Research On Vehicle Scheduling In Open Pit Mine Based On Closed Queuing Theory

Open pit transportation system is a large-scale production system with mining as the center and trucks as the means of transportation.In order to realize the production plan indicators and task objectives,the organization and implementation of the production process are completed by means of the unified scheduling of mining equipment and transportation tools.Unreasonable truck shovel ratio will often cause trucks to pile up,increase the waiting time of electric shovels and trucks,make it difficult to give full play to the efficiency of mining and transportation equipment,and limit the improvement of economic benefits of open-pit mines.How to use the existing resource conditions to reasonably dispatch electric shovels and trucks and give full play to the efficiency of mining and transportation equipment is of great significance to improve the efficiency of mining enterprises.Firstly,this paper expounds the basic situation of vehicle scheduling system in open-pit mine,introduces the relevant queuing theoretical basis in vehicle scheduling in open-pit mine,and analyzes the regular distribution of truck arrival interval and shovel service time.According to the operation characteristics of open-pit transportation system and the content of this paper,the main evaluation indexes of open-pit queuing model are determined.The closed queuing network of open-pit mine with shovel as mining center and truck as transportation tool is constructed by using queuing theory.The loading,transportation and unloading in the transportation system are divided into four queuing subsystems,and the basic performance indexes of different queuing systems under steady-state conditions are analyzed.Based on the difference between the queuing models of waiting system and hybrid system,the ESUM algorithm is improved to calculate the relationship between the shift production capacity of the system and the number of vehicles.The simulation software is used to establish the fixed car allocation model of open-pit mine,and the results are tested to prove the calculation accuracy and applicability of the algorithm.In actual production,the equipment often breaks down and has randomness.In order to give full play to the equipment efficiency,this paper monitors and analyzes the status of key equipment through DHMM model.Since the state of key equipment cannot be observed directly,the fault data of key parts of equipment are mapped into observation sequence values to perceive the nature and characteristics of the state.An example is used to predict the operation state of electric shovel equipment,and the prediction results are evaluated.Finally,taking Anjialing Open Pit Mine as an example,the shovel truck stochastic dynamic programming model is established to minimize the total waiting time,transportation cost and total transportation volume of trucks.Monte Carlo method is used to randomly simulate the numerical range of real dynamic rate of key equipment,and calculate the optimal vehicle shovel ratio for vehicle scheduling.Based on the above analysis,the simulation model is used to test the results,and the results verify the effectiveness of this method for vehicle scheduling optimization.