Innovative sliding negative pressure adsorptive approach applied to an underwater climbing adsorption robot

Traditional underwater climbing robots that use vacuum, thrusters, or magnetism as adsorption sources have many drawbacks, such as the inability to move on coarse surfaces and overcome obstacles and poor adsorption forces. In this paper, a new sliding negative pressure adsorption mechanism (SNPAM) is proposed and applied to the design of an underwater climbing adsorption robot. First, this paper theoretically analyzes the pressure and force characteristics of noncontact SNPAMs based on the Bernoulli theorem. Then, factors that influence the adsorption force—such as the outer radius, flow rate, and gap height—and their cause are calculated, simulated, and verified experimentally, and discussed from the application perspective. Finally, the SNPAM was finally applied to an underwater climbing robot. The results show that the robot can generate a maximum adsorption force of 600 kgf at a gap height of 12 mm in adsorption mode, and can maintain a maximum force of 363 kgf at a gap height of 28 mm in locomotion mode. The mathematical model allows the robot to adjust both the gap height and adsorption force according to various adsorbate surface conditions. Application experiments confirm the SNPAM's ability to help an underwater climbing robot to perform adsorption and locomotion.