三轴加速度计灵敏度矩阵协同修正三轴动态标定研究

Since the sensitive axes of the tri-axial accelerometer cannot be completely parallel to the orthogonal axes of the tri-axial vibrations to be measured, there are coupling response relations between the three sensitive axes. Therefore, the definition of sensitivity must be changed from the traditional three axis-independent sensitivities into 3 × 3 matrix form. The traditional tri-axial synchronous dynamic calibration based on laser vibrometers may generate coupling detection errors for the excitation signals, which affect the calibration accuracy of the sensitivity matrix. In this project, we study the dynamic calibration theory and technology for the tri-axial accelerometer sensitivity matrix, which could realize the quantitative characterization and collaborative correction of the coupled detection errors. Firstly, a new method for detecting tri-axial excitation signals by three groups of uniaxial accelerometers and a cubic detection block is proposed, and the corresponding coupling detection error characterization mechanism is revealed; then, the coupling error correction principle is studied based on mutually anti-phase tri-axial excitation signals, and the parametric correction model is constructed for the tri-axial accelerometer sensitivity matrix based on the neural network inverse system modeling method; finally, the dynamic calibration principle of the model parameters based on linear independent tri-axial excitations is explored and a three-axis dynamic calibration system is set up for experimental testing. This project aims to achieve accurate detection of excitation signals and sensitivity matrix for tri-axial accelerometer based on tri-axis dynamic calibration method. The research results can provide theoretical and technical support for accurate traceability of vibration values and technology progress in related industry application fields.

三轴加速度计使用中各敏感轴不能完全与待测三轴振动各正交轴平行，造成各轴间存在耦合响应关系，所以，其灵敏度需由传统三轴独立灵敏度组合定义方式转变为3×3矩阵形式。传统基于激光测振仪的三轴同步动态标定存在激励信号耦合检测误差，影响灵敏度矩阵标定精度。本项目研究可实现耦合检测误差定量表征及协同修正的三轴加速度计灵敏度矩阵动态标定理论与技术。首先，提出由三组单轴加速度计及立方检测块检测三轴激励信号新方法，并揭示相应的耦合检测误差表征机理；然后，研究基于两两反相三轴激励信号的耦合误差协同修正原理，并基于神经网络逆系统建模方法构建三轴加速度计灵敏度矩阵参数化修正模型；最后，探究模型参数基于线性独立三轴激励的动态标定原理并搭建三轴动态标定系统进行实验测试。本项目旨在实现三轴加速度计三轴动态标定激励信号的准确检测及灵敏度矩阵高精度标定，研究成果可为相关领域振动量值精确溯源及行业技术进步提供理论及技术支撑。

传统基于激光测振仪的三轴加速度计灵敏度矩阵三轴同步动态标定存在三轴激励信号耦合检测误差，影响标定精度。为此，本项目研究三轴振动激励信号耦合检测误差的定量表征原理及协同修正方法，实现三轴加速度计灵敏度矩阵的高精度标定。完成的主要研究内容为：.1）首先，完成了三轴振动轨迹合成与分解原理分析，实现了对三轴加速度计三轴动态标定过程中激励信号轨迹的直观描述及定性表征；基于遗传算法迭代寻优方法及变结构单轴激振器磁路结构优化原理，实现了单轴激振器回复簧片及磁路结构的优化设计，有效扩展了振动台的稳定工作频率范围，降低了输出振动的横向分量；进一步基于对单轴加速度计检测三轴振动耦合误差分析，完成了对三轴激励信号耦合检测误差的定量表征。.2）然后，基于三组单轴加速度计对具有不同相位组合关系的三轴激励输入的耦合响应特性分析，提出了基于误差补偿原理的三轴振动激励信号耦合检测误差的修正方法，进而建立了各轴检测误差量与激励输入间的多输入-多输出响应模型，实现了三组单轴加速计检测三轴振动信号耦合检测误差的准确、快速计算修正，完成了三轴振动激励信号的高精度检测。.3）最后，研究了三轴激振器多孔质气浮与正交簧片复合解耦原理，实现了不同参数气膜轴向承载及刚度特性的对比优化及回复簧片非线性导致的大行程振动谐波失真准确表征；基于传递函数模型，实现了电磁激振器输出振动幅值及谐波的准确迭代控制；进一步，构建了三轴动态标定实验平台，实现了基于三轴激励信号耦合检测误差协同修正的三轴加速度计灵敏度矩阵高精度实验标定。.本项目提出的三轴振动检测方法及误差修正原理可有效提高三轴振动标定中激励信号的检测精度及灵敏度矩阵标定精度，构建的仿真优化分析方案可直接适用于其它类型激振器的设计开发，相关研究成果可为三轴加速度计等具有耦合响应特性的振动检测仪器高精度标定及相关应用领域技术进步提供理论依据及创新方法，具有显著的成果推广应用价值和前景。