关键词: 超低频振动/
滑模鲁棒算法/
主动控制/
冷原子重力仪
English Abstract
Ultra-low frequency active vibration control for cold atom gravimeter based on sliding-mode robust algorithm
Luo Dong-Yun,Cheng Bing,
Zhou Yin,
Wu Bin,
Wang Xiao-Long,
Lin Qiang
1.Center for Optics and Optoelectronics Research, Collaborative Innovation Center for Bio-Med Physics Information Technology, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
Fund Project:Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFC0601602, 2016YFF0200206) and the National Natural Science Foundation of China (Grant Nos. 61727821, 61475139, 11604296).Received Date:22 August 2017
Accepted Date:09 October 2017
Published Online:20 January 2019
Abstract:An ultra-low frequency vibrational noise isolation apparatus from external vibration can be a critical factor in many fields such as precision measurement, high-technology manufacturing, scientific instruments, and gravitational wave detection. To increase the accuracies of these experiments, well performed vibration isolation technology is required. Until recently the cold atom gravimeter has played a crucial role in measuring the acceleration due to gravity and earth gravity gradient. The vibration isolation is one of the key techniques in the cold atom gravimeter. To reduce the vibrational noise caused by the reflecting mirror of Raman beams in the cold atom gravimeter, a compact active low-frequency vibration isolation system based on sliding-mode robust control is designed and demonstrated. The sliding-mode robust control active vibration isolation method is used to solve the vibration problem of Raman mirror in the cold atomic gravimeter. The purpose of vibration control is that the controller enables the system to be at zero state as the system states are away from the equilibrium due to vibration disturbance. In this system, the mechanical setup is based on a commercial passive isolation platform which only plays a role at higher frequency. A sliding-mode robust control subsystem is used to process and feed back the vibration measured by a seismometer which can measure the velocity of the ground vibration. A voice coil actuator is used to control and cancel the motion of a passive vibration isolation platform. The simulation and experiment results of vibration isolation platform show, on the one hand, that the vibration noise power spectral density decreases by up to 99.9%, and that the phase noise in cold atom interferometry produced by vibration decreases by up to nearly 85.3% compared with the results of the passive vibration isolation platform. On the other hand, compared with the lead-lag control method, the vibration noise power spectral density decreases by up to 83.3% and the phase noise in cold atom interferometry produced by vibration decreases by nearly 40.2%. Therefore, the sliding-mode robust control has the advantages of less tuning parameters, strong anti-interference ability, and more obvious vibration isolating effect.
Keywords: ultra-low frequency vibration/
sliding-mode robust algorithm/
active control/
cold atom gravimeter
