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Updated: May 3, 2026

Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method
Li-Di Quan1, Chao Xue1, Cheng-Gang Shao1
1MOE Key Laboratory of Fundamental Physical Quantities Measurements, School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China.
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.
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