基于矢量图的力状态映射法辨识参数误差分析

摘要

力状态映射法被常用于辨识非线性连接结构的等效动力学参数，该方法需要用到实验仪器测量得到或者经过微分或积分计算得到的激励力、速度、位移、加速度等数据。而往往这些数据的相位会出现失真，这会直接导致通过力状态映射辨识得到的系统参数出现误差。用矢量图法计算得到了单自由度系统在强迫振动和自由振动两种情况下出现测量数据或计算数据小幅度相位失真时的误差计算公式，结果表明这种小幅度相位失真对系统阻尼系数的影响明显大于对系统刚度系数的影响，且当激励力频率等于固有频率时辨识参数的误差最小。%The force-state mapping is usually used to identify the equivalent dynamic parameters of a nonlinear joint,which needs lots of data from instruments or from differential or integral,such as excitation force,velocity, displacement,and acceleration.If those signals happen to suffer phase distortion,parameters identified from the force-state mapping will carry errors.Error formulations of identified parameters were derived by the vector diagram when the single degree of freedom system suffered a narrow range of phase distortion.The results indicate that the system stiffness is influenced heavily by the narrow range of phase distortion compared with the system damping.