55 results about "Discrete event system" patented technology

A system and method is provided for fault detection in a turbine engine. The fault detection system and method uses discrete event system modeling to provide improved fault diagnosis and prognosis. The fault detection system and method receives sensor taken at multiple dynamic events occurring in different time windows. An event determination mechanism evaluates the received sensor data to determine if specified events have occurred. Indications of the occurrence of specified events are then passed to a discrete event system model. The discrete event system model analyzes the timing and sequencing of the event occurrences to determine if a fault has occurred. This method does not require a detailed modeling of the system, and thus can be applied to complex systems such as turbine engines.

A Discrete Event System model created or provided in a time domain modeling and simulation environment and / or an event domain modeling and simulation environment may be divided into multiple independent regions, e.g. “subgraphs”, to achieve interleaved execution of the components from different domains. The subgraphs are automatically identified by the modeling and simulation environment during the compilation. Each subgraph consists of one or more interconnected event-driven components. Each subgraph is associated with an event calendar that controls the execution of the associated subgraph. Such multiple event calendar design enables multi-domain simulation, where event-driven components modeled by an event domain modeling environment and time-driven components modeled by a time domain modeling environment are simulated in an integrated fashion.

The invention discloses a method for automatically adjusting urban rail transit train operation. According to the scheme, the situation that a train operation adjustment system is a discrete event system is taken into consideration, formal modeling is conducted on the system, and decisions are made with the total delay time of trains and the delayed train number as the indicator to select different adjustment methods to adjust the trains; after a dispatcher selects an adjustment mode according to hints at a workstation HMI, the train operation adjustment system is informed of the selected adjustment mode information through data in the JSON format; a news subscription mechanism is adopted for the train operation adjustment system and station arriving events and station departing events of online trains are obtained in a CORBA mode; a station arriving event triggering system or a station departing event triggering system of the trains enables train operation to be restored to a normal and orderly state rapidly according to the set adjustment mode. The method has the advantages of being scientific, reasonable, easy to implement, high in adjustment efficiency and practical.

The invention belongs to the field of a brain machine connector and provides a vague discrete event shared control method of a brain-controlled robotic system. The vague discrete event shared control method of the brain-controlled robotic system utilizes a method of combing a human brain control command and robot autonomous control based on the vague discrete event system to distinguish a motor imagery brain electroencephalogram online and take the motor imagery brain electroencephalogram as a control command with the highest priority degree to control a robot to advance, turn left and turn right. When no brain control command exists, the autonomous control module which is based on the vague discrete event system is operated to blur autonomous control states of obstacle avoidance and traveling close to a wall of the robot and forms the vague discrete event system aiming at the size of a barrier in a route, the length of distance and the like. The vague discrete event shared control method of the brain controlled robotic system makes up the problems that information transmission speed of the brain machine connector is low, distinguish error rate is high, control is delayed and the like through the shared control method and strengthens the adaptive capacity of the robot in a complex environment.

A discrete event system (DES) modeling environment models the occurrence of events independent of continuous model time. In a DES modeling environment, state transitions depend not directly on time, but rather aperiodic discrete incidents known as events. A discrete event modeling environment can be used to model a control system using one or more discrete event-driven components. The event-driven components can be used to model certain portions of a control system that cannot be accurately modeled using a time-based model.

A discrete event system (DES) modeling environment models the occurrence of events independent of continuous model time. In a DES modeling environment, state transitions depend not on time, but rather asynchronous discrete incidents known as events. A discrete event modeling environment can be used to model a control system using one or more discrete event-driven components. The event-driven components can be used to model certain portions of a control system that cannot be accurately modeled using a time-based model.

A method of building discrete system simulations, comprising a sequential set of questions asked of the author of the system, the inclusion of said questions being dependent upon answers to preceding questions and thus context-sensitive, comprising steps of implementing said sequence in software as an interactive process and skipping any steps that are irrelevant in view of earlier input. The method further comprises steps of providing an engine for a simplified, directed construction in logical top-down order of a model for simulation of a discrete-time system providing an engine for the conversion of a model created by a model-building apparatus to human-readable textual output that uniquely specifies the model.

The embodiment of the present invention provides a method for positioning the hidden danger of a door system of a train based on a probability petri network. Firstly, faults, which occur and possibly occur, at each key position of the system are analyzed to determine the hidden danger; a probability Petri network (PPN) model is established according to observation events of the hidden danger of the system and a logical relationship so as to describe a time sequence and a causal relationship between the events; then according to system initial information and the established probability Petri network model, an initial identification M0, a related matrix C and a transition sequence U are generated; a state equation is utilized to analyze the state description changing process of the probability Petri network; and finally, the hidden danger occurrence probability of the system is combined and the established system probability Petri network model is adopted to perform inference analysis on a discrete event system. By analyzing a probability value of a system hidden danger place in a stable state, positioning on the system hidden danger can be realized.

The invention provides a clock synchronization method for network simulation environment of discrete event. The method comprises the steps of: 1) determining a virtual clock tick count value corresponding to occurrence time of a discrete event when the discrete event occurs, and sending the tick count value as a target count value to a kernel-state program; controlling operation of all timers of real software accessing to a network simulation environment of discrete event by using the virtual clock tick count value; 2) summating the virtual clock tick count value gradually by using 1 as step length to reach the target count value by the kernel-state program; for a real software accessing to a network simulation environment of discrete event, determining whether the timer of the real software overtimes or not each time when the virtual clock tick count value is added by 1. The method of the invention assists in avoiding distortion caused by time inconsistence between simulation environment and real environment. In the invention, the real software can be applied in network simulation environment of discrete event directly without modification.

A discrete event system (DES) modeling environment models the occurrence of events independent of continuous model time. In a DES modeling environment, state transitions depend not on time, but rather asynchronous discrete incidents known as events. A user may customize selected parameters of a block or other component able to support at least one entity passing therethrough holding a value of arbitrary data type in a DES modeling environment. For example, a user can enable and disable ports a discrete event execution block in a discrete event execution model using a graphical user interface, such as a dialog box. Based on user-selected dialog inputs, a discrete event execution program can automatically update a specification for a block, for example, by adding ports to the graphical representation of the block.

The invention discloses a communication delay-existing discrete event system distributed supervision and control method. The communication delay-existing discrete event system distributed supervision and control method comprises the following steps that: 1) automata models of component models in a discrete event system are constructed, and an overall model G of the discrete event system is obtained according to the component models; 2) distributed controllers LOCi of the component models when communication delay is zero, and state shift is made to occur in one distributed controllers LOCi, and events that do not occur in a component model corresponding to the distributed controllers LOCi are recorded as communication events; 3) delay limits of each communication event are obtained, and when the communication events are located in the range of the delay limits, the total properties of the discrete event system are optimal and non-blocking; and 4) and the distributed controllers complete control on the discrete event system by means of corresponding communication models according to the delay limits of the communication events. With the communication delay-existing discrete event system distributed supervision and control method of the invention adopted, the distributed controllers can still effectively control the discrete event system when communication delay is not zero.

The invention discloses a combined failure causal chain decoupling method of a discrete event system. The combined failure causal chain decoupling method comprises the following steps: performing modeling on the discrete event system by adopting an expansion time Petri net according to an observation event set and a relationship set of failures; obtaining a time-probability Petri net model according to an inversion algorithm of the expansion time Petri net; performing reasoning analysis on the discrete event system by adopting the time-probability Petri net model; and performing decoupling and analysis of a causal china on the reasoning result of the time-probability Petri net model according to a time-probability decoupling algorithm of the causal chain and an analysis algorithm of a pure failure causal chain.

The invention discloses a method and a device for determining the security diagnosability of a stochastic discrete event system. After a stochastic automaton corresponding to a stochastic discrete event system is determined, an error-free automaton used for representing the specification language of the stochastic discrete event system is created. Then, an illegal language recognizer used for distinguishing forbidden event strings on an illegal language set is created based on the error-free automaton. Next, a security verifier is created based on the illegal language recognizer, and necessary and sufficient conditions used to determine whether the stochastic discrete event system is securely diagnosable are determined. Finally, whether the stochastic discrete event system is securely diagnosable is determined according to the security verifier and the necessary and sufficient conditions. The time complexity corresponding to the creating process of the security verifier and the time complexity corresponding to the determination process of security diagnosability based on the security verifier are polynomial time. Thus, the complexity of security diagnosis of a stochastic discrete event system is reduced.

The invention relates to a parallel runway capacity calculating method based on random simulation. The method includes the steps of setting initial parameters for calculating runway capacity, generating rising and landing type vectors of aircrafts, generating aircraft type vectors, allocating one corresponding arriving or departure point for each arriving or departing aircraft according to proportion, allocating one runway for each flight and generating runway vectors, sequentially calculating the interval Si, i+1 of i flight and i+1 flight from the first flight, calculating the taking-off and landing moments of each subsequent flight, calculating the flight number as the capacity value of current random conditions, taking a mean value as a runway capacity value after simulation for N times, and displaying the calculating result. Variable randomness is simulated through the monte-carlo method, and the taking-off and landing moments of each flight is calculated in a recursion way according to discrete event system principles. The capacity value is obtained by calculating the flight number in one hour. Scientific runway planning scheme evaluation is realized, and reasonable arrangement of flight schedule and precise flow management are realized.

The invention relates to a discrete event system monitoring controller on the basis of an event control function and a control method thereof. The discrete event system monitoring controller comprises a control device; the control device comprises a plurality of control units, a management unit, an even selection unit and a system state tracking unit; the system state tracking unit is used for combining a state of an integral system at the current moment and outputting the state to each control unit and the management unit; each control unit has a function of ensuring the controlled system to meet the requirements on control indexes; the management unit is used for managing each control unit and coordinating an output of each control unit; and control and management signals are output to the event selection unit by the control units and the management units and an enabled even is selected by the even selection unit according to the control and management signals and is output to the system so as to complete controlling the controlled system. According to the invention, the problem of explosive increase of the state of the controller can be effectively avoided; the control problem of one type of discrete event system is solved; and the operation characteristics of a closed-loop system is ensured to meet the requirements on the control indexes and is ensured non-blocking.

The invention relates to a discrete event system fault diagnosis method, which comprises the following steps: S1, a fault system model is built, an observation event sequence of each element of the system is acquired via an observation set, and according to the observation event sequence of each element, fault events related to each element observation event sequence are acquired and recorded via the fault system model; S2, a possible fault sequence of the fault events related to each element is enumerated, a pruning rule is applied, and pruning treatment is carried out on the possible fault sequence of each element; and S3, whether the fault sequence through pruning treatment coincides with an observation event sequence of a corresponding element is judged, and in the case of coincidence, the fault sequence and the corresponding element serve as a diagnosis result to be outputted. According to the method provided by the invention, computation complexity is low, and compared with the prior art, the diagnosis efficiency is greatly improved.

An aviation command guaranty optimization method based on a discrete event system comprises the following steps: firstly, obtaining an aviation command guaranty simulation task and dividing an aviation command guaranty process into a shipboard sub-process, a takeoff sub-process and a landing sub-process; obtaining all discrete events of each sub-process and establishing a discrete event model of the aviation command guaranty process; finishing the aviation command guaranty simulation task to obtain the discrete event system corresponding to the aviation command guaranty simulation task; establishing a discrete event system corresponding to a simulated aviation command guaranty simulation task in process simulation software; finally, obtaining an operation time threshold value range of each discrete event and comparing to obtain an abnormal discrete event which is used as a discrete event needing to be adjusted, and outputting the abnormal discrete event. By adopting the aviation command guaranty optimization method, analysis of the aviation command guaranty process and simulation of a landing success probability are realized, and the abnormal discrete event of an aviation command guaranty system can be found and are pointedly optimized, so that the aviation command guaranty optimization method has better applicable value.

A system and method graphically display ports in a discrete event system (DES) environment. A graphical representation of a model having at least one DES component is provided in the DES environment. A first port of the DES component and a second port of the DES component are indicated by symbols. The first port is indicated by a first symbol representing a port type of the DES environment and the second port is indicated by a second symbol representing a port type of a non-DES environment.

The invention discloses a random discrete event system mode diagnosability judgment method based on the technical field of model diagnosis in artificial intelligence. The method comprises the steps offirstly modeling a to-be-diagnosed system, establishing a corresponding random finite state automaton, needing to establish a mode automaton according to the system characteristics, wherein the modeautomaton is a finite state automaton with a termination state, and defining the PA-diagnosability, constructing a random mode recognizer through synchronous operation, establishing a random mode diagnostor, and judging whether the state of a permanent fault in the random mode diagnostor is fuzzy or not. According to the present invention, by defining the PA-diagnosability in the mode fault diagnosis of the random discrete event system, and judging the PA-diagnosability, the mode fault diagnosis problem of the random discrete event system is solved.

The invention provides a passive space perception interaction method of entities in campaign simulation based on discrete events. A space perception interaction model is arranged, wherein the model includes a space grid list, a campaign entity list and a sensor list. A space perception interaction manager is used for providing a function calling interface for a campaign entity model and sensor components. When the situation that the campaign entities enter or leave the space grid is discovered, a space perception interaction event is transmitted so that the corresponding campaign entities in the sensor list are enabled to receive the space perception interaction event and then detect the campaign entities entering or leaving the space grid. The simulation propulsion mechanism based on thediscrete events is adopted, and the time step of simulation propulsion is not a constant and is determined by the occurrence time of the event so that the computation burden can be reduced and the simulation efficiency can be enhanced. The space perception interaction manager is embedded in the simulation engine in the form of a component so that the expandability of the simulation system and thereusability of the simulation model can be enhanced and the simulation model development efficiency can be enhanced.

The invention discloses a fault predictability detection method for a discrete event system and a fault predictor. A class 1 mark state and a class 2 mark state are used, and the system can be quicklyjudged to be unpredictable when the class 2 mark state exists in the system, so that the efficiency is higher. Model simplification is further proposed to finally obtain a simplified verifier automaton VG, so that the spatial complexity is reduced. Required observables are fewer, i.e. fewer sensing devices are needed when judging the system fault predictability and fault prediction, so that the stability of the fault predictability detection method and the fault prediction is higher. The verifier automaton VG finally obtained by the fault predictability detection method can also serve as a fault predictor to perform online prediction on the system fault.

The invention discloses a method for generating a suboptimal supervisory controller of a discrete event system. The method comprises the following steps of 1, constructing an automaton model PLANTi= (Qi, sigma i, delta i, qi0, Qim) of each component Gi in the system, wherein Qi, sigma i, delta i, qi0 and Qim are a state set, event set, transfer function, initial state and identity state set of the ith component respectively, and calculating a global automaton model PLANT of the system; 2, converting performance indexes E described by characters into an automation model SPECA0 of the performance indexes E; 3, calculating an event set DAT and an uncontrollable event weight DATu when each state of the performance indexes E is forbidden; 4, calculating an adjacent controllable event set J (sigma) corresponding to each uncontrollable event sigma and an event set sigma defined with sigma at the same time in the automaton model PLANTi of each component Gi; 5, obtaining a set delta formed by the transfer functions of the automation model SPECA0 of the performance indexes E; 6, generating the suboptimal supervisory controller of the discrete event system according to the set delta formed by the transfer functions of the automation model SPECA0 of the performance indexes E. Through the adoption of the method, the suboptimal supervisory controller of the discrete event system can be generated according to the performance indexes.

The invention discloses a method for automatically adjusting urban rail transit train operation. According to the scheme, the situation that a train operation adjustment system is a discrete event system is taken into consideration, formal modeling is conducted on the system, and decisions are made with the total delay time of trains and the delayed train number as the indicator to select different adjustment methods to adjust the trains; after a dispatcher selects an adjustment mode according to hints at a workstation HMI, the train operation adjustment system is informed of the selected adjustment mode information through data in the JSON format; a news subscription mechanism is adopted for the train operation adjustment system and station arriving events and station departing events of online trains are obtained in a CORBA mode; a station arriving event triggering system or a station departing event triggering system of the trains enables train operation to be restored to a normal and orderly state rapidly according to the set adjustment mode. The method has the advantages of being scientific, reasonable, easy to implement, high in adjustment efficiency and practical.

The present invention provides a battery system for active fault detection, including the active control, which means that the controller controls the charging and discharging of single or multiple batteries in the battery system; and then obtains battery working information through sensors or information acquisition devices; Then, through the diagnostic module with discrete event system monitoring theory and algorithm, the relationship between events is analyzed, so as to determine whether the state of the single battery in the battery pack is abnormal; thereby realizing the alarm and the controller to take isolation measures, it is the battery energy storage The system works safely and reliably.

The invention discloses a discrete event system mode fault online diagnosis method based on a Petri network diagnostor. The method comprises the following steps: firstly, constructing a fault recognition automaton for each mode fault string according to a given mode fault set to identify a mode fault; secondly, a marking state automaton is constructed according to the discrete event system and allthe fault recognition automatons to mark the faulted state in the discrete event system; converting the mark state automaton into a Petri net, finally constructing a Petri net diagnostor according tothe Petri net obtained by conversion, and carrying out mode fault online diagnosis on the discrete event system by utilizing the diagnostor. The problem that an existing method is not suitable for online diagnosis of complex mode faults is solved, and the method can be used for online diagnosis of S-type mode faults and T-type mode faults and can also be used for online diagnosis of traditional single fault events. The complexity is in linear relation with the state number and the event number of an original system, the complexity of fault diagnosis can be reduced, and the fault diagnosis efficiency is improved.

The application discloses an information safety discrimination method based on a learning diagnostor, which is applied to an incomplete DES (Discrete Event System). An incomplete model is processed byintroducing the learning diagnostor with learning capacity and a candidate state algorithm, and by using a mode in the candidate state algorithm, which not only can carry out simulation on assumptivestate transfer, but also can recover missing state information of the system under a learning function of the learning diagnostor by keeping trying so as to convert the incomplete model into a complete model, the incomplete DES accords with the precondition of verifying opaqueness of a state so as to discriminate whether the incomplete DES successfully implements confidentiality on certain information and meanwhile, expand the application field of the learning diagnostor to the field of verifying opaqueness of the state. The application simultaneously further discloses an information safety discrimination system and device based on the learning diagnostor and a computer readable storage medium, which have the beneficial effects above.

The present application discloses an information security discrimination method based on a rough set theory, the method being applied to a discrete event system. A rough set theory is combined with the discrete event system, the rough set theory is taken as a tool to extract knowledge from the discrete event system, and the opacity of the discrete event system is verified by constructing the finite state machine information system and decision table. Unlike the exponential time complexity of the existing language-based opacity verification methods, the special knowledge extraction method basedon the rough set theory can effectively reduce the verification time complexity, greatly reduce the verification time consumption and improve the verification efficiency, so as to provide feedback ofthe security situation of the confidential information in the system in time, meanwhile, the application scenario of the rough set theory can be extended to the field of opacity verification. The invention also discloses an information security discrimination system and device based on the rough set theory and a computer-readable storage medium, which have the above beneficial effects.

The present invention discloses a simulation method of a dynamic switching-based hydropower engineering transportation system. The method comprises: by collecting data of relevant activities in a construction area, identifying a lasting time model of the activities and constructing a lasting time model library; and molding a transportation system in the construction area by using a simulation model in a discrete event system, and finally performing simulative calculation and analysis. In the course of simulation, a corresponding lasting time model is dynamically selected by determining a time segment of the simulation clock, and system parameters are modified according to a construction progress, thereby implementing a mechanism of dynamic switching. Compared with the prior art, the method according to the present invention can dynamically change the lasting time of the activities according to the specific transportation condition, and more practically simulates the actual transportation system in hydropower engineering, and creates significance to the relevant research.

The invention belongs to the field of aviation / helicopter operation support, and relates to an offshore oil spill disposal-oriented helicopter task simulation process construction method. The method comprises the following steps: determining oil spill accident information; constructing a discrete event system model of the oil spill disposal process; describing a multi-agent discrete event system model by using the multi-agent discrete event system model, and constructing a multi-agent discrete event system model; constructing a mathematical model of the disposal scheme to represent the task distribution condition of the emergency power and the time sequence attribute of the behavior of dispatching the emergency power to a task area to execute the task; based on the mathematical model of the disposal scheme, constructing an evaluation index system of the disposal scheme, and then determining a weight coefficient of each index in the evaluation index system by adopting an analytic hierarchy process; carrying out helicopter task deduction simulation for marine oil spill, and calculating each index value. According to the method, the normalization of helicopter oil spill disposal is improved, and a basis is provided for simulation and evaluation of the helicopter oil spill disposal; meanwhile, the time cost for making a disposal scheme can be saved, and the decision-making efficiency is improved.

The invention provides a time sequence propelling method and device for co-simulation of white-box and black-box discrete event systems, and belongs to the technical field of co-simulation time sequence consistency. The method comprises the following steps: determining a current safety time distance and current simulation time of each white-box system according to a current step length of each white-box system in the discrete event system; calculating the current safety simulation time of each black-box system according to the current safety time distance and the current simulation time of each black-box system in the discrete event system; according to the current simulation time of each white-box system and the current safety simulation time of each black-box system, determining a next propulsion subsystem in simulation; and advancing simulation according to the event table of the next advanced subsystem. The defects of optimistic propelling strategies in black and white box model co-simulation are overcome, an improved time sequence propelling method is introduced, and time sequence consistency is achieved under the condition that black-box model simulation rollback is avoided as much as possible.