Abstract: To address the motion instability issues of existing wall-climbing robots in internal/external right-angle transition scenarios, this study proposes a rigid-wheeled magnetic adhesion robot integrated with an auxiliary transition mechanism and investigates its multi-surface motion characteristics and transition mechanisms. First, a static mechanics model is established to derive mechanical equations under right-angle transition conditions, determining the critical adsorption force range for slip-free and anti-tipping failure. Through analysis of the robot’s right-angle transitional states, the influence of discontinuous geometric wall features on adsorption forces during internal/external right-angle transitions is revealed, and the required output torque conditions for the auxiliary mechanism during external transitions are derived. Subsequently, a multi-wheel group coordinated control strategy for internal/external transitions is designed. Furthermore, the functional relationship between air gap spacing and magnetic adhesion force is clarified through magnetic field simulations, and permanent magnet spatial layout parameters are optimized using contact mechanics theory. A prototype is developed and validated through multi-condition experiments, demonstrating that the designed robot exhibits excellent load capacity and wall adaptability. Compared to traditional wheeled structures, its internal/external transition performance is significantly improved, verifying the effectiveness of the structural design, mechanical analysis, and control methodology.

Key words: wall-climbing robot, permanent magnet adhesion, right-angle transition, stability analysis