Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method

Li-Di Quan; Chao Xue; Cheng-Gang Shao; Shan-Qing Yang; Liang-Cheng Tu; Yong-Ji Wang; Jun Luo

doi:10.1063/1.4861189

Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method

Rev Sci Instrum. 2014 Jan;85(1):014501. doi: 10.1063/1.4861189.

Authors

Li-Di Quan¹, Chao Xue¹, Cheng-Gang Shao¹, Shan-Qing Yang¹, Liang-Cheng Tu¹, Yong-Ji Wang², Jun Luo¹

Affiliations

¹ MOE Key Laboratory of Fundamental Physical Quantities Measurements, School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China.
² School of Automation, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China.

PMID: 24517789
DOI: 10.1063/1.4861189

Abstract

The performance of the feedback control system is of central importance in the measurement of the Newton's gravitational constant G with angular acceleration method. In this paper, a PID (Proportion-Integration-Differentiation) feedback loop is discussed in detail. Experimental results show that, with the feedback control activated, the twist angle of the torsion balance is limited to [Formula: see text] at the signal frequency of 2 mHz, which contributes a [Formula: see text] uncertainty to the G value.