Research On Lean Operation And Key Issues Of Mechanized Crop Harvesting-to-transport System

With the improvement of agricultural mechanization in China, agro-machinery socialization service becomes an important source of incomes to farm workers. Meanwhile, due to the extensive management of agricultural field operations(AFO), there exist various wastes during AFOs, thus affecting the operation performance of agro-machinery operation organization as well as the income growth of farmers. How to reduce or eliminate wastes for improving the operating effect of AFOs becomes a long-term concern of many scholars.The working effect of the AFOs process is under the influence of various factors such as human, machine and working environment so on. To achieve an efficient allocation and rational use of production resources, and finally realize the lean operation of AFOs process, it requires the support of a highly integrated management system with a variety of management methods and means. In this paper, the theory and method of lean production are introduced into AFOs process management, and putting forwards a lean operation model of crop harvesting and transport system. Based on field investigation, the mechanized crop harvesting and transport system is considered as the research object, and some key issues including the lean operation model, the lean planning of AFOs route and biomass handling system in the lean operation of crop harvesting and transport system are studied using the methods of system analysis, modeling and case study. The main research contents are as follows:This paper describes the definition, connotation and basic pattern of crop harvesting and transport system, analyszes its key operational activities and various wastes existing in crop harvesting and transport system, and then put forwards a set of indicator system and a solution framework for eliminating various wastes existing in mechanized crop harvesting and transport system. Then, a lean operation model of mechanized crop harvesting and transport system is structured according to the theory of viable system model, from the perspective of wastes elimination.For minimizing the non-working distance of harvester operating within a field, considering the situation of harvester operating within a field with one or more fixed depots at headlands, field coverage is expressed as the traversal of a weighted graph, and then solved by ant colony algorithm with unloading control factor. Experimental results show that 1)the model and its algorithm can effectively plan both field paths and depots layout in corresponding actual situation, 2)by using optimum paths, the total non-working distance can, comparing with adjacent traversal, be reduced by up to 33.3%, it is beneficial to improve the efficiency of harvester and reduce operation cost, and 3)the absence of any pear-shaped turns with the optimum patterns leads to two significant benefits. The first one is reduced soil disturbance and the second is a reduction in the headland area itself.Considering the coordination of the logistical activities between harvesting unit and storage unit in mechanized crop harvesting and transport system, two lean planning models of biomass handling system are built in different biomass handling pattern respectively. Firstly, the operation process of biomass handling system under independent transportation pattern is built, while its operational parameters are determined by a queque system model which used to describe the operational mechanism of biomass handling system in mechanized crop harvesting and transport process. The results of case study show that less waiting waste exist in planned biomass handling system. Finally, the planning problem of biomass handling system under combinable transportation pattern is cast as vehicle route problem with time window(VRPTW), and then solved using quantum ant colony algorithm(QACA). Case study shows that proposed model can be able to determine the quantity of transport unit and the optimum response sequence of unloading.Finally, the researched models and methods are preliminarily applied to the mechanized cotton harvesting and transport process at a state-run farm in XPCC, and improve the lean operation system of the cotton harvesting and transport process. The results of a preliminary implementation proved the availability of this research.