基于LabVIEW的mN级微推力测量系统研究

Research of The Micro-Thrust Measurement System with mN-Level Based on LabVIEW

摘要:

针对卫星和航天器上的微小推力测量问题，设计一种mN级稳态微推力测量系统。推力架结构采用扭摆式测量原理，通过非接触式的激光位移传感器测量扭臂的偏转角度，并结合可调节的电磁平衡力来进行动态的闭环控制。微推力测量系统采用NI的控制器和采集板卡，在LabVIEW软件中编写PID控制算法，并开发了测量和标定的应用软件来实现mN级微推力测量。试验测试利用一组精密砝码通过3次加载和卸载过程来进行系统标定性能的验证。试验结果表明，微推力测量系统能够满足量程在10mN~200mN范围的测量，经分析，通过最小二乘法拟合获得的标定直线显示了良好的线性和重复性，加载和卸载过程的数据也具有较高的一致性，测量精度可达0.31%，满足mN级微推力测量的要求，确保了测量的稳定性和可靠性。

Abstract:

Aiming at the measurement problem of micro-trust on the satellite and spacecraft, a steady-state micro-trust measurement system with mN-level was designed. The measurement principle of torsion pendulum was applied on the structure of thrust stand. By the non-contact laser-displacement sensor, the drift angle of torsion arm was measured, which was combined with the adjustable electromagnetic balance force to carry out the dynamic closed-loop control. The controller and collector of NI company was used to the micro-thrust measurement system. The PID control algorithm and application software of measurement and calibration was developed on the LabVIEW platform to realize the mN-level micro-thrust measurement. The experiment was designed to verify the system calibration performance by the upload and unload process of 3 times with a series of precise weights. The results demonstrate that the micro-thrust measurement system is satisfied with the measurement range of 10~200mN. In this analysis, the calibration curve obtained by the least squares fit exhibits a good linearity and repeatability, and the data of upload is consistent with the data of unload. The accuracy of measurement is 0.31%, which is satisfied with the requirement of mN-level micro-thrust measurement and ensures the stability and reliability of measurement.