168 results about "Active fault" patented technology

A solution to the general problem of Secure Storage and Retrieval of Information (SSRI) guarantees that also the process of storing the information is correct even when some processors fail. A user interacts with the storage system by depositing a file and receiving a proof that the deposit was correctly executed. The user interacts with a single distinguished processor called the gateway. The mechanism enables storage in the presence of both inactive and maliciously active faults, while maintaining (asymptotical) space optimailty. This mechanism is enhanced with the added requirement of confidentiality of information; i.e., that a collusion of processors should not be able to learn anything about the information. Also, in this case space optimality is preserved.

The invention relates to a spacecraft attitude integral sliding mode fault tolerance control method taking consideration of a performer fault and provides a robustness attitude active fault tolerance control method based on an integral sliding mode surface for problems of the performer fault, external disturbance and control moment amplitude limits in a spacecraft attitude control process. The method comprises steps that firstly, a spacecraft attitude dynamics model taking consideration of the performer fault and containing external disturbance is established; secondly, on the condition that a performer is not in fault, a designed nominal controller can guarantee system stability, and input saturation amplitude limits can be easily satisfied through adjusting controller parameters; lastly, the fault information is introduced to design an integral sliding mode controller, robustness of external disturbance and the performer fault can be effectively improved, system stability is analyzed on the basis of an Lyapunov method. The method is advantaged in that stability of the attitude control system is guaranteed when a spacecraft operating on orbit generates the performer fault, and relatively strong fault tolerance capability and external disturbance robustness are realized.

The present invention is a method for detecting and isolating fault modes in a system having a model describing its behavior and regularly sampled measurements. The models are used to calculate past and present deviations from measurements that would result with no faults present, as well as with one or more potential fault modes present. Algorithms that calculate and store these deviations, along with memory of when said faults, if present, would have an effect on the said actual measurements, are used to detect when a fault is present. Related algorithms are used to exonerate false fault modes and finally to isolate the true fault mode. This invention is presented with application to detection and isolation of thruster faults for a thruster-controlled spacecraft. As a supporting aspect of the invention, a novel, effective, and efficient filtering method for estimating the derivative of a noisy signal is presented.

The invention discloses an active fault-tolerant control method for a lienar multi-agent tracking system on the basis of slip form control. A distributed fault-tolerant control strategy is put forwardby a distributed observer and a slip form control method by considering the executor faults, the sensor faults, the inherent nonlinearity and the leader unknown control input of a general linear multi-agent tracking system. Firstly, a state tracking error system is established by aiming at each follower, and a sensor fault signal is taken as an auxiliary state amount to establish an augmented tracking error system. In order to simultaneously estimate various faults and the leader unknown control input, an intermediate variable is imported. On the basis of neighbor set output information, a distributed observer is designed for the augmented tracking error system and the intermediate variable, and a global estimation error system is proved to be finally uniformly bounded. According to the obtained observation information, a nonlinear slip form surface is designed for the tracking error system of each follower agent, system robustness is enhanced, and the stability of a sliding mode is proved. According to the fault observation information and the neighbor set output information, a distributed slip form controller is put forward, the state of the error system is guaranteed to reach and be kept at the slip form surface within limited time, and therefore, the fault-tolerant tracking stability of the multi-agent system is realized. The method is used for the fault-tolerant control of the linear multi-agent tracking system with executor faults and sensor faults.

The invention provides an aero-engine active fault-tolerant control method based on an error interval observer, and belongs to the technical field of aviation control. The method comprises the steps that an aero-engine tracks the state and the output of a reference model through an error feedback controller; an aero-engine control system with a disturbance signal and with an actuator fault and a sensor fault is compensated through a virtual sensor and a virtual actuator; the error between an aero-engine fault system and the reference model of the aero-engine fault system is observed through the error interval observer, and the error is fed back to the error feedback controller; and finally, the difference between the reference model output of the fault system and the virtual actuator output is used as a control signal to achieve active fault-tolerant control of the aero-engine. According to the method, when the actuator and the sensor of the aero-engine breaks down, even the disturbance signal exists, the system can be ensured to operate in a desired state without changing the controller, so that the system has good fault-tolerant capability and anti-interference capability.

The invention provides a low-voltage distribution network active fault diagnosis method based on an intelligent distribution terminal. The method is characterized in that real-time monitoring and analysis of the local information of distribution transformers, low-voltage branch boxes, meter boxes and user intelligent meters are performed based on the intelligent distribution terminal, distributededge computing of the intelligent distribution terminal is utilized, user power outages are actively mastered, fault investigation and determination on the spot are developed, fault repair is timely and actively performed at a positioning fault interval for low-voltage distribution network faults, the shut-down time of users is reduced, and active service and the excellent service level are improved.

A method and system for characterization of fault conditions within a subterranean volume. In one embodiment, the system comprises means for generating a mathematical model of stress conditions within the volume, from which breakout conditions along a borehole trajectory can be predicted. The system further comprises means for sensing actual breakout conditions along a borehole extending through the volume. Predictive breakout data is compared with the actual sensed breakout conditions to assess the degree of correlation between the predictive data and the actual data, and thus the accuracy of the stress model. Means are provided for enabling a user to cause the mathematical model to be revised to reflect the presence of at least one active fault plane in the volume, where the presumed fault plane is not intersected by the borehole. The revised model is used to generate new predictive breakout data. The process of revising the stress model and assessing the correlation between predictive breakout conditions derived from the model and actual breakout conditions is repeatable in an iterative fashion to achieve an optimal correlation and hence an optimally accurate stress model reflecting fault conditions in the vicinity of but not necessarily penetrated by the borehole.

The invention uses the idea of hierarchical structure control optimization to provide a manipulator actuator fault tolerant control system based on a double-layer structure and a method thereof, which belongs to the technical field of automatic control. In order to reduce the computational complexity and improve the instantaneity, a discrete system model under an actuator fault is established in an expansion manner through Taylor series. An FDD unit is designed to initiatively deal with a fault problem. The estimated fault information is introduced into a fault model to realize active fault tolerance. Uncertainties of the actual system are considered. A feedback correction mechanism is used for compensation. A manipulator fault tolerant controller is composed of a trajectory planning layer and a tracking control layer. According to different control objectives of each layer, a controller is designed separately, which is more specific to the problem. The fault tolerant control of the double-layer structure can deal with the existing system constraints, has strong robustness, can effectively solve the problem of the constant deviation fault of a complex manipulator actuator, and ensures the stability and the control performance of the whole system.

The invention discloses a double-layer Kalman filter-based intermittent failure diagnosis and active fault-tolerant control method. The method includes the following steps that: a linear discrete timesystem model on which an intermittent failure occurs is established; double-layer Kalman filter-based intermittent failure diagnosis is performed; and fault-tolerance control for the intermittent failure is performed. The invention provides the above method for one type of linear discrete time systems on which intermittent failures occur. With the method adopted, the occurrence time and disappearance time of the intermittent failure can be accurately and effectively detected under the condition of noise disturbance, and the solving problem of the intermittent failure is converted into the optimization problem of minimum variance unbiased estimation under an intermittent failure gain constraint, so that an optimal estimation value can be obtained accurately; and a failure diagnosis processis combined with the design process of a fault-tolerant controller, so that the real-time performance and rapidity of fault-tolerant control can be ensured. The active fault-tolerant controller is simple in structure and is easy to implement, and can ensure the stable operation of the system even when the intermittent failure occurs.

In one embodiment, a technique for detecting a break in a pseudowire and automatic shutting down user network interface (UNI) ports affected by the break is provided. In response to the loss of connectivity on the shut down ports, customer edge devices may automatically switch over to redundant circuits (e.g., other UNI ports not affected by the break in the pseudowire) and establish a different pseudowire.

The invention discloses a flexible spacecraft active fault tolerant control method based on dynamic output feedback control, which belongs to the field of spacecraft attitude control. The method comprises the steps that a dynamic equation of a flexible spacecraft attitude control system is transformed into a general state space equation; a fault model with additive sensor measurement offset is established; a fault detection and identification module composed of an unknown input observer and a filter is established; real-time detection and on-line estimation are carried out on unknown sensor fault; and a fault tolerant controller based on dynamic output feedback is designed based on acquired fault estimation information. According to the invention, when a flexible spacecraft can normally reach an expected posture in the case of an additive sensor measurement offset fault; the influence of disturbance generated by modeling uncertainty and flexible accessory is considered in a design process; and a fault diagnosis and identification module and the fault tolerant controller can be independently designed, and can be easily realized by a project.

In a system for alerting an operator of a vehicle to a highest priority fault condition, the operating conditions of the vehicle are obtained and compared to predetermined values in order to identify the fault conditions of the vehicle. Each of the fault conditions of the vehicle has a corresponding operator action associated therewith which identifies the actions that must be performed by the operator in order to manage the fault condition. By prioritizing the fault conditions on the basis of the operator actions that are necessary to manage the faults, the system is able to output to the operator only the operator action associated with the highest priority fault condition, without any compromise in safety or additional risk of damage to the vehicle, while providing the ability for the operator of the vehicle to manage all of the active fault conditions by performing only the operator action associated with the highest priority fault condition.

The invention discloses an active fault tolerance and fault relief system based on steer-by-wire dual motors and a mode switching control method of the active fault tolerance and fault relief system.The system comprises an acquisition unit, a steering wheel assembly, an ECU control module, a front wheel steering assembly and a fault tolerance controller, wherein the acquisition unit, the steeringwheel assembly, the ECU control module and the front wheel steering assembly are sequentially connected. The control method of the system includes the steps that the acquisition unit transmits an acquired automobile signal to the ECU control module, and a corresponding compensation strategy is selected through a fault tolerance control strategy unit, a yaw velocity calculation unit, a stability control unit and a dual-motor compensation unit and acts on a rack mechanism. By the adoption of the provided system and method, an active fault tolerance mode and a fault relief mode can be switched according to different fault working conditions of the faulty motor, optimum control of the real-time performance of an automobile is achieved, and the traveling performance and high performance of theautomobile under an automobile field fault condition are guaranteed.

The invention discloses an active fault-tolerant predictive control method for faults of multiple actuators in a discrete system, especially provides an active fault-tolerant control method which considers common partial faults of multiple actuators in the discrete control system and combines with a discrete sliding mode observer and a model predictive control. According to an initial state modelof the system, considering the step type disturbance and error, an augmented state model of an embedded integrator is designed and predictive control rules are designed. According to a fault model, asecond-order discrete sliding mode observer is designed to detect fault factors of the faults of the multiple actuator, compensate the predictive control rules, and finally form a complete active fault-tolerant predictive controller. The active fault-tolerant predictive control method for the faults of the multiple actuators in the discrete system accurately estimates the fault factors by designing the second-order sliding mode observer, and designs the predictive control rules by using the model predictive control algorithm, can realize an online optimization of the control rules and effectively improves the control precision of the controlled system, provides good fault tolerance to the fault control system with multiple actuators. The active fault-tolerant predictive control method forthe faults of the multiple actuators in a discrete system is used for the active fault-tolerant control of the faults of the multiple actuators in the discrete system.

An active fault-tolerating method of software based on chain list includes using application software to realize all function, dividing application software to be multiple function module as each module containing a master algorithm and N numbers of backup algorithms, using fault-tolerant software to monitor operation of each function module and revising module relation chain list to start up relevant backup algorithm for tolerating error by fault-tolerant software when master algorithm of certain function module is on error as well as shielding off said function module by fault-tolerant software when N numbers of backup algorithms are all on error.

The invention discloses an online learning-based super computer node active fault-tolerant method, and aims at overcoming the defect of large fault tolerance overhead in a system level checkpoint method. A technical scheme comprises the following steps: for a constructed super computer system, a service node collects history state data of a new fault node, performs centralized online learning on a node fault behaviour by utilizing the data, and acquires an updated fault predictor; each calculating node acquires respective state data, predicts whether the calculating node is going to fail or not by utilizing the new fault predictor, if so, process migration is performed on an application process which is operated on the corresponding node; then, the service node and the calculating nodes sleep to wait for a specified active fault-tolerant time interval delta, and continue a new turn of active fault-tolerant process. By adopting the online learning-based super computer node active fault-tolerant method, a super computer node fault can be predicted in advance and low-overhead active fault tolerance is implemented, so that the problem of the large fault tolerance overhead in the system level checkpoint method is solved; the availability of the super computer system is improved.

The invention provides a passive fault-tolerant control method of an automotive active suspension and relates to the technical field of automobile suspension control. The fault pre-considered passive fault-tolerant control method of the automotive active suspension is offline designed by using the active suspension of the automobile as the research object, combining the shortcomings or defects existing during completed fault-free component and part based research by combining current automotive active suspension control based on a fault-tolerant control theory, using the reliability and usage quality improvement of automotive active suspension control and suspension design method optimization as targets, avoiding parameter perturbation and actuator faults of the automotive active suspension and meanwhile considering time-domain hard constraints of a suspension system. The passive fault-tolerant control method can ensure the stability and safety of the active suspension system, and the taking comfort and control stability of an automobile are improved.