中文摘要：

以受迫Holmes—Duffing系统为研究对象，对系统施加时滞速度反馈控制，研究周期激励引起的系统安全域的分形侵蚀及时滞速度反馈对分形侵蚀安全盆的控制作用．利用Melnikov函数法给出时滞受控系统的安全盆的边界分形条件．再以时滞量为变参数，运用四阶Runge—Kutta方法和点映射方法数值研究了时滞对受控系统安全盆的影响规律．结果表明在弱反馈下，时滞量的增大能够提高安全盆边界分形的阈值，从而抑制安全盆的分形侵蚀．说明时滞速度反馈能够有效抑制系统的安全盆侵蚀．

英文摘要：

A forced Holmes-Dulling system is considered in this paper. A delayed velocity feedback is opplied to the system. The erosion of safe basin, caused by the periodic excitation, and the effects of delayed velocity feedback on the controlling of the fractal eroded safe basin are investigated. The conditions of fractal erosion of the basin boundary are obtained by the Melnikov method. Then considering the time delay as a variable parameter, the evolutions of safe basin with time delay are presented numerically by the 4th Runge-Kutta and the point-to-point mapping method. It is found that the increase of time delay can enhance the threshold of the fractal erosion of the basin boundary under a weak and positive feedback gain so as to reduce the basin erosion. These imply that the delayed velocity feedback can control the basin erosion of the system effectively.