AFM-TM微悬臂梁系统混沌运动及控制算法分析OACSTPCD

To address the issue of measurement accuracy in atomic force microscope in tapping mode(AFM-TM)caused by the chaotic motion of the AFM-TM cantilever beam system,this study focused on analyzing the dynamic characteristics and control algorithm of the system.Through numerical simulation,the Lyapunov index,bifurcation diagram,Poincaré cross section,and phase diagram were used to analyze the evolution of the motion characteristics of AFM-TM microcantilever beam system when the external excitation amplitude changes.The delayed feedback control and fuzzy adaptive delayed feedback were proposed to control the chaotic motion of the system.Finally,the two control algorithms were compared.The results showed that the system exhibited obvious chaotic motion characteristics when the dimensionless external excitation amplitude was within the range of values such as[0.65,0.85].Both the time-delay feedback control and the fuzzy adaptive time-delay feedback control could effectively pull the chaotic motion of the system back to the periodic orbit,but the fuzzy adaptive time-delay feedback was more suitable for the complex situation of the change of the AFM-TM sample.The research results provide a significant theoretical reference for selecting external excitation parameters of AFM-TM microcantilever beams,analyzing complex dynamic characteristics of nonlinear systems and controlling chaotic motion.