Research on characteristics of adsorption and stability of electromagnetic bionic sucker

To improve the universality and safety of the adsorption system in bridge inspection robot, an electromagnetic bionic composite sucker is proposed. In order to explore the influence of contact excitation and time-varying stiffness on the adsorption stability of electromagnetic bionic suction, the coupling relationship between electromagnetic and bionic sucker is derived based on Hertz contact theory and Maxwell theory, and the surface distortion caused by Maxwell force and Van der Waals force is calculated. The nonlinear dynamics model of composite suction system is established considering the contact load, the surface friction factor, Maxwell stress and time-varying stiffness, adsorption air gap and other factors. Two control parameters are selected to analyze the effect of excitation amplitude and frequency on system stability, and the corresponding simulation is completed. The simulation results show that due to the fluctuation of excitation amplitude and frequency in the adsorption process, the system exhibits obvious nonlinear phenomenon, and the stability of adsorption can be improved by controlling the reasonable threshold.