Development of an Omnidirectional Mobile Passive-Compliant Magnetic-Wheeled Wall-Climbing Robot for Variable Curvature Facades

Wall-climbing robots are increasingly being used to inspect and maintain large ship facades, ensuring structural safety and reliability. However, conventional rigid robots often struggle with adaptability and flexibility on complex curved surfaces. To address this, we propose an omnidirectional magnetic-wheel wall-climbing robot with a passive-compliant suspension system. This design allows all magnetic wheels to adhere simultaneously to inclined surfaces with varying curvatures, and each wheel can independently rotate to any angle. We quantitatively analyzed the relationship between configuration parameters and the spatial position mapping of the robot on complex elevations to verify its adaptability to variable curvatures. Based on normalized surface configurations of varying curvatures on ship facades, we establish the robot's kinematic transformation flow. We develop spatial dynamic models for three motion modes on variable-curvature surfaces using energy conservation principles, analyzing driving-wheel motion constraints and friction-type differences across the modes to enable precise calculation of robot motion parameters. The proposed robot enhances ship facade maintenance by enabling stable, flexible motion on variable-curvature surfaces, improving efficiency, safety, and adaptability.