Abstract:

To address the issue of adsorption instability encountered by magnetic wheel adsorption-type underwater welding robots during operation, this paper proposes a critical adsorption force calculation theory for magnetic wheels based on centroid offset and vector superposition. This theory comprehensively considers multiple failure modes, including traditional slippage failure, detachment failure, overturning failure, and the less-studied spin-slip failure, effectively resolving the adsorption instability problems caused by the low accuracy of traditional adsorption force calculations. Firstly, based on the robot chassis structure, static models corresponding to four non-instability adsorption states are established. Furthermore, a vector superposition principle is proposed, incorporating static coupling relationships. This principle fully accounts for the influence of centroid offset on adsorption stability during actuator motion, providing a theoretical foundation for the precise calculation of the critical adsorption force of magnetic wheels. Secondly, taking an existing permanent magnet adsorption chassis of an underwater welding robot as a case study, static results are obtained through Matlab simulations. The variation law of the critical adsorption force of the chassis with maximum centroid offset at different spatial angles is summarized. Finally, an experimental setup is constructed to test the adsorption stability of the robot under various operational conditions. The experimental results demonstrate that the vector superposition principle based on centroid offset can effectively improve the adsorption stability of underwater welding robots, offering novel theoretical support for the design and magnetic force optimization of subsequent magnetic adsorption chassis.

Key words: underwater welding robot, permanent magnet adhesion, static model