高精度多通道飞行器结构载荷测量系统设计方法

飞行器是在大气层内或大气层外空间飞行的器械,包括航空器、航天器、火箭和导弹。飞行器在机动过程中,飞行器结构的截面载荷是结构设计的重要依据,截面载荷测量结果的准确度直接关系到结构设计的可靠性。针对导弹在飞行过程中结构内部应力难以测量的问题,提出了利用载荷测试仪实测应变载荷与LS-DYNA软件结合仿真分析的方法,该方法通过对单个桁条组件的应力性能进行有限元仿真验证,确认每个桁条组件的测点布局,设计载荷测试仪进行高精度载荷测量,测试仪由8通道应变测量模块与6通道温度测量模块组成,系统由单片机与FPGA共同控制,通过应变信号调理电路与温度信号调理电路提升信号的线性度,采用Flash实现大量数据的存储,通过RS422转USB将数据上传至上位机。通过上述工作验证了载荷测试仪高精度采集方案,结果表明载荷测试仪采集到的应变数据与温度数据呈高线性度,对导弹的弹体结构设计有一定的参考价值。

Design method of high precision multi-channel missile structure load measurement system

Aircraft are instruments flying in the atmosphere or outer space, including aircraft, spacecraft, rockets and missiles. During the maneuver of aircraft, the sectional loads (tension, compression, bending and torsion) of aircraft structure are important basis for structural design. The accuracy of load measurement results directly affects the reliability of structural design.Aiming at the difficulty of testing the internal stress of missile structure during flight, a method combining the measured strain load of load tester and LS_DYNA software for simulation analysis was proposed. Firstly, the stress performance of a single stringer component is verified by finite element simulation to confirm the measurement point layout of each stringer component. The load tester is designed for high-precision load measurement. The tester is composed of 8-channel strain measurement module and 6-channel temperature measurement module, and the system is jointly controlled by MCU and FPGA. The linearity of the signal is improved through strain signal conditioning circuit and temperature signal conditioning circuit, and a large amount of data is stored by Flash. Upload data to the last computer via RS422 to USB. Load tester for high precision acquisition scheme is verified by the above work, the results show that the load tester to the data of strain and temperature data has high linearity, were superior to the existing load test device, for the projectile structure design of missile has the certain reference value.