42 results about "Failure detection and isolation" patented technology

The invention discloses a fault-tolerance autonomous navigation method of a multi-sensor of a high-altitude long-endurance unmanned plane. The method comprises the following steps of: firstly, carrying out theory analysis on work environment and work characteristics of three navigation sensors including GPS (Global Position System), CNS (astronomy) and SAR (Synthetic Aperture Radar), and establishing an observation linearity measurement equation by combining a geography system based on a position combined observation principle of inertia / GPS, inertia / astronomy and inertia / SAR under an airborne geography system; then analyzing error characteristics of a navigation sensor and simulating the output during the fault of GPS, and establishing a corresponding fault detection algorithm unit to carry out fault detection and isolation on a filter; and finally, designing and completing an inertia / GPS combined navigation system mathematic model based on the assistance of astronomy and SAR, and optimally evaluating the error state of the inertia navigation by means of federated filtering. The invention has high navigation precision, and can fully play the role of evaluating the error state quantity of an airborne inertia navigation system by the combined navigation of the multi-sensor under the geography system.

The invention provides a fault tolerance flight control system based on control surface faults. The fault tolerance flight control system based on control surface faults comprises a sensor, a fault detection and insulation module, a monitor module, a controller module and a control distribution module, wherein the sensor is arranged at the corresponding part of an airplane body; the fault detection and insulation module transmits an airplane state parameter estimation value to the controller module, judges the health situation of control surfaces and the types of the generated faults, calculates the probability of the type of faults on each control surface, transmits the probability to the monitor module, detects the deviation angle of each control surface to obtain a deviation angle estimation value of each control surface, and transmits the deviation angle estimation value of each control surface to the monitor module; the monitor module determines the faults positions of the control surfaces, and provides a control distribution basis for the control distribution module; the controller module generates a virtual control command vector, and transmits the vector to the control distribution module as virtual control input; the control distribution module calculates the control surface deviation angle vector of each control surface deviation angle given value. When the control surface faults occur, based on fault detection and diagnosis results, the fault tolerance flight control system based on control surface faults provided by the invention compensates faults, thereby guaranteeing the continuous and safe flight of an airplane.

The invention discloses a distributed fault detection method for an intelligent power distribution network. The method comprises the following steps that a protective range of each intelligent power distribution terminal is determined; each intelligent power distribution terminal communicates with an adjacent intelligent power distribution terminal in a peer-to-peer manner, and interacts network topology structure information of a position where the intelligent power distribution terminal is located; each intelligent power distribution terminal judges a fault position on the basis of a regional longitudinal comparison protection principle and according to fault information obtained by calculation of the acquired adjacent intelligent power distribution terminal; after a line with the fault position is determined, a switch type corresponding to the line is determined according to a network topology structure, and a corresponding fault isolation strategy is made according to the switch type. The method disclosed by the invention has the beneficial effects that each intelligent power distribution terminal can interact the fault information with the adjacent intelligent power distribution terminal in the peer-to-peer manner according to the current network topology structure, so that a faulty region is accurately and effectively isolated, and the requirements on quickness, flexibility and reliability of fault detection and isolation of the intelligent power distribution network are met.

The invention provides an integrated navigation system of a strapdown inertial navigation system (SINS) / a central nervous system (CNS) / a global navigation satellite system (GNSS) of a geostationary earth orbit (GEO) transfer vehicle. The SINS serves as a core of the integrated navigation system. Navigation information of the GEO transfer vehicle is calculated and output by the SINS in real time, fault detection and isolation are conducted to data output by a GNSS receiver, a globe sensor and a star sensor by utilizing a residual error chi 2 detecting method improved by a kalman filter. Information fusion is conducted to output information of the globe sensor and the star sensor in a celestial navigation system, pseudorange measuring information output by the GNSS receiver and the navigation information output by the SINS. Navigation errors, inertial device errors, globe sensor errors and GNSS receiver time errors of the GEO transfer vehicle are evaluated in real time, and the navigation errors of the GEO transfer vehicle are corrected through a manner of closed loop feedback correction in real time so that in-orbit self navigation with high precision and high reliability of the GEO transfer vehicle is achieved, and therefore meaningful effects of good subjectivity, high precision, good robustness and high reliability are obtained.

Methods for reducing the resources needed to detect and identify faulty pseudorange measurements in a GNSS receiver are described. In a Receiver Autonomous Integrity Monitoring (RAIM) method, a position solution is calculated using a weighted least squares method on measurements from satellites of one or more GNSS constellations. A test statistic is calculated from residuals and a threshold is calculated based on a probability function. If the test statistic is greater than or equal to the threshold, a subset is selected from the set of pseudorange measurements using a metric indicative of possible measurement error. A measurement is selected from the subset using a metric indicative of signal strength or some other metric and discarded from the set of pseudorange measurements. If the number of measurements remaining in the set of pseudorange measurements is greater than five, the method loops back to the step of calculating a position solution.

Method for detecting faults in a device comprising the steps of receiving a plurality of performance parameters, applying the plurality of performance parameters to a first model to produce a plurality of estimated performance parameters, applying the plurality of performance parameters to a second model to produce a plurality of estimated device parameters, computing a plurality of residuals from the plurality of estimated device parameters, computing a plurality of distance measuring from the plurality of residuals, detecting at least one parameter deviation using the plurality of residuals and the plurality of estimated performance parameters, and setting at least one detection flag if the detected at least one parameter deviation is persistent.

The invention discloses an intelligent distribution network oriented distribution type fault detection and isolation system and a working method. The distribution type fault detection and isolation system comprises intelligent power distribution terminals arranged in each measurement point of the intelligent distribution network, and a management maintenance work station arranged in a transformer substation; the intelligent power distribution terminals are in peer-to-peer communication; and the intelligent power distribution terminals and the management maintenance work station are in master-slave mode communication. The intelligent distribution network oriented distribution type fault detection and isolation system has the beneficial effects that the management functions of the management maintenance work station on remote measuring, remote signaling, remote control and the intelligent terminals can be realized due to the communication between the intelligent power distribution terminals, and the communication between intelligent power distribution terminals and the management maintenance work station; and the intelligent power distribution terminals can realize peer-to-peer fault information interaction with adjacent intelligent power distribution terminals according to the current network topology so as to realize accurate and effective isolation for the fault regions, and satisfy the demands of rapidness, flexibility and reliability of the intelligent distribution networks on the fault detection and isolation.

The invention discloses a fault detection and isolation synthesis method based on testability modeling data. The method includes the first step of establishing correlation matrixes of a system, the second step of establishing a BIT fault dictionary, the third step of establishing a manual testing correlation matrix of BIT fuzzy set faults and generating an artificial isolation diagnostic tree of the BIT fuzzy set faults, the fourth step of establishing a manual testing correlation matrix of BIT undetectable faults and generating an artificial detection isolation diagnostic tree of the BIT undetectable faults, and the fifth step of synthesizing the BIT fault dictionary, the artificial isolation diagnostic tree of the BIT fuzzy set faults and the artificial detection isolation diagnostic tree of the BIT undetectable faults and carrying out fault detection and isolation when the system is maintained and checked. According to the method, BIT test results can be directly used, manual testing optimization of the BIT fuzzy set faults and the BIT undetectable faults is achieved, and diagnosis efficiency and integrality are improved.

Method for detecting faults in a device comprising the steps of receiving a plurality of performance parameters, applying the plurality of performance parameters to a first model to produce a plurality of estimated performance parameters, applying the plurality of performance parameters to a second model to produce a plurality of estimated device parameters, computing a plurality of residuals from the plurality of estimated device parameters, computing a plurality of distance measuring from the plurality of residuals, detecting at least one parameter deviation using the plurality of residuals and the plurality of estimated performance parameters, and setting at least one detection flag if the detected at least one parameter deviation is persistent.

The invention discloses a four-gyro redundant strapdown inertial navigation system fault detection and isolation method in a dynamic environment, which belongs to the technical field of strapdown inertial navigation systems. A redundant inertial navigation system inertial device is used to output data to build an inertial device error model, a fault detection and isolation method based on the combination of a generalized likelihood ratio, Kalman filter and linear estimation ideas is designed, and an inertial navigation system with hard fault is detected; and a linear estimation method is usedfor processing data, the prediction value of the inertial device at the fault moment is obtained, the difference between the prediction value of each group of inertial device and the output value is compared, and a fault inertial device is positioned and isolated. When hard fault happens to a single inertial device of the four-gyro redundant strapdown inertial navigation system in the dynamic environment, the reliability of the strapdown inertial navigation system is ensured.

The invention provides a multi-model-based high speed train suspension system multi-actuator fault detection and isolation method. The method involves a first bullet train, a trailer and a second bullet train and comprises the following steps that (1) a suspension system, of a two-bullet-train and one-trailer structure, of a train is modeled to obtain a suspension system model; (2) a fault model is built for each actuator of the suspension system of the two-bullet-train and one-trailer structure; (3) a sliding-mode observer matched with each fault model is arranged based on the corresponding fault model, and the corresponding residual quantity is generated; (4) a fault warning threshold value is generated according to the train operating environment and suspension system working conditions, and a logic controller is used for decision making for all residual quantities to judge whether an alarm needs to be given out or not and point out the fault occurrence position. The application of the fault detection and isolation technology is the effective way for improving the system reliability, and an alarm is given in time when a fault occurs, particularly, the fault occurrence position is pointed out when the multiple actuators break down, and fault screening and system maintenance are facilitated.

The invention discloses a distributed inertial network-based high accuracy transfer alignment method, belonging to the application category of the technical fields of inertial navigation and transfer alignment. According to the method, a distributed inertial network is established according to the demands and the actual situation, and a plurality of inertial systems are configured at the different parts of a carrier (such as an aircraft, a ship or the like), so that information of a plurality of inertial nodes can be obtained. The reliability of the data output of an inertial device is guaranteed by means of fault detection and isolation; the information of all the nodes is transferred to a certain sub-node for performing data fusion according to a transfer matrix, and inertial measurement information at the certain sub-node is obtained. On the basis of error modeling, a filtering equation is established so as to realize the transfer alignment between the inertial navigation main nodes and the inertial navigation sub-nodes. After the scheme is adopted, external equipment does not need to be additionally arranged, effective redundant inertial information can be provided for the carrier, and local measurement is provided for carrier equipment such as radar tracking and weapon load, so that the accuracy and reliability of the transfer alignment are guaranteed; furthermore, the method has the characteristics of being low in cost, high in autonomy, and the like.

The invention discloses a multi-source self-adaptive fault-tolerant federated filtering integrated navigation system and a navigation method. The system comprises a strapdown inertial navigation system, a satellite navigation system, a Doppler velocity measurement system, a celestial navigation system, and a main filter and three sub-filters that are in information connection with the systems respectively; the three sub-filters are all in information connection with the strapdown inertial navigation system, and are connected to the main filter through a fault detection and isolation module, the strapdown inertial navigation system is connected to the fault detection and isolation module through a state transmitter, and an output result of the fault detection and isolation module passes through an information sharing factor calculation module, then the calculation result is input into the main filter; and the main filter outputs the fused information and synchronizes a fusion result tothe three sub-filters and the state transmitter. According to the system and the method disclosed by the invention, the state of each sub-filter can be tracked more accurately, and a more precise fusion result can be obtained.

The invention provides a novel detecting and isolating system for a fault of a RS-485 port, which comprises a bus and a plurality of slave nodes connected with the bus, wherein each of the slave nodes comprises an RS-485 communication circuit, an MCU (Micro Controller Unit) and a relay; the MCU is connected with a normally opened end of the relay and the RS-485 communication circuit; and the relay is connected with the RS-485 communication circuit and an RS-485 bus. The slave nodes of the novel detecting and isolating system for the fault of the RS-485 port can judge whether the RS-485 bus communication is abnormal or not. If the communication is abnormal, the slave nodes can automatically disconnect from the RS-485 system bus and can carry out data communication with the RS-485 communication circuit through IO ports of the slave nodes, so as to detect whether the RS-485 communication circuit can normally work or not.

The invention discloses a fault detection and classification method of a valve-controlled electro-hydraulic servo system based on an observer group, comprising: step 1) of performing module division on the system; step 2) of modeling for a common fault; step 3) of reorganizing a system state equation according to a state space distribution of the fault, and establishing a reorganized actuator fault state equation and a reorganized sensor fault state equation; step 4) of constructing a nonlinear robust fault detection and isolation observer group; step 5) of detecting a system fault, namely judging whether a fault exists in the system; and step 6) of starting a fault isolation observer group for judging the type of the fault once it is judged in step (5) that the fault exists in the system.The invention has the advantageous effects that: the invention can perform real time state monitoring and performance prediction on the valve-controlled electro-hydraulic servo system, and can perform automatic online judgment of whether the fault exists in the system and which fault occurs under an unknown time-varying external interference force.

The invention belongs to the field of aerospace servo technology, and particularly relates to an integrated dual-channel control driver for a permanent magnet synchronous servo motors. The invention aims to provide the integrated dual-channel control driver used for the permanent magnet synchronous servo motors and with remarkably-improved integration level and reliability. The integrated dual-channel control driver comprises a bus interface circuit, a DSP and peripheral circuit, two power main circuits, two detection circuits, a failure detection and isolation circuit, a secondary power conversion circuit, a signal acquiring and processing circuit and a sensor, wherein the bus interface circuit, the failure detection and isolation circuit and the signal acquiring and processing circuit are all connected with the DSP and peripheral circuit; the DSP and peripheral circuit is connected with a logical circuit through two channels; the two power main circuits comprise a power driving and main circuit 1 and a power driving and main circuit 2; and the logical circuit is connected with the power driving and main circuit 1 and the power driving and main circuit 2.

The invention provides a virtual simulation test method. The virtual simulation test method comprises constructing a test model and performing failure analysis on the constructed model. The virtual simulation test method is feasible and effective in the evaluation of modeling analysis of a product testability design, and can be used for evaluating the product testability design in related fields, so that the testability design is improved; the inherent testability of products is improved; and valuable suggestions are given to further failure diagnosis of equipment and optimization of an existing test method. Through implementation of the virtual simulation test method, the failure detection and isolation time can be shortened greatly, so that the maintenance time is shortened greatly; technical requirements on maintenance personnel are lowered; the task reliability is improved; the use efficiency of a system and the equipment is increased; and the cost in a life cycle is lowered. A failure detection rate (FDR) can be up to 95-98 percent; a failure isolation rate (FIR) can be up to 95-99 percent (isolation to a single LRU); and a false alarm rate (FAR) can be up to 1-5 percent.

The invention relates to the field of fault diagnosis, and discloses a traction system main loop grounding fault diagnosis method and system based on characteristic correlation, so as to reduce the influence of measurement noise and transient working condition change on the fault diagnosis performance and improve the accuracy of fault detection and isolation. The method comprises the following steps: selecting a historical operation data training set, and extracting characteristic variables associated with a traction system main loop grounding fault from original data; calculating corresponding characteristic indexes according to the characteristic variables to form a characteristic index data set, and calculating typical correlation analysis parameters and a fault detection threshold by utilizing the characteristic index data set; selecting a historical fault data set to model a fault vector, and constructing a fixed residual error direction library of various faults; and selecting atest data set, calculating a residual error according to the test data set and the typical correlation analysis parameters, comparing the residual error with the fault detection threshold, and if a fault occurs, calculating a residual error direction of fault data and matching the residual error direction with thee fixed residual error direction library to realize fault isolation.

A method for real-time fault detection and isolation of multi-dimensional signals belongs to the field of sensor detection. The invention solves the real-time problem of fault detection and isolationof multi-dimensional signals of sensors in equipment or instruments. According to the invention, approximate basis of normal training set is extracted, The approximate basis of training samples in normal state is formed, and the fault detection model of KPCA is constructed by using the approximate basis of training samples in normal state. When the fault is detected by the fault detection model ofKPCA, the position of all the fault gas sensors is detected by the contribution method based on reconstruction. The real-time fault isolation method of multi-dimensional signals adopts the contribution method based on reconstruction to construct the fault direction candidate set of the fault information at the previous time and isolate the fault at the current time. The present invention is usedto determine the accuracy and reliability of a multidimensional signal of a sensor.

The invention relates to a GPS and inertial measurement unit-based train combined positioning system. The GPS and inertial measurement unit-based train combined positioning system includes a GPS receiver, an inertial measurement unit, a fault detection and isolation layer, a data fusion layer and an output layer; the output layer includes a map matching unit and a map database connected with the map matching unit; the GPS receivers and the inertial measurement unit are connected with the fault detection and isolation layer; the fault detection and isolation layer is connected with the data fusion layer; the data fusion layer is connected with the map matching unit; and positioning output is carried out. With the GPS and inertial measurement unit-based train combined positioning system adopted, high-precision and high-reliability train positioning can be realized; and under different train positioning conditions, system performance requirements can be satisfied, and security can be ensured. The GPS and inertial measurement unit-based train combined positioning system has high environmental adaptability and high practical application value.

The invention discloses a method and device for generating a center device relationship topology map based on data, and belongs to the technical field of computers. The method comprises the followingsteps: initializing a tree map root node to obtain a starting node for generating the topology map; creating a canvas for displaying scalable vector graphs in a browser according to the starting node;obtaining node data of a next level associated device from the background according to the node; calculating an X axis offset and a Y axis offset of the node on each layer of the canvas according tothe node data, and constructing a node offset table; and obtaining node location offset data from the node offset table, calculating an actual node location according to a unit length, and generatinga machine room device topology map. According to the method and device disclosed by the invention, the machine room device relationship topology map is generated in the browser by using the SVG technology, thereby improving the generation efficiency of the topology map, moreover, the device has a simple structure, is easy to manage and maintain, and is convenient to achieve fault detection and isolation when a fault occurs.

The invention relates to a fault-adaptive carrier rocket intelligent control semi-physical simulation method, and belongs to the technical field of carrier rocket semi-physical simulation. The methodcomprises the steps: step 1, establishing a carrier rocket six-degree-of-freedom simulation model including a kinetic model, a mass model, a gravitational attraction model, an aerodynamic force model,an engine model and a sensor model; step 2, establishing a GNC model of the carrier rocket comprising a navigation model, a guidance model and a control model; step 3, establishing a real-time faultdetection and isolation model; judging whether the engine has a fault or not according to the real-time fault detection and isolation model; step 4, planning an optimal trajectory curve of the rocketafter any fault. According to the invention, the adaptability to rocket faults is realized, a semi-physical simulation system based on a carrier rocket six-degree-of-freedom simulation computer and highly integrated rocket-borne comprehensive electronics is built, so that the semi-physical simulation verification of rocket intelligent control in a fault state is realized.

The invention discloses a fault detection and isolation method for an integrated navigation system of an unmanned aerial vehicle, which comprises the following steps of performing fault detection andisolation according to original data output by an IMU (Inertial Measurement Unit), and performing fault detection and isolation on each piece of measurement information to ensure high reliability of the integrated navigation system of the unmanned aerial vehicle. According to the method, the calculated amount is small, IMU faults and measurement faults can be detected in real time, sensors with faults are isolated, and the number of IMUs installed in a non-coaxial mode is not limited. According to the method, the IMU unit data source is directly detected, IMU faults can be prevented from beinginjected into the filter, it is guaranteed that the filter is not polluted by the faults, fault detection and isolation are carried out on each measurement, and the method is suitable for fault detection and isolation of various sensors with different rates.

The invention provides a polar zone centralized filter-based integrated navigation system residual vector fault detection and isolation method. In view of a polar zone integrated navigation system with a grid inertial navigation system as a basic navigation device, based on a residual X<2> test method, through designing a residual vector, a residual vector X<2> fault detection and isolation methodis designed, fault detection and isolation on a centralized filter are realized, and the reliability of the integrated navigation system based on the centralized filter group for the polar zone is improved. Compared with a federated filter, the centralized filter has better filter precision. The method enables the centralized filter to have the fault detection and isolation capability, and enhancement of the fault-tolerant capability of the integrated navigation system is realized on the premise of not sacrificing the filter estimation accuracy.

The invention provides an integrated navigation system of a strapdown inertial navigation system (SINS) / a central nervous system (CNS) / a global navigation satellite system (GNSS) of a geostationary earth orbit (GEO) transfer vehicle. The SINS serves as a core of the integrated navigation system. Navigation information of the GEO transfer vehicle is calculated and output by the SINS in real time, fault detection and isolation are conducted to data output by a GNSS receiver, a globe sensor and a star sensor by utilizing a residual error chi 2 detecting method improved by a kalman filter. Information fusion is conducted to output information of the globe sensor and the star sensor in a celestial navigation system, pseudorange measuring information output by the GNSS receiver and the navigation information output by the SINS. Navigation errors, inertial device errors, globe sensor errors and GNSS receiver time errors of the GEO transfer vehicle are evaluated in real time, and the navigation errors of the GEO transfer vehicle are corrected through a manner of closed loop feedback correction in real time so that in-orbit self navigation with high precision and high reliability of the GEO transfer vehicle is achieved, and therefore meaningful effects of good subjectivity, high precision, good robustness and high reliability are obtained.

The invention provides a PHM-based middle and low voltage power distribution network operation and maintenance system and method. The system comprises a data information acquisition and processing module, a state monitoring and fault early warning module, a fault detection and isolation module and a power distribution network health state evaluation module. The zero-sequence voltage abrupt change energy E(k) of the neutral point of the power distribution network is used as a starting criterion of fault early warning of the power distribution network; when a certain feeder reaches an early warning level, a fault detection and isolation module is started, positive sequence current fault components measured by each terminal node on the fault feeder are used for fault direction discrimination and fault positioning, and the amplitude of each phase of voltage is used for fault type identification; and after a master station completes fault positioning and recognition, a small resistor is actively put into the neutral point of the power distribution network for fault isolation. The operation state of the power distribution system can be monitored in real time, the health state of the power distribution system is managed, and the operation efficiency and the operation and maintenance work level of the power distribution system are improved.

The invention provides an instrument self-testing display component construction method based on a three-state selection tree. The method includes the specific steps: firstly, summarizing complete instrument self-testing items and logical relations; secondly, creating an empty three-state selection tree; thirdly, inserting a complete machine name, an assembly name, a part name and a self-testing item name serving as a node of the tree into the three-state selection tree according to the self-testing items and the logical relations summarized in the first step; fourthly, sequentially accessing nodes by an inorder traversal algorithm of the tree and establishing a three-state selection relation among the nodes in the three-state selection tree; fifthly, testing the testing items according to testing nodes selected by a user. By the aid of the scheme, an instrument is clear in self-testing item logical level, reasonable in structure and simple and convenient to operate, the state of the instrument can be checked in real time, failure detection and isolation time is shortened, system availability is improved, and the use and maintenance cost of the instrument is reduced.

The invention discloses an intelligent distribution network oriented distribution type fault detection and isolation system and a working method. The distribution type fault detection and isolation system comprises intelligent power distribution terminals arranged in each measurement point of the intelligent distribution network, and a management maintenance work station arranged in a transformer substation; the intelligent power distribution terminals are in peer-to-peer communication; and the intelligent power distribution terminals and the management maintenance work station are in master-slave mode communication. The intelligent distribution network oriented distribution type fault detection and isolation system has the beneficial effects that the management functions of the management maintenance work station on remote measuring, remote signaling, remote control and the intelligent terminals can be realized due to the communication between the intelligent power distribution terminals, and the communication between intelligent power distribution terminals and the management maintenance work station; and the intelligent power distribution terminals can realize peer-to-peer fault information interaction with adjacent intelligent power distribution terminals according to the current network topology so as to realize accurate and effective isolation for the fault regions, and satisfy the demands of rapidness, flexibility and reliability of the intelligent distribution networks on the fault detection and isolation.

The invention provides a novel detecting and isolating system for a fault of a RS-485 port, which comprises a bus and a plurality of slave nodes connected with the bus, wherein each of the slave nodes comprises an RS-485 communication circuit, an MCU (Micro Controller Unit) and a relay; the MCU is connected with a normally opened end of the relay and the RS-485 communication circuit; and the relay is connected with the RS-485 communication circuit and an RS-485 bus. The slave nodes of the novel detecting and isolating system for the fault of the RS-485 port can judge whether the RS-485 bus communication is abnormal or not. If the communication is abnormal, the slave nodes can automatically disconnect from the RS-485 system bus and can carry out data communication with the RS-485 communication circuit through IO ports of the slave nodes, so as to detect whether the RS-485 communication circuit can normally work or not.

The invention discloses a fault detection and isolation synthesis method based on testability modeling data. The method includes the first step of establishing correlation matrixes of a system, the second step of establishing a BIT fault dictionary, the third step of establishing a manual testing correlation matrix of BIT fuzzy set faults and generating an artificial isolation diagnostic tree of the BIT fuzzy set faults, the fourth step of establishing a manual testing correlation matrix of BIT undetectable faults and generating an artificial detection isolation diagnostic tree of the BIT undetectable faults, and the fifth step of synthesizing the BIT fault dictionary, the artificial isolation diagnostic tree of the BIT fuzzy set faults and the artificial detection isolation diagnostic tree of the BIT undetectable faults and carrying out fault detection and isolation when the system is maintained and checked. According to the method, BIT test results can be directly used, manual testing optimization of the BIT fuzzy set faults and the BIT undetectable faults is achieved, and diagnosis efficiency and integrality are improved.