94 results about "Intermittent fault" patented technology

Component malfunctions in passive optical networks (PON) can increase bit error rates and decrease signal-to-noise ratio of communications signals. These faults may cause the receivers of the signals, either the optical line terminal (OLT) or optical network terminals (ONTs), to experience intermittent faults and/or may result in misinterpreted commands that disrupt other ONT's communication, resulting in a rogue ONT condition. Existing PON protocol detection methods may not detect these types of malfunctions. An embodiment of the present invention identifies faults in a PON by transmitting a test series of data patterns via an optical communications path from a first optical network node to a second optical network node. The test series is compared to an expected series of data patterns. An error rate may be calculated as a function of the differences between the test series and expected series. The error rate may be reported to identify faults in the PON. Through use of the embodiment, network faults can be identified and optionally automatically corrected, saving a network service provider from expending technician time and maintaining an operating state of the network.

Component malfunctions in passive optical networks (PON) can increase bit error rates and decrease signal-to-noise ratio in communications signals. These faults may cause the receivers of the signals, either the optical line terminal (OLT) or optical network terminals (ONTs), to experience intermittent faults and/or may result in misinterpreted commands that disrupt other ONT's communication, resulting in a rogue ONT condition. Existing PON protocol detection methods may not detect these types of malfunctions. An embodiment of the present invention identifies faults in a PON by transmitting a test series of data patterns via an optical communications path from a first network node to a second network node. The test series is compared to an expected series of data patterns. An error rate may be calculated as a function of the differences between the test series and expected series. The error rate may be reported to identify faults in the PON.

The invention provides a comprehensive detection method for high resistance ground faults of an electric power system and belongs to the field of emergency protective circuit devices. The detection method comprises two parts of utilizing a transient state direction to recognize faulty lines and utilizing intermittent detection to detect intermittent faults; fault component current and voltage are calculated based on voltage and current waveforms before fault startup and a fault direction is obtained by utilizing the fault component voltage and current waveforms to calculate transient idle work; with regard to forward pulse counting, a pulse count is compared with a pre-set threshold value to judge a fault when detection time is cut off so as to more sensitively detect intermittent high resistance ground faults and cut off the fault lines in time; and furthermore, the sensitivity of a power supplying line protective device is improved so as to be good for improving the continuous and stable operation of a whole middle-voltage power distribution system and ensure the safety performance of a whole power supply system. The comprehensive detection method can be widely applied to the fields of high resistance ground fault detection and relay protection of the middle-voltage power distribution system with an effectively-grounded neutral point.

A method for diagnostic reasoning of faults appearing in a vehicle health monitoring system (VHM) is provided. One of alternatively a signal mode or a failure mode state is identified based on an input. If a signal is identified, the signal is queried to determine if the signal indicts a failure mode. If the signal indicts the failure mode, an intermittent watch flag is set for the failure mode. A count representing a number of occurrences of the signal as an intermittent fault is incremented. It is determined if the count exceeds a predetermined threshold. If the count exceeds the predetermined threshold, the intermittent fault is determined to be a permanent fault.

The invention belongs to urban railway system vocation education equipment which can realize multi-type failure simulation of a metro passenger car door system and bidirectional communication linkage based on analog simulation software. The analog simulation software can set a failure to an experiment table and also can collect the state of the experiment table to realize structural dismounting, a work principle and an overhauling flow in a three-dimensional manner. The method and the device disclosed by the invention can be used for realizing practical training, checking and scientific researches of the metro passenger car door system. The whole device comprises six parts including a passenger car door assembly experiment table, an integrated array type control and collecting module, an embedded type handheld failure simulation terminal, a handheld failure setting device, a connecting wire, a data conversion connector, a main control computer, and analog simulation and control software. The type of simulated failures comprises an EDCU (Electronic Door Control Unit) failure, short circuit, open circuit, earth connection, deadlock, an intermittent failure, device damages, signal interference and the like. The method and the device can be used for researching a car door clamping force, a bypath door control line and the like.

A method and system for diagnosing any combination of persistent and intermittent faults. The behavior of a system under test is obtained by measuring or probing the system at a particular location(s). The predicted behavior of a modeled system corresponding to the system under test is investigated by drawing inferences based on at least conditional probabilities, prior observations and component models. The predictions are compared to their corresponding points in the system under test. A determination is made if a conflict exists between the measured behavior and the predicted behavior, and the conditional probabilities are adjusted to more and more accurately reflect the action fault(s) in the system under test. The conflicts or deviations between the obtained predicted behavior and the actual behavior are used to isolate the components of the system causing the faults.

A diagnostic tool that includes components that allow the diagnostic tool to record data while the vehicle is driven in order to capture data for intermittent faults. The diagnostic tool can operate in harsh conditions such as high and low temperatures. The diagnostic tool includes a capacitor to power the diagnostic tool in order to prevent complete drainage of the vehicle battery. The diagnostic tool includes a support module that can couple with a socket and a plug in order to keep them mated together during use.

Computing environments, each executing at least one software program, are monitored for failures occurring during execution of the software program. Information associated with the failure, such as an identification of the software program and a failure type describing the failure, is recorded. The failure information is quantified to report the number of times the software program has failed or the number of times a particular failure has occurred. The quantified data may provide help in prioritizing what program or what failures merit investigation and resolution. Reports may be received from failing computing systems stopped at a state following the occurrence of the failure. In response, hold information is checked to determine whether to instruct the failing computing system to hold a state existing upon the occurrence of the failure.

The invention provides a method and system for diagnosing a fault of a clutch control failure. The method comprises the steps that whether a fault category is a disengagement fault or an engagement fault is judged according to a sent clutch control instruction and clutch actual position information fed back by a position sensor; a clutch control instruction of the same first electromagnetic valve driving type in the failure category is sent out according to the fault category, closed-loop control is carried out, an operator continues to judge whether a clutch successfully acts or not, and if the clutch successfully acts, an intermittent fault happens; if the clutch does not successfully act, the operator continues to send out the clutch control instruction of the first electromagnetic valve drive type, open-loop control is carried out, and the operator continues to judge whether the clutch successfully acts; if the clutch successfully acts, problems exist in a control model of a clutch; if the clutch does not successfully act, the electromagnetic valve drive type is changed, the operator continues to send out a clutch control instruction of a second electromagnetic valve drive type, and if the clutch successfully acts, a first electromagnetic valve in the first electromagnetic valve drive type fails. According to the method and system, the specific type of the fault of the clutch can be accurately judged in detail.

Production control systems and methods are presented for estimation of production resource failure probabilities in which a set of four count values are maintained and updated for each resource including a first count value m₁₁ indicating a number of plans where the resource m was used and failed, a second count value m₁₀ indicating a number of plans where the resource m was used and succeeded, a third count value m₀₁ indicating a number of plans where the resource m was not used and failed, and a fourth count value m₀₀ indicating a number of plans where the resource m was not used and succeeded, and the current fault probability for each resource is estimated and stored for single or multiple, persistent or intermittent faults based on the corresponding count values.

A method is used in managing loop interface instability. It is determined that a loop has excessive intermittent failures. It is determined, based on whether the intermittent failures are detectable on another loop, whether the cause of the excessive intermittent failures is within a specific category of components. A search procedure is executed that is directed to the specific category of components, to isolate the cause of the excessive intermittent failures.

An optical network including multiple nodes is subject to intermittent faults that may raise alarms in the system. The invention focuses on an optical network based on the Any rate architecture. A single fault such as a client failure at a node in such a network can give rise to a loss of client signal leading to multiple alarms detected at multiple points. To alleviate this problem this invention provides switching in a special Signature signal in place of the lost client signal. By detecting the Signature signal containing a specific code, the fault on the any rate-based architecture can be uniquely identified. In addition to fault identification, the Signature signal on the network makes it possible to maintain Clock and Data Recovery Locks at downstream nodes. The Signature signal serves also as a vehicle for carrying a special optical tag called Wavekey provided by the Wavelength Tracker technology developed by the Applicant. This optical tag includes a low frequency modulation of one or more dither tones onto an optical channel, which is uniquely identified by the tag. Maintaining the Wavekey is important for tracing the end-to-end path and power level of the signal on each wavelength. A method and a Field Programmable Gate Array-based system for the generation and identification of such a Signature signal that not only identifies the fault that has occurred on the optical network but also provides for the maintenance of the Wavekey, are described.

The invention provides a method and apparatus for fault detection in a controller area network. A controller area network (CAN) has a plurality of CAN elements including a communication bus and a plurality of controllers. A method for monitoring the CAN includes detecting occurrences of a first short-lived fault and a second short-lived fault within a predefined time window. A first fault set including at least one inactive controller associated with the first short-lived fault and a second fault set including at least one inactive controller associated with the second short-lived fault are identified. An intermittent fault is located in the CAN based upon the first and second fault sets.

Diagnosing electrical circuit faults can be accomplished with a variety of tools. Voltmeters are frequently used to measure voltage to determine whether a short is present, but are not well-suited for finding intermittent faults caused by corroded connectors or excessive voltage drop under operating loads. Measuring a static voltage without load using a voltmeter can yield misleading results. A diagnostic tool that is simple to use and that yields a definitive result is preferred in certain applications such as automotive electrical system diagnosis due to the varying skill level of technicians and the variation in field conditions in automotive shops. A simple, inexpensive diagnostic tool that can be used with minimal or no training allows rapid diagnosis of circuit faults that result from a the inability of a measured circuit to supply a minimum current at a minimum voltage.

The invention discloses a determination method for a high resistance grounding fault of a power distribution line, comprising a fault intermittent detection and determination process and a fault direction detection and determination process. The fault direction detection process collects a zero-sequence current traveling wave and a zero-sequence voltage traveling wave, and judges based on the traveling wave information to obtain a direction in which the fault occurs. The fault intermittent detection and determination process collects zero-sequence current, and judges based on the zero-sequencecurrent amplitude change data to obtain a specific judgment result. According to the determination method for the high resistance grounding fault of the power distribution line, due to the adoption of directional components, the method is guaranteed to be selective in principle, and on the basis of this, the flexible adjustment of the threshold of intermittent fault characteristic detection makesthe method highly sensitive.

A method of detecting and diagnosing system faults, includes detecting the noisy status of a monitor during operations and incorporating a quantified monitor uncertainty level to support fault isolation reasoning. A sequential probability ratio test is used to statistically test the noisy status of a monitor and Shannon's entropy theory is used to quantify the uncertainty levels of the monitor to support the use of the monitor values in fault isolation.

The invention discloses a BIT (built-in test) intermittent-fault diagnosis method based on sparse representation. The method specifically includes the following steps: (1) collecting different equipment history BIT data of which types include a normal data type, an intermittent-fault data type and a permanent-fault data type, selecting 70% of data from each data type to use the same as a trainingsample set, and removing labels of the remaining data to use the same as a test sample set; (2) utilizing a k-singular-value-decomposition (K-SVD) learning algorithm to carry out learning training onthe training sample set, and constructing an overcomplete dictionary D; (3) utilizing the overcomplete dictionary D to carry out sparse representation on the obtained test sample set to obtain sparsecoefficients; (4) utilizing a sparse representation classifier (SRC) to carry out sparse reconstruction on the sparse coefficients to obtain reconstruction residuals; and (5) categorizing to-be-testedsamples into categories of smallest reconstruction residuals, and thus obtaining diagnosis results of to-be-tested BIT data. The method can highly effectively and accurately diagnose BIT intermittent-faults, has higher diagnosis precision, and decreases a BIT false-alarm rate.

A system and method for detecting an intermittent failure of an injector that injects hydrogen gas fuel into the anode side of a fuel cell stack in a fuel cell system. The method includes operating the injector at a fixed injector pulse width and frequency, which causes the stack to generate a constant current, and therefore, a constant fuel consumption rate. While at a constant current, the injector is commanded to a constant duty cycle and frequency that matches the rate of fuel consumption in the fuel cell system. The resulting fuel pressure feedback is then monitored, and if it diverges from a defined nominal value, either in a constant or oscillatory manner, it can be determined that the injector has an intermittent opening failure. In one embodiment, the determination of the injector failure is performed during a shut-down sequence of the fuel cell system.

The invention relates to a bus fault diagnosis method for a CAN (Controller Area Network), particularly, a network-level adaptive fault diagnosis (NAFD) method for the CAN. The method is mainly applied to a car CAN network communication system. The method comprises model analysis and a fault diagnosis method. On the basis of a CAN bus topology model, a fault diagnosis model is established. Nodes in a CAN network are divided into test nodes and tested nodes. In a mode of carrying out diagnosis among the nodes in sequence, fault types of fault nodes are judged. The fault types of the nodes are divided into a normal state, an intermittent fault state and a permanent fault state. The fault nodes are closed through two times of diagnosis. Node state misjudgment and node resource waste resultingfrom external factor interference are avoided. Cache content in each node only comprises states of the corresponding nodes, so data volume in the network is reduced. The reliability of the CAN bus network is improved, and moreover, the performance of the network is improved.

The invention discloses a nonlinear system self-adaptive neural fault-tolerant control method. A multi-input multi-output nonlinear system is established, and an intermittent fault model is adopted toobtain an actuator state; a multi-input single-output extreme learning machine neural network is adopted to approach an uncertainty function in the multi-input multi-output system; then an inequalityis introduced to avoid the singularity problem of the controller; and finally the bounded performance of the estimated parameters is guaranteed by adopting a projection operator. According to the method, the uncertain function of the system is approached by adopting the extreme learning machine, so that the dependence on system prior knowledge is reduced; a continuous inequation is introduced, sothat the singularity of the controller is avoided, and meanwhile, the bounded performance of the estimated parameters is guaranteed by adopting the projection operator; the boundary of jump parameters caused by the fault of the intermittent actuator is determined clearly, so that the influence of an unknown actuator intermittent fault and an unknown correlation item on the system can be effectively compensated.