Effect of Feedback Control on the Bifurcation Stability of a Nonlinear Servohydraulic System: An Experimental Investigation

2003 ◽  
Author(s):  
Amit Shukla ◽  
David F. Thompson ◽  
Srinivas Kowta
Keyword(s):  
Experimental Investigation ◽  
Feedback Control ◽  
Hydraulic System ◽  
Control Structure ◽  
Linear Feedback ◽  
Hydraulic Systems ◽  
Order Model ◽  
Stability Behavior ◽  
Bifurcation Stability ◽  
System A

Servo-hydraulic systems are commonly used for motion and force control. In this work, an experimental investigation is performed to study the effect of feedback control on the bifurcation stability of a nonlinear servo-hydraulic system. A low-order model of the experimental test stand is developed, validated and analyzed. It is shown that the use of appropriate feedback control structure can improve the bifurcation stability of a nonlinear servo-hydraulic system. Parametric space investigation is conducted to study the bifurcation stability behavior of the system and stability boundaries are developed to demonstrate the effect of linear feedback on the nonlinear systems.

Integration of a plug-and-play desktop robotic system

Robotica ◽  
2009 ◽  
Vol 27 (3) ◽  
pp. 403-409 ◽  
Author(s):  
Jianbo Su ◽  
Yanjun Zhang
Keyword(s):  
Feedback Control ◽  
Distributed Control ◽  
Personal Computer ◽  
Pid Control ◽  
System Reliability ◽  
Control Algorithm ◽  
Control Structure ◽  
Robotic System ◽  
Universal Serial Bus ◽  
Plug And Play

SUMMARYThis paper describes the development of a desktop robotic system that enables the plug-and-play function through the USB (universal serial bus) port of a personal computer (PC). Thus a new kind of desktop PC peripheral is invented that has programmable manipulability. The robotic system is realized on an internally distributed control structure that facilitates higher system reliability. A PID control algorithm is implemented on a prototype of the proposed system, to demonstrate the system's ability to implement feedback control. Experimental results show the performance and properties of the proposed system.

Singe-Phase Grid-Connected Inverter Based on Voltage-Oriented Control in Photovoltaic Generation Systems

2013 ◽  
Vol 765-767 ◽  
pp. 2498-2502
Author(s):  
Yong Yang ◽  
Chun Qing Qi ◽  
Ji Suo ◽  
Feng Wen Cao
Keyword(s):  
Feedback Control ◽  
Reference Frame ◽  
Single Phase ◽  
Control Structure ◽  
Current Control ◽  
Control Loop ◽  
Excellent Performance ◽  
Photovoltaic Generation ◽  
Control Scheme ◽  
Grid Connected Inverter

The paper proposes a new control of a transformerless singe-stage single-phase grid-connected inverter in photovoltaic generation systems. The control scheme is mainly based on voltage-oriented control (VOC) with help of second order Generalized Integrator (SOGI). A cascaded control structure with an outer dc link voltage control loop and an inner current control loop is used. The currents are controlled in a synchronous dq reference frame using a decoupled feedback control. The simulated results have proven an excellent performance and verified the validity of proposed system.

scholarly journals LMI-Based State Feedback Control Structure for Resolving Grid Connectivity Issues in DFIG-Based WT Systems

Eng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 562-591
Author(s):  
Muhammad Arif Sharafat Ali
Keyword(s):  
Feedback Control ◽  
Power Plants ◽  
State Feedback ◽  
Control Structure ◽  
Rapid Onset ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Grid Voltage ◽  
Grid Connection ◽  
Doubly Fed

Pertaining to the connectivity issues in wind power plants with grids, this study introduces an efficient mechanism based on a state feedback control structure to establish a fast and stable grid connection for a wind-driven doubly-fed induction generator (DFIG). Owing to a direct link through stator windings, a DFIG is significantly vulnerable to grid disturbances and experiences sizable inrush currents when connected to the power grid. The proposed control structure is designed based on a linear matrix inequality stabilization criterion, which is framed using a suitable Lyapunov candidate function. The control objective is to ensure that the stator voltage can exponentially converge to the grid voltage, accounting for balanced and unbalanced grid conditions. This is achieved by generating appropriate rotor voltage references for rotor-side converter control. This study also explores the capability of the proposed control structure to enhance the system’s robustness to external disturbances and uncertain parametric variations. Simulations confirmed the effectiveness and suitability of the developed structure in mitigating the adverse effects of the rapid onset of the grid voltage at the stator terminals of the DFIG under various grid conditions; the proposed structure could thus establish a reliable connection with negligible effects on the DFIG and the grid.

scholarly journals Modified Structures for Hybrid Active Sound Quality Control System Disturbed by Gaussian Random Noise

2020 ◽  
Vol 10 (2) ◽  
pp. 510 ◽  
Author(s):  
Shanjun Li ◽  
Guoyong Jin ◽  
Xiaobo Li ◽  
Tiangui Ye
Keyword(s):  
Quality Control ◽  
Control System ◽  
Feedback Control ◽  
Control Structure ◽  
Random Noise ◽  
Reference Signal ◽  
Sound Quality ◽  
Noise Cancellation ◽  
Quality Control System ◽  
Line Spectrum

A hybrid active sound quality control system, in which a hybrid feedforward and feedback structure is applied, can not only be used in cases where the line-spectrum noise is obtained easily with reference sensors, but it can also improve the comfortability of noise and eliminate unexpected Gaussian random noise. However, the traditional structure for a hybrid active sound quality control system, whereby a reference signal in the feedback control structure is synthesized by the output signals of the feedforward control filter, feedback control filter, and line-spectrum noise cancellation control filter, introduces couplings of the three control filters. To remove the coupling interactions of the feedforward and feedback control structures and to reduce the complexity of the control system, two modified structures with less computational complexity or a smaller increase in computation are investigated in this paper. The first one involves a simplified structure in which the reference signal in the feedback control structure is replaced by the summation of the residual error signal and the output signal of the line-spectrum noise cancellation control filter, and the second one is a modified structure which integrates the output signals of the feedback control filter and the line-spectrum noise cancellation control filter for the reference signal in the feedback control structure. Numerical simulations are carried out to show the performance of the modified structures. The results illustrate that the two modified structures have the ability to cancel Gaussian random noise and to reduce or enhance the amplitude of line-spectrum noise to promote sound quality. Moreover, a simplified structure with a new leaky filtered-x least mean square (FxLMS) algorithm is proposed to upgrade the noise reduction performance and elevate stability in the feedback control structure. The effectiveness of the proposed algorithm also is proven by the simulation results.

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