A wall climbing robot with vacuum caterpillar wheel system operated by mechanical valve

This paper describes a new concept of the robot that can climb on vertical planes. The engineering design problem of the main structure is presented and the experimental results (climbing speed, payload) regarding a new mechanism of climbing on the vertical wall are discussed. The continuous locomotive motion of the robot is realized by using a series chain of two caterpillar wheels on which 24 suction pads are installed. While each caterpillar wheel rotates on the vertical plane, the suction pads are activated in sequence based on the sequential opening by specially designed mechanical valves. The detail mechanism and design feature of the vacuum caterpillar wheel including mechanical valve are described in this paper. The overall size of the robot is around 460 mm in width and length and 200 mm in height. Its mass is slightly over 14 kg. The maximum climbing speed is about 15 m/min and the static payload is about 23 kg. The main mechanical structure of the robot consists of driving motors, vacuum caterpillar wheel system, vacuum pump, wireless control module and battery. The performance of the robot is controlled remotely and verified on the vertical wall. Finally, an optimization experiment to maximize vacuum pressure and minimize the fluctuation of vacuum pressure of suction pads using Taguchi methodology is presented.