A novel Raman-gain control method by detecting the Rayleigh backscattering of pump lights

2003 ◽  
Author(s):  
Hiroji Masuda ◽  
Yutaka Miyamoto ◽  
Masahito Tomizawa
Keyword(s):  
Control Method ◽  
Gain Control ◽  
Raman Gain ◽  
Rayleigh Backscattering

A CMOS Wideband Variable Gain LNA with Novel Gain Control Method

2010 ◽  
Vol 32 (11) ◽  
pp. 2772-2775
Author(s):  
Fei-hua Chen ◽  
Xin-zhong Duo ◽  
Xiao-wei Sun
Keyword(s):  
Control Method ◽  
Gain Control ◽  
Variable Gain

scholarly journals Adaptive Gain Control Method of a Phase-Locked Loop for GNSS Carrier Signal Tracking

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Zhibin Luo ◽  
Jicheng Ding ◽  
Lin Zhao
Keyword(s):  
Control Method ◽  
Tracking Error ◽  
Gain Control ◽  
Phase Locked Loop ◽  
Satellite System ◽  
Error Characteristic ◽  
Loop Gain ◽  
Target Movement ◽  
Signal Tracking ◽  
Global Navigation Satellite

The global navigation satellite system (GNSS) has been widely used in both military and civil fields. This study focuses on enhancing the carrier tracking ability of the phase-locked loop (PLL) in GNSS receivers for high-dynamic application. The PLL is a very popular and practical approach for tracking the GNSS carrier signal which propagates in the form of electromagnetic wave. However, a PLL with constant coefficient would be suboptimal. Adaptive loop noise bandwidth techniques proposed by previous researches can improve PLL tracking behavior to some extent. This paper presents a novel PLL with an adaptive loop gain control filter (AGCF-PLL) that can provide an alternative. The mathematical model based on second- and third-order PLL was derived. The error characteristics of the AGCF-PLL were also derived and analyzed under different signal conditions, which mainly refers to the different combinations of carrier phase dynamic and signal strength. Based on error characteristic curves, the optimal loop gain control method has been achieved to minimize tracking error. Finally, the completely adaptive loop gain control algorithm was designed. Comparable test results and analysis using the new method, conventional PLL, FLL-assisted PLL, and FAB-LL demonstrate that the AGCF-PLL has stronger adaptability to high target movement dynamic.

scholarly journals Digital Control of a Stepping Motor for Eliminating Rotation Speed Fluctuations Using Adaptive Gains

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1335
Author(s):  
Daishin Isobe ◽  
Noriyuki Hori ◽  
Shin Kawai ◽  
Keisuke Yagi ◽  
Triet Nguyen-Van
Keyword(s):  
Digital Control ◽  
Control Method ◽  
Rotation Speed ◽  
Gain Control ◽  
Lyapunov Stability Theory ◽  
Stepping Motor ◽  
Control Loop ◽  
Hybrid Stepping Motor ◽  
Speed Fluctuation ◽  
Switching Structure

Nowadays, stepping motors are usually used as precise actuators in various new scientific fields, such as syringe pumps, blood analyzers, and bio-3D printers. Controlling rotation of the stepping motor without speed fluctuation under no-load conditions plays an important role in improving the accuracy of the machine’s drive. This paper proposes a digital control method for a five-phase hybrid stepping motor. The proposed controller includes an original control loop and a PI adaptive integration gain control loop. The original digital control loop is redesigned from the analog controller by using the direct PIM method. The PI adaptive control loop is added to the original control loop in a parallel way to remove a steady deviation of the motor and suppress a physical saturation factor inside the plant. Lyapunov stability theory is used to prove a stability condition of the PI regulator gains. Experimental results show that the proposed controller can suppress the chattering caused by the switching structure and gives performances as good as that of the commercial analog controller in a high rotation speed range without fluctuation.

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