Experimental comparison of drag-wiper and roller-wiper glass-cleaning robots

Purpose Glass-cleaning robots were developed to perform the difficult, time-consuming and dangerous job of cleaning windows that had traditionally been done by humans. The wiping mechanism is the most important functional component of a glass-cleaning robot, which indirectly affects the design of the adsorption and transport mechanisms. This study aims to compare two types of wiping mechanisms – the drag-wiper and roller-wiper –through an analysis and an actual experiment, providing theoretical and measured data that can be applied to the optimization of the design of future glass-cleaning robots. Design/methodology/approach The authors undertook a theoretical force and energy consumption analysis of glass-cleaning robots and, based on the obtained results, undertook an analysis the two wiper types. They verified the theoretical analysis by conducting several experiments including studying the relationship between a wiper’s friction force and rotational speed, measuring the contact normal forces of the suckers, wiper and crawlers relative to the glass wall, measuring the energy consumed to drive the robot and studying the relationship between the vacuum pump’s power consumption and the adsorption force. The authors also compared the wiping efficacy of the drag-wiper robot and roller-wiper robot. Findings The drag-wiper offers the advantages of simplicity while being able to wipe the area around the edge of a window frame. Meanwhile, the use of a roller-wiper not only improves the robot’s driving performance and reduces the required adsorption force but can also reduce the amount of energy consumed to drive both the robot itself and also the vacuum pump; in addition, the roller-wiper is more flexible and energy- and time-efficient when dealing with dirt that is difficult to remove. Originality/value This study has, through a detailed analysis of the advantages and disadvantages of a drag-wiper and roller-wiper robot, from the three aspects of force analysis, energy consumption and wiping efficacy, obtained theoretical and measured data that can be applied to the optimization of the design of future industrial and household glass-cleaning robots.