1563results about How to "Promote engineering application" patented technology

A deepening controlling method of an underactuated automatic underwater vehicle based on a neural network back stepping method relates to the technical field of control of the underactuated automatic underwater vehicle. The deepening controlling method includes first collecting pressure information through a pressure sensor, obtaining corresponding depth of the automatic underwater vehicle (AUV) by calculation according to the pressure information, then building a mathematical model of the underactuated automatic underwater vehicle and a robust deepening controller model, building a mathematical model of the underactuated AUV according to ocean current environment and AUV water power parameter, designing the robust deepening controller model by adopting the feedback gained back stepping method, finally obtaining online learning arithmetic based on neural network weight and self-adaptive law of self-adaptive robust controller parameter, conducting online recognition and error estimation on uncertainty existing in the obtained mathematical model, compensating and optimizing final output signals of the controller, and achieving deepening control of the underactuated AUV by adopting the controller.

The invention relates to a harmless disposal method of kitchen garbage, which comprises the following steps of: (1) pretreatment: after unloading the kitchen garbage, performing solid-liquid separation, rough crushing, crushing and sorting and performing magnetic separation, and recycling metal substances mixed in the kitchen garbage; (2) hydrothermal hydrolysis: after the pretreatment, adopting the hydrothermal hydrolysis to fully inactivate viruses and bacteria in the kitchen garbage, separating out animal and vegetable fatty oil from the kitchen garbage, and hydrolyzing organic materials at the same time; (3) using the fatty oil obtained in the step (2) as an industrial fatty oil material or further performing deep processing to obtain fatty acid methyl ester or biodiesel; mixing and proportioning the pasty organic materials and then conveying into an anaerobic fermentation system; and conveying large granular organic materials into an aerobic biological fermentation device. The method provided by the invention realizes harmless disposal of the kitchen garbage mainly by the pretreatment and the hydrothermal hydrolysis process, increases the conversion rate of biological energy of the kitchen garbage and increases the economic benefit of kitchen garbage recycling products.

The invention discloses a vehicle flowrate and vehicle type identification system, which comprises one or a group of magnetic sensor for detecting the interference signal of vehicle to earth magnetic field in static state or in motion, a signal amplification unit, a filtering unit for filtering the amplified signal, a collection unit for converting the analog signal into digital signal, a signal processing unit for classified identification of digital signal according to vehicle type and automatic detection of vehicle flowrate and a display unit for displays the identification result. After experiment, it is proved that the invention is able to accurately identify different vehicle characteristics, precisely work out the identification result of vehicle type and vehicle flowrate, prevent the interference of climate and weather and ensure high identification rate.

The invention discloses an accelerated degradation test prediction method based on fuzzy theory, which comprises the following steps: collecting test data; performing the analysis of regression aimingat performance degradation data under each stress level; extrapolating the performance degradation rate of the product under a normal stress level; estimating a diffusion coefficient sigma in an excursion Brownian motion with drift by adopting a maximum likelihood estimation method; establishing an accelerated degradation test life and reliability predication model based on the fussy theory; andpredicting the life and the reliability of the product by adopting the fussy life and reliability prediction model. The method firstly introduces the fussy concept into an accelerated degradation testto enable the prediction result of the accelerated degradation test to be more reasonable, avoids the condition of rash routine reliability estimation result through considering the fussiness fuzziness of the performance degradation threshold, solves the problem of failed performance degradation in the engineering reality, and is suitable for the accelerated degradation tests of step stress and progressive stress and unaccelerated performance degradation prediction for the problem of the performance degradation failure.

The invention discloses a life prediction method of accelerated life test based on grey RBF neural network. An original curve of reliability and failure time is constructed by collecting test data; class ratio test is conducted on failure time data; a curve of reliability and accumulated failure time is constructed; three layers of RBF artificial neural network are established; RBF artificial neural network is trained; the well-trained neural network is used for prediction; and finally the prediction value of the dummy accumulated failure time obtained by prediction is reduced so as to obtain the life information of the products under normal stress. The method has no need of establishing physical accelerator model and resolving complex multivariate likelihood equation set, thereby avoiding the introduction of system error in the life prediction, solving the problem of needing a large number of training samples for artificial neural network modeling in accelerated life test, also being applied to small sample test data, and facilitating the application in actual engineering. Compared with the existing BP neural network prediction method, the life prediction precision is obviously improved.

The invention relates to a lithium battery charge state estimating method and belongs to the technical field of batteries of electric vehicles. The lithium battery charge state estimating method aims at estimating the charge state of a lithium battery under the complex working conditions of charging and discharging at different multiplying power levels through an estimation method based on a parameter time varying observer. The lithium battery charge state estimating method specifically comprises the step that a battery charge state is regarded as a state variable to be introduced into a lithium ion battery continuous model, the upper limit of hysteresis voltages is determined according to the charging and discharging open-circuit voltage, the battery hysteresis phenomenon is considered to be a first order dynamic process related to the current absolute value, a battery polarization voltage model with parameters changing along with currents and an internal resistance model with parameters changing along with currents are structured through RC rings, battery model end voltages are structured, and a nonlinear parameter time-varying battery model is obtained. The lithium battery charge state estimating method is based on a parameter time-varying lithium ion battery equivalent circuit model, the model parameters are calibrated to be a function of current multiplying power, the characteristics of the battery can be accurately expressed, and meanwhile an existing estimation method can be easily used.

The invention relates to an active-disturbance-rejection trajectory linearization control method suitable for hypersonic velocity maneuvering flight. The active-disturbance-rejection trajectory linearization control method regards a part different from a nominal model as a general disturbance, establishes a hypersonic aircraft attitude and angular velocity dynamic model with multi-source complex uncertainty and strict feedback form, designs attitude ring and angular velocity ring model auxiliary expansion state observers, adopts a non-linear tracking differentiator to arrange a transition process for a given guidance command and generate a nominal command of an attitude ring, designs an active-disturbance-rejection trajectory linearization attitude ring controller containing a feedforward tracking control law, a feedback stabilization control and a disturbance compensation term, and designs an active-disturbance-rejection trajectory linearization angular velocity ring controller containing a feedforward tracking control law, a feedback stabilization control and a disturbance compensation term. The active-disturbance-rejection trajectory linearization control method achieves high-precision anti-disturbance control under the given conditions of large-margin guidance command and control constraint, and has high adaptability for multi-source disturbance large-scale perturbation in hypersonic velocity long-span maneuvering flight.

The invention relates to an idling slide protective control method of a locomotive. The method comprises the following steps of: detecting the acceleration d omega / dt of a locomotive wheel pair in real time, when the acceleration exceeds a protective threshold, i.e. domega / dt is more than ag, starting to unload a moment, and continuously searching the peak value of the acceleration, i.e. when d<2>omega / dt<2>=0 in the unloading process, searching the peak value; and instantly stopping to unload the moment when the peak value is searched, wherein the change rate of a motor torque dT / dt is 0, the adhesion of a locomotive wheel track recovers again and the change rate of the adhesive force of the locomotive wheel track dF / dt is more than 0. The invention can overcome the over-deepness unloading problem very well in the prior art, the problem cause the locomotive tractive effort loss to be great, affects the adhesion utilization of the locomotive and causes the front and back impacts of the locomotive.

The invention provides a hydraulic hard and soft mechanical arm control method based on two-parameter singular perturbation, and relates to the technical field of intelligent machine and robot control. Through the principle of the two-parameter singular perturbation of the method, a reduced order is carried out on a hydraulic hard and soft mechanical arm system to enable the hydraulic hard and soft mechanical arm system to become a fast subsystem driven by representation hydraulic servo, a secondary fast subsystem driven by representation elastic vibration, and a slow subsystem driven by representation wide-range rigid movement, wherein a self-adaptive sliding mode controller is adopted in a fast subsystem control module, an optimal controller is adopted in a secondary fast subsystem control module to restrain the elastic vibration, and a second-order sliding mode controller is adopted in a slow subsystem control module to achieve joint trajectory tracking control. According to the control method based on the two-parameter singular perturbation, the reduced order is carried out on the complex hydraulic hard and soft mechanical arm system, multiple time-scale subsystem controllers are designed, and thus the control method is greatly simplified and is more practical.

The invention discloses a servo system self-adaptive robust controller with dynamic frictional compensation, which is used for improving output tracking precision and fast response of a motor servo system and is particularly suitable for a precise motor servo system with requirements on high precision and fast response. The servo system self-adaptive robust controller comprises a parameter self-adaptive adjusting module, a dynamic frictional compensator and a robust control module. The online estimation of a frictional force value is realized by adopting a frictional model approximator constructed by a LuGre dynamic frictional model Lipschitz coefficient through self-adaptive adjustment of a parameter of the frictional approximator, and accordingly, the frictional compensation is carried out for overcoming the adverse effect of frictional force on the output tracking precision and the fast response of the servo system. The controller adopts a robust control law and ensures that the servo system has enough disturbance resistance. Because the controller can realize rapid and accurate frictional compensation and effectively inhibit the influence of external disturbance, the output tracking precision and the fast response of the servo system can be greatly improved.

The invention belongs to the field of machine vision and intelligent control for achieving fast self-adaptation of traffic video monitoring target detection. The method comprises the steps of building an initial training sample bank; training an AdaBoost classifier based on Haar characteristics and a support vector machine (SVM) classifier based on histograms of oriented gradients (HOG) characteristics respectively; and detecting monitoring images frame by frame by employing of the two classifiers, wherein the detection process is divided into steps of predicting of sub-images in a detection frame through the two classifiers respectively, performing of confidence-degree determination on predicted results, adding of prediction labels corresponding to large confidence-degree and the sub-images into additional training sample banks of the classifiers corresponding to small confidence-degree till the size of the detection frame reaches half the sizes of detected images, retraining of the two classifiers by using the updated training sample banks and detecting of a next frame of image till all images are detected, and the final classifiers can be used for detecting targets of vehicles, pedestrians and the like in actual traffic scenes.

The invention discloses a preparation method for graphene conductive slurry. The preparation method comprises the steps of dissolving a dispersing agent into a solvent firstly, and performing ultrasonic oscillation to form a uniform solution; then adding graphene and a conductive carbon material into the solution to be mixed and stirred; next, performing full dispersion through a way of ultrasonic oscillation; and finally transferring the well-dispersed slurry to a high-speed shearing emulsification homogenizing machine to be sheared and dispersed to obtain the uniform and consistent and fully-dispersed graphene conductive slurry. The preparation method is simple and easy to implement and applicable to engineering production.

The invention provides lift energy feedback, reactive compensation and switched-off emergency running method and system. The system comprises an energy feedback module, a reactive compensation module and a lift switched-off emergency running module. The energy feedback module comprising an inverted circuit, a control circuit and a filter circuit and the reactive compensation module can feed back energy generated when a lift brakes to a power grid and generate reactive current for compensating reactive power when the lift is in an electric running state; and a lift switched-off emergency running circuit can ensure that lift control power is taken over by the switching of a switch under abnormal power supply of the power grid, run the lift to the leveling position and open a car door and a hall door so that a passenger safely walks out of the lift. The system has the advantages of simple structure, reliable running, less loss, low cost, high power factor and no harmonic pollution on the power grid and integrates various functions of lift frequency converter plug-in type energy feedback, reactive compensation, emergency leveling, and the like.

The invention relates to a method and device for quickly measuring a building material emission key parameter, belonging to the field of indoor environmental tests. The method comprises the following steps: building an effect model for concentration in the measuring device in the building material VOC (volatile organic compounds) emission process; controlling the temperature of the measuring device to be always kept at a set value by a temperature controlling device (such as a constant-temperature water bath); putting a building material to be measured into the measuring device, and sealing the measuring device; in the building material emission process, measuring the concentration of target VOC in the measuring device for several times; finally, taking the average value of the concentration results of the last 2-3 times as a balanced concentration, and taking other concentration results as a hourly concentration; tidying into the mode of logarithm; and then, carrying out linear fit for emission time to obtain a slope and an intercept so as to obtain three key parameters, i.e. initial concentration, diffusion coefficient and distribution coefficient in the building material emission process. The environmental chamber system and the measuring method are simple, have the advantages of short test time and higher precision and are convenient for engineering application.

The invention discloses a coarse tuning and fine tuning combined infrared image automatic focusing method which is characterized by controlling a motor to operate positively and negatively according to an automatic focusing command; controlling the motor to move to the negative direction with a relatively-large step length from the extreme position; in the moving process, calculating definition evaluation function value in real time; and when the function value reaches maximum value, controlling the motor to move to the negative direction again with a relatively-small step length and calculating definition evaluation function value in real time, and the maximum value place is the clearest imaging place. According to the method, combination of coarse tuning and fine tuning is realized through different motor movement step lengths, and automatic focusing calculation is carried out through two image definition evaluation functions, thereby guaranteeing an infrared imaging system to enable the focal length to be adjusted to the clearest imaging place quickly and realizing the optimum focusing effect; and the method is less in computation burden, high in real-time performance, beneficial to engineering application, and capable of meeting the definition requirement of the infrared imaging system.

The invention relates to an improved auto-disturbance rejection controlling method, and provides the improved auto-disturbance rejection controlling method to overcome the defect that a nonlinear auto-disturbance rejection controlling method has a plurality of parameters which are difficult to set. According to the improved auto-disturbance rejection controlling method, an extended state observer in a traditional auto-disturbance rejection controlling method is designed as a disturbance observer which is not based on a system model; the disturbance observer is designed to be only related to two parameters by using a linear auto-disturbance rejection controller parameter setting method, so as to achieve the purpose of reducing the amount of setting parameters. Moreover, the improved auto-disturbance rejection controlling method fully integrates the advantages and disadvantages of linear auto-disturbance rejection and nonlinear auto-disturbance rejection, so that the performance of the controller is maximized; the controlling method can reduce the error of the traditional auto-disturbance rejection controlling method, and improves the control accuracy of the system.

The invention provides a control method for a photoelectric tracking and stabilization platform of a moving carrier. An integral stabilization mode is adopted, and the method comprises the following steps of: designing a high-bandwidth current loop; establishing a mathematical object model, testing the frequency characteristics of an object by using a dynamic signal analyzer, and performing fitting to obtain an object transmission function Gm(s); designing an internal model controller Gimc(s) according to the established object model by adopting a two-step method, and regulating a parameter epsilon of the internal model controller Gimc(s) to obtain the high robustness of a system; and adding a parallel control loop on the basis of internal model control to realize two-port internal model control, and improving the low-frequency gain of the system to improve the accuracy of the system by designing a second control port. An additional sensor is not required, and equivalent complex control is realized by improving a control algorithm. The method is simple in control structure, engineering implementation is facilitated, and the stabilization accuracy of the photoelectric tracking and stabilization platform is greatly improved.

The invention relates to a preparation method of a vitrification substrate for radioactive nuclear wastes, which is characterized by comprising the following steps: mainly taking (NH4) H2PO4, Fe2O3 and H3BO3 as raw materials, proportioning, mixing, melting for 2-3.5 hours at the temperature of 1100-1250 DEG C, forming, and annealing, thereby preparing a vitrification body with glass of an iron-boron-phosphorus system as the substrate. The invention combines the advantages of high irradiation stability of the vitrification body of the borosilicate system and large waste-loading capacity of thevitrification body of the iron phosphate system. The prepared vitrification body has the advantages of excellent chemical stability and good thermal stability. Moreover, the invention has the advantages of simple preparation process and easy engineering, and can be widely applied in the curing treatment of radioactive nuclear wastes.

The invention relates to a calculation method for ultimate bearing capacities of rock slopes with rock bridges, and belongs to the field of rock slope stability analysis. The method comprises the following steps of: dispersing a rock slope with rock bridges by adoption of a composite element method on the basis of a theory of the plastic ultimate analysis lower limit method; establishing a nonlinear mathematic programming model for stability analysis of rock slopes with rock bridges by taking an ultimate load and a strength reserve coefficient of the rock slope as target functions; and solving maximum values of the ultimate load and the strength reserve coefficient by using a mathematic programming optimization algorithm. According to the method provided by the invention, the plastic ultimate analysis lower limit method, a composite element method dispersion technology and a mathematic programming measure are combined to establish a rock slope ultimate bearing capacity solution method which not only can simulate the continuous media characteristics of the rock bridges, but also can simulate the non-continuous media characteristics of rock blocks. The method provided by the invention has the characteristics of being clear in concept and high in calculation precision, and can be applied to the analysis of bearing capacities of the rock bridges in rock slopes.

The invention discloses a method, a device and a system for controlling photovoltaic grid connection on the basis of a virtual synchronous machine. A photovoltaic grid connection system on the basis of the virtual synchronous machine comprises a photovoltaic cell panel, a DC / DC converter and a DC / AC inverter. The photovoltaic cell panel is connected with direct-current bus, one end of the DC / DC converter is connected with the direct-current bus, the other end of the DC / DC converter is connected with an energy storage cell, the direct-current bus is connected with a direct-current side of the DC / AC inverter, and an alternating-current side of the DC / AC inverter is connected into a transformer. The method, the device and the system have the advantage that the problem that an existing photovoltaic grid connection system is incapable of simultaneously controlling photovoltaic array terminal voltages and implementing functions of an existing virtual synchronous machine can be solved by the aid of the method.

The invention provides a method and a system for over-modulating three-level space vectors. The method comprises the following steps: calculating the modulation ratio and angle of a reference voltage; dividing the modulation ratio into a first setting interval and a second setting interval; positioning the modulation ratio in the first setting interval and calculating the duty cycle of a short vector, a long vector and a medium vector by intervals according to the angle of the reference voltage; correcting the duty cycle of the short vector, the long vector and the medium vector respectively according to the magnitude of the short-vector duty cycle; calculating the N-action duty cycle and the P-action duty cycle of each phase according to the corrected duty cycle; positioning the modulation ratio in the second setting interval and calculating the keeping angle of the reference voltage; calculating the N-action duty cycle and the P-action duty cycle of each phase by intervals according to the resulting of comparing the keeping angle with the angle of the reference voltage; and conversing the N-action duty cycle and the P-action duty cycle of each phase into action time and mapping the action time back to the prior sector. The method and the system have the advantage of ensuring that SVPWM over-modulation is simple in calculation steps and higher in modulation precision.

The invention relates to a rational-polynomial-coefficients (RPC)-based method for improving and calibrating the block adjustment of a three-linear array three-dimensional satellite, which comprises the following steps of: (1) determining the mapping relationship between ground points and image points, namely a strict imaging model; (2) solving RPC parameters of each image in three linear arrays according to the strict imaging model, and searching for connection points among the three linear arrays by image matching; (3) listing three affine transformation formulas of fore sight, front sight and back sight of the three-linear array images; (4) establishing an error equation and solving to acquire corrections of affine transformation parameters, and revising the affine transformation formulas by utilizing the corrections; (5) listing the affine transformation formulas of the fore sight and the back sight again by utilizing camera parameters and the revised affine transformation formula of the front sight; and (6) solving the revised affine transformation formulas of the fore sight and the back sight in the step (4) and the listed affine transformation formulas of the fore sight and the back sight in the step (5) simultaneously to acquire the corrections of the camera parameters, and revising the camera parameters to improve and calibrate the block adjustment of the three-linear array three-dimensional satellite.

The invention relates to an electric split-phase non-interruption flexible connection-compensation device and method for a traction electric network, belonging to the technical fields of railway transportation equipment and electric power and electronics. The device comprises a two-phase back-to-back converter set and three position sensors, wherein the two-phase back-to-back converter set comprises two single-phase converter sets Va and Vb sharing a DC side capacitor set, and two single-phase reduction transformer sets Ta and Tb respectively connected with AC sides of the two single-phase converter sets Va and Vb, or a single-phase reduction transformer set Ta or Tb connected with the AC side of the single-phase converter set Va or Vb, and also comprises three electric quantity sensors, a killer switch, a controllable fling-cut switch and a main controller. The device can work in two modes, and realizes that an electric locomotive passes through split phases without interruption and with loads. The device has functions of active power transfer, reaction power compensation and harmonic compensation, and can solve the problems of three-phase voltage imbalance, voltage fluctuation, low power factor, harmonic pollution and the like in a traction substation.

The invention discloses a soft landing relay obstacle avoiding method which is used for completing soft landing of a celestial body through two matched stages, namely a rough obstacle avoiding stage and a fine obstacle avoiding stage, wherein in the rough obstacle avoiding stage, a visible-light camera is used for carrying out rough detection on a larger range and larger obstacles to remove largeobstacles which directly threaten landing safety; and then the surface of the celestial body is subjected to accurate three-dimensional obstacle detection by utilizing laser scanning in a safe area selected in the rough obstacle avoiding stage so as to obtain and remove obstacles with smaller dimensions and ensure landing safety to the maximum extent. The soft landing relay obstacle avoiding method disclosed by the invention has good autonomy and high reliability, can be used for soft landing detection of the celestial body with more complicated terrain, and is especially applicable to soft landing of deep-space unmanned celestial bodies in a longer distance; the soft landing relay obstacle avoiding method greatly improves the obstacle avoiding capacity and lengthens the obstacle avoidingdistance, and improves the landing safety; and the soft landing relay obstacle avoiding method reduces the technical index requirement on sensors, reduces the difficulty in research of visible-light / laser imaging sensors, and is beneficial to engineering application.

The invention provides a resin matrix composite with a super-hydrophobic bionic surface and a preparation method of the resin matrix composite. The method comprises steps as follows: the surface of a matrix of the resin matrix composite is polished until the surface turns white; the matrix of the resin matrix composite is processed through ultrafast laser, and a microstructure is formed on the surface; a first coating is sprayed on the microstructure surface of the matrix of the resin matrix composite through a pneumatic type paint spray gun to form a bonding layer, a second coating containing nanosilicon dioxide particles is sprayed to form a surface hydrophobic function layer, and the resin matrix composite with the super-hydrophobic bionic surface is obtained. The preparation method is simple to operate and facilitates production, the prepared resin matrix composite with the super-hydrophobic bionic surface can allow water drops to freely slip off, and the real self-cleaning super-hydrophobic function is realized.

The invention discloses a geometric-programming-based gliding aircraft terminal area energy management trajectory planning method which is used for solving the technical problem that an existing gliding aircraft terminal area energy management trajectory planning method is poor in practicability. According to the technical scheme, on the basis of the state of an aircraft entering a TAEM section, a geometric programming method is utilized for rapidly planning a reasonable and feasible TAEM plane trajectory; on the basis of the TAEM plane trajectory planning, height deduction is performed, and therefore a complete trajectory planning strategy is given. Due to the fact that the aircraft enters an entry of an automatic landing section in a spiral-line mode in the geographic planning process, the sudden overload change phenomenon is effectively avoided, and therefore the requirement for the aircraft maneuverability is lowered; meanwhile, during trajectory planning, the state of the aircraft at the TAEM section at the initial moment is considered, corresponding flight paths are planned in a classified mode for the entering state of the aircraft, the reasonable trajectory can be rapidly planned, the requirements for different entering directions are met, and the planning speed is high through simulation verification.

The invention discloses a low cycle fatigue life prediction method for metal material and based on asymmetrical cyclic stress control load. The method comprises the following steps: (1) acquiring a low cycle fatigue life of a metal material through fatigue experiments of asymmetrical cyclic stress control; (2) according to working conditions of the fatigue experiments and fatigue properties of the material, determining a function relationship of fatigue strength coefficient sigma' f, fatigue strength exponent b, and the peak stress and tensile limit of the material; and (3) establishing a prediction model of low cycle fatigue life of the metal material under asymmetric cyclic stress control conditions, and predicting fatigue life of the material. The method provided by the invention can quickly predict the fatigue life of the metal material under asymmetric cyclic stress load conditions, and provides a theoretical reference for the reliable design and evaluation of parts.

The invention discloses a fuel cell output prediction method and system based on a mixing model, the method and the system enable the mixing dynamic model to have higher accuracy in both statical and dynamic aspects. In the present method, a statical mechanism model of fuel cell output voltage, a dynamic mechanism model of a fuel cell anodic and cathode gas flow dynamic mechanism models of fuel cell anodic gas flow and fuel cell cathode gas flow, a statical neural network and a variable structure neural network are established. The output of two dynamic mechanism models are used as part input parameters of the statical mechanism model. Vout is acquired after using the statical neural network to complement the output of the statical mechanism model. The variable structure neural network is used to approach the derivative of the error Ve between the fuel cell actual output and the Vout, then integration is performed on the output of the variable structure neural network to acquire the error estimation value, and the fuel cell output voltage estimation value will be acquired by superposition of the error estimation value and the Vout.

The invention provides an intrusion prevention system of fiber grating perimeter and an alarm method thereof; the system comprises a piece of on-site optical fiber detecting equipment and a piece of control equipment; the on-site optical fiber detecting equipment comprises detecting passages, and each detecting passage comprises cascaded optical fiber vibration detectors; the control equipment comprises a fiber grating signal demodulator and an alarm management computer, which are connected with each other; and the detecting passages are connected with the fiber grating signal demodulator. The alarm method comprises the steps of: firstly, updating a fiber grating wavelength reference value; and then, performing time domain processing on the wavelength sequences received by the fiber grating signal demodulator to distinguish the operation states of the optical fiber vibration detectors, and entering a pre-alarm state if the operation states of the detectors are normal and an abnormal signal is captured; and distinguishing the frequency domain of the wavelength information of the abnormal signal at the pre-alarm state, and retaining the effective illegal intrusion behavior information to finish the alarm process. The intrusion prevention system of the invention has the advantages of high sensitivity, good alarm performance and low false alarm rate.

The invention discloses a method for estimating calendar life of an aircraft structure, belonging to the technical field of aircraft life estimation and particularly relating to improvement on the method for estimating the calendar life of the aircraft structure. The method mainly comprises three steps of: 1, compiling a fatigue load spectrum under the condition of considering influence of calendar time; 2, establishing relation between the calendar time and fatigue life; and 3, estimating the calendar life of the structure by using a linear accumulated damage theory. The method has the advantages that: influences of the calendar time and an environmental factor are simultaneously considered during estimation of fatigue life; a load-environment process which is actually suffered by the aircraft structure can be really reflected; a few parameters are required to be determined; and engineering application is facilitated.