Study on the performance of vortex suction cup for an underwater inspection robot

Abstract

Using robots to detect Marine structures is very important for maintaining the safety of Marine structures. This paper presents an underwater inspection robot specifically engineered for the assessment of underwater structures. The integration of reliable adhesion technology is identified as a critical factor in the development of such robots. The vortex suction cup, employed by the robot as its primary adhesion mechanism, outperforms traditional adhesion methods by enabling non-contact attachment while consuming less power. As the vortex suction cup is the core component of the underwater inspection robot , this study comprehensively investigates how variations in the vortex suction cup’s structural and operational parameters influence its adhesion performance, measured from an energy efficiency ratio perspective. Initially, we delineate the vortex suction cup’s design and succinctly explicate the mechanism underpinning the generation of negative pressure. Subsequently, we establish an evaluative parameter, the energy efficiency ratio (η=F/P), that is, the adsorption force obtained per watt of power consumption of the suction cup, serving as a metric for the adhesion performance. By simulating the structural and operational parameters of the suction cup, we extract the corresponding adhesion force, torque, and energy efficiency ratio. Lastly, we construct an experimental apparatus to measure the suction cup’s adhesion force and output torque, validating the veracity of the simulated outcomes. Our simulation and experimental findings indicate that increasing the height of the suction cup housing enhances the adsorption force, however, this simultaneously diminishes its energy efficiency ratio performance. Likewise, an increase in the chamber inner radius amplifies the adhesion force, and the energy efficiency ratio commensurately increases. Augmenting the radius of the negative pressure effect board improves the adhesion force, decreases the required torque, and consequently amplifies the energy efficiency ratio. The suction cup’s adhesion force and required torque display a direct relationship with its speed, but the energy efficiency ratio is minimally affected by speed. When the distance is close (h ¡ 4 mm), changes in the adhesion gap profoundly impact the suction cup’s torque and energy efficiency ratio. However, when the adhesion gap ranges between 5–15 mm, the energy efficiency ratio exhibits a gradual decline.