Design Of End-effector Motion Control System For Dual Rollers Safflower Picking Robot

At present,most of the existing safflower picking machines are semi-automatic picking,which adopts the manual carrying or hand-held operation mode.The manual labor intensity is high.If the intelligent picking of safflower can be realized,it is of great significance to promote the development of safflower industry.With the continuous development of science and technology,the application of picking robot in agricultural field is more extensive and in-depth.According to the characteristics of different spatial distribution of safflower bulbs and small filaments,higher requirements are required for the accuracy,stability and smoothness of the end-effector movement of the safflower picking robot.Therefore,the corresponding research and design are made in this thesis for the end-effector movement control system of the safflower picking robot.It mainly includes the overall scheme design of end-effector motion control system,end-effector kinematics analysis and picking path planning research,motion control system design,construction and testing.The specific research content and design are as follows:First,combined with the growth environment and morphological parameters of safflower plants,the overall structure of the dual rollers type safflower picking robot was determined,the working scheme of the end-effector motion control system was designed,and the core hardware of the control system was selected.Secondly,according to the structure and size of the designed picking manipulator,the D-H parameter method was used to establish the kinematics model of the end-effector.The forward and inverse kinematics analytical formulas were deduced and calculated,and the parameters of each joint and their working space were precisely calculated,which provided a strong theoretical support for the motion control and implementation of the end-effector.Then,aiming at the problem of end-effector motion path planning in the picking process of safflower,the end-effector picking path planning was considered as the traveling salesman problem.The influence of position and posture of safflower on the motion path was considered,Angle induction factor and improved distance factor were introduced,and the transfer probability of traditional ant colony algorithm was optimized.The picking path of safflower was planned from two aspects: picking track and picking sequence.Finally,according to the working scheme of the end-effector motion control system,the hardware circuit design and software control program design of core modules such as STM32F407 as the main controller,stepper motor and steering gear are completed.Finally,a prototype was built to test the motion function of the end-effector motion control system to verify the effectiveness and reliability of the end-effector motion control system.