensated with the phase error obtained by rough estimation, and then phase error fine estimation and fine compensation are carried out,so that image focusing quality is finally improved. The method, system and application disclosed by the invention greatly reduce dependence on a high-precision inertial navigation measurement system and have high processing efficiency and engineering practicability.

The invention discloses a process for measuring the tracking precision of a photovoltaic tracking system based on a vector decomposition method. The process comprises the following steps: determining the mounting position and the mounting orientation of a photovoltaic assembly; judging which photovoltaic system is used, determining the elevation angle of the photovoltaic assembly through using an electronic protractor, testing the all-day azimuth operation case of the photovoltaic assembly and recording the test date and the test result if it is a single-axis photovoltaic tracking system, and testing the all-day azimuth operation and elevation angle operation case of the photovoltaic assembly and recording the test data and the test result if it is a double-axis photovoltaic tracking system; and calculating and determining the test result through utilizing the vector decomposition method to obtain the tracking precision of the photovoltaic system. The method has the advantages of no affection by the weather, no need of mounting of equipment on the photovoltaic assembly, and test and mounting time saving. The method allows coordinate transformation to be carried out as needs to satisfy test requirements of different single-axis tracking systems.

The invention discloses a method for determining shortest route of network on RDT sheet. The present method requires multitime circulating calculation, so that the time consumption is big. The inventive method comprises the steps: building a coordinate system for the RDT network and determining the node number and the position of the communication node at first, then determining the mirroring superset M'(d) of the target node D and determining the optimal supper mirror point and building the X1-Y1 coordinate system, determining the vector decomposition result between the S and the M by using a VR method, storing the route project between the S and the D, starting the fault tolerance treatment mechanism. The invention effectively combines the advantage of the VR route method with the advantage of the CCVR route method, at the same time, overcomes the respective defect, can obtain the shortest route of any two points in the network on the RDT(n,1) sheet in the lesser calculation consumption. The fault tolerance mechanism provided by the invention can better solve the problem that the performance is lower in the present method.

The invention discloses an optimized selection method of the voltage vectors for direct torque control of an asynchronous motor on the basis of limited switching state of an inverter. The optimized selection method comprises the following steps: S1, setting acting time t1 of each voltage vector inputted by the asynchronous motor to be a highest switching-frequency allowed value; S2, raising an optimized evaluation index by the action mechanism of the voltage vector to the variation of flux linkage and the torque of the motor and computer simulation; S3, at the fixed time of each sampling period, calculating the increment of torque T1 and the flux linkage generated by action of 7 voltage vectors by an optimized vector calculation method, and selecting one optimized voltage vector to act on the inverter according to the obtained evaluation index; S4, constructing a rapid prototyping experiment system of direct torque control by utilizing a DSP microprocessor and an IGBT module, and carrying out calculation on vector decomposition and electromagnetic torque on the flux linkage of the motor so as to realize production line type calculation, reduce the calculation amount of a controller, increase the switching frequency of the inverter, and further improve the real-time performance of the system. The optimized selection method disclosed by the invention has the beneficial effect that the dynamic performance of the system can be greatly improved according to the optimization control principle.

The invention discloses a method for determining transverse dynamic displacement of a girder of a large-span bridge structure. The method includes the following steps that (1), GPS displacement monitoring data in a girder span are collected; (2) vector decomposition and mean value processing are conducted on the monitoring data to obtain transverse dynamic displacement data; (3) fitting is conducted on the power spectral density of the transverse dynamic displacement data by the adoption of the Gaussian series; (4) the harmony superposition method is used for obtaining the dynamic displacement fitted value of the girder. According to the method, a mathematical modeling method is used on the basis of the monitoring data, and transverse dynamic displacement of the girder can be determined more accurately.

The invention provides a collaborative filtering method, a collaborative filtering device and a collaborative filtering system, and belongs to the technical field of house information processing. Themethod comprises the following steps: determining a first house resource set, and forming a first preference data set corresponding to a selected user from preference data of house resources in the first house resource set; determining a position area range, selecting a part of users according to the position area range, determining a second house resource set, and forming a second preference dataset corresponding to the part of users from the preference data of the house resources in the second house resource set; and obtaining a trained vector decomposition model through the second preference data set, obtaining a feature vector set corresponding to the house resources in the second house resource set by utilizing the second preference data set and the trained vector decomposition model, calculating the similarity of the feature vector set, and forming a similarity set after the calculation is completed. The method and system are used for determining the recommended house resourceswith the user preference characteristics through similarity calculation.

The invention provides an equal-mode vector decomposition image encryption analysis method based on a novel full convolutional network. The method comprises four parts of an encryption system based onequal-modulus vector decomposition, a network model of encryption analysis and network training and encryption system analysis. A designed encryption analysis network model is trained by inputting aplaintext-ciphertext pair, and then a ciphertext image is input through the trained encryption analysis network model, so that an attack analysis result, namely a recovered high-quality plaintext image, can be obtained. Compared with a traditional attack method, the provided encryption analysis method has the advantages that effective encryption analysis can be realized without knowing an encryption secret key or a private key, other encryption system parameters and the like, and a high-quality plaintext image can be recovered; the provided deep learning method is short in training time, and the training speed is increased by 7 times compared with a traditional method; the method provided by the invention has good generalization ability, and one image library can be adopted for training while the other image library can be adopted for successful testing; finally, the method also has good robustness for noise and clipping in transmission.

The present invention belongs to the technical field of structural design, and relates to a tool used for single-axis vibration vector decomposition. The tool is characterized by comprising an equipment installation bottom surface and a vibration product working surface. Through adoption of the tool of the present invention, a single-axis vibration vector can be decomposed, and vibration test requirements of a product in three axis directions, i.e., X axis, Y axis and Z axis, can be satisfied at the same time, so that a vibrated object has quantitative vibration response respectively in the three axis directions, thereby overcoming the defect that single-axis vibration equipment can only achieve single-direction vibration response of a product at the same time, greatly shortening a vibration test period, and improving working efficiency.

The present invention discloses a bin automatic frequency-adjustment anti-clogging machine, including an arch eliminating plate, a shock wave unit, a bin wall, bin holes, a shock wave device, a chute,solid rubber springs, hollow T-rubber springs, a bin bolt, shock blocks, a shock wave string, and a shock wave adjusting button. The characteristics of the machine are as follows: vector decomposition is performed on an arched adhesive wall, low frequency vibration is subjected to kinetic momentum buffering, asynchronous multiplication for kinetic momentum conduction is realized, the whole material molecular structure is changed, resonance splitting is generated, and bin cleaning and clogging prevention are realized. The machine can be installed on storage bins, buffering bins, front furnacebins, raw coal bins, clean coal bins, under-shaft bins and standby coal bins, replaces air cannons, bin wall vibration machines, glass-ceramic plates, high molecule plates, loosening machines, rotaryloosening machines, blasting and artificial cleaning modes, saves manual operation and cost, and can facilitate dispersion.

The invention provides a galloping starting method based on power-frequency-to-variable-frequency switching of a nine-phase motor, comprising the following steps: first, after the motor is switched from power frequency to variable frequency, the frequency converter first gives an initial output voltage of the motor in rotation, and at the same time, the given frequency of the frequency converter is gradually ramped down from the rated frequency to 0 Hz; 2, detecting the nine-phase current of the rotating electric machine, transforming the 9 s -> 2 r coordinate vector, and decomposing the vector; 3, judging the inflection point of the frequency search of the rotating electric machine; When the mode length of the nine-phase current vector decomposition is detected to have an ''inflection point'', the rotational frequency of the motor is searched; 4, carry out frequency conversion operation after the frequency inflection point is successfully search, returning the output voltage to the corresponding "fullness" voltage at the frequency in the V / F curve of the frequency converter, output the output voltage to the motor to reach the frequency conversion stable operation of the motor, andstarting the motor successfully; The nine-phase motor can be directly switched from power-frequency operation to variable-frequency operation without waiting for the motor to be stationary.

The invention discloses a radar three-dimensional deformation field reconstruction technology based on general least squares adjustment, which is characterized in that a synthetic aperture radar satellite is used for acquiring a sight line deformation field technology; an atmospheric effect influence technology is removed; an error equation for the three-dimensional direction deformation is listed; a general least squares adjustment principle is used for solving the three-dimensional direction deformation amount; and an analysis technology is verified. The radar three-dimensional deformation field reconstruction technology based on general least squares adjustment has the following advantages that the modern advanced measurement technology and equipment are used, and a station does not need to be built in a monitoring region; the spatial domain in the case of monitoring is maintained to be continuous; three-dimensional distribution situations in the surface deformation space are acquired; and defects of low three-dimensional vector decomposition accuracy in traditional methods such as a pixel offset estimation method, a multi-aperture interference method and an external measurement assisting method can be overcome.

The invention discloses a high-modulation-ratio voltage-sharing method for a diode-clamped five-level inverter. According to the high-modulation-ratio voltage-sharing method for the diode-clamped five-level inverter, twelve peaks of a hexagon of the second layer of a diode-clamped five-level inverter vector diagram are used as centers, the five-level vector diagram is divided into twelve two-level vector diagrams, and 18 triangular areas are obtained through area division. Twelve vector sequences are established in each triangular area, the direct-current side capacitor voltage is controlled to be balanced through combination of the objective function optimization method and the inner hexagon vector decomposition method. Algorithm switching is conducted through the setting of a voltage error hysteresis; the objective function optimization voltage-sharing algorithm is applied when the voltage error is within the hysteresis; the inner hexagon vector decomposition voltage-sharing algorithm is selected so as to enable rapid voltage balance to be achieved when the voltage error exceeds the hysteresis. According to the high-modulation-ratio voltage-sharing method for the diode-clamped five-level inverter, the direct-current side capacitor voltage balance control over the diode-clamped five-level inverter at the high modulation-ratio is achieved, and the inverter has good harmonic characteristics.

The invention provides an asynchronous motor control method based on slip frequency limitation. The asynchronous motor control method comprises the following steps: calculating a slip frequency in closed loop vector control, and if the calculated slip frequency exceeds twice of a rated slip frequency, carrying out amplitude limiting processing on the slip frequency; calculating the slip frequency in open-loop vector control, and if the calculated slip frequency exceeds twice of the rated slip frequency, carrying out amplitude limiting processing on the slip frequency; simultaneously, obtaining an estimated speed value by adopting a speed estimation algorithm, if the estimated speed value is out of the ranges of two fluctuated rated slips of a set speed value, carrying out amplitude limiting processing on the estimated speed value. According to the asynchronous motor control method, the slip range is determined through the relationship between the torque and the slip; the slip frequency calculated by motor parameters is subjected to amplitude limiting processing, and thus an excessive deviation between the estimated speed value and an actual speed value, and an excessive deviation of a vector decomposition angle are avoided at any time; the anti-jamming capability is effectively improved; the reliability of a product is improved.

The invention provides a ballistic deviation analysis and prediction algorithm considering the high-order disturbance gravitation influence. The method comprises the steps of high-order disturbance gravitation vector decomposition and state deviation analysis forecasting model derivation, wherein the decomposition of the disturbance gravitation vector of any order comprises the following processesof firstly obtaining a function expression of a disturbance gravitation vector sigma g at any point P on a two-body trajectory with respect to a true short-point angle, then obtaining an expression of a disturbance gravitation three-component, and finally obtaining the expression; and the state deviation analysis and prediction model derivation specifically comprises the following steps of obtaining an integral solution expression of the trajectory deviation of the free flight section of the missile according to a state space perturbation theory, and substituting and integrating the integralsolution expression to obtain an expression of a trajectory deviation analysis solution of the free section considering the influence of disturbance gravitation. The resolving efficiency of the methodis 10 -3 s magnitude, the calculation error of any downward position is smaller than 5 meters, the calculation result is expressed in an inertial system, and the method can directly participate in missile-borne guidance calculation without extra coordinate conversion.

The invention provides a string type photovoltaic inverter SVPWM (Space Vector Pulse Width Modulation) modulation method and system, and the method comprises the steps: a space voltage vector sector division step: dividing a space voltage vector into six large sectors, dividing each large sector into four small sectors A, B, C and D, and enabling the vector in each small sector to have a corresponding decomposition method; in the vector decomposition step, the space voltage vectors are divided into three types according to the modulation degree, vector decomposition is conducted on corresponding sectors according to the types of the space voltage vectors and the corresponding decomposition principle, and the action time of the vectors is calculated; and a vector sequence selection step: sorting according to the state of the vector to obtain a control signal in each switching period. According to the invention, by reasonably configuring vectors, reducing the switching action times and adopting small vectors with closer switching states to participate in modulation, the bridge arm breaking times are greatly reduced, so that the switching loss of the photovoltaic inverter is reduced.

The invention discloses a complex electromagnetic environment construction method. The method comprises the following steps of: 1, carrying out vector decomposition on a space complex electromagneticenvironment to obtain a vector decomposition signal waveform set; step 2, carrying out vector signal waveform clipping on the vector decomposition signal waveform set; 3, normalizing the clipped vector decomposition signal waveform set to obtain a vector construction signal waveform set, converting the vector construction signal waveform set into an actual electromagnetic signal, and amplifying the actual electromagnetic signal; and step 4, constructing a signal waveform set by using the amplified vector to carry out space complex electromagnetic environment vector synthesis reconstruction. According to the complex electromagnetic environment construction method, a complex motion simulation mechanism is not needed, complex electromagnetic environment simulation encountered in the motion process of an effector can be completed in the static state of the effector, the construction difficulty of the complex electromagnetic environment is greatly simplified, and the construction fidelity is improved.