AN IMPROVED METHOD FOR DETERMINING PERIODIC SOLUTIONS OF NOLINEAR DYNAMICAL SYSTEM
求解非线性动力系统周期解的改进打靶法

Boundary value problems for dynamical systems with periodic solutions can be turned into initial value problems.With this point in mind,the paper improves the shooting method.In the process of computing derivatives of boundary conditions' algebraic equations,which are functions of unknown initial value parameters, the node function values are obtained through Runge-Kutta method,and by using Runge-Kutta method once more,the derivatives can be obtained.The validity of such a method is verified by using it to obtain periodic solutions of Duffing equation and nolinear rotor-bear system,and comparing the results with those computed by traditional method.Meanwhile,we discuss the stability of the solutions by Floquet theory.