杆式应变天平变负载动态建模和分段动态补偿

Dynamic modeling and staged compensation of bar-shaped strain gauge balance with changing load

杆式应变天平安装在飞行器模型中,用于测量飞行器模型在风洞实验中所受的空气动力和力矩。模型相当于天平的负载。为了研究负载对天平动态特性的影响,通过改变天平上的配重砝码质量,进行不同负载下的天平动态标定实验。采用OE模型描述在不同负载下,天平各通道的数学模型。根据模型得到动态特征参数。通过曲线拟合,表示天平特征参数与负载质量之间的变化规律。为了保证在不同负载下,天平均具有较好的动态响应性能,提出依据负载变化的分段动态补偿的思路,实现对不同负载实验数据的动态补偿,取得较好效果。

In the wind tunnel experiment, bar-shaped strain gauge balance installed in aircraft model is used to measure the aerodynamic forces and moments applied to the aircraft model. The aircraft model can be regarded as the load of the balance. In order to research the effect of load on the dynamic characteristic of the balance, the dynamic calibration experiments are conducted with different loads that are realized by changing weights. The system identification method based on output error model is adopted to describe the dynamic mathematical models for various channels of the balance with different loads. Their dynamic characteristic parameters are obtained according to the models. The curve fitting method is used to present the varying pattern between the characteristic parameters of the balance and the mass of loads. A kind of staged dynamic compensation solution is proposed to ensure good dynamic response performance under different loads. It implements the dynamic compensation for experimental data of different loads, and achieves good results.