| Maize is an important food crop in China,and in recent years,in order to protect soil fertility and increase maize production,most areas have adopted conservation tillage in a wide and narrow row pattern for planting.This planting pattern provides a good growing environment for corn while also leading to the breeding of pests and diseases.Regular inspection is an effective way to reduce pests and diseases in maize.The traditional inspection is mainly done by hand,and even though it takes a lot of time,it is difficult to achieve deadend monitoring.Therefore,it is imperative for agricultural machinery to replace manual inspection work.The premise of the inspection work is that the agricultural machinery runs automatically in the cornfield.At this stage,there are self-propelled agricultural machinery at home and abroad,which cannot meet the demand.Therefore,this paper designs an inspection vehicle chassis and control system to meet the driving requirements of the inspection work in the corn field of conservation tillage.This paper researches and improves the heading tracking control algorithm for the difficult problem that it is difficult for the chassis of the inspection vehicle to steadily carry out heading tracking driving in the corn field of conservation tillage.The main research contents and conclusions are as follows:(1)Combined with the protective farming cornfield environment,the work requirements and design requirements of the inspection vehicle chassis are analyzed,and the control key points are obtained through kinematics analysis.On this basis,the structure of the inspection vehicle chassis and the control system are determined.Select and layout the sensors,motors,motor drive boards and batteries required for the system,and design the hardware circuit with stm32f103c8t6 as the main controller.(2)Research on the heading tracking control method of inspection vehicle chassis.Analyze the heading tracking control requirements and strategies.Based on the design of dual closed-loop motor speed controller,the differential pd controller is designed to realize the heading tracking control.For the drawback of fixed parameters of differential pd controller,the parameters are adjusted with fuzzy controller.For the problem that the fuzzy rules are idle when the deviation is small,the fuzzy controller is optimized by introducing the idea of variable domain.The simulation analysis results show that the differential variable theory domain fuzzy pd controller has high stability,strong anti-interference ability,short regulation time,and meets the control requirements.(3)The design of the inspection vehicle chassis control system program is carried out using keil5 software.Based on the modular decomposition of the overall control process,the ground identification and steering program,lateral adjustment program,heading tracking program,motor current and speed sampling program,etc.were designed.(4)The prototype was built and tested for heading tracking,lateral adjustment and automatic driving.The test results show that when the inspection vehicle chassis is controlled by the differential variable universe fuzzy PD controller,the adjustment speed of heading error is fast,the heading tracking driving stability is high,the absolute value of the maximum heading deviation is 1.4 °,and the average transverse deviation is 3.7cm.The inspection vehicle chassis can effectively carry out horizontal adjustment,headland identification and steering to meet the working requirements.The chassis and control system of the inspection vehicle designed in this paper have the functions of heading tracking,head identification and steering,lateral adjustment,etc.to meet the driving requirements.It lays a good foundation for the design of the whole vehicle of inspection vehicle.It effectively optimizes the heading tracking control method and provides a new idea for the research of heading tracking control. |
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