| With the development of mushroom greenhouse technology,the mushroom production has gradually become large-scale,automated and intelligent.However,in order to ensure the commercial appearance of fresh mushrooms,the mushroom greenhouse workshop still has to invest a lot of manpower for inspecting,picking,transporting,storing and etc.at intervals.The instability of working time makes it difficult to hire labor,which undoubtedly increases production costs,so the development of automatic mushroom picking technology becomes more and more important.This article takes the large-scale and aseptically grown Portabella in the workshop as the research object,and designed the overall scheme of the automatic mushroom picking system.Based on the initial implementation of the picking module,the article researched and tested the key technologies of the storing module and the scheduling module,which further improved the automatic mushroom picking system.The main contents of this article are as follows:(1)Based on the actual conditions such as the greenhouse environment,the structure of the seedbed,the characteristics of the mushrooms,etc.,the functional requirements and designing principles of the automatic mushroom picking system was put forward.Then the overall design scheme was proposed:on the basis of the picking module,the storing module and the scheduling module were added and the overall workflow was designed.A brief introduction to the communication mode and the communication protocol of the automatic mushroom picking system was followed;(2)In order to achieve the functions of storing mushrooms and replacing trays,a storing module based on a mobile hydraulic lifting platform was designed,including the structural design of the moving mechanism,the storing mechanism,the shelf,etc.and the control system design;(3)Aiming at the problem of scheduling for picking on the mushroom seedbed in the workshop,which is actually a parallel machine scheduling problem with due windows,based on the characteristics of mushroom picking,the problem was modeled based on genetic algorithm,and the simulation was verified by Matlab.The result revealed that genetic algorithm can minimize the maximum earliness and tardiness penalty,and a near-optimal scheduling scheme can be obtained.(4)Aiming at the problem that the picking platform cannot change layers,in other words,the rails of the mushroom seedbed and the lifting platform are not aligned during the exchange process of the picking platform,a leveling and rail-aligning scheme was designed: with the under-constrained platform,the weakly-adjustable system and the complex target,a layer-changing strategy of leveling point by point and step-by-step tracking is proposed,by establishing feedback with introducing inclination and distance sensors to the layer-changing mechanism,which achieved the layer-changing function of the automatic mushroom picking system.The feasibility and stability of the strategy was verified by the real system;(5)On the basis of the above research,the hardware and software were completed.Through the cyclic test of the overall system under the simulated field,the continuous circular picking of the mushroom model distributed on the two-layer mushroom bed was carried out.The test results revealed that the success rate of picking is 78.6%,the average picking time is 12.9s,which are basically consistent with the field test and meet the project requirements,the average time for changing trays is69.8s,and the average time for changing layers is 89.7s,which can basically meet the needs of the picking system. |
