寒地稻谷干燥中心定位—路径问题研究

发布时间：2018-04-21 15:56

本文选题：寒地稻谷 + 干燥中心　；参考：《东北农业大学》2017年硕士论文

【摘要】：稻谷是我国主要粮食作物之一,其收获、干燥和加工等过程,都影响着稻谷的产量和品质。寒地稻谷主要以粳稻为主,种植在我国北方地区,有着日照时间短,生长周期长,耐寒等特点。因为粳稻最佳的干燥时间是在收获后的4-8小时,最晚不能超过8小时,否则会发生霉变。根据这个特点,为了保证寒地稻谷的品质和产量,建立寒地稻谷的干燥中心变得十分重要,而干燥中心的选址及稻谷运输车辆的路径优化则是首先要解决的问题。本文主要以满足寒地稻谷产后干燥的时限要求为出发点,探讨建立干燥中心的定位-路径问题,主要研究内容如下:(1)根据寒地稻谷最佳干燥时间是在收获后4-8小时,最晚不能超过8小时的特点,将干燥中心选址与配送路径问题综合分析研究,在传统的定位-路经问题模型上进行改进,对稻谷的干燥时间、运输车辆的最短路径及运输的总成本方面深入探讨,建立了多目标带时间窗的寒地稻谷干燥中心LRP模型。(2)在LRP问题求解方法上,应用启发式算法和智能优化算法相结合的两阶段法:1)在定位-配给问题(LAP)阶段,建立P-中值模型,应用贪婪取走启发式算法求解;2)在车辆-路线问题(VRP)阶段,考虑稻谷干燥时间约束及多个干燥中心等条件,建立带农户时间窗的多干燥中心车辆路径模型(MDVRPTW)。考虑到多干燥中心的复杂性,应用聚类分析将多个干燥中心配送车辆路径问题转换成多个相对简单的干燥中心配送车辆路径问题,结合模型特点,应用改进后的遗传算法—单点交叉多子代遗传算法,对最优的运输路线方案和最小成本进行求解。(3)实证分析。以五常市为研究对象,结合其地理位置、稻谷产量等相关数据,应用寒地稻谷干燥中心LRP模型及其算法进行求解。分别应用Excel软件中VBA程序,SPSS和MATLAB软件进行编程实现,得出干燥中心位置、车辆运输路线方案及运输的总成本,证明模型和解法的可行性和有效性。寒地稻谷干燥中心的建立可以有效的减少粮食在晾晒干燥过程中的损失,保证其品质和营养。应用启发式算法结合智能优化算法求解寒地稻谷干燥中心的LRP模型,在满足寒地稻谷时间约束的条件下进行选址并路径优化,有效的控制时间和物流成本,为实际的选址与路径优化问题提供重要参考依据。
[Abstract]:Rice is one of the main grain crops in China. Its harvest, drying and processing affect the yield and quality of rice. Japonica rice is the main rice in cold region, which is planted in the north of China. It has the characteristics of short sunshine time, long growth period and cold tolerance. Because the best drying time of japonica rice is 4-8 hours after harvest, the latest can not exceed 8 hours, otherwise mildew will occur. According to this characteristic, in order to guarantee the quality and yield of rice in cold region, it is very important to establish the drying center of rice in cold region, and the location of drying center and the route optimization of rice transportation vehicle are the first problems to be solved. Based on the time limit of post-partum drying of rice in cold region, this paper discusses the location-path problem of establishing drying center. The main contents are as follows: 1) according to the optimum drying time of rice in cold region is 4-8 hours after harvest. With the characteristic of no more than 8 hours at the latest, the comprehensive analysis and research on the location of the drying center and the route of distribution are carried out, and the traditional location-road problem model is improved to improve the drying time of the rice. In this paper, the shortest path of transportation vehicle and the total cost of transportation are discussed in depth, and the LRP model with multi-objective time window is established to solve the LRP problem. The two-stage method of combining heuristic algorithm and intelligent optimization algorithm: 1) in the phase of location-rationing problem (LAP), the P- median model is established, and the greedy heuristic algorithm is used to solve the problem of VRP2) in the stage of vehicle-route problem (VRP). Considering the constraints of rice drying time and several drying centers, the vehicle routing model of multi-drying center with farmer's time window was established. Considering the complexity of multiple drying centers, the distribution vehicle routing problem of multiple drying centers is transformed into several relatively simple distribution vehicle routing problems by cluster analysis, combining with the characteristics of the model. An improved genetic algorithm, single point crossover genetic algorithm, is used to solve the optimal transportation route scheme and minimum cost. Taking Wuchang city as an object of study, the LRP model and its algorithm were applied to solve the problem of rice drying center in cold region by combining the relevant data such as location and yield of rice. The VBA program and MATLAB software in Excel software are used to realize the program, and the position of drying center, the plan of vehicle transportation route and the total cost of transportation are obtained. The feasibility and validity of the model and solution are proved. The establishment of rice drying center in cold region can effectively reduce the loss of grain during drying and ensure its quality and nutrition. The heuristic algorithm combined with intelligent optimization algorithm is applied to solve the LRP model of rice drying center in cold region, and the location and path optimization are carried out under the condition of satisfying the time constraint of rice in cold region, which can effectively control the time and logistics cost. It provides an important reference for the practical location and path optimization problems.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：F326.5;F252

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