A pruning robot with a power-saving chainsaw drive

We present a novel pruning robot that uses self-weight and a power-saving chainsaw drive. The pruning robot consists of a climbing up-and-down mechanism, a chainsaw mechanism, and a controller. The climbing up-and-down mechanism has four active wheels equipped with a steering mechanism and a two-DOF posture adjustment mechanism to keep the pruning robot in a horizontal posture. The robot can stay on a tree without energy consumption by using its own weight. The chainsaw mechanism consists of a chainsaw and a two-DOF pose adjustment mechanism, which has a liner joint to maintain a specified distance between the tree surface and chainsaw, and a tilt joint to keep the chainsaw in a specified posture against the tree surface. In the chainsaw power-saving drive, there are two modes of a high input and a low input, and its switching is executed based on the disturbance estimation. It is shown experimentally that the developed robot can do pruning work with low power consumption.