CN112132459B

CN112132459B - Petri net-based chemical leakage event emergency disposal flow performance analysis method

Info

Publication number: CN112132459B
Application number: CN202011004337.1A
Authority: CN
Inventors: 刘聪; 陆婷; 李会玲; 王雷; 邢林林; 王绍卿; 张立晔; 孙福振; 何华
Original assignee: Shandong University of Technology
Current assignee: Shandong University of Technology
Priority date: 2020-09-22
Filing date: 2020-09-22
Publication date: 2023-10-10
Anticipated expiration: 2040-09-22
Also published as: CN112132459A

Abstract

The invention discloses a chemical leakage event emergency disposal flow performance analysis method based on a Petri network, which comprises the following steps: 1) Analyzing emergency tasks related to the emergency treatment process of the chemical leakage event and associated time information and resource information; 2) Formally modeling the whole chemical leakage event emergency treatment process based on the Petri net; 3) Analyzing the time performance of the chemical leakage event emergency treatment process based on the Petri network model of the chemical leakage event emergency treatment process under the condition of not considering resource factors; 4) Under the condition of considering resource factors, a detection algorithm of potential resource conflict is provided; 5) And (3) a conflict resolution strategy based on task priority is provided, and the time performance of the emergency treatment process of the chemical leakage event after the strategy is applied is analyzed. The invention provides a conflict detection method and a strategy for eliminating resource conflict, and is applied to the model construction of the emergency disposal flow of the chemical leakage event, thereby promoting the practical application of the time performance analysis of the emergency disposal flow of the chemical leakage event.

Description

Petri net-based chemical leakage event emergency disposal flow performance analysis method

Technical Field

The invention relates to the technical field of business process management, in particular to a chemical leakage event emergency disposal process performance analysis method based on a Petri network.

Background

The Petri network is used as an effective tool for modeling and analyzing a discrete event system, has wide application in the aspect of processing the concurrency and conflict problems of the system, and is also widely applied to the aspects of modeling, analyzing, controlling and verifying a workflow system, and the modeling of the workflow by using the Petri network has three advantages: 1. the Petri net is a graphic language and has accurate semantic definition; 2. the Petri network is based on state events, so that a model based on the Petri network can describe and analyze the execution state of the system in detail; 3. the methods of analyzing the properties of Petri nets have been intensively studied, and these methods can be directly applied to actual engineering, but the existing methods of modeling and analyzing workflows cannot be directly used to model emergency treatment flows because the emergency treatment flows have characteristics different from those of conventional workflows: 1. emergency handling procedures show great flexibility and uncertainty; 2. in an emergency treatment process, tasks and resources show extremely close association; 3. sudden events can lead to fires, explosions, toxic fog, etc., which are serious hazards to human life, property safety and the environment, which are not common in traditional workflows. Therefore, the emergency management system has high requirements on successful completion of the emergency task; 4. the emergency treatment process is a real-time treatment process, and the time performance is crucial to ensure the smooth completion of the process. Research on emergency management systems has received extensive attention from academia and industry, especially with respect to time and resource management; however, in view of the uncertainty of task execution time and the number of resources required for a task during emergency treatment, modeling and analysis of such emergency treatment procedures for a chemical leakage event emergency treatment procedure using formalized methods is still lacking.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art, provides a Petri network-based chemical leakage event emergency disposal flow performance analysis method, breaks through the problems that the existing workflow modeling and analysis method models and analyzes the chemical leakage event emergency disposal flow by a few formalized methods when the uncertain execution time and the resource quantity of tasks are considered, and detects conflicts and eliminates the influence of the existing resource conflicts.

In order to achieve the above purpose, the technical scheme provided by the invention is as follows: the Petri net-based chemical leakage event emergency disposal flow performance analysis method comprises the following steps:

1) Analyzing emergency tasks related to the emergency treatment process of the chemical leakage event and associated time information and resource information;

2) Formally modeling the whole chemical leakage event emergency treatment process based on the Petri net;

3) Analyzing the time performance of the chemical leakage event emergency treatment process based on the Petri network model of the chemical leakage event emergency treatment process under the condition of not considering resource factors;

4) Under the condition of considering resource factors, a detection algorithm of potential resource conflict is provided;

5) And (3) a conflict resolution strategy based on task priority is provided, and the time performance of the emergency treatment process of the chemical leakage event after the strategy is applied is analyzed.

In step 1), the emergency tasks and associated time and resource information involved in the chemical leak event emergency treatment process are formally described as resource and uncertain time constrained chemical leak event emergency treatment processes, comprising<Activity,Resource,Time,Relation,f _AR ,F _TT >The method comprises the following steps: (1) activity defines all tasks involved in a chemical leak event emergency disposal procedure; (2) resource defines all resources required in the chemical leak event emergency disposal procedure; (3) time defines the Time constraint of the task; any one task Activity in all task set activities, if the actual execution time is Atime, atime must satisfy 0 or more, and f _n (activity)≤Atime≤f _u (activity), wherein f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; (4)is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (2); (5) f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ )…q(r _i )>Representing that task x uses a limited number of resources { r ₁ ,r ₂ ,…,,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); (6) f (F) _TT ＝{f _n ,f _u The time function of the task is, for any one task activity, f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; />Activity∪Resource，f _n (activity)≤f _u (activity)。

In step 2), combining the emergency task related to the emergency treatment process of the chemical leakage event in step 1) with the associated time information and resource information, and performing formal modeling on the whole emergency treatment process of the chemical leakage event to obtain a Petri Net model of the emergency treatment process of the chemical leakage event, wherein the Petri Net model is an ERP-Net; the ERP-Net is a 7-tuple, ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e },B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } ₁ ,r ₂ ,…,,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

the emergency tasks and associated time and resource information involved in the chemical leak event emergency treatment procedure referred to above are formalized descriptions of a resource and uncertain time constrained chemical leak event emergency treatment procedure, comprising<Activity,Resource,Time,Relation,f _AR ,F _TT >The method comprises the following steps: (1) activity defines all tasks involved in a chemical leak event emergency disposal procedure; (2) resource defines all resources required in the chemical leak event emergency disposal procedure; (3) time defines the Time constraint of the task; any one task Activity in all task set activities, if the actual execution time is Atime, then Atime must satisfy 0 or more, and f _n (activity)≤Atime≤f _u (activity), wherein f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; (4)is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (2); (5) f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ )…q(r _i )>Representing that task x uses a limited number of resources { r ₁ ,r ₂ ,…,,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); (6) f (F) _TT ＝{f _n ,f _u The time function of the task is, for any one task activity, f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; />Activity∪Resource，f _n (activity)≤f _u (activity)；

The definition of the front set involved in ERP-Net definition is as follows: for any one xE.B.U.T, yE.B.U.T, B represents the library set, T represents the transition set, F represents the relation set, ^· x= { y|y∈b u T Λ (y, x) ∈f } represents the front set of x;

and the initiation rules of ERP-Net are the same as those of the traditional Petri network: if the flag is M, any one of the transitions T in the transition set T, if ^· All b in t are marked with a value greater than or equal to 1, then t can be initiated, wherein ^· t represents a front set of t; but note that in ERP-Net, libraries are used to represent tasks; the number of resources is expressed as an attribute of the task, i.e., the library; the task has two time functions, which respectively represent the minimum execution time and the maximum execution time;

the Petri net mentioned in the above is a four-tuple, Σ= (B, T; F, M) ₀ ) B represents a library set, T represents a transition set, F represents a relationship set, M ₀ Representing an initial tag, satisfying the condition that the pool set B is a finite set of pools; the transition set T is a finite set of transitions;is a set of directed arcs, called a flow relationship; initial marking M of each library ₀ Taking {0,1,2, … }; />

Formalized modeling is carried out on the whole chemical leakage event emergency disposal flow, and the specific steps of the ERP-Net of the chemical leakage event emergency disposal flow are as follows:

2.1 In the form description of the chemical leakage event emergency treatment process constrained by the resources and the uncertain time, taking the formalized description of the chemical leakage event emergency treatment process as an input of formalized modeling of the chemical leakage event emergency treatment process, and initializing ERP-Net of the predefined chemical leakage event emergency treatment process, wherein all libraries, transitions, flow relationships, initial marks, resource attribute functions of tasks, minimum execution time functions of task completion and maximum execution time functions of task completion are all empty;

The formalized description of the resource-and time-independent chemical leak event emergency treatment procedure in this step, i.e., containing the emergency tasks involved in the chemical leak event emergency treatment procedure and the associated time information and resource information;

2.2 Assigning values to the initialized ERP-Net libraries, and adding time and resource attributes to each library, namely a resource attribute function of a task represented by each library, a minimum execution time function of task completion and a maximum execution time function of task completion;

2.3 Adding a transition connection order task; if task b _i Is task b _j Front collection task of (1) satisfiesTransition t _ij Added to b _i And b _j The middle is used for connecting two sequential tasks;

2.4 Adding a start transition and an end transition for a plurality of parallel tasks; if task b _i And task b _j Can be executed concurrently, add transition t _i And transition t _j To represent b _i And b _j Is a start and end of (1);

2.5 Adding a starting library and starting transition for tasks without a front set; the starting transition to merge tasks without a front set is t _s Then add to the starting library b _s Start transition t _s Satisfy the following requirements ^· t _s ＝{b _s }，t _s ^· ＝{b _i |b _i No front set task }, b _i Is a task in the task set, and the starting library b _s Satisfy the following requirementsb _s ^· ＝{t _s -a }; wherein the method comprises the steps of ^· t _s Representing t _s Front set of t _s ^· Representing t _s Is used for the collection of the rear set of the (c), ^· b _s representation b _s Front set of (b) _s ^· Representation b _s Is a post-set of (2);

the definition of the postset in this step is as follows: for any one xE_B_U.T, yE_B_U.T, B represents the library set, T represents the transition set, F represents the relation set, and x ^· = { y|y e B u T ∈ (x, y) e F } represents the postamble of x;

2.6 Adding an ending library and ending transition for tasks without a postset; the end transition of merging tasks without a post-set is t _e Then add to the end pool b _e Ending transition t _e Satisfy the following requirements ^· t _e ＝{b _i |b _i No post-set task }, t _e ^· ＝{b _e }，b _i Is a task in the task set, and ends the library b _e Satisfy the following requirements ^· b _e ＝{t _e }，Wherein the method comprises the steps of ^· t _e Representing t _e Front set of t _e ^· Representing t _e Is used for the collection of the rear set of the (c), ^· b _e representation b _e Front set of (b) _e ^· Representation b _e Is a post-set of (2);

2.7 Will start library b) _s Adding initial identifier M of ERP-Net ₀ The method meets the following conditions: if the library is the starting library, M ₀ (b) =1, otherwise M ₀ (b) =0, finally outputting the ERP-Net model;

the relationship referred to in the above steps is an information attribute in the formal description of the resource-and time-constrained chemical leakage event emergency treatment flow,is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (1).

In step 3), without considering resource factors, based on the ERP-Net of the obtained chemical leakage event emergency treatment process, the time performance of the whole chemical leakage event emergency treatment process is analyzed, and then the specific steps of the ideal execution time of the chemical leakage event emergency treatment process are as follows:

3.1 Calculating the earliest starting time of the task b when all tasks are completed with the minimum execution time and the maximum execution time respectively;

if all tasks are completed with their minimum execution time, the earliest start time of task b is denoted by T _e1 (b) Indicating that if b is the start pool b _s T is then _e1 (b) =0, otherwise T _e1 (b)＝max{T _e1 (b’)+α(b’)|b’∈ ^· ( ^· b) -a }; wherein the method comprises the steps of ^· ( ^· b) A (b ') represents the minimum execution time value for b' to complete;

if all tasks are completed with their maximum execution time, the earliest start time of task b is denoted by T _e2 (b) Indicating that if b is the start pool b _s T is then _e2 (b) =0, otherwise T _e2 (b)＝max{T _e2 (b’)+β(b’)|b’∈ ^· ( ^· b) -a }; wherein the method comprises the steps of ^· ( ^· b) A front set representing a front set of b, β (b ') representing a maximum execution time value for b' to complete;

3.2 To ensure that the process can be completed within the ideal execution time, calculate the latest start time of task b; wherein the ideal execution time of the flow when the task is completed with the minimum execution time and the maximum execution time is respectively T _E1 And T _E2 Is represented by T _E1 ＝T _e1 (b _e )，T _E2 ＝T _e2 (b _e ) The method comprises the steps of carrying out a first treatment on the surface of the Wherein b _e Is a termination store, T _e1 (b _e ) Indicating that task b is completed with its minimum execution time _e Is the earliest start time of (2); t (T) _e2 (b _e ) Indicating that task b is completed at its maximum execution time _e Is the earliest start time of (2);

to ensure that the flow can be at T _E1 Completion in time, the latest start time of task b is T _n1 (b) Indicating that if b is the end pool b _e T is then _n1 (b) The ideal execution time of the flow when the task is completed with the minimum execution time, otherwise T _n1 (b)＝min{T _n1 (b’)-α(b)|b’∈(b ^· ) ^· -a }; wherein b' is a member belonging to the group (b) ^· ) ^· ，(b ^· ) ^· A post-set representing a post-set of b, α (b) representing a minimum execution time value for completion of task b;

to ensure that the flow can be at T _E2 Completion in time, the latest start time of task b is T _n2 (b) Indicating that if b is the end pool b _e T is then _n2 (b) The ideal execution time of the flow when the task is completed with the maximum execution time, otherwise T _n2 (b)＝min{T _n2 (b’)-β(b)|b’∈(b ^· ) ^· -a }; wherein b' is a member belonging to the group (b) ^· ) ^· ，(b ^· ) ^· A post-set representing a post-set of b, β (b) representing a maximum execution time value for completion of task b;

the ERP-Net in this step is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

the Petri net mentioned in the above is a four-tuple, Σ= (B, T; F, M) ₀ ) B represents a library set, T represents a transition set, F represents a relationship set, M ₀ Representing the initial mark, satisfying the condition:library set B is a finite set of libraries; the transition set T is a finite set of transitions; Is a set of directed arcs, called a flow relationship; initial marking M of each library ₀ Taking {0,1,2, … }; />

The definition of the front and rear sets referred to in the above is as follows: for any one xE.B.U.T, yE.B.U.T, B represents the library set, T represents the transition set, F represents the relation set, ^· x= { y|y∈b u T Λ (y, x) ∈f } represents the front set of x; x is x ^· = { y|y∈b u T ∈Λ (x, y) ∈f } represents the postamble of x.

In step 4), without taking into account resource factors, the ideal execution time of the chemical leak event emergency disposal procedure has been obtained in step 3); during execution of the chemical leak event emergency disposal procedure, however, resource conflicts exist, which are referred to in ERP-Net,b _j ∈B _A (b _i ≠b _j )，B _A is a task set of the emergency disposal procedure of the chemical leakage event, < +.>Representation b _i And b _j There is a potential resource conflict, and the conditions need to be satisfied: b _i Θb _j ；[T _start (b _i ),T _end (b _i )]And [ T ] _start (b _j ),T _end (b _j )]With overlap, T _start (b _i ) And T _end (b _i ) Respectively represent task b _i True start and end time, T _start (b _j ) And T _end (b _j ) Respectively represent task b _j Real start and end times;

b referred to in definition of resource conflict above _i Θb _j Representation b _i And b _j There is a resource dependency, defined as follows: in the case of an ERP-Net,b _j ∈B _A (b _i ≠b _j )，b _i Θb _j representation b _i And b _j Resource dependence exists, and the conditions need to be satisfied: χ (b) _i ) ^T ·χ(b _j ) Not equal to 0; wherein χ (b) _i ) ^T Representing task b _i Transpose of resource attribute function vector, χ (b) _j ) Representation b _j Is a resource attribute function vector of (1);

the ERP-Net described in the above definition is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A Any one of tasks b, beta (b) is greater than or equal to 0, and satisfies beta (b) is greater than or equal to alpha(b) The method comprises the steps of carrying out a first treatment on the surface of the (6) Any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

The definition of the front and rear sets referred to in the above is as follows: for any one xE.B.U.T, yE.B.U.T, B represents the library set, T represents the transition set, F represents the relation set, ^· x= { y|y∈b u T Λ (y, x) ∈f } represents the front set of x; x is x ^· = { y|y e B u T ∈ (x, y) e F } represents the postamble of x;

under the condition of considering resource factors, for the resource conflict existing in the emergency disposal flow of the chemical leakage event, represented by ConflictSet, the specific steps of the potential resource conflict detection algorithm are as follows:

4.1 Using ERP-Net as input, initializing Conflictset to make Conflictset be empty set, T _e1 (b _s )、T _n1 (b _s )、T _e2 (b _s )、T _n2 (b _s ) The value of (2) is 0; wherein T is _e1 (b _s ) Representing task b when all tasks are completed with their minimum execution time _s Is the earliest start time of (2); t (T) _n1 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _s Is the latest start time of (a);T _e2 (b _s ) Representing task b when all tasks are completed at their maximum execution time _s Is the earliest start time of (2); t (T) _n2 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the maximum execution time, task b _s Is the latest start time of (a);

4.2 Detecting resource dependencies between tasks; when the condition is satisfiedb _j ∈B _A (b _i ≠b _j ) Time B _A Is a task set of emergency treatment process of chemical leakage event, and is called χ (b) _i ) ^T ·χ(b _j ) If χ (b) _i ) ^T ·χ(b _j ) Not equal to 0, then (b) _i ,b _j ) There is a resource conflict, join in ConflictSet (b _i ,b _j ) The method comprises the steps of carrying out a first treatment on the surface of the Wherein χ (b) _i ) ^T Representing task b _i Transpose of resource attribute function vector, χ (b) _j ) Representation b _j Is a resource attribute function vector of (1);

4.3 Detecting whether task execution intervals with resource dependence overlap; if Conflictset+.0, then there is a resource conflict task for any two of Conflictset (b _i ,b _j ) Calculate T _e1 (b _i )、T _e2 (b _i )、T _e1 (b _j )、T _e2 (b _j ) Is a value of (2); if [ T ] _e1 (b _i ),T _e2 (b _i )+β(b _i )]∩[T _e1 (b _j ),T _e2 (b _j )+β(b _j )]Not equal to 0, then step 4.3) is performed again, otherwise, the two tasks (b) with resource conflict are removed in the obtained Conflictset _i ,b _j ) Finally, a ConflictSet of a chemical leakage event emergency disposal flow resource conflict set is obtained; wherein beta (b) _i ) Representing task b _i The maximum execution time function value completed.

In step 5), based on the resource conflict during the execution of the emergency treatment process of the detected chemical leakage event in step 4), a task-based proposal is madeA conflict resolution strategy of priority is called a task priority strategy; the task priority policy is defined as follows: suppose b _i Θb _j If b _i ∈PriorityActivitySet,b _j PriorityActivitySet，b _i Higher priority than b _j The method comprises the steps of carrying out a first treatment on the surface of the That is, task b _i Without waiting for task b _j Execution completion may be performed while task b _j Must wait for task b _i The execution can be performed after the execution is completed and the occupied resources are released; the PrioritiyActivitySet represents a priority set task; analyzing the time performance of the emergency treatment process of the chemical leakage event after the task priority strategy is applied;

5.1 If there is a resource conflict during the execution of the chemical leak event emergency treatment process, and the resource conflict has been detected in step 4), the specific steps of the method for calculating the actual execution time of the chemical leak event emergency treatment process are as follows:

5.1.1 Calculating the real earliest starting time of the task b when all tasks are completed with the minimum execution time and the maximum execution time respectively;

a. When all tasks in the process are completed with the minimum execution time, the real earliest starting time of the task b is E ₁ (b) Indicating that if task b is the start pool b _s Then E ₁ (b) =0, otherwiseWherein, the liquid crystal display device comprises a liquid crystal display device, representing b and b ₁ There is a potential resource conflict, b ₁ Is a task with potential resource conflict with b, T _e1 (b) Representing the ideal earliest opening of task b when all tasks are completed at their minimum execution timeStart time, W ₁ (b,b ₁ ) Is when b and b ₁ Task b waits for task b when it is completed with minimum execution time ₁ Releasing the waiting time of the occupied resources;

the above W ₁ (b,b ₁ ) The calculation method of (2) is as follows: if T _e1 (b ₁ )+α(b ₁ ) Less than or equal to T _e1 (b) W is then ₁ (b,b ₁ ) =0, otherwise W ₁ (b,b ₁ )＝T _e1 (b ₁ )+α(b ₁ )-T _e1 (b) The method comprises the steps of carrying out a first treatment on the surface of the Wherein T is _e1 (b ₁ ) Indicating that task b is completed with its minimum execution time ₁ Is set to the ideal earliest start time of (a); alpha (b) ₁ ) Is task b ₁ And E ₁ (b _e ) Is the shortest execution time for the whole chemical leak event emergency disposal procedure;

b. when all tasks in the process are completed with the maximum execution time, the real earliest starting time of the task b is E ₂ (b) Indicating that if task b is the start pool b _s Then E ₂ (b) =0, otherwiseWherein the method comprises the steps of Representing b and b ₁ There is a potential resource conflict, b ₁ Is a task with potential resource conflict with b, T _e2 (b) Represents the ideal earliest start time, W, of task b when all tasks are completed at their maximum execution time ₂ (b,b ₁ ) Is when b and b ₁ Task b waits for task b when all are completed with maximum execution time ₁ Releasing the waiting time of the occupied resources;

the above W ₂ (b,b ₁ ) The calculation method of (2) is as follows: if T _e2 (b ₁ )+β(b ₁ ) Less than or equal to T _e2 (b ₁ ) W is then ₂ (b,b ₁ ) =0, otherwise W ₂ (b,b ₁ )＝T _e2 (b ₁ )+β(b ₁ )-T _e2 (b) The method comprises the steps of carrying out a first treatment on the surface of the Wherein T is _e2 (b ₁ ) Indicating that task b is completed at its maximum execution time ₁ Is set to the ideal earliest start time of (a); beta (b) ₁ ) Is task b ₁ Maximum execution time of (2);

any one task b, E in the task set ₁ (b) And E is ₂ (b) The earliest start time of b when the task is completed with minimum and maximum execution times, respectively, E ₁ (b) Less than or equal to E ₂ (b)；

5.1.2 Calculating the real latest starting time of the task; when the task is completed with minimum execution time and maximum execution time, the real execution time of the flow is respectively used as TF ₁ And TF (TF) ₂ Represented, and TF ₁ ＝E ₁ (b _e ) And TF (TF) ₂ ＝E ₂ (b _e ) Wherein b _e Representing an ending library; e (E) ₁ (b _e ) Representing the shortest execution time of the whole chemical leak event emergency disposal procedure when all tasks in the procedure are completed with their minimum execution time; e (E) ₂ (b _e ) Representing a shortest execution time for the entire chemical leak event emergency disposal procedure when all tasks in the procedure are completed at their maximum execution times;

a. To ensure that the flow can be at TF ₁ Completion in time, the latest start time of task b is L ₁ (b) Indicating that if task b is the end pool b _e L is then ₁ (b)＝E ₁ (b) Otherwise L ₁ (b)＝min{L ₁ (b’)-α(b)|b’∈(b ^· ) ^· -a }; wherein E is ₁ (b) When all tasks in the process are completed with the minimum execution time, the real earliest starting time of the task b is represented, and alpha (b) represents the minimum execution time of the task b;

b. to ensure that the flow can be at TF ₂ Completion in time, the latest start time of task b is L ₂ (b) Indicating that if task b is the end pool b _e L is then ₂ (b)＝E ₂ (b) Otherwise L ₂ (b)＝min{L ₂ (b’)-β(b)|b’∈(b ^· ) ^· -a }; wherein E is ₂ (b) Represents the earliest real start time of task b when all tasks in the flow are completed with their maximum execution time, β (b) represents the maximum execution time of task b, (b) ^· ) ^· A back set representing the back set of b;

5.2 In order to ensure that the whole emergency treatment process of the chemical leakage event is completed in the shortest time, the task priority strategy is utilized to resolve the resource conflict, and the specific steps of obtaining the priority task set through the task priority strategy are as follows:

5.2.1 With Conflictset conflict set and (B, T; f, M ₀ ,f _AR Alpha, beta) as input, and initializing PrioritiyActivitySet, let PrioritiyActivitySet be empty, let BufferRange, W (b) _i ,b _j )、T _e1 (b _s )、T _n1 (b _s ) A value of 0; wherein BufferRange (b) _i ) Representing task b _i Is a maximum buffer time zone of (a); b represents a library set, T represents a transition set, F represents a relationship set, M ₀ Representing an initial mark; f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ )…q(r _i )>Representing that task x uses a limited number of resources { r _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); alpha represents the minimum execution time function for task completion; beta represents the maximum execution time function of task completion; t (T) _e1 (b _s ) Indicating that all tasks are completed with their minimum execution time, task b _s Is the earliest start time of (2); t (T) _n1 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _s Is the latest start time of (a); conflictSet represents the set of resource conflicts detected in step 4);

5.2.2 When meeting(s)At the time, calculate T _e1 (b _i ),T _n1 (b _i ),T _e1 (b _j ),T _n1 (b _j ),W(b _i ,b _j ),W(b _j ,b _i ) Is a value of (2); t (T) _e1 (b _i ) Indicating that task b is completed with its minimum execution time _i Is set to the ideal earliest start time of (a); t (T) _n1 (b _i ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _i Is the latest start time of (a); t (T) _e1 (b _j ) Indicating that task b is completed with its minimum execution time _j Is set to the ideal earliest start time of (a); t (T) _n1 (b _j ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _j Is the latest start time of (a);

5.2.3 Will T) _n1 (b _i )-T _e1 (b _i ) Set as BufferRange (b) _i ) The method comprises the steps of carrying out a first treatment on the surface of the Will T _n1 (b _j )-T _e1 (b _j ) Set as BufferRange (b) _j )；

5.2.4 If W (b) _i ,b _j )-BufferRange(b _i ) Greater than or equal to W (b) _j ,b _i )-BufferRange(b _j ) Will b _i Add to PrioritiyActivitySet, otherwise, will b _j Adding the obtained product into PrioritiyActivitySet to obtain final PrioritiyActivitySet;

the resource conflict mentioned in this step means that in ERP-Net,b _j ∈B _A (b _i ≠b _j )，B _A is a task set of the emergency disposal procedure of the chemical leakage event, < +.>Representation b _i And b _j There is a potential resource conflict, and the conditions need to be satisfied: b _i Θb _j ；[T _start (b _i ),T _end (b _i )]And [ T ] _start (b _j ),T _end (b _j )]With overlap, T _start (b _i ) And T _end (b _i ) Respectively represent task b _i True start and end time, T _start (b _j ) And T _end (b _j ) Respectively represent task b _j Real start and end times;

the ERP-Net described in the above definition is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

The definition of the preamble referred to in the above is as follows: for any one xE.B.U.T, yE.B.U.T, B represents the library set, T represents the transition set, F represents the relation set, ^· x= { y|y∈b u T ∈Λ (y, x) ∈f } represents the front set of x.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention provides formalized description of the emergency treatment flow of the chemical leakage event constrained by resources and uncertainty time for the first time, which is beneficial to acquiring task information and resource information required by modeling the emergency treatment flow of the chemical leakage event;

2. the ERP-Net based on the Petri network is provided for the first time, so that formal modeling of the emergency treatment flow of the chemical leakage event is facilitated;

3. The invention provides a calculation method of ideal execution time of an ERP-Net-based chemical leakage event emergency treatment process for the first time, obtains a specific time value, and is favorable for analyzing the time performance of the chemical leakage event emergency treatment process;

4. the invention provides a method for detecting the resource conflict for the first time, which is beneficial to analyzing the resource conflict condition of the emergency disposal flow of the chemical leakage event in the actual process;

5. the invention provides a conflict resolution strategy for the first time, the actual execution time of the process is calculated based on the strategy, and the proposal of the strategy is favorable for analyzing the time performance of the emergency disposal process of the chemical leakage event under the actual condition;

6. the method has wide application space in modeling of the emergency treatment process model of the chemical leakage event, and has wide prospect in modeling of the emergency treatment process model of the chemical leakage event of the emergency event and time performance analysis.

Drawings

FIG. 1 is a schematic diagram of a logic flow of the present invention.

FIG. 2 is a diagram of an ERP-Net model for a single task.

FIG. 3 is a diagram of an ERP-Net model for two sequential tasks.

FIG. 4 is an ERP-Net model diagram of two concurrent tasks.

FIG. 5 is a diagram of an ERP-Net model for three task without front set.

FIG. 6 is a diagram of three ERP-Net models without a post-set task.

FIG. 7 is an ERP-Net model diagram of a chlorine leak disposal flow.

Detailed Description

The invention will be further illustrated with reference to specific examples.

As shown in fig. 1, the method for analyzing the performance of the chemical leakage event emergency treatment process based on the Petri Net provided in the embodiment firstly obtains a formal description of the chemical leakage event emergency treatment process, then converts the chemical leakage event emergency treatment process into ERP-Net, and finally analyzes the time performance of the chemical leakage event emergency treatment process based on the obtained ERP-Net, which includes the following steps:

1) Analyzing emergency tasks related to the emergency treatment process of the chemical leakage event and associated time information and resource information; the emergency tasks and associated time and resource information involved in the chemical leak event emergency treatment process are formally descriptive of a resource and uncertain time constrained chemical leak event emergency treatment process, comprising<Activity,Resource,Time,Relation,f _AR ,F _TT >The method comprises the following steps: (1) activity defines all tasks involved in a chemical leak event emergency disposal procedure; (2) resource defines all resources required in the chemical leak event emergency disposal procedure; (3) time defines the Time constraint of the task; any one task Activity in all task set activities, if the actual execution time is Atime, then Atime must satisfy 0 or more, and f _n (activity)≤Atime≤f _u (activity), wherein f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; (4) is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (2); (5) f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ )…q(r _i )>Representing that task x uses a limited number of resources { r ₁ ,r ₂ ,…,,r _i Number of }Vector, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); (6) f (F) _TT ＝{f _n ,f _u The time function of the task is, for any one task activity, f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; />Activity∪Resource，f _n (activity)≤f _u (activity)。

Analysis is performed herein in connection with a chemical leakage event emergency disposal procedure for a chlorine tank leakage, the main tasks in this emergency disposal procedure being rescue of injured personnel and treatment of the leaked chlorine, the tasks and resources involved in the procedure being described as follows:

A ₁ : monitoring personnel to monitor casualties; a is that ₂ : monitoring personnel and emergency personnel monitor the chlorine leakage condition; a is that ₃ : medical staff rush to the site with medicines, such as sodium bicarbonate solution, medical oxygen and the like; a is that ₄ : emergency personnel dispose of the leaked chlorine gas; a is that ₅ : rescue of the light injured person; a is that ₆ : rescue of severely injured people; a is that ₇ : assessing an emergency treatment flow; a is that ₈ : post treatment of emergency flow treatment;

r ₁ : monitoring personnel; r is (r) ₂ : monitoring; r is (r) ₃ : sodium bicarbonate solution; r is (r) ₄ : medical oxygen; r is (r) ₅ : emergency personnel;

table 1 depicts task information for a chlorine tank leaked chemical leak event emergency disposal procedure, including time constraints, inter-task relationships, resource requirements, and the like. Table 2 presents resource information, including the number of resources available in the flow, as explained below for tables 1 and 2:

(1) the chlorine tank leakage disposal flow involves 8 tasks, noted activity= { a _i I1.ltoreq.i.ltoreq. 8,i is a positive integer }, A according to Table 1 ₁ Is A ₃ Preamble task (or A) ₃ Is A ₁ Subsequent tasks of (a)；

(2) The Resource set involved in the emergency treatment process is denoted as resource= { r _j 1.ltoreq.j.ltoreq. 5,j is a positive integer, according to Table 1, A ₁ And A ₂ All require reusable resources r ₁ . That is, r ₁ From A ₁ And A ₂ Sharing, at the same time r ₁ Available less than A ₁ And A ₂ The sum of the required amounts, thus, if A ₁ And A ₂ Simultaneous execution may have resource conflicts;

③ERP＝<Activity,Resource,Time,Relation,f _AR ,F _TT >wherein: for any task, a time function f _n Representing a minimum execution time, another time function f _u Represents the maximum execution time, f _n (A ₁ ) =10 and f _u (A ₁ ) =12 represents a ₁ The minimum and maximum execution times of (1) are 10 and 12 time units, respectively.

TABLE 1 task information for chemical leakage event Emergency handling procedure for chlorine tank leakage

Activity	f _n	fu	Pre-Activity	f _AR ＝<r ₁ ,r ₂ ,r ₃ ,r ₄ ,r ₅ >
					A ₁	10	12	Null	<8,4,0,0,0>
A ₂	3	7	Null	<12,8,0,0,5>
					A ₃	15	20	{A ₁ }	<0,0,30,20,0>
A ₄	10	15	{A ₂ }	<0,0,0,0,0>
					A ₅	5	15	{A ₃ }	<0,0,0,0,0>
A ₆	10	20	{A ₃ }	<0,0,0,0,0>
					A ₇	10	18	{A ₄ }	<0,0,0,0,4>
A ₈	1	2	{A ₅ ,A ₆ }	<0,0,0,0,0>

TABLE 2 Emergency treatment Process resource information for chemical leakage event for chlorine tank leakage

Resource	Quantity
		r ₁	14
r ₂	10
		r ₃	30
r ₄	20
		r ₅	5

2) Combining the emergency tasks related to the emergency treatment process of the chemical leakage event in the step 1) with associated time information and resource information, and formally modeling the emergency treatment process of the whole chemical leakage event; first define ERP-Net model of single task as shown in FIG. 2, library b _i Representing task A _i Transition t _i1 And t _i2 Representing task A _i Is to be added to the start and end of (c). If b _i Contains a token indicating that a task is being executed; resource function χ (b) _i ) And a time function alpha (b _i )、β(b _i ) Marked at b _i Applying; combining the case of the emergency treatment process of the chemical leakage event leaked from the chlorine tank, the specific steps of the ERP-Net model of the emergency treatment process of the chemical leakage event leaked from the whole chlorine tank are as follows:

2.3 Adding a transition connection order task; if task b _i Is task b _j Front collection task of (1) satisfiesTransition t _ij Added to b _i And b _j The middle is used for connecting two sequential tasks; as shown in fig. 3, transition t _ij Representing task b _i End and task b _j Is started by (1);

2.4 Adding a start transition and an end transition for a plurality of parallel tasks; if task b _i And task b _j Can be executed concurrently, and add transition t _i And transition t _j To represent b _i And b _j As shown in fig. 4;

2.5 Adding a starting library and starting transition for tasks without a front set; as shown in FIG. 5, three ERP-Net without front set tasks, where b _s Is the starting warehouse, t _s Is b _i 、b _j And b _k Is a start transition of (1); the starting transition to merge tasks without a front set is t _s Then add to the starting library b _s Start transition t _s Satisfy the following requirements ^· t _s ＝{b _s }，t _s ^· ＝{b _i |b _i No front set task }, b _i Is a task in a task set, and starts the library b _s Satisfy the following requirementsb _s ^· ＝{t _s -a }; wherein the method comprises the steps of ^· t _s Representing t _s Front set of t _s ^· Representing t _s Is used for the collection of the rear set of the (c), ^· b _s representation b _s Front set of (b) _s ^· Representation b _s Is a post-set of (2);

2.6 Adding an ending library and ending transition for tasks without a postset; as shown in FIG. 6, three ERP-Net without post-set tasks, where b _e Is the end warehouse, t _e Is b _i 、b _j And b _k Ending transition of (2); the end transition of merging tasks without a post-set is t _e Then add to the end pool b _e Ending transition t _e Satisfy the following requirements ^· t _e ＝{b _i |b _i No post-set task }, t _e ^· ＝{b _e }，b _i Is a task in a task set, and ends the library b _e Satisfy the following requirements ^· b _e ＝{t _e }，Wherein the method comprises the steps of ^· t _e Representing t _e Front set of t _e ^· Representing t _e Is used for the collection of the rear set of the (c), ^· b _e representation b _e Front set of (b) _e ^· Representation b _e Is a post-set of (2);

2.7 Will start library b) _s Adding initial identifier M of ERP-Net ₀ The method meets the following conditions: if pool b is the starting pool, M ₀ (b) =1, otherwise M ₀ (b) =0, the final output ERP-Net is shown in fig. 7.

In this step, ERP-Net is a 7-tuple, ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e },B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A Any of the followingMeaning a task b, β (b) is greater than or equal to 0, and satisfies β (b) is greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

the emergency tasks and associated time and resource information involved in the chemical leak event emergency treatment procedure referred to above are formalized descriptions of a resource and uncertain time constrained chemical leak event emergency treatment procedure, comprising<Activity,Resource,Time,Relation,f _AR ,F _TT >The method comprises the following steps: (1) activity defines all tasks involved in a chemical leak event emergency disposal procedure; (2) resource defines all resources required in the chemical leak event emergency disposal procedure; (3) time defines the Time constraint of the task; any one task Activity in all task set activities, if the actual execution time is Atime, then Atime must satisfy 0 or more, and f _n (activity)≤Atime≤f _u (activity), wherein f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; (4) Is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (2); (5) f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ )…q(r _i )>Representing that task x uses a limited number of resources { r _1, r _2,…, ,r _i Number vector of }, r _i Representing the last resource of the limited number of resources,q(r _i ) Representing task x using resource r _i Is the number of (3); (6) f (F) _TT ＝{f _n ,f _u The time function of the task is, for any one task activity, f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; />Activity∪Resource，f _n (activity)≤f _u (activity)。

The definition of the front and rear sets involved in this step is as follows: for any one xE.B.U.T, yE.B.U.T, B represents the library set, T represents the transition set, F represents the relation set, ^· x= { y|y∈b u T Λ (y, x) ∈f } represents the front set of x; x is x ^· = { y|y∈b u T ∈Λ (x, y) ∈f } represents the postamble of x.

And the initiation rules of ERP-Net are the same as those of the traditional Petri network: if the flag is M, any one of the transitions T in the transition set T, if ^· All b in t are marked 1 or more, then t can be initiated, where ^· t represents a front set of t; but note that in ERP-Net, libraries are used to represent tasks; the number of resources is expressed as one attribute of the task (library); the task has two time functions, representing a minimum execution time and a maximum execution time, respectively.

3) Under the condition of not considering resource factors, based on an ERP-Net model of the obtained emergency treatment process of the chemical leakage event of the chlorine tank leakage, the time performance of the emergency treatment process of the chemical leakage event of the whole chlorine tank leakage is analyzed, and the ideal execution time of the emergency treatment process of the chemical leakage event of the chlorine tank leakage is obtained in the case as follows:

3.1 Calculating the earliest start time of task b when all tasks are completed with their minimum execution time and maximum execution time, respectively.

a. If all tasks are completed with their minimum execution time, the earliest start time of task b is denoted by T _e1 (b) Indicating that if b is the start pool b _s T is then _e1 (b) =0, otherwise T _e1 (b)＝max{T _e1 (b’)+α(b’)|b’∈ ^· ( ^· b) -a }; wherein the method comprises the steps of ^· ( ^· b) A (b ') represents the minimum execution time value for b' to complete;

b. if all tasks are completed with their maximum execution time, the earliest start time of task b is denoted by T _e2 (b) Indicating that if b is the start pool b _s T is then _e2 (b) =0, otherwise T _e2 (b)＝max{T _e2 (b’)+β(b’)|b’∈ ^· ( ^· b) -a }; wherein the method comprises the steps of ^· ( ^· b) A front set representing a front set of b, β (b ') representing a maximum execution time value for b' to complete;

a. to ensureThe security flow can be at T _E1 Completion in time, the latest start time of task b is T _n1 (b) Indicating that if b is the end pool b _e T is then _n1 (b) The ideal execution time of the flow when the task is completed with the minimum execution time, otherwise T _n1 (b)＝min{T _n1 (b’)-α(b)|b’∈(b ^· ) ^· -a }; wherein b' is a member belonging to the group (b) ^· ) ^· ，(b ^· ) ^· A post-set representing a post-set of b, α (b) representing a minimum execution time value for completion of task b;

b. to ensure that the flow can be at T _E2 Completion in time, the latest start time of task b is T _n2 (b) Indicating that if b is the end pool b _e T is then _n2 (b) The ideal execution time of the flow when the task is completed with the maximum execution time, otherwise T _n2 (b)＝min{T _n2 (b’)-β(b)|b’∈(b ^· ) ^· -a }; wherein b' is a member belonging to the group (b) ^· ) ^· ，(b ^· ) ^· A post-set representing a post-set of b, β (b) representing a maximum execution time value for completion of task b;

the ERP-Net in this step is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b usageResource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

In combination with the case of emergency treatment flow of chemical leakage event of chlorine tank leakage, the tasks in FIG. 7 are solved for T respectively _e1 (b)，T _e2 (b)，T _n1 (b) And T _n2 (b) As shown in table 3:

TABLE 3T _e1 (b),T _e2 (b),T _n1 (b),T _n2 (b)

activity	A ₁	A ₂	A ₃	A ₄	A ₅	A ₆	A ₇	A ₈	b _e
										T _e1 (b)	0	0	10	3	25	25	13	35	36
T _e2 (b)	0	0	12	7	32	32	22	52	54
										T _n1 (b)	0	13	10	16	30	25	26	35	36
T _n2 (b)	0	15	12	22	37	32	36	52	54

According to Table 3, the ideal execution time for a chemical leak event emergency disposal procedure that can result in a chlorine tank leak is 36 time units.

4) The ideal execution time of the chemical leakage event emergency disposal procedure has been obtained in step 3) without taking resource factors into consideration; however, in the chemical processDuring the execution of the emergency disposal flow of the leakage event of the chemicals, the resource conflict exists, wherein the resource conflict refers to the situation that in ERP-Net,b _j ∈B _A (b _i ≠b _j )，B _A is a task set of the emergency disposal procedure of the chemical leakage event, < +.>Representation b _i And b _j There is a potential resource conflict, and the conditions need to be satisfied: b _i Θb _j ；[T _start (b _i ),T _end (b _i )]And [ T ] _start (b _j ),T _end (b _j )]With overlap, T _start (b _i ) And T _end (b _i ) Respectively represent task b _i True start and end time, T _start (b _j ) And T _end (b _j ) Respectively represent task b _j True start and end times.

B referred to in definition of resource conflict above _i Θb _j Representation b _i And b _j There is a resource dependency, defined as follows: in the case of an ERP-Net,b _j ∈B _A (b _i ≠b _j )，b _i Θb _j representation b _i And b _j Resource dependence exists, and the conditions need to be satisfied: χ (b) _i ) ^T ·χ(b _j ) Not equal to 0; wherein χ (b) _i ) ^T Representing task b _i Transpose of resource attribute function vector, χ (b) _j ) Representation b _j Is a resource attribute function vector of (1).

The ERP-Net described in the above definition is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing the attribute of the task resource, α is a function representing the taskThe minimum execution time function completed, β is the maximum execution time function representing the completion of a task, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ )…q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, ,r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

4.1 Using ERP-Net as input, initializing Conflictset to make Conflictset be empty set, T _e1 (b _s )、T _n1 (b _s )、T _e2 (b _s )、T _n2 (b _s ) The value of (2) is 0; wherein T is _e1 (b _s ) Indicating that all tasks are completed with their minimum execution time, task b _s Is the earliest start time of (2); t (T) _n1 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _s Is the latest start time of (a); t (T) _e2 (b _s ) Representing task b when all tasks are completed at their maximum execution time _s Is the earliest start time of (2); t (T) _n2 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the maximum execution time, task b _s Is the latest start time of (a);

4.3 Detecting whether task execution intervals with resource dependence overlap; if Conflictset+.0, then there is a resource conflict task for any two of Conflictset (b _i ,b _j ) Calculate T _e1 (b _i )、T _e2 (b _i )、T _e1 (b _j )、T _e2 (b _j ) Is a value of (2); if [ T ] _e1 (b _i ),T _e2 (b _i )+β(b _i )]∩[T _e1 (b _j ),T _e2 (b _j )+β(b _j )]Not equal to 0, then step 4.3) is performed again, otherwise, the two tasks (b) with resource conflict are removed in the obtained Conflictset _i ,b _j ) Finally, a ConflictSet of a chemical leakage event emergency disposal flow resource conflict set is obtained; wherein beta (b) _i ) Representing task b _i The maximum execution time function value completed;

in combination with the case of emergency treatment process of chemical leakage event of chlorine tank leakage, based on the steps, A can be obtained ₁ And A ₂ There is a potential resource conflict. Due to A ₁ Requiring 8 monitoring personnel, A ₂ 12 monitoring personnel are needed, and the total number of the monitoring personnel is 14, so that resource conflict can occur in the process of executing the flow; if the total number of inspectors exceeds 20, the conflict does not occur; if the total number of inspectors is less than 8, the whole emergency treatment process cannot be completed normally due to shortage of inspectors.

5) Based on the detection of resource conflict in the execution process of the emergency treatment process of the chemical leakage event in the step 4), a conflict resolution strategy based on task priority is provided and is called a task priority strategy; the task priority policy is defined as follows: suppose b _i Θb _j If b _i ∈PriorityActivitySet,b _j PriorityActivitySet，b _i Higher priority than b _j The method comprises the steps of carrying out a first treatment on the surface of the That is, task b _i Without waiting for task b _j Execution completion may be performed while task b _j Must wait for task b _i The execution can be performed after the execution is completed and the occupied resources are released; the PrioritiyActivitySet represents a priority set task; analyzing the time performance of the emergency treatment process of the chemical leakage event after the task priority strategy is applied;

a. when all tasks in the process are completed with the minimum execution time, the real earliest starting time of the task b is E ₁ (b) Indicating that if task b is the start pool b _s Then E ₁ (b) =0, otherwiseWherein (1)> Representing b and b ₁ There is a potential resource conflict, b ₁ Is a task with potential resource conflict with b, T _e1 (b) Represents the ideal earliest start time, W, of task b when all tasks are completed at their minimum execution time ₁ (b,b ₁ ) Is when b and b ₁ Task b waits for task b when it is completed with minimum execution time ₁ Releasing the waiting time of the occupied resources;

the above W ₁ (b,b ₁ ) The calculation method of (2) is as follows: if T _e1 (b ₁ )+α(b ₁ ) Less than or equal to T _e1 (b) W is then ₁ (b,b ₁ ) =0, otherwise W ₁ (b,b ₁ )＝T _e1 (b ₁ )+α(b ₁ )-T _e1 (b) The method comprises the steps of carrying out a first treatment on the surface of the Wherein T is _e1 (b ₁ ) Indicating that task b is completed with its minimum execution time ₁ Is set to the ideal earliest start time of (a); alpha (b) ₁ ) Is task b ₁ And E ₁ (b _e ) Is the shortest execution time for the entire chemical leak event emergency disposal procedure.

the above W ₂ (b,b ₁ ) The calculation method of (2) is as follows: if T _e2 (b ₁ )+β(b ₁ ) Less than or equal to T _e2 (b ₁ ) W is then ₂ (b,b ₁ ) =0, otherwise W ₂ (b,b ₁ )＝T _e2 (b ₁ )+β(b ₁ )-T _e2 (b) The method comprises the steps of carrying out a first treatment on the surface of the Wherein T is _e2 (b ₁ ) Indicating that task b is completed at its maximum execution time ₁ Is set to the ideal earliest start time of (a); beta (b) ₁ ) Is task b ₁ Is performed at a maximum execution time of (a).

Any one task b, E in the task set ₁ (b) And E is ₂ (b) The earliest start time of b when the task is completed with minimum and maximum execution times, respectively, E ₁ (b) Less than or equal to E ₂ (b)。

5.1.2 Calculating the real latest starting time of the task; when the task is completed with minimum execution time and maximum execution time, the real execution time of the flow is respectively used as TF ₁ And TF (TF) ₂ Represented, and TF ₁ ＝E ₁ (b _e ) And TF (TF) ₂ ＝E ₂ (b _e ) Wherein b _e Representing an ending library; e (E) ₁ (b _e ) Representing the shortest execution time of the whole chemical leak event emergency disposal procedure when all tasks in the procedure are completed with their minimum execution time; e (E) ₂ (b _e ) Representing the shortest execution time of the entire chemical leak event emergency disposal procedure when all tasks in the procedure are completed at their maximum execution time.

b. to ensure that the flow can be at TF ₂ Completion in time, the latest start time of task b is L ₂ (b) Indicating that if task b is the end pool b _e L is then ₂ (b)＝E ₂ (b) Otherwise L ₂ (b)＝min{L ₂ (b’)-β(b)|b’∈(b ^· ) ^· -a }; wherein E is ₂ (b) Represents the real earliest start time of task b when all tasks in the flow are completed with their maximum execution time, β (b) represents the minimum execution time of task b, (b) ^· ) ^· A back set representing the back set of b;

5.2.2 When meeting(s)At the time, calculate T _e1 (b _i ),T _n1 (b _i ),T _e1 (b _j ),T _n1 (b _j ),W(b _i ,b _j ),W(b _j ,b _i ) Is a value of (2); t (T) _e1 (b _i ) Indicating that task b is completed with its minimum execution time _i Is set to the ideal earliest start time of (a); t (T) _n1 (b _i ) Representation ensures that the process can be completed at the minimum execution time of the taskCompleting the process in ideal execution time, task b _i Is the latest start time of (a); t (T) _e1 (b _j ) Indicating that task b is completed with its minimum execution time _j Is set to the ideal earliest start time of (a); t (T) _n1 (b _j ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _j Is the latest start time of (a);

case of emergency treatment flow of chemical leakage event combined with chlorine tank leakage, priority task set PrioritiyActivitySet= { A ₁ Based on task priority policy, solve its E for the tasks in FIG. 7, respectively ₁ (b)，E ₂ (b)，L ₁ (b) And L ₂ (b) As shown in table 4;

table 4E ₁ (b)，E ₂ (b)，L ₁ (b) And L ₂ (b)

activity	A ₁	A ₂	A ₃	A ₄	A ₅	A ₆	A ₇	A ₈	b _e
										W ₁ (b,b _i )	0	10	0	0	0	0	0	0	0
E ₁ (b)	0	10	10	13	25	25	23	35	36
										W ₂ (b,b _i )	0	12	0	0	0	0	0	0	0
E ₂ (b)	0	12	12	22	32	32	37	52	54
										L ₁ (b)	0	13	10	16	30	25	26	35	36
L ₂ (b)	0	15	12	22	37	32	36	52	54

As can be seen from comparison of table 3, the execution time of the emergency treatment process time of the chemical leakage event corresponding to the leakage of the chlorine tank is consistent with the ideal execution time, so that it can be explained to a certain extent that the task priority strategy can effectively eliminate resource conflict and optimize the overall time performance of the process.

In summary, after the scheme is adopted, the invention provides a new method for the time performance analysis of the chemical leakage event emergency disposal process based on the Petri net, the chemical leakage event emergency disposal process is modeled and analyzed from the aspects of resources and time by using a formalized method while considering the uncertain execution time and the quantity of the resources of the task, a detection method for resource conflict and a strategy for eliminating the resource conflict are provided, and the development of the chemical leakage event emergency disposal process modeling and time performance analysis method is effectively promoted, so that the method has practical application value and is worthy of popularization.

The above embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, so variations in shape and principles of the present invention should be covered.

Claims

1. The Petri net-based chemical leakage event emergency disposal flow performance analysis method is characterized by comprising the following steps of:

2) The method comprises the steps of formally modeling the whole emergency treatment process of the chemical leakage event based on a Petri network to obtain a Petri network model of the emergency treatment process of the chemical leakage event, which is an ERP-Net; the ERP-Net is a 7-tuple, ERP-Net= (B, T; F, M) ₀ χ, α, β), whereinB represents a library set, T represents a transition set, F represents a relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e },B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

4) Under the condition of considering resource factors, a detection algorithm of potential resource conflict is provided, and for the resource conflict existing in the emergency treatment flow of the chemical leakage event, the resource conflict is represented by ConflictSet, the specific steps of the detection algorithm of potential resource conflict are as follows:

4.1 Using ERP-Net as input, initializing Conflictset to make Conflictset be empty set，T _e1 (b _s )、T _n1 (b _s )、T _e2 (b _s )、T _n2 (b _s ) The value of (2) is 0; wherein T is _e1 (b _s ) Representing task b when all tasks are completed with their minimum execution time _s Is the earliest start time of (2); t (T) _n1 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _s Is the latest start time of (a); t (T) _e2 (b _s ) Representing task b when all tasks are completed at their maximum execution time _s Is the earliest start time of (2); t (T) _n2 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the maximum execution time, task b _s Is the latest start time of (a);

4.2 Detecting resource dependencies between tasks; when the condition is satisfiedTime B _A Is a task set of emergency treatment process of chemical leakage event, and is called χ (b) _i ) ^T ·χ(b _j ) If χ (b) _i ) ^T ·χ(b _j ) Not equal to 0, then (b) _i ,b _j ) There is a resource conflict, join in ConflictSet (b _i ,b _j ) The method comprises the steps of carrying out a first treatment on the surface of the Wherein χ (b) _i ) ^T Representing task b _i Transpose of resource attribute function vector, χ (b) _j ) Representation b _j Is a resource attribute function vector of (1);

4.3 Detecting whether task execution intervals with resource dependence overlap; if Conflictset+.0, then there is a resource conflict task for any two of Conflictset (b _i ,b _j ) Calculate T _e1 (b _i )、T _e2 (b _i )、T _e1 (b _j )、T _e2 (b _j ) Is a value of (2); if [ T ] _e1 (b _i ),T _e2 (b _i )+β(b _i )]∩[T _e1 (b _j ),T _e2 (b _j )+β(b _j )]Not equal to 0), step 4.3) is performed again, otherwise, the two existing assets are removed from the resulting ConflictSetTask of Source conflict (b _i ,b _j ) Finally, a ConflictSet of a chemical leakage event emergency disposal flow resource conflict set is obtained; wherein beta (b) _i ) Representing task b _i The maximum execution time function value completed;

5) Based on the detection of resource conflict in the execution process of the emergency treatment process of the chemical leakage event in the step 4), a conflict resolution strategy based on task priority is provided, which is called a task priority strategy, and the definition of the task priority strategy is as follows: suppose b _i Θb _j If b _i ∈PriorityActivitySet,b _i Higher priority than b _j The method comprises the steps of carrying out a first treatment on the surface of the That is, task b _i Without waiting for task b _j Execution completion may be performed while task b _j Must wait for task b _i The execution can be performed after the execution is completed and the occupied resources are released; the PrioritiyActivitySet represents a priority set task; and analyzing the temporal performance of the chemical leakage event emergency disposal procedure after the strategy is applied;

In order to ensure that the whole emergency treatment process of the chemical leakage event is completed in the shortest time, the task priority strategy is utilized to resolve the resource conflict, and the specific steps of obtaining the priority task set through the task priority strategy are as follows:

5.2.1 With Conflictset conflict set and (B, T; f, M ₀ ,f _AR Alpha, beta) as input, and initializing PrioritiyActivitySet, let PrioritiyActivitySet be empty, let BufferRange, W (b) _i ,b _j )、T _e1 (b _s )、T _n1 (b _s ) A value of 0; wherein BufferRange (b) _i ) Representing task b _i Is a maximum buffer time zone of (a); b represents a library set, T represents a transition set, F represents a relationship set, M ₀ Representing an initial mark; f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing that task x uses a limited number of resources { r _1, r _2,…, r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); alpha represents the minimum execution time function for task completion; beta represents the maximum execution time function of task completion; t (T) _e1 (b _s ) Indicating that all tasks are completed with their minimum execution time, task b _s Is the earliest start time of (2); t (T) _n1 (b _s ) Representing a process ensuring that the process can be completed within the ideal execution time of the process when the task is completed with the minimum execution time, task b _s Is the latest start time of (a); conflictSet represents the set of resource conflicts detected in step 4);

the resource conflict mentioned in this step means that in ERP-Net,B _A is a task set of the emergency disposal procedure of the chemical leakage event, < +.>Representation b _i And b _j There is a potential resource conflict, and the conditions need to be satisfied: b _i Θb _j ；[T _start (b _i ),T _end (b _i )]And [ T ] _start (b _j ),T _end (b _j )]With overlap, T _start (b _i ) And T _end (b _i ) Respectively represent task b _i True start and end time, T _start (b _j ) And T _end (b _j ) Respectively represent task b _j Real start and end times;

b referred to in definition of resource conflict above _i Θb _j Representation b _i And b _j There is a resource dependency, defined as follows: in the case of an ERP-Net,b _i Θb _j representation b _i And b _j Resource dependence exists, and the conditions need to be satisfied: χ (b) _i ) ^T ·χ(b _j ) Not equal to 0; wherein χ (b) _i ) ^T Representing task b _i Transpose of resource attribute function vector, χ (b) _j ) Representation b _j Is a resource attribute function vector of (1);

the ERP-Net described in the above definition is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Represents an initial mark, χ is a representationThe function of the task resource attribute, alpha is the minimum execution time function representing the task completion, and beta is the maximum execution time function representing the task completion, satisfying the following conditions: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

2. The Petri net based chemical leakage event emergency disposal procedure performance analysis method of claim 1, wherein: in step 1), the emergency tasks and associated time and resource information involved in the chemical leak event emergency treatment process are formally described as resource and uncertain time constrained chemical leak event emergency treatment processes, comprising<Activity,Resource,Time,Relation,f _AR ,F _TT >The method comprises the following steps: (1) activity defines all tasks involved in a chemical leak event emergency disposal procedure; (2) resource defines all resources required in the chemical leak event emergency disposal procedure; (3) time defines the Time constraint of the task; any one task Activity in all task set activities, if the actual execution time is Atime, atime must satisfy 0 or more, and f _n (activity)≤Atime≤f _u (activity), wherein f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; (4)is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (2); (5) f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing any oneService x uses a limited number of resources { r _1, r _2,…, r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); (6) f (F) _TT ＝{f _n ,f _u The time function of the task is, for any one task activity, f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; /> f _n (activity)≤f _u (activity)。

3. The Petri net based chemical leakage event emergency disposal procedure performance analysis method of claim 1, wherein: in step 2), formally modeling the entire chemical leakage event contingency disposal procedure in combination with the contingency tasks involved in the chemical leakage event contingency disposal procedure in step 1) and the associated time information and resource information, the contingency tasks involved in the chemical leakage event contingency disposal procedure and the associated time information and resource information being formalized descriptions of the chemical leakage event contingency disposal procedure subject to resource and uncertainty time constraints, comprising <Activity,Resource,Time,Relation,f _AR ,F _TT >The method comprises the following steps: (1) activity defines all tasks involved in a chemical leak event emergency disposal procedure; (2) resource defines all resources required in the chemical leak event emergency disposal procedure; (3) time defines the Time constraint of the task; any one task Activity in all task set activities, if the actual execution time is Atime, then Atime must satisfy 0 or more, and f _n (activity)≤Atime≤f _u (activity), wherein f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete; (4)is a relation set representing the connection relation between tasks; any two task activities in all task set activities ₁ And activity of ₂ If (activity) ₁ ,activity ₂ ) E Relation, representing activity ₁ Is activity of ₂ Preamble task or activity ₂ Is activity of ₁ Subsequent tasks of (2); (5) f (f) _AR Is a function representing the resource attribute of a task, and any one of the tasks x, f _AR (x)＝<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing that task x uses a limited number of resources { r _1, r _2,…, r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task x using resource r _i Is the number of (3); (6) f (F) _TT ＝{f _n ,f _u The time function of the task is, for any one task activity, f _n (activity) represents the minimum time for task activity to complete, f _u (activity) represents the maximum time for task activity to complete;f _n (activity)≤f _u (activity)；

and the initiation rules of ERP-Net are the same as those of the traditional Petri network: if the flag is M, any one of the transitions T in the transition set T, if ^· All b in t are marked with a value greater than or equal to 1, then t can be initiated, wherein ^· t represents a front set of t; but note that in ERP-Net, libraries are used to represent tasks; the number of resources is expressed as an attribute of the task, i.e., the library; the tasks have two timesA space function which respectively represents a minimum execution time and a maximum execution time;

2.6 Adding an ending library and ending transition for tasks without a postset; the end transition of merging tasks without a post-set is t _e Then add to the end pool b _e Ending transition t _e Satisfy the following requirements ^· t _e ＝{b _i |b _i No post-set task }, t _e ^· ＝{b _e }，b _i Is one of the set of tasks,end warehouse b _e Satisfy the following requirements ^· b _e ＝{t _e }，Wherein the method comprises the steps of ^· t _e Representing t _e Front set of t _e ^· Representing t _e Is used for the collection of the rear set of the (c), ^· b _e representation b _e Front set of (b) _e ^· Representation b _e Is a post-set of (2);

4. The Petri net based chemical leakage event emergency disposal procedure performance analysis method of claim 1, wherein: in step 3), without considering resource factors, based on the ERP-Net of the obtained chemical leakage event emergency treatment process, the time performance of the whole chemical leakage event emergency treatment process is analyzed, and then the specific steps of the ideal execution time of the chemical leakage event emergency treatment process are as follows:

to ensureThe security flow can be at T _E2 Completion in time, the latest start time of task b is T _n2 (b) Indicating that if b is the end pool b _e T is then _n2 (b) The ideal execution time of the flow when the task is completed with the maximum execution time, otherwise T _n2 (b)＝min{T _n2 (b’)-β(b)|b’∈(b ^· ) ^· -a }; wherein b' is a member belonging to the group (b) ^· ) ^· ，(b ^· ) ^· A post-set representing a post-set of b, β (b) representing a maximum execution time value for completion of task b;

the ERP-Net in this step is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, r _i Number vector of }, r _i Represents the last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

the Petri net mentioned in the above is a four-tuple, Σ= (B, T; F, M) ₀ ) B represents a library set, T represents a transition set, F represents a relationship set, M ₀ Representing the initial mark, satisfying the condition: library set B is a finite set of libraries; the transition set T is a finite set of transitions;is a set of directed arcs, called a flow relationship; initial marking M of each library ₀ Taking {0,1,2, … }; />

5. The Petri net based chemical leakage event emergency disposal procedure performance analysis method of claim 1, wherein: in step 4), without taking into account resource factors, the ideal execution time of the chemical leak event emergency disposal procedure has been obtained in step 3); during execution of the chemical leak event emergency disposal procedure, however, resource conflicts exist, which are referred to in ERP-Net,B _A is a task set of the emergency disposal procedure of the chemical leakage event, < +.>Representation b _i And b _j There is a potential resource conflict, which needs to be satisfiedConditions are as follows: b _i Θb _j ；[T _start (b _i ),T _end (b _i )]And [ T ] _start (b _j ),T _end (b _j )]With overlap, T _start (b _i ) And T _end (b _i ) Respectively represent task b _i True start and end time, T _start (b _j ) And T _end (b _j ) Respectively represent task b _j Real start and end times;

b referred to in definition of resource conflict above _i Θb _j Representation b _i And b _j There is a resource dependency, defined as follows: in the case of an ERP-Net, b _i Θb _j Representation b _i And b _j Resource dependence exists, and the conditions need to be satisfied: χ (b) _i ) ^T ·χ(b _j ) Not equal to 0; wherein χ (b) _i ) ^T Representing task b _i Transpose of resource attribute function vector, χ (b) _j ) Representation b _j Is a resource attribute function vector of (1);

the ERP-Net described in the above definition is a 7-tuple ERP-Net= (B, T; F, M) ₀ χ, α, β), wherein B represents the pool set, T represents the transition set, F represents the relationship set, M ₀ Representing an initial mark, χ is a function representing a task resource attribute, α is a minimum execution time function representing task completion, and β is a maximum execution time function representing task completion, satisfying the following condition: (1) (B, T; F, M) ₀ ) Is a Petri net; (2) b=b _A ∪{b _s ,b _e }，B _A Is the task set of the emergency disposal process of the chemical leakage event, b _s And b _e Respectively representing a start task and an end task; (3) χ is a function vector representing the attributes of task resources, where task set B _A Any one of tasks b, χ (b) =<q(r ₁ ),q(r ₂ ),…,q(r _i )>Representing task b using a limited number of resources { r } _1, r _2,…, r _i Number vector of }, r _i Representation ofThe last resource of the finite number of resources, q (r _i ) Representing task b using resource r _i Is the number of (3); (4) alpha is the minimum execution time function representing the completion of the task, satisfying task set B _A Alpha (b) is greater than or equal to 0; (5) beta is the maximum execution time function representing the completion of the task, satisfying task set B _A β (b) is greater than or equal to 0, and satisfies β (b) being greater than or equal to α (b); (6) any one of the libraries B, ifM is then ₀ (b) =1, otherwise M ₀ (b) =0, wherein ^· b represents a front set of b;

6. The Petri net based chemical leakage event emergency disposal procedure performance analysis method of claim 1, wherein: said step 5) comprises the steps of:

the above W ₁ (b,b ₁ ) The calculation method of (2) is as follows: if T _e1 (b ₁ )+α(b ₁ ) Less than or equal to T _e1 (b) W is then ₁ (b,b ₁ ) =0, otherwise W ₁ (b,b ₁ )＝T _e1 (b ₁ )+α(b ₁ )-T _e1 (b) The method comprises the steps of carrying out a first treatment on the surface of the Wherein T is _e1 (b ₁ ) Indicating that task b is completed with its minimum execution time ₁ Is set to the ideal earliest start time of (a); alpha (b) ₁ ) Is task b ₁ And E ₁ (b _e ) Is the shortest execution time for the whole chemical leak event emergency disposal procedure；

b. When all tasks in the process are completed with the maximum execution time, the real earliest starting time of the task b is E ₂ (b) Indicating that if task b is the start pool b _s Then E ₂ (b) =0, otherwiseWherein-> Representing b and b ₁ There is a potential resource conflict, b ₁ Is a task with potential resource conflict with b, T _e2 (b) Represents the ideal earliest start time, W, of task b when all tasks are completed at their maximum execution time ₂ (b,b ₁ ) Is when b and b ₁ Task b waits for task b when all are completed with maximum execution time ₁ Releasing the waiting time of the occupied resources;

b. to ensure that the flow can be at TF ₂ Completion in time, the latest start time of task b is L ₂ (b) Indicating that if task b is the end pool b _e L is then ₂ (b)＝E ₂ (b) Otherwise L ₂ (b)＝min{L ₂ (b’)-β(b)|b’∈(b ^· ) ^· -a }; wherein E is ₂ (b) Represents the earliest real start time of task b when all tasks in the flow are completed with their maximum execution time, β (b) represents the maximum execution time of task b, (b) ^· ) ^· Representing the postset of b.