Optimal Design And Research On End-effector Of Intra-row Weeding Robot In Vegetable Field

The intra-row weeding robot is a mechanical weeding machine which is based on the technology of multi-sensor information,machine vision and automation control.The end-effector is the key component of the weeding robot which can influence directly the effect of weeding.This dissertation took the end-effector of intra-row weeding robot as the research object,studied the optimal design methods of the end-effector to achieve the best effect of weeding according to the different soil situation and vegetable planting pattern in our country,developed intra-row weeding robot mechanism.The main contents are as follows:(1) Method of optimal design and research on the end-effector with claw tooth was studied. A new evaluation index of the coverage rate and inbreaking rate is proposed instead of the weeding rate and wounded seedling rate.The structure and working principle were introduced,and the optimum structure parameters were given out through the analysis of the trajectory of the claw tooth by the established kinematics model.(2) Method of optimization combination of the structure parameters for the rotating disc of the crescent end-effector was researched.The geometry model and kinematic model were established for the rotating disc.Then the virtual orthogonal experiment was done in different factors and different levels.In order to obtain the best structure parameters in combination,the effects of weeding performances of the rotating disc in diverse parameters were analyzed.(3) Method to control the rotation speed of the rotating disc was studied for a better operation effectiveness.The trajectory of the rotating disc was designed by controlling the rotation speed,and an optimization analysis was done by simulating its working process.(4)Method to design the optimum structure shape of the rotating disc was proposed.On the basis of the relative motion theory,the trajectory of the plant was analyzed relative to the rotating disc of the crescent end-effector,and an optimization model was established to obtain the optimum structure shape, which provided a theoretical basis for design.Then7kinds of the rotating disc were designed to fit the different plant spacing.(5)The intra-row weeding robot mechanism and hydraulic system were developed,and field performance tests were conduced.The results showed that the prototype worked with a good operation effectiveness,and the weeding rate reached to96.2%,the wounded seedling rate was1.4%with the plant spacing of400mm.When the plant spacing was300mm, the weeding rate was95.4%and the wounded seedling rate was1.3%.