车辆调度（Vehicle scheduling）W indows.Distribution vehicle scheduling should be carried out according to the principle of rationalization of distributionThats ok。 The principle of rationalization of distribution calls for timely, accurate and safe transportation,Economics。 To select the best with the short distance, fast speed, low costOrganize goods delivery by way of delivery. But we should also note that reasonable transportation is oneA relative concept. It is affected by many factorsThe current traffic conditions and possible, to develop a reasonable distribution meterMark. If only from the best route conditions, without considering the vehicleOther factors, such as energy and road conditions, may backfireTo the purpose of reasonable distribution.Vehicle operation often encounter some affiliated in the organizationUnforeseen problems, such as household demand change, loading and unloading machinesEquipment failure, vehicle running on the technical failure, temporaryBridge circuit breaker resistance and so on, which need to be targeted to analyze and reconcileNo. The dispatching department shall keep abreast of the status of goods supply, the condition of the car and the road condition,Climate change, the driver thought state, to ensure traffic safety.Line of work plan carried out smoothly. Specific functions are as follows: guarantee transportationFinish on time; understand the implementation of transportation task in timeEnter the transportation and related work in an orderly manner, to achieve minimum capacity investment;People.Exact algorithms generally use linear programming (includingBranch and bound method for gate processing, cut plane method and labeling method) and nonMathematical programming techniques, such as linear programming, are used to obtain the optimal problemSolution. In the early stage of VRP research, is the main source of single car some pies,Study how to use the shortest route (or in the shortest possible time) to a certain numberThe number of demand points for vehicle scheduling, and therefore the main use of accurate calculationThe optimal solution of the problem is obtained. Accurate algorithms generally have the followingMethods: Branch definition method, cut plane method, network flow algorithm and dynamic methodState programming method, etc. The exact algorithm follows the complexity and tuning of the distribution systemWith the increase of degree target, the computation amount increases exponentiallyThe exact optimal solution of a system is becoming more and more difficult and solved by computerThe time and cost of large optimization problems are too large, and hence the advantages of such optimizationsThe method is now generally used to solve the local optimization of distribution schedulingQuestion.In order to overcome the shortcomings of the exact optimization method, someThe rule of thumb reduces the mathematical accuracy of the optimization model and leads to excellenceThe tracking correction process is used to obtain the satisfactory solution of the transportation system. Heuristic methodThe algorithm can satisfy the needs of describing and solving problems in detailThe exact algorithm is more practical. The most representative of heuristic algorithmsThis is the savings method proposed by Clarke and Wright.At present, parallel algorithms are based on parallel computersGenetic algorithm, neural network theory and so onThere are some applications and developments in the VRP problem. Among them, taboo searchArtificial neural network, genetic algorithm, simulated annealing algorithm and artificial neural networkThe method is mainly applied to heuristic algorithms for solving and improvingThe category of hair shaping algorithms.In the above several modern optimization methods, the neural network methodIn the past few years relatively hot, but now has obviously cool down, because it onlyWith an anti propagation algorithm, it is difficult to develop ideas and letters from peopleInterest. But tabu search algorithm, simulated annealing algorithm and genetic algorithm are usedThe application of solving the problem of vehicle scheduling in logistics has just begun,Although some studies have been made, the potential remains to be further exploredDig.Then how to solve the vehicle scheduling problem in the ideal condition?We analyze it with a typical saving method.W ULIUL a few UNYUSHU NWhen the distribution center uses the same type of delivery vehicle (mainly loading)When the volume and volume are the same, the vehicle scheduling problem is called the ideal stateMathematical models can be established as follows:Distribution center: P, mark 0;The available vehicle sets are Q, k=l, M, and Q is the payloadThe amount of;User T, i=1, N, J