Research On The Autonomous Driving And Layered Control Method Of The Crawler Plant Protection Machine Based On The Pure Path Tracking Algorithm

The high plant,narrow row distance and poor air circulation in the middle and late stage of corn make it difficult to carry out the plant protection work.The utilization rate of large-scale plant protection machinery pesticides such as high gap is low and it is not suitable for the plant protection in the middle and later stage of corn,and the dispersion of UAV plant protection drugs is poor.In view of the above problems,3yz-80 a plant protection robot developed by the intelligent agricultural machinery equipment Engineering Laboratory of Anyu province is used as the test platform.As a small plant protection machine,it has good passing ability among agricultural and technical industries,but the research work on navigation self-propelled is less.This paper designs the autonomous walking and operation control system of plant protection robot through the parameters and motion characteristics of the whole machine.The main research contents and conclusions are as follows:(1)Consulting a large number of literature on agricultural robot navigation technology,summarizing and analyzing the main work and shortcomings in the current agricultural robot navigation area,and using the existing research results,3yz-80 a plant protection robot is selected as the control test platform to select the sensor,controller and other software and hardware.The position sensor selects Beidou navigation system,the upper computer selects PIPO industrial control computer,the lower computer selects stm32f4 single chip microcomputer,and selects the driving electric machine,the supporting driver,lithium battery and other components through calculation.(2)The two wheel differential car model is used to establish the kinematic model of the crawler plant protection machine chassis,and the coordinate system is established to describe the robot motion state with the center of the driving wheel distance as the origin of the local coordinate system,and the global coordinate system is established to describe the robot position.Based on the characteristics of chassis motion,PID speed closed-loop control algorithm is used to control the speed of the left and right driving wheels of the chassis during the moving process.The pure tracking algorithm is used as the path tracking algorithm of the plant protection robot,and the robot kinematics model is simulated in Lab VIEW to verify the feasibility of the algorithm.The preliminary verification of the control accuracy of the algorithm is carried out in the road test.The mean lateral deviation of the three walks of the plant protection robot in the straight-line tracking of the cement pavement is 0.043 m,0.001 m,0.004 m.(3)Design planning layer,Control layer The idea of hierarchical control of executive layer.The planning layer completes the acquisition and processing of perceptual information,and carries out path planning for standard fields,and defines the target path;The target line speed and angular speed information of left and right wheels are output to the control layer by the upper computer.The control level converts the control quantity to calculate the two PWM waves sent by the target speed of the left and right motors to the driver for execution;According to the current position of the plant protection robot,the execution state of the sprayer and other institutions is decided,and the execution instructions are issued.(4)The results of the experiment show that the mean deviation value of the system is0.005 m in the simulation field experiment;In the field experiment,the lateral deviation is0.048 m,and the sprayer is accurate under the instruction of the field switch.In order to complete the operation in anticipation state,the predefined path can be tracked quickly and accurately,and according to the design of the system,the switch action of the sprayer is completed during the turning of the field head,and the feasibility of the system is verified.