569 results about "Fault modeling" patented technology

Methods and apparatus are provided for analyzing a complex system that includes a number of subsystems. Each subsystem comprises at least one sensor designed to generate sensor data. Sensor data from at least one of the sensors is processed to generate binary evidence of a sensed event, and complex evidence of a sensed event. The complex evidence has more sophisticated mathematical properties than the binary evidence. The complex evidence comprises one or more of: a condition indicator (CI), a health indicator (HI), and a prognostic indicator (PI). A system fault model (SFM) is provided that defines statistical relationships between binary evidence, complex evidence, and an underlying failure mode (FM) that is occurring in the complex system. The binary evidence and the complex evidence are processed to identify failure modes taking place within one or more of the subsystems. Based on the binary evidence and the complex evidence and the SFM, diagnostic conclusions can be generated regarding adverse events that are taking place within the complex system, and prognostic conclusions can be generated regarding adverse events that are predicted to take place within the complex system.

The embodiment of the invention provides a modeling method of an early warning model of mixed failures and a modeling system. The modeling method provided by the invention comprises the following steps of: generating a function analyzing module on the basis of HAZOP (Hazard and Operability Analysis) or FMEA (Failure Mode and Effects Analysis); generating a degeneration analyzing module on the basis of FMEA analyzing results and a theory of stochastic processes; generating an accident analyzing module according to state monitoring data and maintenance action information; generating an action analyzing module according to output results of the function analyzing module and the degeneration analyzing module through combining a DBN (Dynamic Bayesian Network) theory; taking the output of the accident analyzing module as an inference evidence and utilizing a DBN inference algorithm to process forward and backward inferences in the same time period to generate an evaluating module for outputting factors and consequences of system failures; taking the output results of the evaluating module and the accident analyzing module as the inference evidence and utilizing the DBN inference algorithm to process forward and backward inferences in the different time periods to generate a predicating module for outputting prospective degeneration tendencies of each member of the system. The model provided by the invention can be used for tracking the failure factors of the system and inferring possible failure consequences and probability.

The invention discloses a fault structure three-dimensional modeling method. The method comprises the steps that fault data are integrated in a three-dimensional visualization system; fault control points are extracted and a fault line is explained and formed; connection analysis of multiple conditions and fault line and fault attribute revision are carried out; the relationship between faults is calculated, and a fault network which reflects the topology structure is established; intersection is carried out on fault faces and a constructed initial stratum model to acquire an initial intersection line of the stratum and the faults; fault distance calculation is carried out on each fault point on the initial intersection line, and a three-dimensional fault line with upper and lower walls is acquired; weight setting is carried out on produced fault data of various kinds, and then fault face fitting is carried out to form a fault face network; and stratum model construction is carried out. Data detection can be effectively carried out. The accuracy of a fault model is ensured. The fault structure three-dimensional modeling method can be applied to petroleum, geology and other fields.

The invention presents a design method of a four-rotor fault-tolerant controller based on a nonlinear observer. The method includes the following steps: establishing a dynamic model of a four-rotor unmanned aerial vehicle (UAV), and dividing the UAV system into an attitude subsystem and a position subsystem; for the attitude subsystem, establishing a fault model, designing a nonlinear fault observer, carrying out real-time detection and online estimation on an unknown actuator fault, and designing a fault-tolerant controller based on a fast non-singular terminal sliding mode method by using the obtained fault estimation information; and for the position subsystem, inversely solving the control rate and the desired attitude angle of the position subsystem by combining a backstepping methodand a sliding mode method and designing an intermediate virtual quantity. A four-rotor UAV is enabled to track the desired position and yaw angle even when the actuator fails, so as to ensure the stability of the pitch angle and roll angle.

A method of generating a vector set, said vector set being used for testing sequential circuits. The method comprises selecting a plurality of fault models, identifying a fault list each for each of said plurality of fault models, identifying a vector set each for each of said fault lists, selecting a tolerance limit each for each of said fault lists, thereby each fault model having an associated fault list, an associated vector set and an associated tolerance limit, compacting each of said vector set such that the compacted vector set identifies all the faults in the associated fault list or a drop in fault list coverage is within the associated tolerance limit; and creating a vector set by combining all vector sets compacted. A system and a computer program product for testing circuits with a compacted vector set where the compacted vector set is created by dropping faults based on a tolerance limit.

The invention discloses a quad-rotor UAV fault tolerance control method based on an adaptive fault estimation observer, and belongs to the field of aviation aircraft control. The method comprises thata fault model of a quad-rotor attitude system is established according to a dynamic model of a quad-rotor UAV by considering a performer fault of a UAV system; a performer of the UAV includes four rotor motors in practicality, faults correspond to the four rotor motors, the fault model is processed, the faults are divided into two groups decoupled mutually, and a final attitude fault model is obtained; according to the provided fault model, the adaptive fault estimation observer is designed, corresponding adaptive laws are provided, the performance fault is estimated, and an H(infinite) method and an interval matrix method are used on external disturbance and parameter nondeterminacy respectively in the design process; and an attitude system error fault model is obtained on the basis of the fault model, a dynamic output feedback fault tolerance controller is designed on the basis of a fault estimated value, and fault tolerance control of the quad-rotor UAV is realized. Influence of the performer fault on performance of the quad-rotor UAV can overcome, and the safety and reliability of the UAV in the flight process are ensured fully.

An operation management apparatus monitors the performance information of a system executing services and extracts correlation variants of the performance information, thus allowing the management to detect and localize performance-degrading faults of the system. It is determined whether or not the range of correlation collapse ascribed to the performance information falls within the normal range of correlation collapse measured in the normal operation of the system. A history is retained with regard to the range of correlation collapse ascribed to the performance information which does not fall within the normal range of correlation collapse. It is determined whether or not the history accumulating the predetermined number of ranges of correlation collapse approximates to the fault range of correlation collapse measured in the faulty operation of the system, thus discriminating a fault model on the basis of the performance information.

The invention discloses an embedded satellite-borne fault-tolerant temperature control system and a verification method thereof. The system comprises a satellite management computer, an on-satellite temperature control system and a ground monitoring and fault injection computer; the on-satellite temperature control system comprises a temperature control calculation host machine, a temperature control calculation standby machine and an environmental simulation computer; and the temperature control calculation host machine and the temperature control calculation standby machine are temperature control computers. The verification method comprises the following steps of: 1, initializing a file allocation; 2, initializing the system; 3, beginning simulation; 4, injecting and executing a fault; 5, processing redundant fault tolerance; 6, monitoring the ground and evaluating the fault; and 7, evaluating a fault model and a redundancy strategy of the temperature control system. The fault injection and the verification process of the whole running stage of the real satellite-borne temperature control system are completely realized; and the method is simple, convenient and reliable, and greatly reduces the test time and expense for the practical system.

The present invention relates to a method, a computer program product and a system for performing functional formal verification. Error detection logic is verified by injecting errors in a hardware design description without any changes to the original design description. With the present invention both permanent and transient faults can be modelled, and the complete error space can be covered for all types of fault models that can be used at the RTL. The number of detected design errors is used to determine the overall coverage in relation to the number of injected errors. The error injection is prepared by adding additional circuits to an RTL netlist representation of the hardware logic design. Signal values for selected signals related to the error detection logic are compared for a modified netlist representation and for the original netlist using a formal verification tool.

The invention discloses a near spacecraft fault diagnosis and fault-tolerant control method. Firstly, a dynamical model of an attitude control system of a reentry phase of a near spacecraft is established and the dynamical model of the attitude control system is transferred to a nonlinear equation in a general type through coordinate transformation; secondly, a fault model with actuator invalidation and actuator dynamic damage existing simultaneously is established; thirdly, real-time online estimation of self-adaption estimation observer to actuator dynamic damage factors and actuator invalidation factors is respectively established; and finally a sliding module fault-tolerant controller is designed through the estimated actuator dynamic damage factors and the estimated actuator invalidation factors and parameters of the controller is updated in real time. According to the near spacecraft fault diagnosis and fault-tolerant control method, in the condition that when the actuator dynamic damage and the actuator invalidation occur simultaneously in a flight control system, fault information can be estimated rapidly and accurately, strong fault-tolerant capacity is achieved and an expected requirement of the flight control system is reached.

A method and system for developing fault models from structured text documents, such as service procedures. A service procedure or other structured text document is parsed using diagnostic rules to extract symptoms, failure modes, and correlations. Testing procedures and repair instructions are also parsed to create a fault tree and identify additional symptoms and failure modes. Reachability analysis is then used to find hidden dependencies in the fault tree, thus yielding additional correlations. The resultant symptoms, failure modes, and correlations are then assembled into a fault model, which can be used for real-time fault diagnosis onboard a vehicle, or for off-board diagnosis at service shops.

Methods, storage mediums, and apparatuses for evaluating the reliability of Three-Dimensional (3D) Network-on-Chip (NoC) designs are described. The described embodiments provide a 3D NoC specific fault-injector tool which is able to model logic-level fault models of 3D NoC specific physical faults in 3D-NoC platform. These embodiments automate the whole process of static and dynamic fault injection base on the user preference and reports the specific reliability metrics for 3D NoC platform as a single tool. The described embodiments can be used for the reliability evaluation and effectiveness of fault-tolerant designs in any of the 3D-many core designs such as manycore systems in different ranges of application from embedded systems in cellphones to larger systems which can be used in next generation of autonomous cars or hypercube memory cells.

Provided are a fault detector and a fault detection method for an attitude control system (ACS) of a spacecraft. The fault detector includes a first interacting multiple model (IMM) fault detection block for generating a normal model filter of the plurality of actuators and a plurality of upper level filters including fault model filters corresponding to the respective actuators, and detecting faults of the plurality of actuators using an IMM estimation technique from the plurality of upper level filters, and a second IMM fault detection block for generating a plurality of lower level filters each including a fault type model filter of the fault-detected actuator in the first IMM fault detection block, and detecting a fault type of the failed actuator using the IMM estimation technique.

The invention provides a flight control simulation system with fault diagnosis capability for an unmanned helicopter. The flight control simulation system with fault diagnosis capability for an unmanned helicopter comprises a simulation general control console, a simulation computer, a flight control management system, a sensor system, physical effect equipment, a servo system, a remote control and remote measurement system, and a task load system, wherein the simulation general control console controls the simulation computer to carry on a power on test, model generation and injection of fault model; the simulation computer selects simulation and interference model and simulates fault injection to carry on flight simulation; the flight control management system receives the information of sensors and the remote control and remote measurement system; the servo system realizes the real reaction of an operating mechanism; and the sensor system transmits the acquired sensor information to the flight control management system. For the flight control simulation system with fault diagnosis capability for an unmanned helicopter, the simulation computer can be embedded into different aircraft mathematical models, so that simulation of a plurality of aircrafts can be realized. For the flight control simulation system with fault diagnosis capability for an unmanned helicopter, the servo system and the sensor system can access a real steering engine of aircraft and real sensors so as to develop the steering engine of aircraft, to make a test flight for the steering engine of aircraft, and detecting working of the sensors.

The invention discloses a high-voltage circuit breaker fault diagnosis method based on an improved BP neural network. The method specifically comprises the steps of classifying collected samples, withclass tags, of a high-voltage circuit breaker into training samples and test samples, then building a BP neural network model based on a breeding algorithm and a particle swarm optimization algorithm, and after the training samples are used for performing training, performing decoding to generate new connection weight and threshold value; performing control by applying an iteration controller, enabling the two algorithms to carry out information interaction every multiple generations, and obtaining an optimal global parameter, wherein contents of the information interaction is relevant information of an optimal particle seed; and decoding an obtained global optimal solution, replacing all weight value and threshold value parameters of an original BP neural network, building an optimized high-voltage circuit breaker fault model, performing fault classification on the test samples, and outputting a result. According to the method, the BA and PSO algorithms are used for replacing an error back propagation-based network learning process to optimize the connection weight and the threshold value of the BP neural network, so that the fault diagnosis precision is effectively improved.

The invention provides a Saber-based circuit failure simulation analyzing method. The method is characterized by comprising the following steps: 1, performing Saber circuit function modeling and simulation; 2, determining the failure mode of a device to be simulated; 3, modeling the failure; 4, injecting the failure; 5, simulating a failed circuit to generate a failure simulation result; 6, setting a failure criterion; and 7, giving a failure analyzing result. Regarding the problem that the conventional circuit failure simulation can be only used for digital circuits, the method provides a practical failure simulation method based on the digital-analog hybrid simulation platform Saber. Furthermore, many failure simulation models which cannot be solved by predecessors are added, and 48 failure modes can be simulated. Realization of automatic failure injection greatly improves the failure simulation efficiency. The direct interface between Saber and failure simulation is broken through,and an effective signal failure determination method is provided.

The invention discloses a method for simulating faults of a power transformer. According to a current mode and method for simulating the internal faults of the transformer, a returned transformer is commonly utilized to conduct fault simulation tests, or the fault stimulation tests are directly conducted in oil in the transformer, workload is large, fault modules need to be frequently replaced, and the simulation effect is poor. According to the method for simulating the faults of the power transformer, an electric power simulation transformer structure and a transformer fault model are used as the foundation, generation, disappearance and intensifying of transformer partial discharge faults and winding deformation faults are directly controlled outside a transformer body through an external regulation control method, and regulation can be safely conducted in the boosting process. By the adoption of the method for simulating the faults of the power transformer, the trouble of replacing the fault model in the fault simulating process is avoided, generation time and intensity of the faults in the boosting process can be conveniently regulated and controlled, and the method is accurate and efficient.

Cell-aware fault models directly address layout-based intra-cell defects. They are created by performing analog simulations on the transistor-level netlist of a library cell and then by library view synthesis. The cell-aware fault models may be used to generate cell-aware test patterns, which usually have higher defect coverage than those generated by conventional ATPG techniques. The cell-aware fault models may also be used to improve defect coverage of a set of test patterns generated by conventional ATPG techniques.

A system and method for providing component and sub-system state of health prognosis in a complex system using fault models and component aging models. The method includes determining a current state of health value for a sub-system using fault signature test results and determining current state of health values for a plurality of components in the sub-system using the fault signature test results. The method also determines current state of health values for components in the system that cannot use fault signature test results using a first probability model and the current state of health values for the plurality of components. The method determines predicted future state of health values for the components in the sub-system using component aging models and determines a predicted future state of health value for the sub-system using a second probability model and the future state of health values of the components.

A functional coverage based test generation technique for pipelined architectures is presented. A general graph-theoretic model is developed that can capture the structure and behavior (instruction-set) of a wide variety of pipelined processors. A functional fault model is developed and used to define the functional coverage for pipelined architectures. Test generation procedures are developed that accept the graph model of the architecture as input and generate test programs to detect all the faults in the functional fault model. A graph model of the pipelined processor is automatically generated from the specification using functional abstraction. Functional test programs are generated based on the coverage of the pipeline behavior. Module level property checking is used to reduce test generation time.

The invention provides a protecting and resuming method which are used in protection and restitution of elastic light outburst ring, it characterized in that it includes following steps: step a, building fault model according to the characters of elastic light outburst ring, the fault model includes various fault types which are corresponding with characters; step b, when one fault is happened, the corresponding fault alarm signal is provided for medium meeting control layer; step c, aiming at the fault alarm signal, the medium meeting control layer is executed corresponding protection rotating method.

The invention relates to an onboard central maintenance system software testing method and its system and belongs to the field of design of onboard electronic systems. The onboard central maintenance system software testing method includes constructing a comprehensive onboard electronic system network configuration which comprises central maintenance system software and an onboard member system, setting connection relations of different ports, and carrying out interconnection through distributed simulation and verification data bus; building all fault models of a model base of peripheral equipment, selecting test case combinations and sending normal or fault data to the onboard central maintenance system software according to the test case combinations; carrying out contrastive analysis according to execution results and the test case combinations to determine whether function of the onboard central maintenance system software meets requirements or not. According to the system, the normal function model base of the peripheral equipment of the whole system is built and the fault model base is also built, effective cutting and optimizing or expanding is carried out according to other different types of airplane onboard electronic system configuration in the future, and thus, testing requirements of other onboard software can be met.

The invention provides a method for diagnosing faults of a multi-model flight control system based on expected model expansion, comprising the following steps: making a statistic of various faults of the flight control system, and building a basic model collection; forecasting the probability of the multiple fault models at the current time, and building an expected model collection; combining the basic model collection with the expected model collection to build a fault model collection at the current time; filtering each fault model in the model collection at the current time, and updating the probability; if the probability of certain fault model in the model collection at the current time is more than or equal to the preset probability threshold value, judging that the flight control system has the fault corresponding to the fault model. The invention further provides a device for diagnosing the faults of the multi-model flight control system based on expected model expansion, comprising a basic model collection building module, an expected model collection building module, a model collection at the current time building module, a filtering and probability updating module and a fault judging module. The invention further provides a flight control system.

The invention provides a memory fault injection method and a simulator thereof for a software BIT. A hardware circuit board carrying out BIT software serves as a mock object of the simulator. An analog module for simulating normal functions of a memory, a fault modeling and model analysis module for establishing and analyzing fault sequence files, a fault injection module for matching the faults to be injected, and a fault behavior analog module and a peripheral cross-linking environment simulation module are added to the simulator. The method includes establishing a fault mode base, writing and analyzing extensive makeup language (XML) fault sequence files into identifiable fault sequences, searching and injecting corresponding faults when a processor accesses the memory, and performing fault simulation when the faults are triggered. According to the method and the simulator, the injected fault modes are complete and fully cover test cases under each fault occurrence for the memory, sufficient tests can be performed on the BIT software on a circuit board level, and only the BIT software after the sufficient tests can guarantee accuracy and timeliness of BIT fault prediction of aeronautical airborne equipment and further guarantee system reliability and safety.

The present invention provides a power distribution and utilization data association-based medium-voltage power grid line fracture fault diagnosis method. The method includes the following steps that: step 1, the data information of a power distribution and utilization information system is inputted to a database, a line fracture fault electric quantity hierarchic data system is constructed; step 2, the output data information in the database is processed, and the time-space distribution characteristics of a medium-voltage power distribution line fracture fault can be obtained; step 3, a medium-voltage power distribution line fracture fault model is built, according to the line fracture fault electric quantity hierarchic data system and strong association rules, parameter optimization is carried out, and the association condition of characteristic quantities of a medium-voltage distribution network when a fault occurs can be determined, so that an association rule set is obtained; and step 4, real-time information inputted by the power distribution and utilization information system is matched with the association rule set, the state of the medium-voltage distribution network can be determined. With the method of the invention adopted, a diagnosis association rule set and an auxiliary rule set can be automatically generated by using an improved association rule algorithm according to line fracture fault historical data without grounding fault characteristics, and therefore, useful information can be provided for the decision making of online fault diagnosis.

The invention belongs to the numerical control machine tool technology field and relates to a numerical control machine tool fault diagnosis method. The method comprises the following steps of 1, dividing a system part into n component; and establishing a corresponding relation of each component and fault time and a fault propagation relation among the components; 2, establishing a component fault propagation digraph and describing a numerical control machine tool system component fault propagation digraph; 3, calculating a numerical control machine tool system component fault influence; 4, converting the fault propagation digraph into a fault-propagation hierarchical model; 5, modeling based on a numerical control machine tool system component failure rate related to time; and 6, positioning a fault main cause and carrying out numerical control machine tool fault diagnosis. In the invention, a system component fault propagation hierarchy relation and the fault propagation influence are considered and a fault time correlation influence of the system component during component failure rate determination is also considered; component fault modeling accuracy is increased; compared to traditional system component fault incidence rate diagnosis based on a graph theory or single data driving, the method possesses real-time performance and accords with realities.

A method and apparatus for generating test patterns used to test an integrated circuit (IC). The apparatus comprises first logic for determining a subset of transition fault sites on an IC to be tested, second logic that identifies a longest sensitizable path through each transition fault site of the subset of transition fault sites, and third logic that generates a bounded set of test patterns that test the identified longest sensitizable paths through each transition fault site of the subset of transition fault sites. The present invention combines various aspects of transition fault modeling and path delay fault modeling to enable global delay testing of an IC within reasonable amount of time.

The invention discloses a batch testing method for complex programmable logic device. Aiming at the characteristic that CPLD (Complex Programmable Logic Device) shall be used after programming, the programming and test of CPLD are unified by the batch testing method to realize the batch testing of CPLD via ATE (Automatic Test Equipment). The JTAG (Joint Test Action Group) programming file and emulation file aiming to the fault model are obtained via the development software of CPLD to be converted to the vector file respectively distinguished by ATE. The number of the parallel test devices shall be determined before starting the batch testing; and all vectors are loaded to ATE at once. While the batch testing is processed, each CPLD to be tested is only connected with an automatic testingdevice once to execute the programming vector and the test vector repeatedly, so that the tests of a plurality of fault models are realized. In the batch testing method for complex programmable logicdevice, the online programming and test of CPLD are realized based on the ATE, the requirements of the mass testing of CPLD are satisfied via the parallel test technology, so that the testing cost isreduced and the testing efficiency is improved.

The invention discloses a vehicle fault processing method, a server, detection equipment and a vehicle system. The method is implemented through the server and comprises the steps of obtaining vehiclestate information of a target vehicle, and constructing a corresponding target vehicle state vector; according to a pre-constructed vehicle fault model, processing the target vehicle state vector, and determining the fault type of the target vehicle and the corresponding fault processing mode. The vehicle fault processing method does not need to depend on manual fault judgment or fault processingdecision making, the fault processing time is shortened, the fault processing human cost is lowered, and the fault processing efficiency is improved. The method is particularly applicable to fault processing of a large batch of vehicles.

A functional coverage based test generation technique for pipelined architectures is presented. A general graph-theoretic model is developed that can capture the structure and behavior (instruction-set) of a wide variety of pipelined processors. A functional fault model is developed and used to define the functional coverage for pipelined architectures. Test generation procedures are developed that accept the graph model of the architecture as input and generate test programs to detect all the faults in the functional fault model. A graph model of the pipelined processor is automatically generated from the specification using functional abstraction. Functional test programs are generated based on the coverage of the pipeline behavior. Module level property checking is used to reduce test generation time.