The state of art of techniques for measurement of in-flight loads is present in this paper. Load measurement for launch vehicle has been doing for the first time in China. A new test was done, namely accuracy verify test through compound loads. The result of this verifying test shows that larger load have strong influence on the smaller load measurement. In order to solve the problem, a linear and a nonlinear fit model is developed based on all test cases. The nonlinear fit model made the load measurement error cut down to 13% from 70%, about five multiple linearity of main load channel. At the same time, correlation coefficient improved to 0.996, and the requirement for load measurement was satisfied. The linear fit model is recommended when coupling effect between different channels is non-significant. And load measurement error is about two multiple linearity of main load channel.%介绍了飞行载荷测量的技术现状,首次开展了国内火箭飞行载荷测量工作,并新增了复合载荷的精度试验工况,发现了大量程载荷对小量程通道的强耦合效应.通过建立多试验状态的线性与非线性耦合效应的载荷矢量拟合模型,将测量误差从70%降低至13%,比主灵敏度线性度大5倍,相关系数提高至0.996,比主灵敏度低一个量级,基本满足载荷测量要求.对于弱耦合效应的载荷测量,采用线性耦合效应载荷矢量拟合模型,也可有效提高火箭飞行载荷测量精度,测量误差为主灵敏度线性度的两倍.
展开▼
