Design of a sliding wall climbing robot with a novel negative adsorption device

Abstract

Although a variety of wall climbing robots were developed, few researcher concentrated effort on adsorption procedure and negative pressure generating device of a wall climbing robot. The aim of paper is to study and develop a sliding wall climbing robot using a novel negative adsorption device that can be well adopted in small irregular places, such as brick walls, cement walls, ship hulls and oil storage tank surfaces so that the robot could be used where direct access by a human operator is very expensive or very dangerous due to the presence of a hostile environment. Firstly, based on force analysis of safety attraction, the least negative pressure value is deduced while the robot is dynamic moving on the wall. Secondly, a mathematical model of the sucking process was made with bond graph theory by reasonable assumptions and the adsorption procedure of wall climbing robot with a large sucker was studied. The relationship between the generated pressure and the negative pressure generator's input voltage was simplified as a first-order expression. A negative pressure generator capable of providing stable negative pressure under variable flow was designed with the Computational Fluid Dynamics (CFD) tool to meet robot's critical demanded working pressure on rough walls. Thirdly, control system was designed and experiment setup was built to evaluate the performance of negative pressure generating system and general abilities of wall climbing robot. With the adsorption device, the wireless wall climbing robot weighed 30N can carry a 54N load at least while moving at a speed of 10m/min upwards for 50min. Test shows the validity of the study and design.