Intelligent control of a pruning robot

We present an intelligent control system for a pruning robot, which consists of a retry function for branch cutting and a velocity adjustment for spiral climbing based on robot state estimation. The retry function works when the inclination of robot is such that the contact position between the branch and chainsaw is not ideal. The function consists of three motions: back spiral moving down, adjustment of the steering angles of four active wheels, and spiral climbing with pruning. The velocity adjustment of spiral climbing is executed to obtain an optimum branch cutting velocity based on the load of the chainsaw, which depends on the diameter of the branch. The system thus increases speed of branch cutting for slight brunches and slows for thick branches. We demonstrate experimentally that the developed intelligent control enhances the reliability and efficiency for our pruning robot.