Development of Pruning Robot flexible for uneven surface of tree

In this research, we aim to develop a pruning robot capable of pruning even for gradually curving or uneven tree without damages by downsizing a cutting machine. Because an area in which branches can be cut will lessen, it becomes necessary to prune actively by moving the small cutting machine. For this purpose, following developments are conducted. 1.Mobile platform Four mobile platforms capable of going up/down tree spirally are made experimentally. As a result, stable climbing is carried out. 2.Mesurement systems A distance measurement system and a diameter measurement system are developed as systems for detecting branches and recognizing their positions. The distance measurement system measures distances between a robot set up from a root and branches. The diameter measurement system measures diameter ; of tree on height in which the robot set up. 3.System for recognizing branches' position This system estimates positions of detected branches based on the Occupancy Grid model using information from the measurement systems. We revealed characteristics for measurements on a surface like a tree and proposed a model specified for a branch detection. Moreover we proposed a method for compressing a map and a method for compensating sensor positions intending use in actual forest environments. 4.Cutting unit To select small cutting mechines, a comparison of cutting characteristics between some ones is conducted. Moreover resistances on pruning of the small cutting mechines are measured. As a result, a roughing endmill is found as one by which stable pruning are carried out with the least power. 5.Motion planning of cutting machine We categorized branches into branches whose positions are recognized and branches which cannot be detected due to occlusion by former ones. Motion planning algorithms for these categories of branches are proposed to carry out active pruning using the cutting unit respectively.