34results about How to "Reduce the number of measuring points" patented technology

The invention discloses a torsional vibration error monitoring method for a shaft system of a steam turbine generator unit, a monitor and a system. The method includes the steps of S1, collecting output signals of rotation speed sensors, key phase sensors and bearing base vibration acceleration sensors on the steam turbine generator unit; S2, conducting Fourier transform on the collected output signal of each bearing base vibration acceleration sensor to obtain vibration spectrum signals; S3, extracting an amplitude value in the vibration spectrum signal of each bearing base vibration acceleration sensor under the corresponding rotation frequency; S4, obtaining the types of to-be-detected frequencies and separately extracting the corresponding amplitude value and phase under each type of to-be-detected frequency from the vibration spectrum signal of each bearing base vibration acceleration sensor to serve as feature parameters; S5, on the basis of a judgment principle and the extractedfeature parameters, judging whether or not torsional vibration errors of the shaft system occur in the steam turbine generator unit. By means of the method, real-time online monitoring of the torsional vibration errors of the shaft system is achieved.

The invention discloses a blade ice-coating failure on-line monitoring method and system based on a wind generation set operation state. According to the method, operation state data acquired by a wind generation set operation set SCADA system is utilized, and ice-coating state characteristic indexes are extracted after proper processing of the data; a built blade ice-coating diagnosis nerve network is input; and characteristic indexes which represent both the ice-coating degree of blades and the ice-coating position of the blades are output. The method is a damage-free, dynamic and real-timemonitoring diagnosis method, and a theoretical basis and technical support can also be provided for diagnosis of blade ice-coating failure in engineering practice; the whole monitoring system is simple and convenient in operation; and the method and system have large promotion value.

The invention belongs to the field of high-temperature high-speed fluid flow researches and particularly relates to a high-temperature high-speed jet reflection velocity field test method. The method is characterized by including firstly, processing an H-shaped test rake, secondly, preparing test equipment, thirdly, starting test after synchronizing a system clock with a jet generator, fourthly, processing data, and fifthly performing analysis and computation. The method has the advantages that the number of measuring points, test data volume and test start-up times are reduced to a bearable range of an external field; the ground of the external field is undestroyed while steadiness of the test rake is guaranteed, and the problem about influence on a plastic piezometric tube due to condensation and high temperature of the external field is solved; a multi-channel acquisition delay unloading method is adopted for massive real-time high-frequency dynamic sampling data, the problem of lack of bandwidth and rate of a data acquisition and storage system is solved, meanwhile data accuracy is improved, start-up times of a jet device are reduced, and test cost is saved; the problem about one-to-one correspondence of the test data and jet states is solved; and a set of data acquisition, processing and analysis method is established.

The invention relates to a voltage monitoring device of a fuel cell stack, comprising a connector assembly, a measuring wiring harness and a voltage measuring unit of the fuel cell stack, wherein theconnector assembly is used for a 121-stitching machine; one end of the measuring wiring harness is respectively connected with an even number of polar plates or a three multiple number of polar plates, and the other end is connected with the voltage measuring unit of the fuel cell stack through the connector assembly used for the 121-stitching machine; and the voltage measuring unit of the fuel cell stack detects the voltage information of each measuring point, which is transmitted by the connector assembly used for the 121-stitching machine, and compares the average voltage of the fuel cell stack with the voltage information of the measuring point to determine whether the voltage of a cell positioned at the measuring point is normal. The voltage monitoring device realizes the voltage monitoring and diagnosing of a fuel cell used for a vehicle and has the advantages of low realization cost, simple structure, safety, reliability, and the like.

The invention discloses a closed space panel acoustic contribution degree identification method. According to the method, a holographic measurement surface close to an inner surface is set at an internal portion of the closed space, sound pressure sensors are arranged on the measurement surface in a mesh mode, and the distance between adjacent grid points is less than half a wavelength; the orthogonal spherical wave superposition method is utilized to establish the transfer relationship between the sound pressure at the measurement surface and source strength of an orthogonal spherical wave source, and the source strength of the orthogonal spherical wave source is calculated; according to the source strength of the orthogonal spherical wave source, the relationship between the surface normal vibration velocity of the closed space structure and the source strength of the orthogonal spherical wave source is established; the acoustical contribution degree of a closed space panel is calculated through utilizing the sound field equivalence principle. The method is advantaged in that the method is suitable for closed sound fields in any shapes, the quantity of required measurement pointsis small, the method is simple and convenient for enforcement; due to mutual orthogonality of different orders of the orthogonal spherical wave source, the ill conditioning property of a transfer matrix is reduced, and computation accuracy is greatly improved.

The present invention relates to a large diameter strap-on carrier rocket modal test measurement point arrangement and optimization method used for the space combination measurement point arrangementof a new generation large diameter strap-on carrier rocket full-rocket modal test. The method considers a combined mode of the five elastic branches of a whole rocket, a core-level large diameter storage box local mode, an engine branch mode and the like, and carries out the iterative optimization on the measurement point arrangement via a trial test method, so that the number and the positions ofthe measurement points are optimal, and the test efficiency is improved. The method can guarantee the situation that all modal parameters in an appointed frequency band can be obtained in a large-scale rocket modal test, thereby not losing the modes.

The invention relate to a method for reconstructing a complex morphology of a flexible platy structure based on a two-dimensional orthogonal curvature. The method comprises steps of: using an optimized discrete-distributed orthogonal optical fiber grating to form a sensor network, and establishing an orthogonal curvilinear net of the platy structure by obtaining two-dimensional orthogonal curvature information of each grating measurement point on the surface of the platy structure and performing meshing of the platy structure on the basis of the continuous curvature; constructing a motion coordinate system on the orthogonal curvilinear net, calculating a relative coordinate of the measurement point in the motion coordinate system by using the motion coordinate system, and on this basis, calculating a world coordinate of the measurement point; and obtaining torsion angles of the motion coordinate system in two directions, and updating the motion coordinate system by using the torsion angles. The method requires hardware including a square flexible platy structure experiment model, an optical fiber grating sensor network which is implanted to the structure surface in an optimized distributed manner, an optical fiber grating network signal analyzer, an algorithm running and graphic processing computer, and a display.

The invention belongs to the technical field of mechanical quality factor measurement, and particularly relates to a method and system for measuring the mechanical quality factor of a vibrating body.The method comprises the steps of driving an ultrasonic transducer by a detection signal wave to excite the vibration of the vibrating body, moving a vibration measuring device along the axial direction of the vibrating body, and measuring the vibration speeds and phases of a plurality of mass points at intervals of delta Z infinitesimal elements on the surface of the vibrating body; carrying outspatial Fourier transform on the vibration speed of the measurement mass points on the vibration body to obtain a frequency spectrum in a wave number space, determining a main wave number k0, removinga wave number above 1.2 k0, restoring a distribution curve of the vibration speed of the mass point in the space, calculating the energy loss delta Ed of the infinitesimal element and the reactive energy delta Er of the infinitesimal element, and obtaining the corresponding relation between the mechanical quality factor of the vibrating body and the amplitude of the vibrating body. According to the present invention, the influence of the energy loss of the connector on the measurement result is avoided in principle, the measurement precision is ensured, the whole calculation process is simpleby using a method of firstly analyzing the infinitesimal and then analyzing the whole through the infinitesimal, and the large-scale application can be carried out.

The invention relates to a railway curve mapping method based on satellite positioning. The railway curve mapping method based on the satellite positioning comprises the following steps that (1) a reference line is determined, specifically, a measuring starting point is determined, a datum point in a pre-set distance away from the measuring starting point on a railway is determined, and the connecting line of the measuring starting point and the datum point is taken as a reference line; (2) a first key mapping point is determined, specifically, the included angle of the connecting line of thecurrent position and the datum point and the reference line and the distance of the connecting line are calculated in real time, when the included angle and the distance of the connecting line of thecurrent position and the datum point reach the pre-set condition, the first key mapping point is reached according to prompts, mapping of the first key mapping point is completed, the mapping circuitdiagram is automatically refreshed, and the connecting line of the first key mapping point and the datum point is set to be a first reference connecting line; (3) a second key mapping point is found out to map; (4) the step (3) is repeated until a mapping destination is reached; and (5) the overall length of the railway curve is calculated. According to the railway curve mapping method based on satellite positioning, key mapping points can be automatically found out, the quantity of the measuring points in a controllable error is reduced, and the measuring precision is high.

The invention aims to provide a free-form surface detection optimal measurement point number determination method, which comprises the following steps of: setting four groups of test schemes, and carrying out surface detection to obtain four groups of shape errors; if the four groups of shape errors are all smaller than the shape tolerance, adding a group of schemes with more measuring points as a fifth group of testing schemes; constructing a gray prediction GM (1, 1) model, and predicting to obtain a fifth group of prediction shape errors; based on the gray interval range, judging whether the processing technology has problems or not; according to the fifth group of test schemes, performing curved surface detection by adopting a high-precision three-coordinate measuring machine to obtain a fifth group of shape errors; comparing whether the absolute value of the difference between the last two groups of detected shape errors is smaller than a threshold value or not, and if so, obtaining an optimal free-form surface measuring point number; otherwise, deleting the first group, changing the second to fifth groups into new first to fourth groups, then adding a scheme of more measuring points as a new fifth group, and repeating the steps. The detection efficiency can be improved.

The embodiment of the invention provides a generator set stator structure and a stator measuring point arrangement method, relates to the technical field of hydro-generator operation on-line monitoring, and can detect whether iron core punching sheets in a stator iron core are mutually compressed or not in real time. The fastening assembly is used for keeping the stator core in a compressed state; and the force measuring assembly comprises a pressure sensor, and the pressure sensor is arranged between the stator core and the fastening assembly and is used for measuring a relative pressure value between the stator core and the fastening assembly. According to the generator set stator structure provided by the embodiment of the invention, the compression state of the stator core can be detected in real time, and a corresponding detection assembly does not need to be arranged on the core punching sheet, so that the influence on the stator core is avoided; as the detection device is arranged outside the stator core, the interference of the stator core is less, and the measurement resolution is high; the generator set stator structure provided by the embodiment of the invention adopts an assembly part nesting mode, and is high in integrity.

The invention discloses a flue partition mixer. The cross section of a flue is divided into a plurality of partitions; each partition is internally provided with a bias flow blade group; bias flow blades in the bias flow blade groups deflect along the same rotation direction; the center lines of the bias flow blades in the bias flow blade groups are tangent to the same circle; the rotating deflection directions of all the bias flow blades in the bias flow blade groups in the adjacent partitions are opposite; the mixer can achieve uniform mixing of smoke in all the partitions; and the number of the partitions is small, so that the investment cost is low.