Design And Test Of Hydraulic Drive And Control System Of Oil Tea Fruit Harvesting Device

With the continuous development of the oil tea industry,the planting base area has been gradually expanded,and the high-yield and high-efficiency machinery and equipment have been upgraded,however,most of the current research is still limited to structural design and parameter optimization,resulting in the oil tea equipment still has a low degree of automation,weak control accuracy and other problems,resulting in serious damage to the buds and limiting the fruit harvesting net rate.Relying entirely on mechanical equipment is not as accurate as automatic control,so it is important and urgent to design an efficient and reliable hydraulic system and control system to develop a harvesting equipment with high yield and low loss,accurate control and high automation.In this thesis,according to the operational requirements of canopy vibration type oil tea fruit harvesting device,the hydraulic drive and control system of canopy vibration type oil tea fruit harvesting device and the frequency control method of the excited picking parts are designed,and the research is carried out in the following four aspects respectively:(1)According to the vehicle structure and working principle of canopy vibration type oil tea fruit harvesting device,a set of hydraulic system drive design scheme applicable to oil tea fruit harvesting device is proposed,and the walking,vibration,harvesting and overall circuit of hydraulic system is designed.Based on the force analysis of the hydraulic system actuators and operational requirements,the calculation and selection of key actuators and auxiliary components are completed so that they meet the action requirements of the oil tea fruit harvesting device in the harvesting process.(2)In order to realize the functional requirements of the drive system of the oil tea fruit harvesting device,the software and hardware design of the control system of the oil tea fruit harvesting device based on Siemens 1200 DC/DC/DC controller is completed using the structured design idea.According to the requirements of the control system,the PLC inputs and outputs are reasonably allocated and the PROFINET communication protocol is determined.According to the program flow and logical sequence type control strategy,the overall program of the control system based on TIA Portal software and the human-machine interface design based on Win CC are completed to realize the purpose of the upper computer controlling the lower computer for smooth operation.(3)With the excitation picking parts as the controlled object,the valve-controlled hydraulic motor creates a transfer function for mathematical modeling and designs a valvecontrolled motor frequency control system based on a BP neural network PID controller.The simulation analysis of the hydraulic system based on AMESim software was carried out to verify the feasibility of the hydraulic system.And based on the joint simulation of AMESim and Simulink,the BP neural network PID controller is simulated under the conditions of unperturbed,perturbed,and simulated load,and analyzed against the conventional PID controller.The simulation results show that the step response of BP neural network PID controller is faster,the oscillation amplitude is smaller,and the vibration frequency control accuracy is more stable,The time required for the excitation picking components to reach the vibration frequency is within 2.58 s,the steady-state error is 0.01,and the maximum overshoot is less than 13.44%,which verifies that the self-tuning effect of the valvecontrolled motor of the BP neural network PID controller meets the demand of intelligent picking equipment.(4)Through the comprehensive performance test of the whole machine,the smoothness of the operation performance of the oil tea fruit harvesting device under the action of hydraulic system and control system was tested.According to the simulation results and the actual no-load operation data comparison of the requested variance is less than 3.36,the actual picking vibration frequency control of the FM control system in the 7.58 Hz ～ 8.40 Hz,to verify the accuracy of the FM control system of the excitation picking components.The field tests showed that the variance obtained by comparing the simulation results with the three groups of test data was less than 2.92,the vibration harvesting efficiency of the test group was 1.42 times higher than that of the control group,and the bloom low loss efficiency of the test group was 1.53 times higher than that of the control group,which proved that the simulation results met the requirements of the actual harvesting operation and verified the better picking effect of the loaded control system.