scholarly journals The Design of Ship Autopilot by Applying Observer - Based Feedback Linearization

2015 ◽  
Vol 22 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Zenon Zwierzewicz
Keyword(s):  
Asymptotic Stability ◽  
Output Feedback ◽  
Feedback Linearization ◽  
High Performance ◽  
Linearization Method ◽  
Nonlinear Observer ◽  
Internal Dynamics ◽  
Highly Nonlinear ◽  
Control System Synthesis ◽  
Ship Autopilot

Abstract The paper considers the problem of ship autopilot design based on Bech’s model of the vessel. Since the model is highly nonlinear and some of the state vector coordinates are unavailable, the control system synthesis is performed by means of an output feedback linearization method combined with a nonlinear observer. The asymptotic stability of the overall system has been proven, including the asymptotic stability of the system internal dynamics. The performed simulations of the ship course-changing process have confirmed a high performance of the proposed controller. It has been emphasized that for its practical usability the system robustification is necessary.

scholarly journals On the ship course-keeping control system design by using robust feedback linearization

2013 ◽  
Vol 20 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Zenon Zwierzewicz
Keyword(s):  
Feedback Linearization ◽  
High Performance ◽  
Linearization Method ◽  
Model Parameters ◽  
Control System Design ◽  
Control Approach ◽  
Ship Model ◽  
Control Techniques ◽  
System Nonlinearity ◽  
Ship Autopilot

Abstract In the paper the problem of ship autopilot design based on feedback linearization method combined with the robust control approach, is considered. At first the nonlinear ship model (of Norrbin type) is linearized with the use of the simple system nonlinearity cancellation. Next, bearing in mind that exact values of the model parameters are not known, the ensuing inaccuracies are taken as disturbances acting on the system. Thereby is obtained a linear system with an extra term representing the uncertainty which can be treated by using robust, H∞ optimal control techniques. The performed simulations of ship course-changing process confirmed a high performance of the proposed controller despite the assumed significant errors of its parameters.

Position and Force Control of Multibody Systems by Feedback Linearization

1992 ◽  
Author(s):  
Christoph Woernle
Keyword(s):  
Force Control ◽  
Multibody Systems ◽  
Feedback Linearization ◽  
Linearization Method ◽  
Robotic Systems ◽  
Input Output ◽  
Internal Dynamics ◽  
Constrained Multibody Systems ◽  
Walking Machines ◽  
Controlled Motion

Abstract A unified formulation of the feedback linearization method to the hybrid position and force control of constrained multibody systems is developed. Similar to the feedback linearization of unconstrained systems, linear decoupled input-output channels for position and force control variables, which can be controlled separately, and a nonlinear nonobservable internal dynamics are obtained. Technical applications are robotic systems with multiple, interacting arms, multifingered grippers grasping an object, mechanisms with controlled motion, or walking machines.

A New Adaptive Control Approach for Robot Manipulators

1992 ◽  
Author(s):  
Jingsheng Ye
Keyword(s):  
Adaptive Control ◽  
Feedback Linearization ◽  
Robot Manipulators ◽  
Linearization Method ◽  
Dynamic Equations ◽  
Unknown Parameters ◽  
Control Approach ◽  
Highly Nonlinear ◽  
Hyperstability Theory ◽  
Model Reference Adaptive

Abstract Dynamic equations of robot manipulators are highly nonlinear with time-varying and unknown parameters. Using the model reference adaptive control (MRAC) technique, a control scheme based on hyperstability theory is developed for robot manipulators. A new adaptive algorithm is proposed for compensating the nonlinear term in the dynamic equations and for decoupling the dynamic interaction among the joints. The main feature of the approach is that the unknown parameters are not estimated separately, but the total influences due to the modeling errors and the disturbances can be directly compensated. Simulations show good results even for large variations of parameters. A comparison of this approach with the feedback linearization method (FLM) is also presented.

Parallel Computing for Tire Simulations

2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar
Keyword(s):  
High Performance ◽  
Effective Means ◽  
Cost Effective ◽  
Turnaround Time ◽  
Careful Consideration ◽  
Rolling Contact ◽  
Element Analysis ◽  
Parallel Solvers ◽  
Design Changes ◽  
Highly Nonlinear

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.

Conditions for the local and global asymptotic stability of the time–fractional Degn–Harrison system

2020 ◽  
Vol 21 (7-8) ◽  
pp. 749-759
Author(s):  
Rachida Mezhoud ◽  
Khaled Saoudi ◽  
Abderrahmane Zaraï ◽  
Salem Abdelmalek
Keyword(s):  
Asymptotic Stability ◽  
Global Asymptotic Stability ◽  
Lyapunov Method ◽  
Sufficient Conditions ◽  
Reaction Diffusion ◽  
Linearization Method ◽  
Direct Lyapunov Method ◽  
Fractional Systems ◽  
Reaction Diffusion Model ◽  
Theoretical Results

AbstractFractional calculus has been shown to improve the dynamics of differential system models and provide a better understanding of their dynamics. This paper considers the time–fractional version of the Degn–Harrison reaction–diffusion model. Sufficient conditions are established for the local and global asymptotic stability of the model by means of invariant rectangles, the fundamental stability theory of fractional systems, the linearization method, and the direct Lyapunov method. Numerical simulation results are used to illustrate the theoretical results.

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