Structure Design And Navigation Research On Mobile Chassis Of Inspection And Transplanting Robot In Seeding Bed

In recent years,greenhouse seedling technology has been widely used in vegetable and flower industries,and replanting transplanting,as one of the important links,is mostly a fixed operation mode,in which the cavity trays are transported to the replanting equipment by manual or logistics system.In order to reduce the labor intensity of workers in the process of handling,for the problems of large span of seedbeds,narrow spacing of seedbeds and complex environment in the facility greenhouse,this paper designs a mobile chassis for walking across seedbeds and studies its inspection and navigation system to lay the foundation for the later realization of inspection and replenishment transplanting operation in the seedling greenhouse,as follows:(1)According to the environmental structure of seedling greenhouse and the demand of inspection and replenishment operation,combining the existing wheel drive method and agricultural chassis structure,a four-wheel independent drive steering upland gap gantry mobile chassis was designed,and the selection of main components and the overall assembly of the chassis were completed.(2)For the seedling replenishment robot across the seedbed inspection navigation needs,based on the reactive navigation method of machine vision technology,a seedbed contour detection algorithm based on improved Canny-Otsu is designed for the effect of different light intensities on image processing,and then the image is segmented using the projection method to determine the automatic ROI region,and the straight navigation line and traverse navigation line are fitted using least squares and Hough transform,respectively.The navigation feature parameters are further extracted and combined with the chassis inspection status to generate navigation parameters for autonomous motion control of the chassis after coordinate transformation.(3)Based on the chassis structure and control requirements,the overall design of the control system of the chassis,through the analysis of the chassis kinematics,the control method of the four-wheel independent drive steering chassis,and then based on the chassis structure and seedbed size,calculated the maximum position deviation and heading deviation when walking across the seedbed,designed a two-input single-output fuzzy controller for the path tracking of inspection walking,and finally the design and implementation of the control system hardware and software such as the main control board module,remote control module,drive module and chassis wiring.(4)In order to verify the feasibility of the navigation system and the actual tracking and walking accuracy of the chassis,static parameter tests and walking tests were conducted under three lighting conditions and different speed levels,respectively,and the static tests showed that the average accuracy of the parameter acquisition algorithm was above 91% and the average time consumed was 205 ms,with good robustness and real-time performance;in the walking tests,under different maximum initial deviations,all speeds could effectively In the walking test,the path can be tracked effectively at all speeds with different maximum initial deviations,and the average values of position deviation and heading deviation after smoothing are 28.3mm and 4°,respectively,with the best tracking effect at 0.2m/s speed,and the average values of position deviation and heading deviation are 26.2mm and 2.2°.