scholarly journals Nonlinear dynamics and robust control of sloshing in a tank

2018 ◽  
Vol 25 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Tingting Zhang ◽  
Jianying Yang
Keyword(s):  
Nonlinear Dynamic ◽  
Closed Loop ◽  
Control Method ◽  
System A ◽  
Fluid Systems ◽  
Optimal Control Method ◽  
Guaranteed Cost ◽  
The Stability ◽  
Nonlinear Dynamic Modeling ◽  
Stability Of Structure

Sloshing is a complex nonlinear dynamic phenomenon which has a significant influence on the stability of structure–fluid systems. In this study, the dynamic equation of sloshing based on Hamilton principle is established and linearized into a state space equation. Considering the uncertainty of the system, a robust H infinite guaranteed cost control method is proposed to mitigate the response of fluid wave height to horizontal acceleration of the tank body. Simulation results are given to demonstrate the closed-loop performance of the nonlinear dynamic modeling and linear optimal control method.

Discrete Time-Delay Optimal Control Method for Experimental Active Chatter Suppression and Its Closed-Loop Stability Analysis

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xingwu Zhang ◽  
Ziyu Yin ◽  
Jiawei Gao ◽  
Jinxin Liu ◽  
Robert X. Gao ◽  
...  
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Control Method ◽  
Trial And Error ◽  
Stability Lobe Diagram ◽  
Weighting Matrix ◽  
Chatter Suppression ◽  
Stability Lobe ◽  
Optimal Control Method ◽  
Discrete Time Delay

Chatter is a self-excited and unstable vibration phenomenon during machining operations, which affects the workpiece surface quality and the production efficiency. Active chatter control has been intensively studied to mitigate chatter and expand the boundary of machining stability. This paper presents a discrete time-delay optimal control method for chatter suppression. A dynamical model incorporating the time-periodic and time-delayed characteristic of active chatter suppression during the milling process is first formulated. Next, the milling system is represented as a discrete linear time-invariant (LTI) system with state-space description through averaging and discretization. An optimal control strategy is then formulated to stabilize unstable cutting states, where the balanced realization method is applied to determine the weighting matrix without trial and error. Finally, a closed-loop stability lobe diagram (CLSLD) is proposed to evaluate the performance of the designed controller based on the proposed method. The CLSLD can provide the stability lobe diagram with control and evaluate the performance and robustness of the controller cross the tested spindle speeds. Through many numerical simulations and experimental studies, it demonstrates that the proposed control method can make the unstable cutting parameters stable with control on, reduce the control force to 21% of traditional weighting matrix selection method by trial and error in simulation, and reduce the amplitude of chatter frequency up to 78.6% in experiment. Hence, the designed controller reduces the performance requirements of actuators during active chatter suppression.

Mode Decoupling Controller for Feedback Model Updating

2004 ◽  
Author(s):  
Hunsang Jung ◽  
Youngjin Park ◽  
K. C. Park
Keyword(s):  
Closed Loop ◽  
Model Updating ◽  
Control Method ◽  
Loop System ◽  
Mode Shapes ◽  
Closed Loop System ◽  
Sensitivity Matrix ◽  
Data Set ◽  
Conventional Methods ◽  
The Stability

A novel concept of feedback loop design for modal test and model updating is proposed. This method uses the closed-loop frequency information for parameter modifications to overcome the problems associated with the conventional methods employing the modal sensitivity matrix. To obtain new modal information from the closed-loop system, controllers should be effective in changing modal data while guaranteeing the stability of the closed-loop system. The present paper proposes a mode-decoupling controller that can alter a target mode while guaranteeing the stability of the closed-loop, and that can be constructed by using the measured open-loop, mode shapes. A simulation based on time domain input/output data is performed to evaluate the feasibility of the proposed control method, which is subsequently corroborated via experiments. Experimental data obtained on a beam via the proposed mode-decoupling controller have been applied to estimate thicknesses of a beam. The results show that the proposed approach outperforms conventional methods with a far less number of data set for the estimation of system parameters.

Reduction Methods of Structure Models for Control System Purposes

2016 ◽  
Vol 248 ◽  
pp. 119-126 ◽  
Author(s):  
Andrzej Koszewnik ◽  
Zdzisław Gosiewski
Keyword(s):  
Control System ◽  
High Frequency ◽  
Closed Loop ◽  
Flexible Structures ◽  
Low Frequency ◽  
Point Of View ◽  
Closed Loop Systems ◽  
System A ◽  
Reduction Methods ◽  
The Stability

To design vibration control system for flexible structures their mathematical model should be reduced. In the paper we consider the influence of the model reduction on the dynamics of the real closed-loop system. A simply cantilever beam is an object of consideration since we are able to formulate the exact analytical model of such structure. As a result of reduction the model with low frequency resonances is usually separated from the high frequency dynamics because high frequency part of the model is naturally strong damped. In order to estimate dynamical system for control purposes in the paper we applied a few orthogonal methods such as: modal, Rayleigh-Ritz and Schur decompositions. As it is shown all methods well calculate resonances frequencies but generate different anti-resonances frequencies. From control strategy in point of view of the flexible structures these anti-resonances have significantly influence on the stability and dynamics of the closed-loop systems.

Switching Control Design for Switched Fuzzy Discrete-Time Systems

2014 ◽  
Vol 1006-1007 ◽  
pp. 711-714
Author(s):  
Hong Yang ◽  
Huan Huan Lü ◽  
Le Zhang
Keyword(s):  
Stability Analysis ◽  
Discrete Time ◽  
Fuzzy Systems ◽  
Closed Loop ◽  
Control Method ◽  
Control Design ◽  
Switching Control ◽  
Discrete Time Systems ◽  
The Stability ◽  
Time Systems

This paper investigates the problems of stability analysis and stabilization for a class of switched fuzzy discrete-time systems. Based on a common Lyapunov functional, a switching control method has been developed for the stability analysis of switched discrete-time fuzzy systems. A new stabilization approach based on a switching parallel distributed compensation scheme is given for the closed-loop switched fuzzy systems. Finally, the illustrative example is provided to demonstrate the effectiveness of the techniques proposed in this paper.

scholarly journals Performance Analysis of Closed loop Control of Diesel Generator Power Supply for Base Transceiver (BTS) Load

2019 ◽  
Vol 8 (9) ◽  
pp. 2483-2495
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Complete System ◽  
Closed Loop Control ◽  
Double Loop ◽  
Diesel Generator ◽  
Unity Power Factor ◽  
Loop Control ◽  
Bridge Rectifier ◽  
The Stability

This paper describes closed loop control of Diesel Generator (DG) supplying power to a Base Transceiver (BTS) load of a telecommunication tower, which is DC in nature. Detail modeling of Diesel Generator set has been presented.. The stability analysis of governor and excitation system has been carried out in frequency domain. When DG source is connected to the BTS load bus through bridge rectifier, the output waveform distorted due to high odd harmonics content. To solve this problem a unity power factor rectifier has been designed. For the control operation of this UPFC rectifier, double loop mode control method has been used and results are presented. The complete system has been simulated in MATLAB-SIMULINK environment.

An Approach to Telerobotic Manipulations

1997 ◽  
Vol 119 (3) ◽  
pp. 431-438 ◽  
Author(s):  
H. Kazerooni ◽  
C. L. Moore
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Sufficient Conditions ◽  
Human Robot Interaction ◽  
Loop System ◽  
Robotic Manipulation ◽  
Closed Loop System ◽  
Robot Interaction ◽  
Minimum Number ◽  
The Stability

This article introduces three areas of study: 1 telefunctioning; 2 a control method for producing telefunctioning; and 3 an analysis of human-robot interaction when telefunctioning governs the system behavior. Telefunctioning facilitates the maneuvering of loads by creating a perpetual sense of the load dynamics for the operator. Telefunctioning is defined as a robotic manipulation method in which the dynamic behaviors of the slave robot and the master robot are functions of each other; these functions are the designer’s choice and depend on the application. (In a subclass of telefunctioning currently referred to as telepresence, these functions are specified as “unity” so that the master and slave variables (e.g., position, velocity) are dynamically equal.) To produce telefunctioning, this work determines a minimum number of functions relating the robots’ variables, and then develops a control architecture which guarantees that the defined functions govern the dynamic behavior of the closed-loop system. The stability of the closed-loop system (i.e., master robot, slave robot, human, and the load being manipulated) is analyzed and sufficient conditions for stability are derived.

scholarly journals Actuator modelling for attitude control using incremental nonlinear dynamic inversion

2020 ◽  
Vol 12 ◽  
pp. 175682932096192
Author(s):  
F Binz ◽  
D Moormann
Keyword(s):  
Attitude Control ◽  
Nonlinear Dynamic ◽  
Closed Loop ◽  
Control Method ◽  
Flight Test ◽  
Small Scale ◽  
Dynamic Inversion ◽  
Electric Aircraft ◽  
The Face ◽  
Nonlinear Dynamic Inversion

Recently, the concept of incremental nonlinear dynamic inversion has seen an increasing adoption as an attitude control method for a variety of aircraft configurations. The reasons for this are good stability and robustness properties, moderate computation requirements and low requirements on modelling fidelity. While previous work investigated the robust stability properties of incremental nonlinear dynamic inversion, the actual closed-loop performance may degrade severely in the face of model uncertainty. We address this issue by first analysing the effects of modelling errors on the closed-loop performance by observing the movement of the system poles. Based on this, we analyse the neccessary modelling fidelity and propose simple modelling methods for the usual actuators found on small-scale electric aircraft. Finally, we analyse the actuator models using (flight) test data where possible.

FLUENT/SIMULINK Collaborative Simulation for Missile Separation from Cavity

2012 ◽  
Vol 591-593 ◽  
pp. 1902-1906
Author(s):  
Tong Han ◽  
Shang Qin Tang ◽  
Chang Qiang Huang ◽  
Kang Sheng Dong
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Control Method ◽  
Data File ◽  
Control Model ◽  
Collaborative Simulation ◽  
Coupled Problem ◽  
System A ◽  
Share Data ◽  
Simulation Results

In order to solve the dynamics and kinematics highly coupled problem which exists in missile separating from cavity and in order to acquire accurate trajectory parameters and import control system, a parallel collaborative simulation platform was established. The data interface between FLUENT and SIMULINK was developed by the way of share data file, which use the Journal file of FLUENT and S-function of SIMULINK. The missile’s rudder control model was established. The aerodynamics characters and trajectory characters during missile separating from cavity were simulated under uncontrolled and closed-loop controlled conditions. The simulation results verify the feasibility of parallel collaborative simulation and show that rudder control method can effectively improve the characteristics of missile separating from cavity.

STABILIZATION OF UNSTABLE PERIODIC SOLUTIONS BY NONLINEAR RECURSIVE DELAYED FEEDBACK CONTROL

2006 ◽  
Vol 16 (10) ◽  
pp. 2935-2947 ◽  
Author(s):  
JIANDONG ZHU ◽  
YU-PING TIAN
Keyword(s):  
Periodic Solutions ◽  
Closed Loop ◽  
Control Method ◽  
Delayed Feedback ◽  
Delayed Feedback Control ◽  
Closed Loop System ◽  
Delayed Feedback Controller ◽  
The Stability ◽  
Geometry Method ◽  
Odd Number Limitation

This paper considers stabilization of unstable periodic solutions of nonlinear systems. Based on differential geometry method, a nonlinear recursive delayed feedback controller is designed. The concept of γ dynamics is introduced and the stability of the periodic solution of the closed-loop system is proved rigorously. The proposed control method does not have the odd number limitation. Simulation results are also presented for validating the effectiveness of the proposed method.

Active Delayed Control of Turning and Milling Dynamics

2017 ◽  
Vol 12 (5) ◽  
Author(s):  
Xinhua Long ◽  
Pingxu Zheng ◽  
Song Ren
Keyword(s):  
Time Delay ◽  
Time Delays ◽  
Control Method ◽  
Controller Design ◽  
Control Performance ◽  
Use Of Time ◽  
Optimal Control Method ◽  
The Stability ◽  
Cutting Processes ◽  
Milling Dynamics

In this paper, a novel controller is developed for control of turning and milling dynamics. The controller design benefits from the use of time-delays in controlling a dynamic system. The gains of the controller are determined by using the discrete optimal control method. Numerical simulations are carried out in order to verify the efficiency of the controller. The findings show that the designed controller can be effective in suppressing chatter in both turning and milling processes as well as improve the stability of the cutting processes with the introduced time-delay. The authors discuss the influence of designed time-delay on control performance and robustness, and point out the advantages of using a time-delayed controller for controlling cutting dynamics.

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