scholarly journals Robust RAM Control for WSR on the Water Surface

2018 ◽  
Vol 7 (3.7) ◽  
pp. 303
Author(s):  
K Chun ◽  
B Kim
Keyword(s):  
Lyapunov Function ◽  
Water Surface ◽  
Controller Design ◽  
Sliding Mode ◽  
Fast Response ◽  
Target Point ◽  
Nonlinear Controller ◽  
Sign Function ◽  
Simulation Results ◽  
The Stability

This paper discusses a robust rotate and move (RAM) controller by considering a water striding robot (WSR) with two wheels. The proposed controller commands the WSR to rotate and move straight toward the desired target by considering the two wheel WSR characteristics. Sliding mode control (SMC) is one of the solutions in nonlinear controller design and it has fast response and robustness. SMC is applied to the WSR RAM control. However, the sliding mode has a problem called chattering because of using sign function in controller design and this will cause the system unstable in WSR control because the chattering make the WSR sink into water easily. As a solution, sign function is replaced by saturation function. The proposed controller is noble and track the target point easily and also has robustness. The stability of the proposed controller is proved by Lyapunov function and the simulation results show the fast response and robustness.  

scholarly journals Sub-Optimal Second-Order Sliding Mode Controller Parameters’ Selection for a Positioning System with a Synchronous Reluctance Motor

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1855 ◽  
Author(s):  
Rajko Svečko ◽  
Dušan Gleich ◽  
Amor Chowdhury ◽  
Andrej Sarjaš
Keyword(s):  
Controller Design ◽  
Sliding Mode ◽  
Design Procedure ◽  
Structure Design ◽  
Nonlinear Controller ◽  
Nonlinear Dynamic Model ◽  
Synchronous Reluctance Motor ◽  
Parameters Selection ◽  
Reluctance Motor ◽  
The Stability

This paper discusses nonlinear controller structure design for a synchronous reluctance motor (SynRM). The SynRM is represented with a nonlinear dynamic model. All presented nonlinearities of the SynRM are respected in the controller design procedure. A nonlinear controller policy is used for a SynRM positing system. The nonlinear controller design is based on the chattering alleviation technique for the super-twisted algorithm (STA). The alleviation technique assumes the presence of a fast parasitic dynamic, or fast, actuator. Based on the motor structure, the STA controller is designed only for the mechanical subsystem, where the electrical part presents the parasitic dynamic, and is taken in to account in the chattering suppression procedure. Chattering rejection is based on the STA describing function and harmonic balance equation. The approach allows determination of fast oscillation parameters, such as amplitude and frequency of oscillation. The conditions for the controller parameters’ selection are derived with regard to the given oscillation parameters. The derived conditions cover the stability analysis for the STA controller, as well as the stability condition for current controllers and chattering amplitude minimization. The result is confirmed with an example.

scholarly journals Nonlinear controller design of a ship autopilot

2010 ◽  
Vol 20 (2) ◽  
pp. 271-280 ◽  
Author(s):  
Mirosław Tomera
Keyword(s):  
High Performance ◽  
Control Method ◽  
Controller Design ◽  
Sliding Mode ◽  
Time Domain Analysis ◽  
Nonlinear Controller ◽  
Calm Water ◽  
Simulation Results ◽  
Nonlinear Controller Design ◽  
Ship Autopilot

Nonlinear controller design of a ship autopilotThe main goal here is to design a proper and efficient controller for a ship autopilot based on the sliding mode control method. A hydrodynamic numerical model of CyberShip II including wave effects is applied to simulate the ship autopilot system by using time domain analysis. To compare the results similar research was conducted with the PD controller, which was adapted to the autopilot system. The differences in simulation results between two controllers are analyzed by a cost function composed of a heading angle error and rudder deflection either in calm water or in waves. Simulation results show the effectiveness of the method in the presence of nonlinearities and disturbances, and high performance of the proposed controller.

Analysis of Sliding Mode Observers Using a Novel Time-Averaged Lyapunov Function

2017 ◽  
Author(s):  
Sagar Mehta ◽  
Krishna Vijayaraghavan
Keyword(s):  
Lyapunov Function ◽  
Gaussian Noise ◽  
Sliding Mode ◽  
Sliding Mode Observer ◽  
Sensor Noise ◽  
Model Uncertainties ◽  
Quadratic Lyapunov Function ◽  
Simulation Results ◽  
Sliding Mode Observers ◽  
The Stability

Sliding mode observers are known to be robust to model uncertainties. However, sliding mode observers have not been well analyzed in the presence of Gaussian disturbances and no previous results exist for a pure sliding mode observer in the presence of sensor noise. A traditional quadratic Lyapunov function that is used to determine the stability of sliding mode observers, fails for noisy systems. Hence this paper introduces a novel Lyapunov candidate function termed the time averaged Lyapunov (TAL) function to analyze the stability of noisy systems. The TAL specifically examines the effect of the Gaussian noise on a sliding mode observer. Using this TAL function, the paper demonstrates that Gaussian sensor noise does not affect the stability or chatter of the observer. Further, the covariance of the noise only affects the convergence rate of the observer. Simulation results are reported to demonstrate the effectiveness of the proposed approach on a Linear system.

scholarly journals Active Sliding Mode for Synchronization of a Wide Class of Four-Dimensional Fractional-Order Chaotic Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Bin Wang ◽  
Yuangui Zhou ◽  
Jianyi Xue ◽  
Delan Zhu
Keyword(s):  
Sliding Mode Control ◽  
Fractional Order ◽  
Wide Class ◽  
Stability Theory ◽  
Chaotic Systems ◽  
Sliding Mode ◽  
Order System ◽  
Fractional Order Calculus ◽  
Simulation Results ◽  
The Stability

We focus on the synchronization of a wide class of four-dimensional (4-D) chaotic systems. Firstly, based on the stability theory in fractional-order calculus and sliding mode control, a new method is derived to make the synchronization of a wide class of fractional-order chaotic systems. Furthermore, the method guarantees the synchronization between an integer-order system and a fraction-order system and the synchronization between two fractional-order chaotic systems with different orders. Finally, three examples are presented to illustrate the effectiveness of the proposed scheme and simulation results are given to demonstrate the effectiveness of the proposed method.

scholarly journals A New Control Strategy for Bi-directional DC/DC Converter in DC Microgrid

2021 ◽  
Vol 233 ◽  
pp. 01051
Author(s):  
Tianze Miao ◽  
Xiaona Liu ◽  
Siyuan Liu ◽  
Lihua Wang
Keyword(s):  
Steady State ◽  
Control Strategy ◽  
Feedback Linearization ◽  
Sliding Mode ◽  
Response Speed ◽  
Fast Response ◽  
Sliding Mode Controller ◽  
Exponential Approximation ◽  
Dc Microgrid ◽  
Simulation Results

The bi-directional DC / DC converter in DC microgrid is a typical nonlinear system which has large voltage disturbance during lead accumulator charging and discharging. In order to solve the problem of voltage disturbance, the linearization of the converter is realized by exact feedback linearization, and the sliding mode controller is designed by using exponential approximation law. The simulation results show that the method has fast response speed, strong anti-interference ability and good steady-state characteristics.

Dynamic Analysis and Sliding Mode Control of a Novel Extendable Modular Multi-DOFs Link

2012 ◽  
Author(s):  
Hak Yi ◽  
Je Hong Yoo ◽  
Reza Langari
Keyword(s):  
Sliding Mode Control ◽  
Dynamic Analysis ◽  
Sliding Mode ◽  
Free Motion ◽  
Modular Robot ◽  
Nonlinear Controller ◽  
Control Approach ◽  
Mode Control ◽  
Reachable Workspace ◽  
Simulation Results

In this paper, we have considered the new extendable modular multi-DOFs link to have a larger reachable workspace and more dexterous manipulability, as compared to a typical link. As a part of the extendable modular robot (EMR), our link is implemented to allow free motion when performing required tasks. In addition, this paper deals with a function of adjusting the link’s length (within 25% of the nominal length). Our investigation also focuses on the dynamics of a multi-DOFs link and the nonlinear controller for a given trajectory. The simulation results show the effectiveness of this control approach.

Sliding Mode Observer and Controller Design for Nonlinear Supersonic Missile

2013 ◽  
Vol 718-720 ◽  
pp. 1228-1233
Author(s):  
Hong Chao Zhao ◽  
Xian Jun Shi ◽  
Ting Wang
Keyword(s):  
Lyapunov Stability ◽  
Controller Design ◽  
Sliding Mode ◽  
Equations Of Motion ◽  
Lyapunov Stability Theory ◽  
Sliding Mode Observer ◽  
Sliding Mode Controller ◽  
Output Redefinition ◽  
Simulation Results ◽  
Nonlinear Equations Of Motion

The nonlinear equations of motion were constructed for a supersonic anti-warship missile. In order to estimate the unknown angle-of-attack, a sliding mode observer was designed. The convergence capability of the sliding mode observer was analyzed according to the Lyapunov stability theory. A sliding mode controller was designed to drive the missile normal overload output to track its command, based on the output-redefinition approach. In order to confirm the performance of the designed sliding mode observer and controller, a simulation example was carried out for nonlinear missile model. The simulation results show the fast convergence capability of the designed sliding mode observer and controller.

Neuro-Fuzzy Sliding Mode Control of Inverted Pendulum

2013 ◽  
Vol 711 ◽  
pp. 432-439
Author(s):  
Khedoudja Kherraz ◽  
Mustapha Hamerlain ◽  
Nouara Achour
Keyword(s):  
Function Method ◽  
Inverted Pendulum ◽  
Sliding Mode ◽  
Robust Controller ◽  
Fuzzy Sliding Mode Control ◽  
Neuro Fuzzy ◽  
Lyapunov Function Method ◽  
Fuzzy Sliding Mode ◽  
Simulation Results ◽  
The Stability

In this paper we develop a robust controller based on sliding mode, neural network and fuzzy logic for the control of a class of under-actuated systems. The stability of the proposed controller is proved with the Lyapunov function method. Simulation results are made on an inverted pendulum.

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