Design Of Control System For Full-Feeding Combine Harvester

China is a large agricultural production country,the combine has played an important role in the process of grain harvest.In view of the low degree of electrification and information of the full-feeding combine harvester at present,the design scheme of the combine control system is proposed.The control system of combine harvester takes the industrial personal computer as the main controller,establishes the communication network through RS485 bus and CAN bus,and uses the motor to drive each moving part of combine harvester directly.According to the structure and function of the combine harvester,the control system is divided into header module,threshing module,grain tank module,traveling module,perception module and control module to design the whole control system.Because the rotation speed of combine harvester moving parts is closely related to the traveling speed when the combine harvester is harvesting,a control model of the traveling speed and rotation speed of combine harvester rotating parts is proposed.By detecting the traveling speed of combine harvester and adjusting the rotating speed of the moving parts of combine harvester,the rate of grain loss is reduced and the efficiency of grain harvesting is improved.According to the functional similarities and differences of each module of combine harvester,the selection of control system components,the determination of installation position of motor and sensor,the construction of communication network and the establishment of control model are carried out respectively.Aiming at the problem of many components and complex communication network in the control system,a communication network construction method based on physical isolation and a control system scheduling algorithm based on priority are proposed,and the simulation experiment is carried out on the MATLAB SIMULINK simulation platform.The simulation results show that the control system has high real-time performance and good speed control effect on components.According to the design method of combine harvester control system,the header was refitted on the experimental prototype,and the rice harvest experiment was carried out in the paddy field.For the other parts that were not refitted,the simulation experiment was carried out using the SIMLINK simulation model.The experimental results show that:(1)The real-time performance of header control system is good.When the walking speed changes,the speed response time of each component is less than 0.2s,and the speed adjustment time is less than 0.4s.(2)The control accuracy of the model is high.The maximum relative error of the rotation speed of the header is less than 4.45% in the rice harvest experiment,which meets the speed control accuracy requirements.(3)The overall control cycle of the system is less than or equal to 0.1s,and the response time to high priority messages is less than or equal to 0.01 s,which meets the real-time requirements of farmland harvesting.