34results about How to "Compatible with practical engineering applications" patented technology

The invention discloses a method of optimal configuration of a plurality of superconducting fault current limiter based on a sensitivity technology, which comprises the steps of: calculating the three-phase short-circuit current of all nodes in a whole system, and finding b nodes with the short-circuit current exceeding the standard value; determining braches for installation and reliable startup of the SFCLs (superconducting fault current limiter) according to startup conditions of the SFCLs; calculating the sensitivity of self-impedance of each station with the short-circuit current exceeding the standard value, sequencing the stations in a sensitivity descending order, and taking the top a branches as candidate braches for installation of the SFCLs; and taking c candidate braches as optimal branches for a multi-objective optimization algorithm NSGA-II (non-dominated sorting genetic algorithm-II) in next step, determining a scheme with the optimal installation positions of the SFCLs, the number of SFCLs to be installed and the impedance, thereby realizing global optimum configuration. By adopting the method, the search space to be understood is reduced greatly, the speed of calculation is increased, and optimization results are more suitable for actual applications. Meanwhile, the problem of weight selection resulting from conversion of multi-objective optimization to single-objective optimization can be avoided, and a decision-maker can make final decisions according to actual engineering needs.

The invention provides a risk assessment method for relative values ​​of lightning parameters of distribution network lines, and relates to the technical field of lightning protection for overhead lines of power system distribution networks. This method comprehensively evaluates the risk level of towers in a specific distribution network line by introducing lightning activity parameters such as the relative value of ground flash density and the relative value of lightning current amplitude induced overvoltage, and accurately finds out the towers with a relatively high level of lightning risk in a specific line. Protection is carried out in order to meet the goal of lightning damage control for distribution network lines in different regions.

The invention discloses a disc hobbing cutter box mechanism of a shield tunneling machine and an application method thereof. The disc hobbing cutter box mechanism comprises a box body and a rotation mechanism, wherein a hobbing cutter installing mechanism is arranged in the box body, one side of the hobbing cutter installing mechanism is fixedly connected with a hobbing cutter, and the rotation mechanism is installed on the other side of the hobbing cutter installing mechanism; the rotation mechanism comprises a rotation mechanism installing block and a rotation box installed on the rotation mechanism installing block. A cutter box is simple in structure and easy to machine, and meets strength requirements. The cutter box is structurally integrated and free of any independent small part, and operation by a robot is convenient. When the disc hobbing cutter box mechanism is used in cooperation with a manipulator, torque generated in the rotation process of the rotation mechanism on the cutter box can be transmitted to the box body through mechanical fingers, and a mechanical arm does not need to bear the torque. A bevel arranged on a left baffle and a bevel arranged on a right baffle of the rotation mechanism installing block can prevent the left baffle and the right baffle from getting stuck in the box body. The rotation mechanism is installed behind the hobbing cutter installing mechanism, and the hobbing cutter is prevented from being scratched by falling rock-soil in the rock-soil cutting process.

The invention discloses a recycled water permeable brick mix proportion design method based on a target water permeable coefficient, a skeleton model of a water permeable brick is fully considered, askeleton is built with recycled aggregate, aggregate gaps are filled with target pores, water, fly ash and cement, and meanwhile, the working performance of slurry under different porosities is ensured by adjusting the mixing amount of a water reducing agent. The method can determine the mix proportion of the regenerated water permeable bricks according to different water permeable coefficient requirements, is clear and clear in design idea and simple and convenient to operate, and better conforms to practical engineering application. Meanwhile, the recycled aggregate with the particle size of4.75-9.5 mm is adopted according to the mixing ratio, the requirements for water permeability and strength can be met, the utilization range of the recycled aggregate is widened, the raw materials are easy to obtain, and the cost is low. According to the invention, cement, water and fly ash are used as main bodies of the cementing material, and the difference between the density of the cement andthe density of the fly ash are fully considered, so that the water permeability coefficient of the regenerated water-permeable brick can be more accurately obtained according to the target water permeability coefficient.

The invention discloses a design method of a harmonic gear device, and designs the harmonic gear device comprising a rigid gear and a flexible gear and the rigid gear and the flexible gear capable ofrealizing space engagement. The design method comprises the following steps: (1) in a direction perpendicular to the axis of the flexible gear, front, middle and back sections of the flexible gear areselected; (2) a discrete point of a tooth profile of each section of the rigid gear is obtained through an envelope method based on a simulation motion trajectory of the flexible gear; and (3) a complete tooth profile of the rigid gear is obtained according to the obtained discrete points of the tooth profiles of the three sections of the rigid gear. The design method prevents defects in the conjugate profile design through single-section motion or adjustment of flexible gear structure in a traditional design method, and is more accordant with actual working conditions of a harmonic gear transmission device; and the designed rigid gear device is high in overlap ratio, stable in transmission and capable of effectively improving the transmission efficiency.

The invention provides a bolt pre-tightening force identification method based on singular value decomposition and a support vector machine, and belongs to the technical field of vibration signal fault detection. The invention provides a bolt pre-tightening force measuring method based on a vibration signal in order to solve the problems that the pre-tightening force of a bolt is reduced and eventhe bolt is separated and falls off due to the fact that mechanical environments such as impact and vibration generated in the operation process of mechanical equipment. The method comprises the stepsof collecting an impact vibration signal of a single bolt connecting beam in a free state through DASP modal analysis software; carrying out empirical mode decomposition and reconstruction on the experimental data to remove noise and trend terms; carrying out feature dimension reduction by combining singular value decomposition, and extracting a vibration signal feature vector; and taking the vibration signal feature vector as an input feature, performing classifier model training through the support vector machine, and finally realizing pre-tightening force identification of the bolt connecting structure by using the trained classifier.

A calibration method based on fixed and variable parameters in three-dimensional scanning system relates to the camera model parameter calibration in the visual system including the following steps: (1) fixed parameters calibration is primarily to acquire coordinates of sampling points on circular contour and heart in image coordinates through image processing techniques, and then use n sampling points to get aspect ratio through least squares method, (2) after obtaining the fixed parameters, it uses the image coordinates of image midpoint and the corresponding space coordinates of world midpoint to demarcate the initial value of variable parameters for the camera, including the equivalent focal length, main point coordinates, axis tilt factor, distortion factor and external parameters, (3) after demarcation, it takes fixed parameters as a constraint for nonlinear optimization objective function to establish a binding target function and get the optimal solution of variable parameters through the nonlinear optimization method.

The invention relates to a Bayesian network-based system measurement node optimization configuration method. According to the method, a bayesian network model of a system is established. According tothebayesian network model, a mutual information matrix between a fault node and a measuring node is calculated. According to the mutual information matrix between the fault node and the measuring node, the contribution degree of the measuring point to the diagnosis of the fault node is calculated, and a comprehensive diagnosis capability index is determined. According to the contribution degree ofthe measuring point to the diagnosis of the fault node, the cost of the measuring point and the number limit of the measuring point, an optimization problem is described. Based on the improved discrete binary particle swarm algorithm, the optimization treatment is carried out. Finally, the optimized configuration result of the measuring pointis obtained. According to the invention, the optimization configuration problem of a sensor under the constraint condition is considered, so that the method is more suitable for practical engineering application. Meanwhile, the fault diagnosis capabilityand the measurement cost problem of the measuring point are considered at the same time, and the optimization treatment is carried out based on the improved optimization algorithm. As a result, an optimal measuring node configuration scheme of the system is found.

The invention discloses a method for evaluating the denitrification ability of an SCR reactor, which comprises the following steps: obtaining historical data of each measuring point of the unit from a data source, performing data preprocessing, correcting the oxygen amount at the outlet and inlet NOx concentrations, and calculating the denitration capacity. In addition to the amount of ammonia consumed per unit of NOx, the working conditions of temperature and outlet NOx concentration are divided and typical working conditions are selected, and the ammonia consumption curve of removing unit NOx is fitted and converted accordingly. The upper limit is determined by the relationship between the amount of ammonia and the slip rate of ammonia, and the denitrification capability of the SCR reactor is evaluated in combination with the slope of the trend line and the upper limit. The method for evaluating the denitrification capability of the SCR reactor provided by the invention can realize steady-state tracking and self-adaptive correction calculation.

The invention relates to a simulation test bench for the cutter head of a shield tunneling machine and a use method of the simulation test bench. The simulation test bench comprises a cutter head, a worm wheel / worm structure, a base, a storage cutter bin and a mechanical arm mounting bin; the cutter head is rotatably mounted on the base through a mounting plate; the storage cutter bin and the mechanical arm mounting bin are both mounted on the base; the worm wheel / worm structure is mounted on one edge of the base and is located at one side of the 1 / 4 of the surface of the cutter head; a worm wheel shaft in the worm wheel / worm structure is coaxially and fixedly connected with the shaft of the mounting plate; the worm wheel / worm structure is provided with a hand wheel; and the hand wheel isfixedly and axially connected with a worm shaft in the worm wheel / worm structure. The test method includes the following steps that: a hobbing cutter box is fixed; a cutter head is rotated; the cutterhead is fixed; a cutter change robot is installed; and cutter change is simulated, position information is inputted to the cutter change robot, and the trajectory planning and motion accuracy of thecutter change robot are verified. According to the simulation test bench of the invention, the worm wheel / worm integrated structure is adopted, so that separate small parts are avoided, and therefore,the simulation test bench has the advantages of convenience in installation and operation, structural simplicity and easiness in processing, and meets a strength requirement and conforms to actual engineering application.

The invention relates to a rapid high-precision relative pointing control method of a noncoplanar rendezvous orbit, in particular to a feedforward PID (proportion, integration and differentiation) control based rapid high-precision relative pointing control method of the noncoplanar rendezvous orbit, and aims to solve the problem that rapid high-precision tracking-pointing control methods related to satellite attitudes under the noncoplanar rendezvous orbit do not exist in the prior art. The feedforward PID control based rapid high-precision relative pointing control method including adopting an Euler angle for attitude description of a spacecraft, creating dynamical and kinematical equations of the spacecraft, and acquiring an precise expected angle theta according to a noise-containing expected angle z by a Kalman filtering algorithm of a spaceborne computer; designing an attitude control law of each axis according to a formula of ; selecting two parallelly-placed single-frame control moment gyroscopes to control a yaw axis, and selecting two flywheels to control a rolling axis and a pitch axis respectively; calculating gyroscopic moment T and flywheel actual output moment uw to complete rapid high-precision relative pointing control of the noncoplanar rendezvous orbit. The feedforward PID control based rapid high-precision relative pointing control method is applicable to rapid high-precision relative pointing control of the noncoplanar rendezvous orbit.

The invention relates to a method for identifying a fault section and a fault branch of a collector line of a wind farm, and belongs to the technical field of electric power system relay protection. Firstly, the zero-sequence current data of one cycle after the fault of each measuring point on the collector line is extracted, and the Hanning window function is selected to add a window to it, and the zero-sequence current sequence value after windowing is calculated. FFT transforms the zero-sequence current sequence values ​​after windowing at each measuring point to obtain the transformed zero-sequence current sequence values, and calculates the zero-sequence current fault component phase spectrum and its phase spectrum mean value of two adjacent measuring points. If the two adjacent measurement points are on the main line, judge whether the section is faulty according to the faulty section identification criterion; Whether the branch is faulty. The invention only adopts the zero-sequence current construction criterion of the wind farm collector line to identify fault sections and branches, the principle is simple, and it is suitable for practical application in engineering.