| There are two problems existing in China’s agricultural machinery scheduling: On the one hand,the persistent contradiction which is between the large-scale operation mode of agricultural equipment and the national situation of agricultural production subject that is still small farmers,on the other hand,equipment management is not meticulous and scheduling information is lag,which is low efficiency,low applicability of the scene.Especially in the harvest link,agricultural machinery scheduling lacks multilink and multi-complex constraint allocation strategy and scheduling mode.Therefore,it is of great significance for agricultural production at the present stage to adapt the scheduling mode of multiple scenarios,meet the complex constraint conditions and achieve a scientific and reasonable harvester scheduling.This study sorted out the actual characteristics of harvester operation stage and scheduling in the harvest link,and summarized the scheduling mode with universality and different emphasis content.According to different operation links in the harvest scenario,the single-region harvester operation model,the multi-region harvester transfer scheduling model and the cooperative response scheduling model of harvesting and transportation were successively established in this paper.At the same time,the corresponding algorithms which combined with the characteristics and constraints of each model were proposed.Finally,the model and algorithm were verified by simulation example in the relevant scenes.The main contents are as follows:1)For one single harvester harvest operations in the area of the fixed link,combining with the characteristics of regional space and actual operation,we combined the turn numbers of harvest operation as the goal,used the scan line algorithm and the rotating step method to solve the global optimal operation direction,simplified the solution of the intersection point of the irregular polygon region,and realized the scheduling scheme of the harvester with the optimal operation direction.2)For the multi-area transfer operation scenario of harvester,a multi-machine cooperative scheduling model was established in this paper,aiming at the distance of route transfer and task time.In the optimization solution process of a large number of orders,the PFIH algorithm was combined with the intelligent heuristic algorithm to solve the problems such as the non-global nature of the traditional algorithm PFIH and the restriction of GA coding.Which realized the task assignment of multiple harvesters in multi-area scenes.The proposed hybrid algorithm can all solve the optimal path scheme satisfying the constraint conditions,and the optimization effect is better than the initial scheme.By the simulation example analysis,hybrid genetic algorithm(GA-PFIH),hybrid simulated annealing algorithm(SA-PFIH)could effectively control the cost,the target optimization degree were 35.82% and 36.84%respectively,and transfer path distance and the average working time optimization was better at 39.08%and 40.96% respectively with higher fairness compared with PFIH when order size to 100;Compared with the initial GA solution,the optimization degree of target value was 15.68% and 17.02%,the optimization effect of path transfer distance and average working time was 30.26% and 32.41%,respectively.By comparing the performance of the hybrid algorithm under the order scale of 50,100,150 and 200,it was found that the optimization degree of the two hybrid algorithms increases gradually with the increase of the order scale,and the optimization effect was more obvious.However,with the increase of scale,the real-time performance of operation was poor,and it is only suitable for static scheduling.Therefore,the hybrid algorithm proposed in this study was more suitable for solving the problem of largescale orders with static scheduling and realizing the reasonable allocation and efficient utilization of rice transplanter scheduling for small farmers.3)Aiming at collector coordinated response in scheduling harvest link,the certain conditions of farmland area are defined as the work unit,and we studied the response between the harvesters and transport vehicles,response model was proposed based on dynamic programming algorithm of task units classification time slot,realized the grain accurate path planning of multipath.It can solve the scheduling optimization problem of harvesting machines under the circumstance of shortage of grain trucks.Through the simulation experiment of an appropriate scale farmland example,the optimization scheme of the minimum non-productive waiting time of the harvester and the minimum transfer distance of the grain truck under the fixed ratio of 3:2 was obtained.The results show that: the total cost of non-productive activities of generating scheme of algorithm is better.When the number of grain transport vehicles is insufficient and there is a significant difference from the number of task units,the transfer distance of grain transport vehicles and the waiting time of harvesters will significantly increase.When the quantity of collection and transportation is 3:2,the harvesting efficiency should be maintained at 0.4 hm2/h to obtain the optimal response operation efficiency,minimum waiting time and transfer distance,and minimum non-production cost under this configuration.The model and algorithm can solve the accurate path planning of multi-path for multi-grain vehicles.In actual production scheduling,the harvesting efficiency should be selected reasonably and the quantity gap between harvesters and grain carriers should be narrowed so as to better solve the scheduling optimization problem under the situation of insufficient grain carriers.Research of this paper can provide effective for agricultural machinery service organization in harvest link scheduling decisions,solve the harvester for large,medium and small-scale regional resource allocation of technical problems,in order to solve many links,many scenes provide the theory basis for agricultural machinery operation,adapt to Chinese farm machinery socialization service,small farmers modernization management has important research significance. |
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