大量程比脉冲力矢量高精度动态测试技术研究

In the field of national key basic research，high-precision and dynamic testing of force vector with high range ratio is a bottleneck problem. To solve this problem, it is important to carry out the research on mapping relation between force vector size, direction and acting point interval values with spatial arrangement of piezoelectric quartz sensor. The mathematical model is built up between the force vector and the sensors outputs. Reverse expression is derived based on the components of force vector characterization parameters, which are the outputs of each sensor with optimized layout. The method obtained from the mechanism to improve measurement accuracy of sensor is discussed. A test structure with high stiffness and integration is put forward to meet the requirement of dynamic inherent frequency. Based on finite element analysis and identification of multiple mode shapes, the preload and partial load, stiffness matching and optimization are researched. The mechanism of interference and decoupling of test structure under the high range ratio is studied. The generator of force vector is studied which can be achieved controllable force size, adjustable direction, and variable acting point. Based on static calibration results, the mapping relation is to be validated. Dynamic vibration calibration method is researched according to the signal feature for the measured object. Using the dynamic response model from the system, the compensation algorithm of dynamic testing process is established. the measurement uncertainty of force vector is carried out to analyze the characteristic of force vector measuring. The ultimate goal is to apply the theory and methods of research in dynamic high-precision measurement of the rocket engine thrust vector.

面向国家重点领域基础性研究中，分力大量程比的力矢量高精度、动态测试的瓶颈问题，开展力矢量大小、方向、作用点区间取值与压电石英式传感器空间布置形式间映射关系研究，建立力矢量输入与传感器输出之间的数学模型, 推导基于优化布局的传感器输出的力矢量表征参数反求表达式, 提出从机理上提高传感器测量精度的方法；设计满足动态测试固有频率要求的高刚度一体化的测试结构,基于有限元分析和多阶模态振型识别，进行刚度匹配与优化研究，攻克大量程比条件下测试结构"向-向"干扰机理与解耦难题；开发大小可控、方向可调、作用点可变的稳定的矢量力发生装置，在原位在线静态标定的基础上，反向验证推导的映射关系；进行基于被测对象信号特征的动态标定方法研究，利用系统动态响应数学模型研究动态测试过程补偿算法；开展力矢量动态测试不确定度研究，全面分析力矢量测量性能。力争实现项目研究成果应用于火箭发动机脉冲推力矢量高精度测量的目标。

以具有代表性的火箭发动机瞬时/连续脉冲点火工作方式下推力矢量高精度动态测量为背景，基于压电效应，开展了大量程比约束条件下力矢量高精度动态测量原理研究。开展了力矢量大小、方向、作用点区间取值与压电石英式传感器空间布置形式间映射关系研究，通过多点空间约束下传感器输出映射应力场研究，进一步提出了力值比的概念，建立力矢量输入与传感器输出之间的数学模型。通过具有自预紧功能的压电三 向测力单元研究，压电测试多维力分载研究，实现了一体化高刚度测试结构设计。通过变力值比下高精度标定和向间干扰解耦，测力单元预紧部件刚度研究，研发了一种小型化多维压电力传感器并进行标定，提出了多种多支点压电测力仪的标定方法。通过温升对测试影响研究，基于归一化标定的压电测力仪测试精度研究，提出了力矢量压电测试不确定度分析方法。研究的映射关系、求解方法、高刚度一体化结构设计方法、标定方法，以及构建的测试装置，已经应用于探月工程中的相关火箭发动机推力矢量检测，为其提供了关键检测数据。通过后续的总结和研究，必将在其他领域得到推广和应用。