148results about How to "Improve engineering applicability" patented technology

The invention belongs to the technical field of motor control, and relates to a permanent magnet synchronous motor sensorless control method, system and hardware circuit, angular velocity estimation is designed based on a q-axis current model under a two-phase rotating coordinate system, angular velocity estimation compensation is designed based on a d-axis current model, and a rotating speed correction coefficient is introduced. And dynamic compensation of the estimated angular velocity value is realized. An accurate angular velocity estimated value and an accurate rotor angle estimated value are obtained by constructing a Romberg observer with an angular velocity estimated value and a rotor angle estimated value as outputs based on a dq rotating coordinate system. Taking an angular velocity error obtained by a motor angular velocity given value and a motor angular velocity estimated value as input of an outer ring PI controller, so as to ensure that the angular velocity estimated value tracks the motor angular velocity given value and output a q-axis current reference value; taking the difference value between the q-axis current reference value and the q-axis current sampling value and the difference value between the d-axis current reference value and the d-axis current sampling value as the input of an inner ring PI controller so as to ensure the bandwidth and the influence capability on the load, and outputting a d-axis voltage reference value and a q-axis voltage reference value; and converting the d-axis voltage reference value and the q-axis voltage reference value into voltage reference values under a two-phase static coordinate system based on the rotor angle estimation value so as to divide SVPWM drive circuit sectors, select voltage vectors, calculate action time, control on and off time of a permanent magnet synchronous motor switching device, and control on-off time of the permanent magnet synchronous motor switching device. And the alternating current speed regulation performance of the permanent magnet synchronous motor without the position sensor under the Romberg observer method is ensured.

The invention relates to a spacecraft three-axis vibration test condition equivalent calculation method, which comprises the following steps: constructing a three-axis vibration dynamic equation and solving a three-axis vibration dynamic response based on a traditional vibration dynamic theory, and obtaining the three-axis vibration dynamic response in a frequency domain through frequency domain conversion; through three-axis simulation analysis and single-axis simulation analysis, dynamic responses under a three-axis vibration boundary and a single-axis vibration boundary are obtained; and establishing a difference value minimization criterion according to the dynamic response under the three-axis vibration boundary and the uniaxial vibration boundary, and solving an optimization problem by taking the difference value minimization as an optimization target and the three-axis vibration condition as an optimization variable. According to the method, the problem of non-real simulation of the active section spacecraft vibration environment of an existing single-axis vibration test method is solved, the multi-axis coupling real state of the active section vibration environment is fully considered, the three-axis vibration test condition is reasonably formulated, the obtained result better conforms to the real situation, and the engineering applicability is higher.

The invention provides a fretting fatigue test device, and belongs to the technical field of test devices. The device comprises a fatigue testing machine for providing a circulating axial load, a transverse load loading mechanism for providing a transverse load required by a test, and a loading test bench for providing a test platform for the transverse load loading mechanism. According to the invention, the constructed structure device is combined with the fatigue testing machine, the fretting fatigue test is carried out on the common fatigue testing machine, the centering position precision of the fretting pad and the sample is ensured through the designed loading test bed and the transverse load loading mechanism, the fretting pad can apply the same transverse load on the two sides of the sample, and the accuracy of the fretting fatigue test is ensured. According to the fretting fatigue testing device, the problems of uneven transverse load stress and the like in the fretting fatigue testing process are solved, the fretting fatigue testing accuracy is improved, the offset amplitude can be continuously applied, the influence of actual complex working conditions on parts can be better simulated, and the engineering applicability of the test is improved.

The invention discloses a recombined bamboo compression creep strain prediction method based on an improved Kelvin-Volight model, and the method comprises the steps: firstly carrying out the creep test of a recombined bamboo under two different stress levels, and employing a new Kelvin-Volight viscoelastic mechanical constitutive relation model defined based on a variable-order R-L fractional order theory to carry out the analysis of the recombined bamboo; obtaining main parameter values of the model under the two stress levels; secondly, respectively adopting an exponential function and a power function to fit the relationship between the stress and the main model parameters to obtain numerical values of the model parameters under any other specified stress level; and finally, on the basis of the parameter values obtained in the previous step and a Kelvin-Volight model, the compression creep of the recombined bamboo under other stress levels is predicted. Research results show that based on the method, the defect that the recombined bamboo is high in mechanical property dispersity can be effectively overcome, the compression creep strain of multiple recombined bamboo test pieces can be accurately predicted, and the method has good engineering applicability.

The invention discloses a post-treatment method of an additive manufacturing metal part, and aims to solve the problem of insufficient fatigue performance caused by large surface roughness, internal residual tensile stress and the like of the additive manufacturing metal part. The fatigue weak part of the part can be directly subjected to high-frequency scanning treatment by using a micro-scale laser shock peening method under the conditions of no absorption protection layer, no water-light coaxial restraint layer and the like, and the surface roughness is reduced through the direct ablation melting effect of micro-scale small-energy pulse laser and the surface of the part; residual compressive stress is formed on the surface layer of the part through the mechanical effect of laser-induced shock waves, the surface smoothness is improved, the fatigue performance is improved, a laser melting / heat affected layer is removed through sand blasting, the surface smoothness is further improved, and therefore rapid post-treatment of the additive manufacturing metal part is achieved, and the method can be directly applied to engineering.

The invention belongs to the field of structural wind-induced vibration control, and relates to a design method of a novel tuned liquid damper with an inerter, which comprises the following steps: S1, respectively determining the mounting floors of a TLD device and an inerter device according to the design of a main body structure; s2, designing the effective mass, the shaking frequency and the damping ratio of the TLD according to the dynamic characteristic parameters of the controlled structure; s3, the geometric dimension and the water storage height of the TLD are designed in combination with the structural plane shape and the space limitation of the floor where the TLD is located; s4, designing an inerter coefficient beta of the inerter device in combination with the mass of the main body structure; s5, calculating the rigidity K of the linear spring element connected with the TLD and the damping coefficient C of the damping element; s6, establishing a main body structure-TLDI system motion equation, and calculating the vibration response and the vibration reduction rate of the main body structure; and S7, judging whether the novel tuned liquid damper (TLDI) with the inerter can enable the controlled structure to achieve an ideal control effect or not. Compared with TLCDI and TMDI devices of the same type, the TLCDI and TMDI device has superiority in economy and space utilization rate.

The invention discloses a reactive voltage risk assessment method and device based on a full-pure embedding algorithm, and the method comprises the steps: obtaining and carrying out the standardized processing of source load historical data, and calculating the power probability density functions of a power supply and a load, a typical operation scene is extracted according to an improved K-means clustering method based on PDF, and upper and lower limit scenes of operation are obtained through an envelope line method; constructing a multi-dimensional full-pure embedded power flow model, and deducing the full-pure embedded power flow model according to a Maclaurin expansion principle; the two scenes are substituted into a multi-dimensional full-pure embedded power flow model for analysis, and voltage analytic solutions of all buses are obtained; and combining the power probability density function to analyze the bus voltage out-of-limit probability in the typical operation scene and the operation upper and lower limit scenes, and evaluating the reactive voltage risk of the regional power grid by using the bus voltage out-of-limit probability. According to the method, the problems that for reactive voltage risk assessment, massive historical data of a traditional power flow algorithm is difficult to process, and an intelligent algorithm is poor in interpretability are solved.

The application discloses a high-stability electrorheological fluid based on a non-ionic eutectic solvent and a preparation method thereof, and belongs to the field of electrorheological fluid materials. The electrorheological fluid is prepared by using a non-ionic eutectic solvent as a carrier liquid and titanium dioxide micro-nanoparticles as a dispersed phase. The mass fraction of the non-ionic eutectic solvent is 70-90 wt%, and the mass fraction of the titanium dioxide micro-nanoparticles is 10-30 wt%. The non-ionic eutectic solvent is formed by hydrogen bond combination of a hydrogen bond donor and a hydrogen bond acceptor. The preparation method comprises the following steps: heating and stirring the hydrogen bond donor and the hydrogen bond acceptor according to a preset molar ratio to prepare the non-ionic eutectic solvent, then adding 10-30 wt% of dry titanium dioxide micro-nanoparticles, and performing ultrasonic dispersion and high-speed vortex treatment to obtain the electrorheological fluid. The molar ratio of the components in the non-ionic eutectic solvent can be adjusted to flexibly control the viscosity and polarization response capacity of the electrorheological fluid system. The obtained electrorheological fluid has low zero-field viscosity, high yield stress and strong sedimentation stability.

A kind of time domain ground penetrating radar intelligent forward method based on physical parameter guidance, comprising the following steps: step one: build underground medium model and generate supervision data;Step two: the ground penetrating radar GPR forward simulation is expressed as the mapping problem of " physical parameter field to radar profile ";Step three: build PhyTANet network based on encoder decoder;Step four: the PhyTANet network obtained by step three is trained, fine-tuned;From the above steps, finally, after training fine-tuning ends, the dielectric constant and conductivity distribution of any given underground medium are input, and the corresponding prediction result is obtained.The purpose of the present application is to solve the technical problems of the existing ground penetrating radar forward technology, such as insufficient accuracy, insufficient modeling of key physical parameter coupling relationship and limited time domain feature expression in complex heterogeneous medium, and the present application is proposed.

The invention discloses a three-dimensional grid robust watermarking method and system based on spherical coordinate statistical characteristics, and the method comprises a watermark embedding stage and a watermark extraction stage, in the watermark embedding stage, three-dimensional grid vertexes are converted to a spherical coordinate space, a stable equivalent binning structure is constructed, and statistical characteristics are extracted, so that the three-dimensional grid robust watermarking is realized. And frequency domain transformation is carried out. In combination with a quantization domain binary mapping mode of quantization index modulation, watermark information is embedded into a frequency domain coefficient, and then a three-dimensional model carrying a watermark is generated through inverse transformation and coordinate reduction. The system comprises a coordinate conversion module, a binning module, a feature extraction module, a frequency domain transformation module, a watermark embedding module, an inverse transformation module, a vertex updating module and a model output module. The method provided by the invention has a large capacity up to 256 bits, and has significant robustness under rotation, scaling, translation, smoothing, simplification, vertex reordering and noise attack. The method can be widely applied to the technical field of three-dimensional data processing.

The invention relates to the technical field of material bonding characteristic testing, in particular to a composite heterogeneous charging structure and a heterogeneous interface peel strength testing method thereof. The composite heterogeneous charging structure comprises a press-fitting structure and a pouring structure, a bonding interface is arranged between the press-fitting structure and the pouring structure, and the bonding interface is formed in the pouring and curing process of the pouring structure. The low bonding strength and peel strength testing method provided by the invention is suitable for accurate characterization of weak interface bonding performance of fragile materials, energetic materials and the like. According to the method, a traditional mechanical testing method is improved, a universal material testing machine is used for carrying out peel strength testing, and quantitative evaluation and failure mode analysis of the bonding strength of the heterogeneous interface are achieved. The method solves the problem that the conventional method is difficult to accurately measure the bonding characteristic determination and brittleness failure behavior of the low-bonding-strength interface, and can be widely applied to the fields of safety evaluation, reliability test and the like of energetic materials.

The invention discloses a ship identification method and system based on dual physical model fusion verification, and relates to the technical field of optical fiber sensing and ocean monitoring. The method aims at solving the problems that ship noise in submarine optical cable DAS signals is prone to interference of environment noise such as low-speed guided waves, the false alarm rate is high, and accurate positioning cannot be achieved. The method comprises the steps that DAS phase data is acquired and preprocessed to generate a channel-time energy diagram; suppressing low-speed guided wave noise through frequency-wavenumber domain slowness scanning, detecting an energy ridge line on the purified energy diagram, and calculating an observation apparent velocity; acquiring AIS data to calculate and predict the apparent velocity; the relative error of the observed apparent velocity and the predicted apparent velocity is firstly matched, and then linear regression is carried out on the arrival time of the candidate ridge line and the AIS distance to verify and fit the root mean square error; the validated ridge line is confirmed as an effective ship event and a directory is generated. According to the technical scheme, through physical mechanism denoising and dual model verification, the accuracy and reliability of ship identification are effectively improved.

The present application relates to the technical field of wireless passive sensing, and discloses a differential sensing system for metal crack detection and a quantitative detection method thereof, which comprises an RFID reader-writer and a passive RFID differential sensing tag; the passive RFID differential sensing tag comprises a communication antenna, an RFID chip, an impedance matching network, a planar inductive sensing module, a radio frequency switching module, an energy recovery module and a data processing unit; the impedance matching network is connected between the communication antenna and the RFID chip; the planar inductive sensing module comprises a reference planar inductor and a sensing planar inductor; after double-state alternate sampling of the reference sensing, difference is performed, so that environmental disturbances such as reading and writing distance, sensor posture, multipath and temperature drift are significantly suppressed, and differential noise suppression is realized; the switching module is powered by the energy collection antenna, voltage doubling rectification and charge management module in the energy collection management module, battery maintenance is avoided, and passive operation is realized.

This invention belongs to the field of airworthiness testing for aero-engines and provides a high-speed imaging device for aero-engines that simulates birds swallowing flocks, based on a multi-splitter flexible imaging fiber bundle. This device is used to simultaneously observe the flight trajectories of multiple simulated birds between the air cannon and the engine inlet. It includes a first multi-splitter flexible imaging fiber bundle, with multiple first split ends each equipped with a first fiber optic lens aligned with the flight path of each simulated bird. A first high-speed imaging component is optically coupled to a first convergence end, simultaneously recording the dynamic images of all paths in a single frame. Each split end is positioned in the free space to the side of the flight path, without penetrating the engine casing. Furthermore, both the convergence and split ends of the fiber bundle have rectangular end faces, with aspect ratios matching the high-speed camera's image sensor, avoiding invalid imaging areas. This invention achieves high-speed imaging of multiple targets, high synchronization, and high space utilization in bird-swallowing tests, and has the advantages of compact structure and strong anti-interference capability.

The invention discloses a photoelectric sensor system conversion efficiency calibration system and method based on a reverberation chamber, and belongs to the technical field of photoelectric sensor conversion efficiency calibration, the system comprises an electric wave reverberation chamber, a transmitting antenna, a reference antenna and a photoelectric field sensor system; the photoelectric field sensor system is composed of a photoelectric sensor, a laser source, a photoelectric detector, a polarization maintaining optical fiber and a single-mode optical fiber. In the calibration process, the reference antenna and the photoelectric sensor system are used as receiving ends respectively, receiving power at different stirring positions in the reverberation chamber is sampled to obtain two groups of transfer functions, and the total efficiency of the photoelectric sensor system is determined by comparing the two groups of transfer functions under the condition that the radiation efficiency of the reference antenna is known. The conversion efficiency of the photoelectric sensor system is obtained by combining the relation among the power, the field intensity and the total efficiency in the free space; and the effective averaging of the incident direction and the polarization state is realized by using the uniform and isotropic electromagnetic field characteristics of the reverberation chamber.

The invention belongs to the technical field of charging power supplies, and particularly relates to an automatic overvoltage protection device for a multi-winding series charging power supply. The multi-winding series charging power supply is mainly composed of an inversion unit, a resonance network, a transformer and n diode rectification modules. The automatic overvoltage protection circuit comprises n isolation units and n overvoltage protection units in one-to-one correspondence with the n isolation units, the n isolation circuits are respectively connected in parallel with the two ends of the n diode rectification modules, and the n overvoltage protection units are respectively connected in parallel with the two ends of the overload; the isolation unit comprises a bleeder resistor R and a switch K which are connected in series; the overvoltage protection unit comprises a light-emitting diode Da, a voltage-regulator tube Db, a divider resistor Ra and a divider resistor Rb, the voltage-regulator tube Db, the divider resistor Ra and the divider resistor Rb are sequentially connected in series, and the light-emitting diode is connected to the two ends of the divider resistor Ra in parallel.

The invention discloses a low-frequency ultrasonic scanning imaging quantitative detection method for large-depth submillimeter-level defects, and belongs to the technical field of ultrasonic nondestructive testing. The method comprises the following steps: acquiring A-type ultrasonic signals p0 (t) of multiple groups of position codes by adopting an ultrasonic detector, calculating a synthetic aperture length and an apodization coefficient according to a sound field distribution rule of an ultrasonic probe, synthesizing a signal ps (t) of each coding position by adopting a delay superposition rule, decomposing the ps (t) into N sub-signals by adopting a split spectrum analysis method with variable center frequency fi and variable bandwidth, and calculating the position code of the A-type ultrasonic signals p0 (t); sub-signals with the same center frequency are combined with coding information to generate a scanning image Imi, the defect size di in the Imi is measured according to a-6dB method, a sound field directivity function is adopted to fit a change curve of di along with fi, and di corresponding to the slope k of the recognition curve =-0.01 is the defect size. According to the method, the problems that the resolution of a traditional synthetic aperture focusing method is limited by the size of a probe and the signal-to-noise ratio of multi-resolution scanning imaging is low are solved, and high-signal-to-noise-ratio and high-precision quantitative detection of submillimeter defect sizes in a large depth range can be realized by adopting low-frequency ultrasound.

The invention discloses a magnetic levitation track irregularity random evolution modeling method, a medium and equipment, and belongs to the field of track engineering and stochastic dynamics modeling. The method comprises the following steps: acquiring irregularity data of a maglev track collected along a line direction, and acquiring track structure parameters and vehicle load statistical characteristics of a corresponding line; the track irregularity state increment between adjacent sampling points is calculated, a state variable set is constructed based on the track irregularity quantity, the track structure parameters and the vehicle load statistical characteristics, state intervals are divided according to the value range of the state variable set, and the condition statistical magnitude of the state increment is counted in each interval; and identifying drift term and diffusion term functions in a stochastic differential equation by using conditional statistical information through statistical inversion, machine learning or a fusion mode thereof, and constructing an orbit irregularity stochastic evolution model. The method can reflect the non-stationary and state related characteristics of the track irregularity under the action of the track structure and the vehicle load, and can be used for track state evaluation, dynamic simulation and maintenance decision.

The application belongs to the technical field of tunnel and underground engineering disaster prevention and control, and particularly relates to a cement-polyurethane composite grouting material suitable for dense soft rock reinforcement and a preparation method thereof. The composite grouting material is mainly formed by mixing a penetration cross-linking liquid and a grout vein skeleton liquid. The penetration cross-linking liquid is formed by mixing a grouting material A component and a grouting material B component. A semi-prepolymer is obtained by pre-polymerization reaction of a polyisocyanate and a polyether polyol, and then a diluent and a catalyst are added to the semi-prepolymer to obtain the grouting material A component; a surfactant, a retarder and water are mixed to obtain the grouting material B component; and cement and water are uniformly mixed in a certain proportion to obtain the grout vein skeleton liquid. The cement-polyurethane composite grouting material and the preparation method thereof can achieve penetration-splitting composite reinforcement effect when grouting in a dense soft rock poor geological section with strong density and poor permeability, and the grout preparation process and grouting operation steps are more simple and efficient.

The present application relates to the technical field of high polymer material flame-retardant modification, and particularly relates to a COF hierarchical modification APP-based core-shell flame-retardant smoke suppressant, a preparation method and application thereof. The flame-retardant smoke suppressant takes APP as a flame-retardant core layer; takes PVP as a soft template agent, and assists in situ growth of melamine-p-phenylenedimethylene formaldehyde (COF) on the surface of APP to adsorb combustible volatile components in the initial pyrolysis stage, provide a gas source, and act as a Fe 3+ coordination skeleton; takes tannic acid as a coordination agent and a carbon source, and constructs a multi-level core-shell structure with Fe 3+ coordination. The present application realizes integration of flame-retardant and smoke suppression functions through hierarchical modification. When the flame-retardant agent is applied to polyurethane, it can significantly reduce the heat release rate, smoke release rate and toxic gas generation amount, and simultaneously improve the compatibility with the matrix, effectively overcoming the defects of poor compatibility and insufficient flame-retardant and smoke suppression performance of traditional APP flame-retardant agents. The present application has simple preparation process and controllable conditions, and is suitable for industrial production.

The application relates to a differential current-voltage integrated sensor and a current-voltage measurement system, and belongs to the technical field of power system monitoring. The application comprises a first half-ring unit and a second half-ring unit based on a double-layer PCB. The two half-ring units are designed in an upper-lower symmetry mode to form an open-close structure. A live bus bar passes through the middle cavity of the two half-ring units, and a Rogowski coil electronic current sensor and a differential D-dot voltage sensor are integrated on the integrated sensor. Based on the integrated sensor, synchronous measurement of current and voltage can be realized, the integrated sensor is highly integrated, the space utilization is extremely optimized, and the integrated sensor has a convenient opening and closing function.

The utility model discloses a kind of press quenching tool for synchronous device sliding sleeve with positioning boss, belong to the technical field of synchronous device sliding tooth cover, press quenching tool includes press quenching core shaft and feeding mechanism;The end of press quenching core shaft is provided with guide cone surface, the side surface of press quenching core shaft is formed with core shaft working surface, and the core shaft working surface is provided with several positioning boss grooves, and the other end of press quenching core shaft is provided with quenching oil circuit;Feeding mechanism includes feeding cylinder, and the lateral wall of feeding cylinder is provided with several positioning grooves, and the bottom of feeding cylinder is connected with mounting column;Feeding mechanism is installed in the feeding carousel of press quenching equipment by mounting column, and press quenching core shaft is installed in the press quenching station of press quenching equipment;Positioning groove is correspondingly arranged with positioning boss groove, so that the positioning boss of synchronous device sliding sleeve with positioning boss is transferred from feeding mechanism to press quenching core shaft, and correspondingly falls into positioning boss groove.The utility model can guarantee the effect of controlling thermal distortion of part in quenching process, realize automatic press quenching, and guarantee production efficiency.

This invention discloses a single-phase and three-phase combined electromagnetic in-phase power supply system and control method, relating to the field of electrified railway traction power supply technology. It includes a single-phase traction transformer, a three-phase-to-two-phase traction transformer, an electromagnetic in-phase compensation device, and a system main controller. During operation, the single-phase traction transformer undertakes the main traction power supply task, while the three-phase-to-two-phase traction transformer and the electromagnetic in-phase compensation device undertake auxiliary traction power supply and negative sequence management tasks. Each unit performs energy management and coordinated control through the main controller. This invention can transform existing traction substations using conventional three-phase-to-two-phase transformers into in-phase traction power supply systems, eliminating phase separation at the traction substation outlet, enabling the traction substation to provide in-phase power to the traction network while meeting grid-connected power quality requirements. The electromagnetic structure boasts high operational reliability and strong engineering applicability, and can be adapted to the retrofitting of existing electrified railway in-phase power supply lines and the integration of new energy sources along the traction side.

The present application relates to steel and non-ferrous smelting slag comprehensive recovery and iron-making resource utilization comprehensive utilization technical field, disclose a kind of copper slag efficient iron-making method based on magnetic separation pretreatment, comprising: to molten iron-silicate base waste slag input by calcium carbide, sodium fluoride and phosphorus component consisting of conditioning agent, using sodium fluoride to build liquid diffusion field exposure reduction interface, induce calcium carbide and iron silicate in situ reduction to generate metal iron core;Heat treatment promotes iron core polymerization growth;Gradient cooling, using phosphorus component induces silicate matrix crystal transformation to generate expansion stress and break matrix;Grinding powder and weak magnetic separation, extract magnetic enrichment product, the present application breaks iron-oxygen-silicon chemical bond, realizes the conversion of combined state iron to independent metal state, achieves iron and gangue phase decoupling, using endogenous stress induction self-pulverization, reduce grinding energy consumption, output high-grade iron powder and simultaneously remove sulfur zinc impurities.

The invention discloses a wind power frequency modulation parameter optimization method considering frequency modulation performance and energy loss. The method comprises the following steps: constructing a power system frequency response model aggregating a single-machine synchronous unit and a wind turbine generator, and constructing a double-index fitting model of a fan rotating speed recovery process and a corresponding energy loss quantification model based on a rotor motion equation; deriving an analytic relationship between the technical index and the energy loss index of the wind power frequency modulation parameter pair; determining the internal weight of the technical index and the weight between the technical index and the energy loss index by adopting a combined weight method, and constructing a comprehensive evaluation index comprising the technical index and the energy loss index; establishing a dual-objective optimization model taking minimization of a technical index and minimization of an energy loss index as a core, and outputting a group of Pareto leading edge optimal solution sets; and according to the calculated relative closeness of each candidate scheme, selecting a solution with the maximum relative closeness as a control parameter for setting the frequency modulation performance and energy loss of the wind turbine generator.

The invention discloses a rock-soil structure bearing path generation method based on plastic limit analysis. The rock-soil structure bearing path generation method comprises the steps that a design domain, external load applying conditions, geometric constraint conditions and boundary constraint conditions of a rock-soil structure are established; introducing a plastic constitutive relation, selecting a yield criterion, and establishing a yield constraint condition; analyzing the rock-soil structure model based on a plastic limit analysis theory; according to a plastic limit analysis result, identifying a main bearing path of the rock-soil structure in a limit bearing state; the rock-soil structure configuration is adjusted, the structural participation degree of a main bearing path area is enhanced, and the structural participation degree of a low-efficiency bearing area is weakened; after adjustment, the plastic limit analysis and bearing path identification process is repeatedly executed until the spatial distribution of the bearing path tends to be stable; and outputting the rock-soil structure configuration which meets the plastic yield constraint condition and is stable in bearing path. According to the method, the main bearing path of the rock-soil structure can be identified in the ultimate bearing state, and a reasonable structure configuration is determined accordingly.

The invention relates to a picometer-level surface shape measuring device for a large-aperture optical element. The picometer-level surface shape measuring device comprises a laser, a first polarization beam splitter, a first acousto-optic modulator, a second polarization beam splitter, a quarter-wave plate, a beam expander group, a local gating measuring surface unit, a 45-degree reflector, a second acousto-optic modulator, a non-polarization beam splitter and a photoelectric detector. The invention further provides a picometer-level surface shape measurement method for the large-aperture optical element, high-precision phase information is obtained based on the double-frequency heterodyne interference principle, regionalized scanning is achieved on the surface of the measured optical element through the local light gating module, and full-aperture high-resolution surface shape measurement can be completed without depending on a mechanical moving platform. The device has the advantages of high mechanical error resistance, high measurement precision, simple system structure and the like, and is suitable for surface shape detection of ultrahigh-precision optical elements.

This invention relates to an event-triggered model predictive obstacle avoidance control method and system, belonging to the field of navigation control technology for unmanned vehicles, automobiles, and robots. The method addresses constrained discrete-time systems by establishing a predictive model of the controlled object and constructing a model predictive control problem in the rolling time domain, encompassing state constraints, input constraints, terminal constraints, and obstacle avoidance constraints, thereby achieving attitude adjustment, trajectory tracking, and safe obstacle avoidance. This invention represents the controlled object's occupied region and the obstacle region as a unified convex set, constructing obstacle avoidance constraints based on minimum distance optimization and its dual transformation, avoiding direct handling of non-smooth distance determination and improving optimization efficiency. Control updates employ an event-triggered mechanism, determining whether to resolve the optimization problem based on the deviation between the actual and predicted states; otherwise, the existing control sequence continues execution. Furthermore, the prediction time domain is adaptively adjusted according to the operational phase, reducing the optimization frequency and computational scale while ensuring obstacle avoidance safety and control performance, thus improving the real-time performance and stability of navigation control under complex constraints.

This application provides a modeling method and system for predicting the core loss of a high-frequency transformer, comprising: measuring the magnetic properties of the core material at different frequencies based on an experimental platform, and obtaining the magnetization curve and loss density curve of the core material according to Ampere's circuital law; inputting the magnetization curve into a constructed geometric model, setting excitation and boundary conditions, establishing a finite element model and performing finite element simulation analysis to obtain the loss density distribution and magnetic flux density distribution within the high-frequency transformer core; and constructing a loss model by introducing a gradient coefficient and the average value of the loss density, the magnitude of the magnetic field strength gradient, and the average value of the magnitude of the magnetic field strength gradient obtained from the finite element model, to predict the core loss. This application provides important basis for material selection, geometric structure optimization, and thermal design of high-frequency transformers, helping to shorten the R&D cycle, reduce trial production costs, and improve the overall performance of high-frequency transformers.

The application discloses a stable control method for power regulation of a two-stage series-connected impulse power station with a regulating pool, which firstly establishes a mathematical model of the series-connected impulse power station with the regulating pool, and proposes a power-water level coordinated control strategy, namely, a proportional integral control strategy with a relative value of a power deviation of a first-stage power station as an input signal for the first-stage power station, and a double proportional integral control strategy with a relative value of a power deviation of a second-stage power station and a relative value of a water level deviation of the regulating pool as input signals for the second-stage power station; on the basis, a stability analysis model of the series-connected power station is constructed, and a determination method for the governor control parameters of the first-stage power station and the second-stage power station is proposed. The control method proposed by the application not only can realize the rapid and stable regulation of the power of the series-connected power station, but also can effectively guarantee the fluctuation stability of the water level of the regulating pool, has the advantages of clear physical meaning and strong engineering applicability, provides a theoretical basis for guaranteeing the synchronous stable operation of the series-connected impulse power station with the regulating pool, and has a wide application prospect.