Development of a Mobile Wall-Climbing Robot with a Hybrid Adhesion System

In this paper, the development process of a mobile wall-climbing robot (WCR) for inspection tasks of vertical concrete structures is presented. The WCR uses a novel hybrid adhesion system based on a combination of negative pressure and thrust. Negative pressure and horizontal thrust are generated using Electric Ducted Fans (EDF) with a custom shroud design, while vertical thrust is generated by a drone-type propulsion unit. The EDF generates a horizontal force that allows the robot to be in contact with the vertical surface, while the drone-type propulsion unit generates a vertical force that helps the robot overcome the gravitational force. This hybrid adhesion system allows the mobile WCR to adhere to most vertical structures, including concrete columns and infrastructure that the robot will inspect. First, a testing prototype of the mobile WCR with a novel hybrid adhesion system is presented. Then, two experimental setups are presented. In the first setup, the EDF and shrouds were tested in different configurations to maximize the adhesion forces, while in the second setup, the BLDC motors were tested with different types and sizes of propellers to optimize the energy consumption in relation to the generated thrust. Based on the obtained results from these two experimental setups, the final hybrid adhesion system configuration is chosen.