title: Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method.
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.
authors: 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.
authors: Li-Di
authors: LD
authors: Quan
authors: 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.
authors: Chao
authors: C
authors: Xue
authors: 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.
authors: Cheng-Gang
authors: CG
authors: Shao
authors: 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.
authors: Shan-Qing
authors: SQ
authors: Yang
authors: 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.
authors: Liang-Cheng
authors: LC
authors: Tu
authors: School of Automation, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China.
authors: Yong-Ji
authors: YJ
authors: Wang
authors: 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.
authors: Jun
authors: J
authors: Luo