闭环控制下单丝扭摆微牛级推力测量系统

Single wire torsion pendulum micro-newton thrust measurement system in closed loop control

针对空间引力波探测任务对微推力测量需求,开发出一套基于闭环控制的单丝扭摆微牛级推力测量系统。基于扭摆式微推力测量原理,给出了微推力测量装置详细设计方案,重点分析了扭丝结构、角位移测量、电磁标定力以及闭环控制系统,通过实验测量对该微推力测量装置进行标定,最后开展误差分析。测试结果表明,开环状态下扭丝刚度约为0.00325 N·m/rad,与理论值误差约4.0%;闭环状态下推力测量范围0.1~246.0μN,最小分辨率优于0.1μN,相对不确定误差为1.174%,满足对微推力器推力测量范围、分辨率和精度的测量要求。

In response to the micro-newton thrust measurement requirements for space gravitational wave detection missions,a singlewire torsion micro-newton thrust measurement system based on closed-loop control has been developed.Based on the principle of torsional pendulum micro-newton thrust measurement,the detailed design scheme of the micro-newton thrust measurement device is given,and the twisted wire structure,angular displacement measurement,electromagnetic calibration force,and closed-loop control system are mainly analyzed.The micro-newton thrust measuring device is calibrated through experimental measurement,and finally the error analysis is carried out.The test results show that the torsion wire stiffness is about 0.00325 N·m/rad in the open-loop state,and the error with the theoretical value is about 4.0%;the thrust measurement range in the closed-loop state is 0.1~246.0μN,and the minimum resolution is better than 0.1μN,which is relatively uncertainty error is 1.174%,which meets the measurement requirements for the thrust measurement range,resolution and accuracy of micro thrusters.