Study On Multi-source Vehicle Scheduling For Dangerous Goods Transport In Time-varying Networks

With China’s industrial development entering a new era,assortments of dangerous goods is gradually diversification,and the demand is increasing.As the delivery carrier,vehicles bear huge risks.How to minimize the risk of dangerous goods transportation,reduce the transportation cost of transportation enterprises to the maximum extent,and optimize the scheduling of dangerous goods transportation vehicles is one of the focus of modern transportation needs to be studied.Based on time-varying network Multi-source points and charging strategy theory,from the perspective of government decision-making,dangerous goods time-varying network double optimization model is established.The upper objective function is to minimize the path transportation risk,the lower objective function is to minimize the path transportation cost,taking toll cost,road risk threshold,path risk threshold and node departure time as constraint conditions.Combined with the space-time safe distance theory of vehicle scheduling,dangerous goods vehicles scheduling double optimization model is established.The upper objective function is to minimize the total risk of the transportation network,and the lower objective function is to minimize the total cost of the transportation network,and taking the time interval of vehicle safety departure,traffic volume and customer time window as the constraint conditions under the time-varying network.On the basis of genetic algorithm,the unique memory function of tabu search algorithm is introduced into the search process,the tabu-genetic hybrid algorithm is constructed,and the crossover operator and mutation operator are recombined to improve the solving efficiency of algorithm.The example was solved for 10 times,and the optimal solution was obtained for 8 times.The running time of the program was about 5 minutes.Finally,taking two dangerous goods distribution companies as an example,they distribute fuel to 10 gas stations within the third ring road of Xi ’an,using MATLAB to solve the vehicle scheduling optimization model.The optimal scheduling scheme based on the lowest transportation risk and the optimal scheduling scheme based on the shortest transportation time are obtained by considering the government decision and the transportation enterprise decision.Compared with distribution enterprise original scheduling scheme,it shows that:the optimal vehicle scheduling scheme based on the lowest transportation risk reduces the total risk of transportation network by 27.64%,and the total cost of transportation network is reduced by 17.50%;the optimal vehicle scheduling scheme based on the shortest transportation time reduces the total risk of transportation network by8.07% and saves the total cost of transportation network by 23.43%.In addition,any two of the 17 transport vehicles participating in the distribution under the two optimization schemes meet the constraints of time-varying network vehicle safety departure time interval.As a result,the established model is scientific and reasonable,and the algorithm is correct and efficient.Multi-source dangerous goods transportation in time-varying network has strong applicability in practical distribution,which provides theoretical basis and practical guidance for the scheduling problem of dangerous goods transportation vehicles.