研究了利用频响数据进行振动系统辨识的问题。将振动系统表示为二阶传递函数之和的形式，通过约束传递函数模型中分母系数为正，可以保证模型的稳定性。采用非线性最小二乘目标函数作为优化准则，分子和分母系数通过分离的方式进行估计。分母系数利用模拟退火算法得到，分子系数通过求解线性最小二乘问题得到。数值仿真算例验证了辨识算法的有效性。

The problem of identifying vibrating systems from frequency response data is considered. The unknown model of a vibrating system is parameterized as a sum of second order transfer functions. The model can be guaranteed to be stable if the denominator coefficients in the second order transfer functions are constrained to be positive. The nonlinear least squares cost function is adopted and the numerator and denominator coefficients are estimated in a separable manner. The denominator coefficients are estimated using simulated annealing and the numerator coefficients are obtained by solving the linear least squares problem. A numerical example is given to demonstrate the validity of the proposed algorithm.