Modeling and Verification of the Magnetic Wheel Adsorption Force in Multiple Working Conditions for Underwater Welding Robots

To address the issue of adsorption instability encountered by magnetic wheel adsorption welding robots during underwater operation, this paper proposed a critical adsorption force calculation method for magnetic wheels based on centroid offset and vector superposition. This method comprehensively considers multiple failure modes, including traditional sliding failure, detachment failure, overturning failure, and the rarely studied skidding failure, effectively addressing the issue of adsorption instability caused by low accuracy in traditional adsorption force calculations. Firstly, based on the robot chassis structure, static models corresponding to four non-instability adsorption states were established, and a vector superposition method was proposed based on static coupling relationships. This method fully accounts for the influence of centroid offset on adsorption stability during actuator motion, providing a theoretical basis for the accurate calculation of the critical adsorption force of magnetic wheels. Then, a case study was conducted based on the permanent magnetic adsorption chassis of the existing underwater welding robots. The static analysis results were solved using Matlab and the variation law of the critical adsorption force of the chassis with maximum centroid offset at different spatial angles was summarized. Finally, an experimental setup was constructed to test the adsorption stability of the robot under various operational conditions. The experimental results demonstrate that the vector superposition method based on centroid offset can effectively improve the adsorption stability of underwater welding robots, providing novel theoretical support for the design and magnetic force optimization of subsequent magnetic adsorption chassis.