Configuration and Robustness in Visual Servo

2004 ◽  
Vol 16 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Graziano Chesi ◽  
◽  
Koichi Hashimoto
Keyword(s):  
Local Stability ◽  
Stability Region ◽  
Visual Servoing ◽  
Eye Position ◽  
Visual Servo ◽  
Control Laws ◽  
Extrinsic Parameters ◽  
Point To Point ◽  
The Stability ◽  
Theoretical Results

Effects of camera calibration errors on the point-to-point task are investigated in static-eye and hand-eye visual servoing realized with position-based and image-based control laws. For these four configurations, the effect of uncertainty on the extrinsic parameters is analyzed. The results show local stability for all configurations under small calibration errors. However, a steady state error is found in the hand-eye position-based configuration. Simulations have been done to confirm the theoretical results and evaluate the effects of the uncertainty in terms of stability region. Another contribution of the paper consists of providing a method for estimating the stability region robust against uncertainty directions for the static-eye position-based case with uncertainty on the camera centers.

Vehicle Lateral Motion Control Based on Estimated Stability Regions

2017 ◽  
Author(s):  
Yiwen Huang ◽  
Yan Chen
Keyword(s):  
Measurement Errors ◽  
Local Stability ◽  
Stability Region ◽  
Control Method ◽  
Linearization Method ◽  
Stability Control ◽  
Lateral Stability ◽  
Shortest Distance ◽  
The Stability ◽  
Yaw Moment

This paper presents a novel vehicle lateral stability control method based on an estimated lateral stability region on the phase plane of vehicle yaw rate and lateral speed, which is obtained through a local linearization method. Since the estimated stability region does not only describe vehicle local stability, but also define the oversteering and understeering characteristics, the proposed control method can achieve both local stability and vehicle handling stability. Considering the irregular geometric shape of the estimated stability region, a stability analysis algorithm is designed to determine the distance between vehicle states and stability region boundaries. State estimation or measurement errors are also incorporated in the distance calculation. Based on the calculated shortest distance between vehicle states and stability boundaries, a direct yaw moment controller is designed to maintain vehicle states stay within the stability region. CarSim® and Simulink® co-simulation is applied to verify the control design through a cornering maneuver. The simulation results show that the proposed control method can make the vehicle stay within the stability region successfully and thus always operate in a safe manner.

T-S Fuzzy observer and controller of Doubly-Fed Induction Generator

2016 ◽  
Vol 7 (3) ◽  
pp. 617
Author(s):  
Fouad Abdelmalki ◽  
Najat Ouaaline
Keyword(s):  
Induction Generator ◽  
Linear Matrix ◽  
Doubly Fed Induction Generator ◽  
Quadratic Lyapunov Function ◽  
Control Laws ◽  
Fuzzy Observer ◽  
Satisfactory Performance ◽  
Doubly Fed ◽  
The Stability ◽  
Theoretical Results

This paper aims to ensure a stability and observability of doubly fed induction generator DFIG of a wind turbine based on the approach of fuzzy control type T-S PDC (Parallel Distributed Compensation) which determines the control laws by return state and fuzzy observers. First, the fuzzy TS model is used to precisely represent a nonlinear model of DFIG proposed and adopted in this work. Then, the stability analysis is based on the quadratic Lyapunov function to determine the gains that ensure the stability conditions. The fuzzy observer of DFIG is built to estimate non-measurable state vectors and the estimated states converging to the actual statements. The gains of observatory and of stability are obtained by solving a set of linear matrix inequality (LMI). Finally, numerical simulations are performed to verify the theoretical results and demonstrate satisfactory performance.

scholarly journals Delay Cournot Duopoly Game with Gradient Adjustment: Berezowski Transition from a Discrete Model to a Continuous Model

Mathematics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 32
Author(s):  
Akio Matsumoto ◽  
Ferenc Szidarovszky ◽  
Keiko Nakayama
Keyword(s):  
Stability Region ◽  
Period Doubling ◽  
Continuous Model ◽  
Delay Model ◽  
Chaotic Oscillations ◽  
Cournot Duopoly ◽  
Numerical Studies ◽  
Inertia Coefficient ◽  
The Stability ◽  
Theoretical Results

This paper investigates the asymptotical behavior of the equilibrium of linear classical duopolies by reconsidering the two-delay model with two different positive delays. In a two-dimensional analysis, the stability switching curves were first analytically determined. Numerical studies verified and illustrated the theoretical results. In the sensitivity analysis it was demonstrated that the inertia coefficient has a twofold effect: enlarges the stability region as well as simplifies the complicated dynamics with period-halving cascade. In contrary, the adjustment speed contracts the stability region and complicates simple dynamics with period-doubling bifurcation. In addition, for various values of τ1 and τ2, a wide variety of dynamics appears ranging from simple cycle via a Hopf bifurcation to chaotic oscillations.

scholarly journals Bifurcation Analysis of a Delayed Infection Model with General Incidence Function

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Suxia Zhang ◽  
Hongsen Dong ◽  
Jinhu Xu
Keyword(s):  
Hopf Bifurcation ◽  
Local Stability ◽  
Infection Model ◽  
Positive Equilibrium ◽  
Hopf Bifurcations ◽  
Incidence Function ◽  
Stability And Instability ◽  
Different Types ◽  
The Stability ◽  
Theoretical Results

In this paper, an infection model with delay and general incidence function is formulated and analyzed. Theoretical results reveal that positive equilibrium may lose its stability, and Hopf bifurcation occurs when choosing delay as the bifurcation parameter. The direction of Hopf bifurcation and the stability of the periodic solutions are also discussed. Furthermore, to illustrate the numerous changes in the local stability and instability of the positive equilibrium, we conduct numerical simulations by using four different types of functional incidence, i.e., bilinear incidence, saturation incidence, Beddington–DeAngelis response, and Hattaf–Yousfi response. Rich dynamics of the model, such as Hopf bifurcations and chaotic solutions, are presented numerically.

scholarly journals Global Dynamics of an SEIR Model with the Age of Infection and Vaccination

Mathematics ◽  
2021 ◽  
Vol 9 (18) ◽  
pp. 2195
Author(s):  
Huaixing Li ◽  
Jiaoyan Wang
Keyword(s):  
Local Stability ◽  
Reproduction Number ◽  
Steady States ◽  
Global Dynamics ◽  
Seir Model ◽  
Age Of Infection ◽  
The Stability ◽  
Theoretical Results ◽  
Disease Free ◽  
The Basic Reproduction Number

This paper is concerned with the stability of a SEIR (susceptible-exposed-infectious-recovered) model with the age of infection and vaccination. Firstly, we prove the positivity, boundedness, and asymptotic smoothness of the solutions. Next, the existence and local stability of disease-free and endemic steady states are shown. The basic reproduction number R0 is introduced. Furthermore, the global stability of the disease-free and endemic steady states is derived. Numerical simulations are shown to illustrate our theoretical results.

Stability and Bifurcation in a State-Dependent Delayed Predator–Prey System

2016 ◽  
Vol 26 (04) ◽  
pp. 1650060 ◽  
Author(s):  
Aiyu Hou ◽  
Shangjiang Guo
Keyword(s):  
Hopf Bifurcation ◽  
Numerical Simulations ◽  
Local Stability ◽  
Perturbation Methods ◽  
Positive Equilibrium ◽  
Predator Prey ◽  
Prey System ◽  
State Dependent ◽  
The Stability ◽  
Theoretical Results

In this paper, we consider a class of predator–prey equations with state-dependent delayed feedback. Firstly, we investigate the local stability of the positive equilibrium and the existence of the Hopf bifurcation. Then we use perturbation methods to determine the sub/supercriticality of Hopf bifurcation and hence the stability of Hopf bifurcating periodic solutions. Finally, numerical simulations supporting our theoretical results are also provided.

scholarly journals Visual Servo Control of a Legged Mobile Robot Based on Homography

2020 ◽  
Author(s):  
Haitao Liu ◽  
Dewei Zhang ◽  
Xianye Wang ◽  
Juliang Xiao
Keyword(s):  
Mobile Robot ◽  
Visual Servoing ◽  
Sliding Mode ◽  
Median Filter ◽  
Three Dimensional ◽  
Servo Control ◽  
Visual Servo ◽  
Visual Servo Control ◽  
Periodic Movement ◽  
The Stability

Abstract Due to the intermittent motion of a legged mobile robot, an additional periodic movement must be introduced that directly affects the image processing accuracy and destabilizes the visual servo control of the robot. To address this problem, this paper investigates a control scheme for the visual servoing of a legged mobile robot equipped with a fixed monocular camera. The kinematics of the legged mobile robot and homography- based visual servoing are employed to allow the robot to achieve the desired pose. By investigating the homographic relationship between the current and desired poses, the approach has no need for transcendental knowledge of the three-dimensional geometry of the target image. The feature points are directly extracted from the images to evaluate the homography matrix. To reduce the effects caused by the intermittent motions of the legged robot, an improved adaptive median filter is proposed. Furthermore, a sliding mode controller is designed, and a Lyapunov-based approach is used to analyze the stability of the control system. With the aid of CoppeliaSim software, a simulation is implemented to verify the effectiveness of the proposed method.

The influence of the Stokes and Archimedes forces on the stability of a two-phase flow

2003 ◽  
Vol 3 ◽  
pp. 266-270
Author(s):  
B.H. Khudjuyerov ◽  
I.A. Chuliev
Keyword(s):  
Spectral Method ◽  
Stability Region ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Solid Phase ◽  
Stability Characteristic ◽  
Phase Flow ◽  
Two Phase ◽  
The Stability

The problem of the stability of a two-phase flow is considered. The solution of the stability equations is performed by the spectral method using polynomials of Chebyshev. A decrease in the stability region gas flow with the addition of particles of the solid phase. The analysis influence on the stability characteristic of Stokes and Archimedes forces.

Enlarging the region of stability in robust model predictive controller based on dual-mode control

2021 ◽  
pp. 014233122110123
Author(s):  
Fatemeh Khani ◽  
Mohammad Haeri
Keyword(s):  
Stability Region ◽  
Linear Matrix ◽  
Input State ◽  
Dual Mode ◽  
Model Predictive Controller ◽  
Mode Control ◽  
Robust Model ◽  
Output Constraints ◽  
Predictive Controller ◽  
The Stability

Industrial processes are inherently nonlinear with input, state, and output constraints. A proper control system should handle these challenging control problems over a large operating region. The robust model predictive controller (RMPC) could be an linear matrix inequality (LMI)-based method that estimates stability region of the closed-loop system as an ellipsoid. This presentation, however, restricts confident application of the controller on systems with large operating regions. In this paper, a dual-mode control strategy is employed to enlarge the stability region in first place and then, trajectory reversing method (TRM) is employed to approximate the stability region more accurately. Finally, the effectiveness of the proposed scheme is illustrated on a continuous stirred tank reactor (CSTR) process.

scholarly journals Dynamics of the rumor-spreading model with hesitation mechanism in heterogenous networks and bilingual environment

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Shuai Yang ◽  
Haijun Jiang ◽  
Cheng Hu ◽  
Juan Yu ◽  
Jiarong Li
Keyword(s):  
Lyapunov Method ◽  
Reproduction Number ◽  
Model Parameters ◽  
Rumor Spreading ◽  
Spreading Model ◽  
Reductio Ad Absurdum ◽  
The Stability ◽  
The Impact ◽  
Theoretical Results ◽  
The Basic Reproduction Number

Abstract In this paper, a novel rumor-spreading model is proposed under bilingual environment and heterogenous networks, which considers that exposures may be converted to spreaders or stiflers at a set rate. Firstly, the nonnegativity and boundedness of the solution for rumor-spreading model are proved by reductio ad absurdum. Secondly, both the basic reproduction number and the stability of the rumor-free equilibrium are systematically discussed. Whereafter, the global stability of rumor-prevailing equilibrium is explored by utilizing Lyapunov method and LaSalle’s invariance principle. Finally, the sensitivity analysis and the numerical simulation are respectively presented to analyze the impact of model parameters and illustrate the validity of theoretical results.

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