一种新的时域动态载荷识别方法

为了准确地识别未知载荷和降低测量噪声对识别结果的影响,基于动态规划方法和Bellman最优化原理,提出了新的时域动态载荷识别方法.从系统的状态空间方程出发,利用最小二乘法建立了系统响应的实际测量值与识别值之间的目标函数,同时引入Newmark积分,得到了基于系统位移、速度和加速度响应的系统离散运动方程;将动态规划方法和Bellman最优化原理应用于目标函数的最小化,推导了动态优化载荷识别公式.通过数值算例对文中方法进行了验证,结果表明:该方法对动态载荷识别适应性强,在测量响应含有10%噪声干扰下,误差均低于25%. 

A New Time-Domain Method for Force Identification

In order to identify unknown load accurately and reduce the influence of measurement noise on identification results, a new time-domain method for dynamic load identification was proposed based on dynamic programming and Bellman optimization principle. First, the objective function between measured and identified system responses was established using the state-space formulation and the least square error method. Then, discrete equations of motion based on the system displacement, velocity, and acceleration responses were obtained by Newmark integration method. Finally, the dynamic programming method and Bellman optimization principle were used for minimization of the objective function to estimate the excitation forces, and identification formulations of optimal dynamic load were deduced. In addition, the numerical example was provided to verify the proposed mathematical model. The results show that the proposed method has a strong adaptability in dynamic load identification; under 10% noise disturbance, the error of measured response is always less than 25%.