Research On Scheduling Optimization Of Mine Locomotive Based On Improved Timed Petri Net

The mine transportation dispatching and control system is a kind of typical discrete event dynamical system.With the rapid development of science and technology and economy,most coal mines now have more perfect "Signal Collection and Closed" system,however,the locomotive dispatching in mine is still subjective and manual.Although the manual dispatching is flexible,there are some problems such as high randomicity in selecting the locomotive route,easy occurrence of locomotive jam,complex and difficult control of locomotive task.The narrow laneway and the large number of locomotives in mines are the main reasons for the difficulty of dispatching.Mine transportation scheduling control is a typical NP hard problem.Petri net is a modeling and analysis tool for discrete systems.It can be used to simulate manufacturing an d scheduling processes in industry.Based on the research background of mine transportation scheduling and the research object of KJ654 Mine Locomotive Monitoring System,this paper presents the method of mine transportation optimal scheduling problem based on Petri Net.The main research contents are as follows:First of all,according to the operation characteristics of mine locomotive,this paper puts forward a half-delay timed transition which is suitable for the modeling of mine locomotive dispatching,improves the traditional modeling method,gives full play to the use efficiency of road section and reduces the task dispatching time;According to the incidence matrix and state equation of the locomotive scheduling Petri net model,the transition trigger vectors are obtained,the trigger times of each transition are calculated according to the constraint condition of the time optimal path;And then improve the restricted place and add it to the transitions according to the number of times the transitions is triggered,the minimum model complexity is obtained under the condition that the maximum limit of reachable graph state space is reached.Secondly,the reachable graph of the model added with the restricted place is obtained,and the optimal transition triggering path of the dispatching task is obtained by Dijkstra algorithm on the reachable graph;and the concurrent transition Gantt chart of the locomotive dispatching model is drawn by the concurrent transition Gantt chart algorithm,based on this,the state change table of locomotive dispatching is obtained,and then the route planning of mine locomotive is analyzed,and the dispatching strategy is summarized.Thirdly,according to the operation chart of a mine which is installed with KJ654 mine locomotive monitoring system,the Petri net model is built,and the simulation calculation is carried out by using the research algorithm in this paper,and the optimal running route and state changing table of different kinds of locomotives are obtained when they are running simultaneously.Finally,the research algorithm is applied to KJ654 mine locomotive monitoring system for simulation test,and the data from the dispatching process before and after referring the dispatching state change table is selected for comparison,and the dispatching time of referring to the dispatching state change table is less,the time allocation is more coordinated and free from subjective scheduling to a great extent,which proves the effectiveness of this method.