Research On A Control System Of Tilling Depth Based On Longitudinal Inclination Angle Of Crawler Cultivator

The automation level of soil preparation machinery in China is relatively backward.The tillage depth of crawler cultivator needs to be controlled by human experience,and there is no suitable automatic control technology.Combined with the working characteristics of the crawler cultivator and electro-hydraulic control technology,an automatic control method for the tillage depth of crawler cultivator based on the longitudinal inclination angle is proposed.The mathematical model of the automatic control method is established,the control system is designed,and the model machine is made,which enable the automatic control for the tillage depth of crawler cultivator.Field experiments have verified the feasibility of this scheme.The main research work is as follows:(1)The present situation and development of automatic control technology about the tillage depth are studied and analyzed at home and abroad.Aiming at the existed problem of automatic control technology about the tillage depth of crawler cultivator,an automatic control method for the tillage depth of crawler cultivator based on the longitudinal inclination angle is proposed.(2)Kinematics analysis for the three-point hitch linkage of crawler cultivator is carried out,and the relationship among the cylinder length increase,longitudinal inclination angle and tillage depth is obtained.And the mathematical model is established,which provides a theoretical basis for the programming of control program and the design of tillage depth controller.(3)The operating principle of the automatic control method is explained.The control system is designed,the electrical and hydraulic components were selected reasonably,and the control circuit board is designed and manufactured,the control program is written,and an electronic control system for the tillage depth is able to be developed.(4)The hydraulic system for the tillage depth automatic control of crawler cultivator is modeled mathematically,the system is simulated and analyzed,and the relevant parameters of PID controller are set.(5)The model machine of the tillage depth automatic control is created.And the debugging of controller parameters and the collection and analysis of test data are completed.Then Field experiments show that the tillage depth automatic control system developed in this paper has obvious effect for the tillage depth control,which verifies the correctness of the theoretical design and the feasibility of the control scheme.