Prediction, Control and Energy Analyses of Hydraulic Transformer Based Heave Compensator

2021 ◽  
Author(s):  
Huan Yu ◽  
Jinhui Fang ◽  
Jianhua Wei ◽  
Shizhen Li ◽  
Hangjun Zhang
Keyword(s):  
Controller Design ◽  
Sliding Mode ◽  
Ship Motion ◽  
Luenberger Observer ◽  
Hydraulic Transformer ◽  
Simulation Results ◽  
The One ◽  
Prediction Control ◽  
Wave Induced ◽  
Better Than

Abstract Heave compensators are widely used in offshore equipments to decouple the load motion from the wave induced ship motion. Hydraulic transformer based heave compensator (HTHC) can better compensate the ship’s heave in comparison with passive heave compensators (PHC) under changing sea conditions, meanwhile the accumulators’ volume is decreased significantly. Here in this paper, some further discussions about HTHC are given on the aspects of prediction, controller design and energy saving through simulation. Results turn out that heave prediction based on sliding mode observer is better than the Luenberger observer based one; chattering can be reduced through back-stepping method. The controller is robust when the load is perturbed by uncertain forces, and energy consumption of HTHC is about 56% of the one in an equal-sized hybrid active heave compensator (HAHC) meanwhile its total installed power can be reduced by 70%.

scholarly journals Discrete EKF with pairwise Time Correlated Measurement Noise for Image-Aided Inertial Integrated Navigation

2014 ◽  
Vol II-2 ◽  
pp. 61-66 ◽  
Author(s):  
N. S. Gopaul ◽  
J. G. Wang ◽  
B. Hu
Keyword(s):  
Kalman Filter ◽  
Inertial Navigation ◽  
Measurement Noise ◽  
Integrated Navigation ◽  
Process Noise ◽  
Shaping Filter ◽  
Egomotion Estimation ◽  
Simulation Results ◽  
The One ◽  
Better Than

An image-aided inertial navigation implies that the errors of an inertial navigator are estimated via the Kalman filter using the aiding measurements derived from images. The standard Kalman filter runs under the assumption that the process noise vector and measurement noise vector are white, i.e. independent and normally distributed with zero means. However, this does not hold in the image-aided inertial navigation. In the image-aided inertial integrated navigation, the relative positions from optic-flow egomotion estimation or visual odometry are <i>pairwise</i> correlated in terms of time. It is well-known that the solution of the standard Kalman filter becomes suboptimal if the measurements are colored or time-correlated. Usually, a shaping filter is used to model timecorrelated errors. However, the commonly used shaping filter assume that the measurement noise vector at epoch <i>k</i> is not only correlated with the one from epoch <i>k</i> &ndash; 1 but also with the ones before epoch <i>k</i> &ndash; 1 . The shaping filter presented in this paper uses Cholesky factors under the assumption that the measurement noise vector is pairwise time-correlated i.e. the measurement noise are only correlated with the ones from previous epoch. Simulation results show that the new algorithm performs better than the existing algorithms and is optimal.

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.

scholarly journals A Double Power Reaching Law of Sliding Mode Control Based on Neural Network

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Xin Zhao ◽  
Tian Wu ◽  
Yan Ma
Keyword(s):  
Neural Network ◽  
Controller Design ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
External Interference ◽  
Reaching Law ◽  
Strong Robustness ◽  
Simulation Results ◽  
Exponential Reaching Law ◽  
Single Power

For discrete system, the reaching law election and controller design are two crucial and important problems. In this paper, an improved double power reaching law of SMC and a controller combined with neural network have been investigated. Theory proves that this method can eliminate the chattering and increase the reaching rate. Furthermore, when there is a certain external interference, the regulating function of neural network can ensure strong robustness of the system. Simulation results show that compared with exponential reaching law, single power reaching law, and traditional double power reaching law, the proposed reaching law has faster convergence speed and better dynamic performance.

scholarly journals H-infinity Sliding Mode Controller Design for a Human Swing Leg System

2020 ◽  
Vol 23 (2) ◽  
pp. 117-126
Author(s):  
Hazem I. Ali ◽  
Azhar Jabbar Abdulridha
Keyword(s):  
Knee Joint ◽  
Hip Joint ◽  
Controller Design ◽  
Sliding Mode ◽  
Knee Joints ◽  
Upper Body ◽  
Double Pendulum ◽  
H Infinity ◽  
Dynamic Output Feedback Controller ◽  
Better Than

In this paper, the H-infinity Sliding Mode Control (HSMC) is designed to produce a new dynamic output feedback controller for trajectory tracking of the nonlinear human swing leg system. The human swing leg system represents the support of human leg or the humanoid robot leg which is usually modeled as a double pendulum. The thigh and shank of a human leg is represented by two pendulum links and the hip joint will connect the upper body to the thigh and the knee joint will connect the thigh to the shank. The external torques (servo motors) are applied at the hip and knee joints to move the muscles of thigh and shank. The results show that the HSMC can robustly stabilize the system and achieve a desirable time response specification better than if only H-infinity or SMC is used. This controller achieves the following specifications:  sec,  for hip joint and sec, for knee joint.

A High Performance Pneumatic Force Actuator System: Part II—Nonlinear Controller Design

1999 ◽  
Vol 122 (3) ◽  
pp. 426-434 ◽  
Author(s):  
Edmond Richer ◽  
Yildirim Hurmuzlu
Keyword(s):  
High Performance ◽  
Controller Design ◽  
Sliding Mode ◽  
Superior Performance ◽  
Nonlinear Controller ◽  
Nonlinear Force ◽  
System Part ◽  
Valve Dynamics ◽  
Actuator System ◽  
The One

In this article we present two nonlinear force controllers based on the sliding mode control theory. For this purpose we use the detailed mathematical model of the pneumatic system developed in the first part of the paper. The first controller is based on the complete model, and exhibits superior performance both in the numerical simulation and experiments, but requires complex online computations for the control law. The second controller neglects the valve dynamics and the time delay due to connecting tubes. The performance of this controller exhibits slight degradation for configurations with relatively short tubes, and at frequencies up to 20 Hz. At higher frequencies or when long connecting tubes are used, however, the performance exhibits significant degradation compared to the one provided by the full order controller. [S0022-0434(00)00703-6]

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 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.

A Global Approach to Vehicle Control: Coordination of Four Wheel Steering and Wheel Torques

1994 ◽  
Vol 116 (4) ◽  
pp. 659-667 ◽  
Author(s):  
Ssu-Hsin Yu ◽  
John J. Moskwa
Keyword(s):  
Control Systems ◽  
Controller Design ◽  
Sliding Mode ◽  
Vehicle Control ◽  
Point Of View ◽  
Sliding Mode Controller ◽  
Global Approach ◽  
Ground Vehicles ◽  
Advanced Control ◽  
Simulation Results

Currently, advanced control systems implemented on production ground vehicles have the goal of promoting maneuverability and stability. With proper coordination of steering and braking action, these goals may be achieved even when road conditions are severe. This paper considers the effect of steering and wheel torques on the dynamics of vehicular systems. Through the input-output linearization technique, the advantages of four-wheel steering (4WS) system and independent torques control are clear from a mathematical point of view. A sliding mode controller is also designed to modify driver’s steering and braking commands to enhance maneuverability and safety. Simulation results show the maneuverability and safety are improved. Although the controller design is based on a four-wheel steering vehicle, the algorithm can also be applied to vehicles of different configurations with slight changes.

scholarly journals Synchronization of Unified Chaotic Systems Using Sliding Mode Controller

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Yi-You Hou ◽  
Ben-Yi Liau ◽  
Hsin-Chieh Chen
Keyword(s):  
Secure Communication ◽  
Chaotic Systems ◽  
Controller Design ◽  
Sliding Mode ◽  
Problem Formulation ◽  
Sliding Mode Controller ◽  
Unified Chaotic System ◽  
Unified Chaotic Systems ◽  
Simulation Results ◽  
Chaotic Secure Communication

This paper presents a method for synchronizing the unified chaotic systems via a sliding mode controller (SMC). The unified chaotic system and problem formulation are described. Two identical unified chaotic systems can be synchronized using the SMC technique. The switching surface and its controller design are developed in detail. Simulation results show the feasibility of a chaotic secure communication system based on the synchronization of the Lorenz circuits via the proposed SMC.

The Model Simulation Analysis of Electro-Rheological Fluid Engine Mounting System

2013 ◽  
Vol 694-697 ◽  
pp. 338-343 ◽  
Author(s):  
Bo Jiang ◽  
Wen Ku Shi
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Vibration Isolation ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Simulation Results ◽  
Set Up ◽  
The One ◽  
The Mathematical Model ◽  
Better Than

The mathematical model of the electro-rheological fluid engine mounting system is set up, Combining the electro-rheological fluid effect with hydraulic mount technology and considering the flexibility of the car frame. The simulation model of electro-rheological fluid engine mounting system is build up by the Simulink module of Matlab software to simulate the representative situations of the system, and the displacement and acceleration characteristic curves of the powerplant and the car frame is received. The simulation results indicate that the vibration isolation capability of the system with electric field is better than the one without electric field.

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