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

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10~200 mN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。

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 10~200 mN.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.