Research On Control System Of Tractor Electro-hydraulic Suspension

With the development of modern science and technology,agricultural production is being mechanized to intelligent transformation.At present,hydraulic suspension system on traditional tractor is gradually replaced by electro-hydraulic suspension system,and the growing development of intelligent control technology and computer technology promote the development of mechanical electro-hydraulic integration technology,the control technology of tractor electro-hydraulic suspension system made rapid progress.the paper focuses on the research of electro-hydraulic suspension control system of tractor.The embedded distributed control technology,intelligent control and control technology and CAN bus technology are applied in the electro-hydraulic suspension control system of tractor,and deeply analysis and research are made to the related control technology.This paper takes the electro-hydraulic suspension system of tractor as the research object and designs a experimental platform of electro-hydraulic suspension system.First,describing the composition,working principle and interrelationship of hydraulic modules,suspension modules and electronic control modules.then by doing simulation of the hydraulic modules to verify the stability and reliability of the system,which lays the foundation for the research of electro-hydraulic suspension control technology.Comparing and analyzing the different control methods of the electro-hydraulic suspension system and putting forward force-position combined control based on the weighting coefficient,developed a control program of the electro-hydraulic suspension for different working environment.Analyzing the adjustment scheme of the weighting coefficient,a automatic adjustment method based on BP neural network of the weighting coefficient is proposed and simulated.According to the features of electro-hydraulic suspension system,choosing fuzzy control algorithm as the core algorithm and design the fuzzy controller.The simulation results show that the force-position control method and the fuzzy control algorithm have good control effect on the adaptive adjustment of tillage.On this basis,the embedded distributed control prototype system is built and the monitoring terminal based on UCGUI graphical human-computer interaction system is developed for inputting control commands and monitoring system parameters;Designing and implementing a node that is made up of the hardware circuit module and the weighting coefficient Adjustment control subroutine,fuzzy control subroutine,AD acquisition subroutine,etc.,for the control of the hydraulic cylinder and the test of system operating parameters;Developing the CAN bus communication protocol and implementing the system communication based on the CAN bus monitoring terminal and hydraulic control node;Designing the power system and improving the stability and reliability of the system.At last,Doing experiments on the experimental platform,which includes the driving experiment of proportional valve,the up and down experiment of plow,tillagedepth response experiment,simulated resistance the loading experiment of simulated resistance and force-position combined control experiment.The experimental data prove that the hardware and software framework of control system is stable and reliable and the control program of control system can realize the adaptive adjustment and the stability adjustment of tillage depth.