MOE Key Laboratory of Fundamental Physical Quantities Measurement and Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
Beijing Institute of Control Engineering, Beijing 100190, China.
Rev Sci Instrum. 2023 Jan 1;94(1):014504. doi: 10.1063/5.0120130.
A decoupling method is proposed for micro-Newton thrust measurement with a torsion pendulum. The basic approach is to reduce the influences introduced by the propellant tube and wires of the thruster. A hollow aluminum tube is used to hang the torsion pendulum and is also chosen as the transport pipe for the propellant of the thruster. The electric control box of the thruster is mounted on the pendulum body, which is powered by an externally installed power supply through a liquid metal conductive unit. The control of the electric control box is performed through wireless transmission. With this design, the influences of the propellant tube and connection wires between the torsion pendulum and the outside device are reduced and the stability of the torsion spring constant of the system can be improved. The use of the liquid metal conductive unit reduces the coupling between the wires and the measurement system. The feasibility of the wireless transmission is analyzed. The error sources during the thrust measurement are analyzed, and the expected three σ uncertainty of the thrust is 0.03+(0.10%*F)μN for the measurement of the cold gas thruster. The scheme provides a thrust measurement with higher precision and stability.
提出了一种微牛级推力测量的解耦方法，该方法采用扭摆。基本方法是减少推进剂管和推进器电线引入的影响。使用空心铝管悬挂扭摆，并将其用作推进器的输送管。推进器的电控箱安装在摆体上，通过液态金属导电单元由外部安装的电源供电。通过无线传输进行电控箱的控制。通过这种设计，可以减少扭摆与外部设备之间的推进剂管和连接线的影响，提高系统扭簧常数的稳定性。使用液态金属导电单元减少了电线和测量系统之间的耦合。分析了无线传输的可行性。分析了推力测量中的误差源，对于冷气体推进器的测量，推力的预期三个 σ 不确定度为 0.03+(0.10%*F)μN。该方案提供了更高精度和稳定性的推力测量。
