Simulation And Experimental Analysis Of Control Strategy For Steering System Of Plot Planter

Therearea large number of population and less farmland in China.It is essential to improve grain yield by breeding work and research.At present,most ofthe farmlandbreeding experiments which made byinstitutes and universities arestill done by hand.Most of the plot planters are invented and made by foreign countries.In order to improve efficiency and accuracy,our research group independently developed anelectricplotplanter.Meanwhile,the plot planter steering system is usually aassistedwith a hydraulic pump.The hydraulic steering system can provide a large power to volume ratio when the vehicle is running.The systemhas many advantages such as running steady,long service life and meetthe requirement of agricultural vehicles.So agricultural vehicles generally use hydraulic steering.However,the hydraulic steering system also has some disadvantages such as its complex structure,heavymachanism,poor steering stability and a serious energy consumption of the hydraulic oil.In order to avoid these problems,we chose an electric power steering system on the electric plotplanter.Electric power steering can provide the best power towards various operating conditions,It is more energy-saving,emission-reducing,lighter and struture-simpler than hydraulic steering.And it is also easier to adjust and detect some problems.The main research contents of this article are as follows:(1)This article first analyzes the development status and development trend of agricultural vehicle steering technology by consulting references.The electric power steering system that applied to small vehicles is relatively mature.Although the working environment of plot planters is quite different from automobiles,the test fields are generally passed through.In the trimmed fields,the working environment is not as complicated as the field environment.Therefore,it is feasible to use the electric power steering on the vehicle for the plot planter.(2)The structure and working principle of the plot planter steering system are introduced.The classification and main advantages of the plot planter are analyzed.The types of main componentsfor the plot planter are selected.The main components include torque sensors,speed reduction mechanisms,Steering gear,electronic control unit,power assist motor and so on.(3)The mechanical structure of the planter's steering parts is analyzed,and its model is simplified.The mathematical modelssuch as the steering wheel,the input shaft,the main motor,the deceleration mechanism,and the rack and pinion are established respectively.(4)According to the three different power assistance characteristic curves of thesteering system,the assist curves for the plot planter are analyzed,the parameters of the assist characteristic curves are analyzed and calculated,and the assist characteristic curve of the plot seeder is obtained.The control strategy of the planter steering in the plot was analyzed,including the control mode and method of the plot planter.The control algorithm of the plot planter is introduced and a fuzzy adaptive PID control strategy is designed.(5)The Simulink module in Matlabis used to establish the simulation model of the plot planter's steering,and the fuzzy self-adaptive PID control strategy was simulated and verified.Compared with the simple PID control strategy,the superiority of the fuzzy self-adaptive PID control strategy is verified.Comparing the simulation results with the actual vehicle test results,it is proved that the fuzzy adaptive PID control strategy has good steering and lightness and road feel.The final result shows that the motor can provide effective assistance when the planter is working.When the steering torque is less than 1 N·m,the motor does not provide assistant power,and the assist current increases with the steering wheel torque.The maximum steering wheel torque designed in this paper is 6 N·m when the torque reaches the maximum value.The maximum of assistant current remains the samewhenthe power assist current is up to its maxmum,with a size of around 20.65 A.When comparing the simulation result data with different steering torques used at different angles when the plot planter is steered in the same situation,it can be concluded that the experimental data is similar to the simulation result data.In summary,the control strategies and assist features designed in this paper are effective.