Course keeping control strategy for large oil tankers based on nonlinear feedback of swish function

2022 ◽  
Vol 244 ◽  
pp. 110385
Author(s):  
Shihang Gao ◽  
Xianku Zhang
Keyword(s):  
Control Strategy ◽  
Nonlinear Feedback ◽  
Oil Tankers

scholarly journals Pressure Control of Insulation Space for Liquefied Natural Gas Carrier with Nonlinear Feedback Technique

2018 ◽  
Vol 6 (4) ◽  
pp. 133
Author(s):  
Jinghua Cao ◽  
Xianku Zhang ◽  
Xiang Zou
Keyword(s):  
Natural Gas ◽  
Control Strategy ◽  
Control Strategies ◽  
Nonlinear Function ◽  
Pressure Control ◽  
Feedback Signal ◽  
Control Input ◽  
Nonlinear Feedback ◽  
Pressure Control System ◽  
Liquid Natural Gas

This paper introduces a novel control strategy into the insulation space for liquid natural gas carriers. The control strategy proposed can improve the effects of control for differential pressure and reduce the energy consumption of nitrogen. The method combines a nonlinear feedback technique with a closed-loop gain shaping algorithm (CGSA). It is designed for the pressure control system which is vital for liquid natural gas carriers (LNGCs) in marine transportation. The control error is modulated using nonlinear function. The deviation signal is replaced with a nonlinear feedback signal. Comparison experiments are conducted under different conditions to prove the effectiveness of this strategy. This paper compares three control strategies: a control strategy with nonlinear feedback based on CGSA, a control strategy without nonlinear feedback based on CGSA, and a two-degree-of-freedom (DOF) control strategy. The simulation results show that this control strategy with nonlinear feedback performs better than the other two. The average reduction of control input is about 38.8%. The effect of pressure control is satisfactory.

scholarly journals Rendering a subcritical Hopf bifurcation supercritical

1996 ◽  
Vol 317 ◽  
pp. 91-109 ◽  
Author(s):  
Po Ki Yuen ◽  
Haim H. Bau
Keyword(s):  
Hopf Bifurcation ◽  
Limit Cycle ◽  
Thermal Convection ◽  
Control Strategy ◽  
Chaotic Motion ◽  
Feedback Controller ◽  
Nonlinear Feedback ◽  
Naturally Occurring ◽  
Subcritical Hopf Bifurcation ◽  
Stable Periodic

It is demonstrated experimentally and theoretically that through the use of a nonlinear feedback controller, one can render a subcritical Hopf bifurcation supercritical and thus dramatically modify the nature of the flow in a thermal convection loop heated from below and cooled from above. In particular, we show that the controller can replace the naturally occurring chaotic motion with a stable, periodic limit cycle. The control strategy consists of sensing the deviation of fluid temperatures from desired values at a number of locations inside the loop and then altering the wall heating to counteract such deviations.

Wheel Synchronization Control in Steer-by-Wire Using Composite Nonlinear Feedback

2014 ◽  
Vol 575 ◽  
pp. 762-765 ◽  
Author(s):  
Sarah Atifah Saruchi ◽  
Hairi Zamzuri ◽  
Saiful Amri Mazlan ◽  
Sheikh Muhammad Hafiz Fahami ◽  
Noraishikin Zulkarnain
Keyword(s):  
Control Strategy ◽  
Front Wheel ◽  
Linear Feedback ◽  
Steering Wheel ◽  
Nonlinear Feedback ◽  
Composite Nonlinear Feedback ◽  
Control Laws ◽  
Simulation Based ◽  
Steer By Wire ◽  
Rising Time

This paper proposes a new control strategy to ensure the steering wheel and front wheel synchronization in Steer-by-Wire (SBW) using a Composite Nonlinear Feedback (CNF) controller. CNF is a combination of linear and non-linear feedback control laws. This controller is designed in order to minimize the delay in settling time, achieve fast rising time and lower the overshoot for the front wheel response. A simulation based on this control strategy was made and compared to analyze the system performance.

scholarly journals Nonlinear and Robust Control Strategy Based on Chemotherapy to Minimize the HIV Concentration in Blood Plasma

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ricardo Aguilar-López ◽  
Rigel Valentín Gómez-Acata ◽  
Gerardo Lara-Cisneros ◽  
Ricardo Femat
Keyword(s):  
Blood Plasma ◽  
Control Strategy ◽  
Sliding Mode ◽  
Drug Dosage ◽  
Nonlinear Feedback ◽  
Hiv Therapy ◽  
Bounded Functions ◽  
Infected Cells ◽  
Uncertain Input ◽  
In Blood Plasma

A nonlinear PI-type control strategy is designed in order to minimize the HIV concentration in blood plasma, via medical drug injection, under the framework of bounded uncertain input disturbances. For control design it is considered a simplified mathematical model of the virus infection as a benchmark. The model is based on mass balances of healthy cells, infected cells, and the virus concentrations. The proposed controller contains a nonlinear feedback PI structure of bounded functions of the regulation error. The closed-loop stability of the system is analyzed via Lyapunov technique, in which robustness against system disturbances is demonstrated. Numerical experiments show a satisfactory performance of the proposed methodology as a HIV therapy, in which the virion particles and the infected CD4+T cells are minimized and, as an interesting result, the drug dosage can be suspended, thus avoiding drug resistance from the virus. Finally, the proposed controller is compared to a standard sliding-mode and hyperbolic tangent controllers showing better performance.

Auto Disturbance Rejection Control Strategy for Large Inertia Servo System

2014 ◽  
Vol 599-601 ◽  
pp. 841-846
Author(s):  
Ke Zhang ◽  
Long Xu Jin
Keyword(s):  
Control Strategy ◽  
Disturbance Rejection ◽  
Control Plant ◽  
Servo System ◽  
Torque Ripple ◽  
System Response ◽  
Feedback Gain ◽  
Control Performance ◽  
Nonlinear Feedback ◽  
Disturbance Rejection Control

For large inertia servo system, improving the system response speed and control precision has always been a difficulty. This paper presents an improved auto disturbance rejection control (ADRC) strategy, which has good control performance for this kind of system. Firstly, transition process is arranged for input signal, which can solve the contradiction between overshoot and rapidity, can also increase the regulation range of feedback gain; secondly, linear extended state observer is designed to identify load changes and other fluctuations; then, for the control plant after observation compensation, a nonlinear feedback controller is designed to obtain better control performance and better disturbance rejection capability. The simulation results show that, compared with the traditional PI controller, with the control strategy suggested in this paper the system has rapid response but very little overshoot, and has strong ability to suppress interference. The design of this controller is simple, easy to implement in Engineering, so it may have important reference value for this kind of large inertia system. Keywords: servo control; large inertia; auto disturbance rejection control; torque ripple; low speed

scholarly journals Improving Vehicle Ride and Handling Using LQG CNF Fusion Control Strategy for an Active Antiroll Bar System

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
N. Zulkarnain ◽  
H. Zamzuri ◽  
Y. M. Sam ◽  
S. A. Mazlan ◽  
S. M. H. F. Zainal
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Control Strategies ◽  
Linear Feedback ◽  
Nonlinear Feedback ◽  
Handling Performance ◽  
Car Model ◽  
Initial Stage ◽  
System Output ◽  
Ride And Handling

This paper analyses a comparison of performance for an active antiroll bar (ARB) system using two types of control strategy. First of all, the LQG control strategy is investigated and then a novel LQG CNF fusion control method is developed to improve the performances on vehicle ride and handling for an active antiroll bar system. However, the ARB system has to balance the trade-off between ride and handling performance, where the CNF consists of a linear feedback law and a nonlinear feedback law. Typically, the linear feedback is designed to yield a quick response at the initial stage, while the nonlinear feedback law is used to smooth out overshoots in the system output when it approaches the target reference. The half car model is combined with a linear single track model with roll dynamics which are used for the analysis and simulation of ride and handling. The performances of the control strategies are compared and the simulation results show the LQG CNF fusion improves the performances in vehicle ride and handling.

scholarly journals Adaptive Fault Compensation and Disturbance Suppression Design for Nonlinear Systems with an Aircraft Control Application

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
X. Yao ◽  
Y. Yang
Keyword(s):  
Nonlinear Systems ◽  
Control Strategy ◽  
Feedback Linearization ◽  
Adaptive Controller ◽  
Nonlinear Feedback ◽  
Asymptotic Tracking ◽  
And Performance ◽  
Mismatched Disturbances ◽  
Adaptive Compensation Control ◽  
Multivariable Nonlinear Systems

A comprehensive adaptive compensation control strategy based on feedback linearization design is proposed for multivariable nonlinear systems with uncertain actuator fault and unknown mismatched disturbances. Firstly, the linear dynamic system is obtained through nonlinear feedback linearization, and the dynamic model of the mismatched disturbances as well as its relevance to the nonlinear system is given. The effect of disturbances on the system output is suppressed with the basic controller of the linearized system. Then, a direct adaptive controller is developed for the multiple uncertain actuator faults. Finally, an integrated algorithm based on adaptive weighted fusion could provide an effective compensation for the effect of multiple uncertain faults and mismatched disturbances. Thus, the stability and asymptotic tracking performance of the closed-loop system are ensured. The feasibility and performance of the proposed control strategy are validated by the numerical simulation results.

Composite Nonlinear Feedback with Disturbance Observer for Active Front Steering

2017 ◽  
Vol 7 (2) ◽  
pp. 434 ◽  
Author(s):  
Sarah 'Atifah Saruchi ◽  
Hairi Zamzuri ◽  
Noraishikin Zulkarnain ◽  
Norbaiti Wahid ◽  
Mohd Hatta Mohammed Ariff
Keyword(s):  
Control Strategy ◽  
Disturbance Observer ◽  
Linear Quadratic Regulator ◽  
Nonlinear Feedback ◽  
Linear Quadratic ◽  
Composite Nonlinear Feedback ◽  
Yaw Rate ◽  
Active Front Steering ◽  
J Curve ◽  
Tracking Response

<p>One of the dominant virtue of Steer-By-Wire (SBW) vehicle is its capability to enhance handling performance by installing Active Front Steering (AFS) system without the driver’s interferences. Hence, this paper introduced an AFS control strategy using the combination of Composite Nonlinear Feedback (CNF) controller and Disturbance Observer (DOB) to achieve fast yaw rate tracking response which is also robust to the existence of disturbance. The proposed control strategy is simulated in J-curve and Lane change manoevres with the presence of side wind disturbance via Matlab/Simulink sotware. Futhermore, comparison with Proportional Integral Derivative (PID) and Linear Quadratic Regulator (LQR) controllers are also conducted to evaluate the effectiveness of the proposed controller. The results showed that the combined CNF and DOB strategy achieved the fastest yaw rate tracking capability with the least impact of disturbance in the AFS system installed in SBW vehicle.</p>

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