Development of a low-cost modular pole climbing robot

There are many agricultural activities that requires access in the vertical direction. Climbing is one of the mean for accessing this. This article reports on the design and development work on a modular pole climbing robot. Modularity was achieved by ensuring similar repeated structures can be coupled and controlled in almost similar fashion. The design considers the rudimentary aspect of climbing and adopts grasp-push-grasp motion arrangement. The resulting design consists of two grippers for grasping and two central arms for climbing and lowering, all of which employs pneumatic cylinders. The whole climbing motion was achieved in six steps and the climbing speed is determined from the rate of filling the pneumatic cylinders involved. Parallel four-bar linkages arrangement was used to ensure the horizontal orientation of the grippers to prevent locking. The structure of the robot are made from aluminum with pin joints throughout to allow for easy assembly. PLC was used at this stage for the motion control. The developed robot can climb a 150 mm diameter pole at a speed of 0.6 m/min.