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.

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.

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.

Targeted Solidification through Self-optimising, Highly Segmented Mould Temperature Control in Injection Moulding

2017 ◽  
Vol 44 (8) ◽  
pp. 1-8
Author(s):  
C. Hopmann ◽  
M. Schmitz
Keyword(s):  
High Precision ◽  
Temperature Control ◽  
High Performance ◽  
Quality Criteria ◽  
Temperature Control System ◽  
Mould Temperature ◽  
Machining Processes ◽  
Control Approach ◽  
Control Techniques ◽  
Production Processes

The precision of manufactured parts is one of the most important quality criteria in mass production processes. While for mechanical machining processes high-precision parts can be achieved by using CNC techniques and high-precision machining, melt-based production processes still have large precision drawbacks, which can only be compensated by time-consuming mould trial iterations or post-processing. The following article discusses a new approach to incorporating a segmented temperature control system in an injection mould, leading to a processing technique which is capable of local adjustment of the part temperature. This segmented local temperature control, which is based on appropriate heating and cooling techniques and a novel control approach, is designed to have a positive effect on the solidification of the melt and shrinkage of the plastics part in order to achieve minimal part warpage. This process control is extremely demanding in terms of temperature control techniques, process measurements and control strategies, which are discussed below. Firstly, temperature control techniques that are able to deliver high performance and allow the most dynamic control of the part's surface temperature are discussed and evaluated. To control this process effectively, various sensors are analysed which are capable of measuring real part temperatures within the process runtime. Finally, the requirements for a control concept that allows efficient control of mould temperature are discussed, taking account of high dead times.

scholarly journals Robust Sensorless Model-Predictive Torque Flux Control for High-Performance Induction Motor Drives

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 403
Author(s):  
Ahmed G. Mahmoud A. Aziz ◽  
Hegazy Rez ◽  
Ahmed A. Zaki Diab
Keyword(s):  
Induction Motor ◽  
High Performance ◽  
Core Loss ◽  
Parameters Estimation ◽  
Torque Control ◽  
Flux Control ◽  
Control Approach ◽  
Light Load ◽  
Wide Range ◽  
Lyapunov’S Theorem

This paper introduces a novel sensorless model-predictive torque-flux control (MPTFC) for two-level inverter-fed induction motor (IM) drives to overcome the high torque ripples issue, which is evidently presented in model-predictive torque control (MPTC). The suggested control approach will be based on a novel modification for the adaptive full-order-observer (AFOO). Moreover, the motor is modeled considering core losses and a compensation term of core loss applied to the suggested observer. In order to mitigate the machine losses, particularly at low speed and light load operations, the loss minimization criterion (LMC) is suggested. A comprehensive comparative analysis between the performance of IM drive under conventional MPTC, and those of the proposed MPTFC approaches (without and with consideration of the LMC) has been carried out to confirm the efficiency of the proposed MPTFC drive. Based on MATLAB® and Simulink® from MathWorks® (2018a, Natick, MA 01760-2098 USA) simulation results, the suggested sensorless system can operate at very low speeds and has the better dynamic and steady-state performance. Moreover, a comparison in detail of MPTC and the proposed MPTFC techniques regarding torque, current, and fluxes ripples is performed. The stability of the modified adaptive closed-loop observer for speed, flux and parameters estimation methodology is proven for a wide range of speeds via Lyapunov’s theorem.

Developing a Linearization Method to Determine Optimum Blending for Surimi with Varied Moisture Contents Using Linear Programming

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Hyeon W. Park ◽  
Jae W. Park ◽  
Won B. Yoon
Keyword(s):  
Linear Programming ◽  
Moisture Content ◽  
Standard Procedure ◽  
Unit Cost ◽  
Linearization Method ◽  
Model Parameters ◽  
Additional Information ◽  
Moisture Contents ◽  
Design Variables ◽  
Critical Moisture

AbstractNovel algorithm to determine the least cost formulation of a surimi blend was developed using linear programming (LP). Texture properties and the unit cost of surimi blend at the target moisture content were used as constraint functions and the objective function, respectively. The mathematical models to describe the moisture content dependence of the ring tensile properties were developed using critical moisture content, and the model parameters were used for the least cost LP (LCLP) model. The LCLP model successfully predicted the quality of surimi blend. Sensitivity analysis was used to obtain an additional information when the perturbations of design variables are provided. A standard procedure to determine the least cost formulation for blending surimi with varied moisture contents was systematically developed.

H∞Control for PMLSM Suspension Platform Based on PDFF

2011 ◽  
Vol 383-390 ◽  
pp. 6886-6892
Author(s):  
Jia Kuan Xia ◽  
Yi Na Wang ◽  
Yi Biao Sun
Keyword(s):  
Feedback Linearization ◽  
High Speed ◽  
Normal Force ◽  
Dynamic Stiffness ◽  
Linearization Method ◽  
Dynamic Decoupling ◽  
Fast Tracking ◽  
Speed Controller ◽  
Simulation Results ◽  
Proportional Controller

Permanent magnet linear synchronous motor (PMLSM) suspension system has the merits of no friction, high-speed, high response and so on, using the normal force achieve the mover suspension. The servo performance is affected by the nonlinear coupling between the horizontal trust and vertical normal force, parameters uncertainties and load disturbances. The feedback linearization method is used to achieve the dynamic decoupling of the PMLSM suspicion system and decoupling it Into two linear subsystems; to solve the conflict between disturbance restraint and fast tracking performance, increase the robustness and dynamic stiffness for system, H∞ speed controller based on PDFF and position proportional controller are designed. Simulation results show that the proposed control strategy guarantees the high speed and high precision positioning performance for horizontal axis; the good rigidity and stability for normal suspension length and the strong robustness against load disturbances and parameters variations for the two axes.

scholarly journals A Novel Modified Super-Twisting Control Augmented Feedback Linearization for Wearable Robotic Systems Using Time Delay Estimation

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 597
Author(s):  
Brahim Brahmi ◽  
Ibrahim El Bojairami ◽  
Tanvir Ahmed ◽  
Asif Al Zubayer Swapnil ◽  
Mohammad AssadUzZaman ◽  
...  
Keyword(s):  
Time Delay ◽  
Feedback Linearization ◽  
High Performance ◽  
Time Delay Estimation ◽  
Robotic Systems ◽  
External Disturbances ◽  
Uncertain Dynamics ◽  
Control Scheme ◽  
Twisting Control ◽  
Dynamics Stability

The research presents a novel controller designed for robotic systems subject to nonlinear uncertain dynamics and external disturbances. The control scheme is based on the modified super-twisting method, input/output feedback linearization, and time delay approach. In addition, to minimize the chattering phenomenon and ensure fast convergence to the selected sliding surface, a new reaching law has been integrated with the control law. The control scheme aims to provide high performance and enhanced accuracy via limiting the effects brought by the presence of uncertain dynamics. Stability analysis of the closed-loop system was conducted using a powerful Lyapunov function, showing finite time convergence of the system’s errors. Lastly, experiments shaping rehabilitation tasks, as performed by healthy subjects, demonstrated the controller’s efficiency given its uncertain nonlinear dynamics and the external disturbances involved.

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