86 results about "Dynamic reliability" patented technology

The invention provides a quantitative analysis method for automatic device dynamic reliability according to the function and work characteristics of the power system automatic device, aiming at searching out the weak link of the system and providing a reference basis for improving reliability of automatic device design and operation. The method comprises the following steps of: firstly, establishing the cumulative failure probability, availability, probability important indexes of basic components; secondly, establishing an automatic device dynamic reliability model conjoining a Markov state space and a dynamic fault tree, and providing a Monte Carlo simulation method based on a dynamic fault tree structure for reliability quantitative evaluation of a correlation system; and finally, verifying the validity of the provided method by examples, and performing correlation analysis. The result shows that the method has referential value for reliability assessment, component impact analysis and weak link recognition of the power system automatic device.

Disclosed is a computing method of storage dynamic reliability for an aviation drive circuit module. The computing method includes steps of selecting, classifying and statistically analyzing main storage environmental stress; determining storage failure modes and failure mechanisms of the aviation drive circuit module; statistically analyzing storage environmental stress magnitudes; obtaining environmental test data of a component or a part on the premise that the failure mechanisms remain unchanged while the test environmental stress changes; computing life distribution characteristic parameters of various failure mechanisms in the module storage process; computing the life distributions of various failure mechanisms in the whole storage period; and obtaining an expression of the life distributions due to the life distribution characteristic parameters are known, integrating life distribution functions of various failure mechanisms in the storage period to obtain a failure probability F p (t) and a R p(t) reliability of various failure mechanisms at various times. According to the computing method of the storage dynamic reliability for the aviation drive circuit module, a more precise assessment result can be obtained on the premise of saving of test costs, and evidence can be provided for the reliability design of the aviation drive circuit module.

The invention discloses a preventative device maintenance method based on dynamic reliability and belongs to the technical field of petrochemical equipment management. The preventative device maintenance method based on the dynamic reliability comprises the following steps of 1 establishing a device basic database including equipment accounts, historical maintenance and repair data, a fault strength analysis data, operation monitoring data and the like; 2 utilizing basic data to conduct operation time analysis, fault strength analysis and alarm state and operation trend analysis on devices; 3 utilizing results to establish a device reliability level and fault strength incidence matrix, formulate DRBPM data analysis logic, automatically screen preventative maintenance devices and generate preventative maintenance planning reports of the devices; 4 examining, verifying and executing the preventative maintenance planning reports of the devices. The preventative device maintenance method based on the dynamic reliability can be used for dynamic analysis and management of states of petrochemical equipment, facilitate formulation of scientific and effective device maintenance measures and provide guarantee for timely device fault elimination and production continuity reliability and can be widely applied to the technical field of petrochemical equipment management.

A dynamic reliability and security capability is provided. The dynamic reliability and security capability may be configured to support use of a dynamic reliability profile (DRP) that specifies the reliability parameters of a customer both as function of time and as a function of the requirements of the application or service of the customer. The reliability parameters may specify reliability requirements and / or goals of the customer, thereby providing a time varying requirements / goals profile. The dynamic reliability and security capability may be configured to dynamically configure the cloud resources to provide the required reliability as specified by the DRP. The RSG capability may be configured to subsequently monitor and meter the behavior to assure that the specified reliability is in fact being delivered, which may include use of self-healing capabilities to provide service assurance.

The invention relates to a method for analyzing an influence degree on the reliability of a numerically-controlled machine tool subsystem, belongs to the technical field of numerically-controlled machine tools, and aims to make up the disadvantages in the prior art that the disturbance of fault time of other subsystems of the numerically-controlled machine tool and test censoring time influences are not considered. The method comprises the following steps: (1) reading an operation recording meter of the numerically-controlled machine tool; (2) reading fault time data of the subsystem; (3) establishing a reliability functional block diagram of a numerically-controlled machine tool system and determining a subsystem reliability relation; (4) processing the disturbance of the fault time of the other subsystems of the numerically-controlled machine tool and the test censoring time influences according to censoring data; (5) establishing a reliability model of the numerically-controlled machine tool subsystem; (6) determining the reliability model of the numerically-controlled machine tool system; (7) calculating the influence degree on the dynamic reliability of the numerically-controlled machine tool subsystem; (8) calculating the influence degree on the core reliability of the numerically-controlled machine tool subsystem. According to the method provided by the invention, the reliability model of the numerically-controlled machine tool system is fitted and compared with an empirical distribution function model and the precision is less than 5%; the actual analysis requirements can be met.

The invention discloses a navigation satellite constellation availability assessment method based on the dynamic reliability estimation. The navigation satellite constellation availability assessment method comprises the steps of introducing a random failure factor, a degradation failure factor and a consumption failure factor of a satellite according to current operation data of an in-orbit constellation to establish a dynamic reliability estimation model and obtaining a time-varying curve of the single-star fault rate according to reliability estimation; then calculating out the constellation fault probability Pk,n (t) and the constellation inherent availability CVn,k value of an n kind of fault combination in the situation where k satellites in M satellites in the constellation are in fault; finally calculating out a time-varying relation of the constellation service availability of the navigation satellite system according to the Pk,n(t) and the CVn,k. The navigation satellite constellation availability assessment method can predict in-orbit reliability of the satellites in real time, can obtain high-accuracy and high-reliability satellite constellation availability and can solve the problems that a method only relying on a constellation configuration design to calculate out constellation availability is inaccurate and incomplete and cannot assess the constellation availability in real time.

A dynamic coupling time varying failure rate analysis method of a on-orbit space flexible gear mechanism comprises the seven steps that firstly, according to the fact that a shaft in the on-orbit space flexible gear mechanism is an elastic body, a kinetic equation of the flexible shaft is built, and the finite element method is adopted for analysis; secondly, a gear kinetic equation is built; thirdly, a nonlinear kinetics equation of coupling of the flexible shaft and a gear in the on-orbit space flexible gear mechanism is built; fourthly, transmission stimulation analysis is performed on the space flexible gear mechanism; fifthly, the Newmark algorithm is adopted to calculate a dynamic load coefficient; sixthly, a gear bending stress reliability limit state function is built in the on-orbit space flexible gear mechanism; seventhly, dynamic reliability and failure rate analysis are performed on the space flexible gear mechanism. The method solves the problem that reliability calculating accuracy is low because of nonlinear factors of a traditional transfer matrix method and mode superposition method, and has engineering practical value for improving reliability of the on-orbit space flexible gear mechanism and other spacecrafts. The method is also suitable for other flexible gear mechanisms.

The invention belongs to the field of reliabilities of numerical control machine tools, and particularly relates to a precision reliability analysis method for a heavy numerical control machine tool based on a multi-body system kinemics theory. The precision reliability analysis method comprises the following steps: constructing a relation model between the output precision error of the heavy numerical control machine tool and a factor affecting the precision of the machine tool, fitting a change relation of the factor affecting the precision of the machine tool along with the time by a random process, finally combining on-site data or data of the same type of sample, and introducing a Bayes evaluation method to update the precision error model of the heavy numerical control machine tool, thus realizing evaluation of the precision reliability of the machine tool. The precision reliability analysis method has the beneficial effects that the Bayes evaluation method is introduced to fit and correct the change tendency of respective factors causing a motion precision error of the machine tool, so that the difficulty that a sufficient statistical sample cannot be formed due to a 'small sample' is solved; and therefore, more scientific and reasonable evaluation is performed on the dynamic reliability of the precision error of the heavy numerical control machine tool.

The invention discloses a situation awareness-based microgrid state estimation method. The situation awareness-based microgrid state estimation method comprises the following steps of (1) situation awareness, in which an uncertainty model in a microgrid is forecasted, a model of an influence factor-forecast value is constructed for an uncertainty value, and the probability forecast is performed onan uncertainty value is performed by combining the randomness of the influence factor; (2) situation understanding, in which the state of a microgrid system is analyzed, a component fault of microgrid equipment is analyzed, and system topology analysis and power situation estimation are performed according to situation awareness data and a running state of the microgrid system; and (3) situationforecast, in which a future situation track model of optimal risk value of the microgrid is researched, the future situation track model of the optimal risk value of the situation awareness-based microgrid is built, and microgrid optimal risk calculation considering state estimation is performed by combining a microgrid safety constraint condition. By the situation awareness-based microgrid stateestimation method, the dynamic reliability estimation of the microgrid is achieved.

The invention discloses a method for polymorphic and dynamic reliability assessment for a shield cutterhead and a drive system. The method comprises the following steps of firstly, establishing a dynamic fault trees for failure of an earth pressure balance shield machine cutterhead and a drive system; secondly, determining a failure rule for a polymorphic and dynamic gate and extending an established dynamic fault tree model to polymorphism; and lastly, establishing a dynamic Bayesian network model for system failure for a dynamic Bayesian network transformation rule according to the dynamic fault tree and determining system reliability. According to the method, a problem that the dynamic reliability analysis of the shield cutterhead and the drive system cannot consider polymorphism, dynamics and interdependency simultaneously is solved, the dynamic reasoning can be carried out according to the statistical data for failure of basic events, and the more efficient and accurate decision information is provided for fault maintenance and repair of a shield machine.

The invention discloses a method for assessing dynamic reliability of lithium ion batteries on the basis of polynomial fitting and life distribution. The method includes the steps of firstly, acquiring function relationship between an operating condition conversion factor and a virtual failure threshold; secondly, acquiring a standard degradation path of a product; thirdly, acquiring state offset of the product at current moment; fourthly, acquiring degree of state offset; and fifthly, acquiring dynamic real-time reliability of the product at each moment. The method has the advantages that like product information and real-time monitoring information of products to be assessed are fully utilized, assessing the dynamic reliability of the lithium ion batteries is achieved, assessing is significantly effective, and the method compared with the existing reliability assessment method provides significantly improved universality and precision.

The invention discloses a cophase power supply system flow controller dynamic reliability evaluating method. The influence of the actual traction load randomness and impact on the junction temperature fluctuation of a power element is taken into account. Power loss and a thermal network model are used to calculate the junction temperature of the power element. A physical model based on a failure mechanism and a linear fatigue damage cumulative model are combined to calculate the power module failure rate of a flow controller. The PFC reliability is analyzed by using a dynamic reliability assessment method which takes into account the variation of the element failure rate. According to the invention, the redundancy of a power module is analyzed; the number of cascaded modules of the flow controller is optimized; and a necessary basis is provided for engineering design and operation maintenance of a cophase power supply system.

The invention discloses a space flexible mechanism dynamic reliability analysis method based on PSO. The space flexible mechanism dynamic reliability analysis method includes the specific steps of (1) building a time-variation reliability model of an in-orbit space flexible mechanism according to the reliability modeling theory, (2) carrying out time discretization on the time-variation reliability model, and dividing the time-variation reliability model into a plurality of time points t1, t2, ..., tn, (3) building performance functions corresponding to the time points, and then building an association coefficient rou(t, t+deltat) between t and t+deltat by deriving normal vectors of the performance functions, (4) obtaining reliability coefficients beta1, beta2, ..., betan with the PSO, (5) calculating the up-crossing rate in cooperation with the association coefficient rou(t, t+deltat) between t and t+deltat, and (6) calculating the failure probability with the up-crossing rate method. By means of the space flexible mechanism dynamic reliability analysis method, the accuracy of a high-dimensional nonlinear flexible time-variation reliability analysis result is improved.

The invention discloses a comprehensive reliability interactive iteration assessment method for regional power grid relay protection equipment. The comprehensive reliability interactive iteration assessment method comprises the following steps of: extracting basic static data of risk assessment of the power grid relay protection equipment; using the static data of the equipment to calculate a static reliability index of the regional power grid relay protection equipment; extracting real-time data of state monitoring of the relay protection equipment in a regional power grid concentrated control system; carrying out interactive iteration calculation on the static reliability index by using the real-time data, so as to obtain a dynamic reliability index of a power grid; and finally, carrying out risk assessment on the regional power grid relay protection equipment. The invention further provides a risk assessment system of the regional power grid relay protection equipment based on comprehensive reliability interactive iteration calculation. With the adoption of the technology provided by the invention, an operation risk of the regional power grid relay protection equipment can be accurately subjected to risk assessment, so as to provide more accurate reference on maintenance arrangement and operation for related operation people in a better way.

The invention discloses a method and device for dynamically adjusting a maintenance strategy, a terminal and a computer storage medium. The method comprises the steps: carrying out the distribution law analysis of fault causes of all maintainable parts of equipment through the historical maintenance data of the equipment, so as to obtain the static reliability; If the newly added inspection and maintenance data is obtained, analyzing the newly added inspection and maintenance data and historical inspection and maintenance data to obtain dynamic reliability; Calculating a difference value between the dynamic reliability and the static reliability; And if the difference value exceeds a preset threshold value, utilizing newly-added maintenance data to carry out analysis so as to dynamically adjust an existing maintenance strategy of each maintainable part. According to the technical scheme provided by the invention, the deviation condition of the equipment reliability can be reflected bythe difference value between the dynamic reliability and the static reliability, the maintenance strategy of the equipment is optimized in real time by carrying out real-time reliability analysis andreliability difference value analysis on the equipment and utilizing difference value early warning, so that maintenance resources and the like are reasonably distributed.

The invention provides a silicon carbide trench type MOSFETs integrated with an SBD and a preparation method thereof. A side wall gate electrode contact of the MOSFETs is located on the side wall of amain trench, a source electrode metal contact is formed at the bottom of the trench, and a Schottky metal contact is integrated. When a first quadrant is conducted forward, electrons flow from bottomto top through an inversion layer of the side wall of the trench, and a reverse conduction channel different from a conventional trench MOSFETs is formed. When a third quadrant is conducted forward,a Schottky diode is conducted at first, effectively inhibiting conduction of an in-vivo parasitic PN diode. During reverse blocking, a p-type shield layer at the bottom of the trench effectively shields a high electric field in a device body region, so that a device gate dielectric electric field and a Schottky contact electric field are greatly reduced, and an avalanche occurs at a PN junction ofthe device body region. The silicon carbide trench type MOSFETs integrated with an SBD has a low total chip area, satisfies good first and third quadrant conduction characteristics and reverse blocking abilities, and enables the static and dynamic reliability of a device to be improved.

The present invention discloses a cutter dynamic reliability and failure rate method based on a random process. A failure criterion of a cutter is first defined, and a reliability mathematical model of the cutter is established based on the criterion. Based on a stress-intensity interference model, a cutter dynamic reliability mathematical model and a cutter failure rate mathematical model that take the number of times of impact loading and a machining time into consideration are established. The method of the present invention directly reflects a relationship between reliability and a failure rate and the number of times of impact loading and a machining time, and reliability and a failure rate of a cutter with any number of times of impact loading at any time may be calculated. When an allowable failure rate of a cutter is given, an early failure period and a random failure period of the cutter can be accurately determined, so as to guide a reliability test of the cutter and determine an index such as a reliable life.

The invention provides a power grid planning method based on a dynamic reliability probability index of a power grid. The method comprises: determining a pre-selection planning design scheme and inputting a parameter; carrying out load flow calculation of normal operation of a power system and simulating fault system transient stability calculation; checking a fault shedding load capacity; carrying out reliability probability index calculation on an event causing security loss of a power grid; carrying out comparison and selection of optimization schemes comprehensively to obtain a final grid planning scheme. With the method provided by the invention, the optimal scheme enables a power accident caused by a fault shedding load capacity to be avoided; and a phenomenon that a planning scheme that only needs to use or adjust security control measures fail to be selected can be prevented to a certain extent. Meanwhile, the short-term grid planning method based on the dynamic reliability probability index of the grid has the great practical guidance significance and application value. The method having high computability and wide adaptability is suitable for dynamic reliability evaluation of the large-scale power system and can be used as a main analysis tool for a scheduling operation and plan design department.

The invention discloses a dynamic reliability assessment method for a coupling fault of a middle trough of a scraper conveyor. The approximation precision of the moment-based saddle point approximation method and the function attribute of the dynamic t-copula are fully utilized; the dynamic reliability evaluation method for the coupling fault of the middle trough of the scraper conveyor is provided, so that the dynamic correlation between failure modes of the middle trough of the scraper conveyor under the condition of small samples is described more accurately, and the accuracy of dynamic reliability evaluation of the coupling fault of the middle trough of the scraper conveyor is improved.

The invention discloses a fuzzy intelligent decomposition-coordination extreme response surface method of reliability-based optimal design. The method comprises the specific steps that the output response of a blade in the corresponding failure mode and the output response of a turbine disc in the corresponding failure mode are obtained respectively through heat-structure coupling certainty analysis; a fuzzy intelligent decomposition-coordination extreme response surface function (FIDCERSF) is constructed; dynamitic reliability sensitivity analysis is conducted by using an MCM; a fuzzy decomposition-coordination reliability-based optimal design model (FDCRBDO) is constructed. The method has strong advantages in the aspect of the overall reliability optimization design of a structure in a multi-component and multi-failure mode.

A method for multi-direction search of dynamic system state probability mapping matrix include the following: establishing the model of system simulation and fault injection, performing the discretization of system state space, randomly sampling a system originate grid element point, configuring system component status, setting simulation time step length and simulation test times, importing system originating grid element point information into simulation model through function assignment, executing and completing simulation test, counting system trajectory migration distribution in grid element, calculating system state conditional migration probability, generating system state transition probability matrix, and establishing system dynamic probability mapping network; initializing the search parameters, carrying out matrix dynamic search analysis, realize the path identification and search of the important risk sequence, calculate and predict the probability distribution of the system reliability with time. The invention can be used for generating system dynamic trajectory and state transition probability matrix, supporting matrix multi-direction searching calculation and obtaining dynamic reliability evaluation index.

The invention relates to a wind turbine generator dynamic reliability evaluation method based on an improved Bayesian network. The method comprises the following steps: 1) constructing a pure reliability Bayesian network of a wind turbine generator based on a fault tree and a cloud model; 2) optimizing the simple reliability Bayesian network by adopting a scale-free network to obtain an improved Bayesian network; 3) performing dynamic Bayesian reasoning on the improved Bayesian network; and 4) quantitatively evaluating the reliability of the unit according to the improved Bayesian network and a dynamic reasoning process. Compared with the prior art, the method has the advantages that real-time state information multivariate heterogeneous characteristics and the coupling incidence relation are considered, the reliability change trend is dynamically obtained, and the evaluation accuracy is high.

The present invention provides a dynamic reliability-based gear system tolerance optimization calculation method. The method comprises a first step of modeling for gear system tolerance degradation, analyzing a design requirement of the gear system and processing routing, and determining a processing characteristic, a distribution characteristic and a cost characteristic of each sensitive tolerance parameter and a time-based degradation rule; a second step of determining a general stress model of the gear system; a third step of determining a strength degradation model of the gear system; a fourth step of calculating dynamic reliability; a fifth step of building a tolerance optimization model; and a sixth step of determining an optimal tolerance. Dynamic reliability is introduced to the field of gear system tolerance optimization, so that the traditional optimization model with total mass loss as the target is changed, and the working capability of the gear system can be evaluated more scientifically and objectively.

The invention discloses a power transmission tower structure wind-induced safety assessment method based on wind speed and dynamic response test. The method comprises the following steps: actually measuring wind field information and structure power wind-induced response of an in-service power transmission tower; generating a real wind load time history acting on the tower body of the power transmission tower; obtaining a high-fidelity finite element model containing structural damage; applying a real dynamic wind load to the high-fidelity finite element model containing the damage, and obtaining real full-field stress distribution of the whole structure at each moment by using a time-history analysis method; and calculating the wind-induced dynamic reliability of the structure by utilizing the full-field stress distribution of the structure obtained by numerical calculation and adopting a Ditlevsen narrow-boundary theory, and evaluating the safety of the power transmission tower structure in a strong wind environment in real time. The authenticity of numerical analysis is guaranteed through field measured data, full-field stress distribution of the power transmission tower is obtained through numerical calculation, the wind-induced power reliability of the whole structure is further evaluated, and the wind-induced failure probability of the in-service power transmission towerstructure can be given in real time.

The invention provides a mine safety information collaborative awareness and disaster real-time pre-warning system. The system comprises an information centre monitoring platform, wherein the information centre monitoring platform is connected with a Beidou satellite wireless communication unit; the Beidou satellite wireless communication unit is connected with an underground optical fiber ring network communication unit; the underground optical fiber ring network communication unit is connected with a bottom layer wireless network communication unit; the bottom layer wireless network communication unit is connected with an underground multi-variant heterogeneous information acquisition control unit; and the underground multi-variant heterogeneous information acquisition control unit is connected with a basic information unit. According to the invention, the mine safety information collaborative awareness and disaster real-time pre-warning system is constructed by utilizing the Beidou satellite wireless communication unit which takes a Beidou satellite as a transmission core, so that multi-source heterogeneous information in a mine Internet of things information system are fused mutually; the unification of real-time monitoring, the network transmission, the dynamic identification and a feedback control technology is realized; and the dynamic reliability of a mine safety control strategy is improved effectively.

The invention discloses a dynamic reliability analysis method for a derrick under the action of multiple random loads, and belongs to the technical field of petroleum drilling machinery reliability. The method comprises the following steps of (1) determining a load mainly born by the derrick and analyzing a probability distribution situation of each load stress; (2) combining load stresses into two combination forms; (3) obtaining laws of change, with time, of a mean value and a variance of each load stress combination; (4) establishing a limit state equation of the derrick; (5) building derrick dynamic reliability models under the conditions of not considering and considering strength degradation respectively; and (6) calculating a dynamic reliability index of the derrick and drawing a curve of change, with the time, of the reliability index of the derrick. According to the method, in combination with a practical loaded condition of the derrick, the derrick reliability is regarded as a dynamic function, and the uncertainty of the law of change, with the time, of the load and the dynamic influence of the strength degradation characteristic of the derrick on the derrick reliability are considered, so that the accuracy of derrick reliability analysis is improved.

The invention discloses a dynamic reliability evaluation method and device considering a multi-dimensional coupling degradation process, and the method comprises: considering the interaction influence of the wear and fatigue of a surface material of an equipment system; dividing the dynamic evolution process of the equipment system into the following five states: a wear and crack initiation state, a wear and small crack propagation state, a wear and long crack propagation state, a wear and crack-free state and a failure state; representing the evolution process of the equipment system: da<t> / dt=F(a<t>, X<t>) by utilizing the following statistical evolution processes; according to models of a function F(.) in various states, further representing the statistical evolution process shown in the description, enabling a mathematical expression of the system degradation amount at a given moment T to be shown in the description; fitting parameters in a deterministic function, a state transition probability matrix and a state space of a Markov process are estimated; and calculating the reliability of the equipment system through a Monte Carlo method based on the estimated parameters.

The invention provides a virtual machine hybrid standby dynamic reliability assessment method based on mode transfer. The virtual machine hybrid standby dynamic reliability assessment method comprisesthe following steps: collecting resources and performance data, and carrying out characteristic selection and standardized processing; predicting the failure probability of the virtual machine basedon HSMM for the standardized data; and carrying out reliability assessment on a cold and hot backup cloud system based on a multi-value decision diagram. In order to accurately and quantitatively evaluate the reliability of the system, the virtual machine hybrid standby dynamic reliability assessment method simplifies the terminal value of the MDD, takes the sum of the occurrence probabilities ofall paths from the root node to 1 as the reliability of the system, divides the virtual machine into three different modes, namely an operation mode, a cold backup mode and a hot backup mode, adopts mode transfer to enable the standby virtual machine to replace a failed working virtual machine to maintain system operation when needed, and adopts a multi-value decision diagram for reliability assessment. Through three groups of contrast tests, the average response time and failure rate of the method are verified to be low, and the reliability is high, and the correctness of the method is verified from the side.

The invention discloses a method for determining time of tool changing based on dynamic reliability. The method comprises the following steps: firstly, building a dynamic reliability model of the whole process flow; then, calculating the reliability of a tool according to the built model, comparing the reliability of the tool with an allowable reliability value, and determining the time of tool changing. As the method builds the dynamic reliability model of the whole process flow, the calculation formula of failure rate of the tool in each procedure is derived, the replaced tool is determined by taking the failure rate of the tool as a criterion, finally the maximum application of the tool is realized, and the cost is saved.