| Due to the quick development of agricultural mechanization,the efficient and green modern agricultural transportation mode that aims at raising seedlings,transplanting,transporting and other agricultural activities,is becoming the important foundation of modern agriculture.But in recent years,behind the huge growth of strawberry production in agricultural,more and more strawberries are damaged due to agricultural transportation.This research is applicable to AGV,which is suitable for automatic,efficient and green transportation of strawberries in agricultural greenhouses.It can complete the last 500 meter rapid transportation from the harvest of strawberry in agricultural greenhouses to the warehouse,and realize the requirement of reducing strawberry damage in agricultural transportation.Based on the application of AGV in agricultural greenhouse environment,the control component based on stm32f103vet6 is designed.Considering the magnetic navigation module established in agricultural environment,the driving system of effective carrier capacity is built,and the vibration damage of strawberry transportation is designed.Then,the transfer function of AGV drive system is obtained and the kinematics model of AGV is built under magnetic navigation.Then,the fuzzy PID controller is established.The speed control of AGV drive system is analyzed by Matlab simulation and the actual speed control experiment is carried out.The simulation and experimental results show that AGV can achieve effective response to speed within 3 seconds under different setting speed requirements,and the error of final stable running is within ± 5%.In view of the variability of agricultural greenhouses road,a piecewise fuzzy PID control is proposed.The control effect of AGV in tracking guidance is analyzed by Matlab simulation,and the trail test is carried out on outdoor hard brick pavement.Simulation and experiment show that the piecewise fuzzy PID control can realize the effective control of AGV to the tracking guidance under different driving speed.The maximum relative position error of the curve path tracking guidance is about ±20 mm.When running steadily in a straight line,the relative position error is kept within ±7.5 mm.In order to explore the influence of AGV vertical vibration performance on strawberries under the environment of agricultural greenhouses,the AGV motion vibration model wasBuilt by Matlab and Adams to simulate the vibration performance of AGV in agricultural greenhouses,and AGV vertical vibration experiment was carried out on outdoor hard brick pavement.Simulation and experiment showed that,when AGV was running at different driving speed,the chassis layer was tested the main frequency of vibration is about20～30 Hz,and it is close to the natural frequency what is 20.5 Hz of strawberry packing parts.The main frequency of carrier layer is about 6～7 Hz,it is far away from the natural frequency of strawberry package and avoids resonance,and the purpose of reducing strawberry transportation damage is realized.Under different number of shock absorption springs,the design of two shock absorbers can realize the operation of more stable and lower vibration frequency of the carrier layer. |
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