Passivity-Based Disturbance Observer Design

2020 ◽  
Author(s):  
Ying-Chun Chen ◽  
Craig Woolsey
Keyword(s):  
Disturbance Observer ◽  
Design Method ◽  
Estimation Error ◽  
Parameter Tuning ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Design Parameters ◽  
Nonlinear Feedback ◽  
Initial Application ◽  
Wide Range

Abstract A design method is proposed for a nonlinear disturbance observer based on the notion of passivity. As an initial application, we consider here systems whose structure comprises a set of integrator cascades, though the proposed approach can be extended to a larger class of systems. We describe an explicit procedure to choose the output of the system and to design the nonlinear feedback law used by the observer, provided the system satisfies a sufficient condition for output feedback semi-passification. The output injection term in the observer scales the measurement residual with a nonlinear gain that depends on the output and a set of static design parameters. We provide guidance for parameter tuning such that the disturbance tracking performance and the transient response of the estimation error can be intuitively adjusted. Example applications to two nonlinear mechanical systems illustrate that the proposed nonlinear observer design method is quite effective, producing an observer that can estimate a wide range of disturbances without any need to know or assume the disturbance dynamics.

Observe-Based Projective Synchronization of Chaotic Complex Modified Van Der Pol-Duffing Oscillator With Application to Secure Communication

2015 ◽  
Vol 10 (5) ◽  
Author(s):  
Ping Liu ◽  
Hongjun Song ◽  
Xiang Li
Keyword(s):  
Secure Communication ◽  
Chaotic Behavior ◽  
Design Method ◽  
Duffing Oscillator ◽  
Scaling Factor ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Projective Synchronization ◽  
Chaotic Oscillator ◽  
Van Der Pol

This paper addresses the projective synchronization (PS) of the complex modified Van der Pol-Duffing (MVDPD for short) chaotic oscillator by using the nonlinear observer control and also discusses its applications to secure communication in theory. First, we construct the complex MVDPD oscillator and analysis its chaotic behavior. Moreover, an observer design method is applied to achieve PS of two identical MVDPD chaotic oscillators with complex offset terms, which are synchronized to the desired scale factor. The unpredictability of the scaling factor could further enhance the security of the communication. Finally, numerical simulations are given to demonstrate the effectiveness and feasibility of the proposed synchronization approach and also verify the success application to the proposed scheme’s in the secure communication.

scholarly journals Development of Fuzzy Observer Gain Design Algorithm for Ship Path Estimation Based on AIS Data

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Chin-Lin Pen ◽  
Wen-Jer Chang ◽  
Yann-Horng Lin
Keyword(s):  
Dynamic Systems ◽  
Design Method ◽  
Fuzzy Model ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Automatic Identification ◽  
Identification System ◽  
Design Algorithm ◽  
Fuzzy Observer ◽  
Takagi Sugeno

This paper develops a Takagi-Sugeno fuzzy observer gain design algorithm to estimate ship motion based on Automatic Identification System (AIS) data. Nowadays, AIS data is widely applied in the maritime field. To solve the problem of safety, it is necessary to accurately estimate the trajectory of ships. Firstly, a nonlinear ship dynamic system is considered to represent the dynamic behaviors of ships. In the literature, nonlinear observer design methods have been studied to estimate the ship path based on AIS data. However, the nonlinear observer design method is challenging to create directly since some dynamic ship systems are more complex. This paper represents nonlinear ship dynamic systems by the Takagi-Sugeno fuzzy model. Based on the Takagi-Sugeno fuzzy model, a fuzzy observer design method is developed to solve the problem of estimating using AIS data. Moreover, the observer gains of the fuzzy observer can be adjusted systemically by a novel algorithm. Via the proposed algorithm, a more suitable or better observer can be obtained to achieve the objectives of estimation. Corresponding to different AIS data, the better results can also be obtained individually. Finally, the simulation results are presented to show the effectiveness and applicability of the proposed fuzzy observer design method. Some comparisons with the previous nonlinear observer design method are also given in the simulations.

scholarly journals Estimation Error Based Disturbance Observer Design for Flexible Loop Shaping

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 358 ◽  
Author(s):  
Sangmin Suh
Keyword(s):  
Disturbance Observer ◽  
Closed Loop ◽  
Control Structure ◽  
Storage Systems ◽  
Estimation Error ◽  
Observer Design ◽  
Experimental Results ◽  
External Disturbances ◽  
Flexible Loop ◽  
Closed Loop Systems

This note presents an estimation error based disturbance observer (EEDOB) to reduce the effects of external disturbances. In the proposed control structure, a difference between an estimator output and a plant output is considered as an equivalent disturbance. Therefore, when a disturbance appears, the proposed disturbance observer (DOB) is activated. Unlike conventional DOB, this method does not require the plant inverse model or additional stabilizing filters. In addition, the proposed method always satisfies closed loop systems stability, which is definitely different from conventional DOB. To verify the effectiveness, this method was applied to commercial storage systems. From the experimental results, it is confirmed that tracking performance is improved by 23.5%.

A Distributed Nonlinear Observer Design Method for Output Estimation in Nonlinear Systems

2011 ◽  
Author(s):  
Javad Mohammadpour ◽  
Ali Hooshmand ◽  
Heidar Malki ◽  
Karolos Grigoriadis ◽  
Robert Provence
Keyword(s):  
Nonlinear Systems ◽  
Design Method ◽  
Observer Design ◽  
Nonlinear Observer

Stochastically Resilient Observer Design for a Class of Discrete-Time Nonlinear Systems

2011 ◽  
Author(s):  
Chung Seop Jeong ◽  
Edwin E. Yaz ◽  
Yvonne I. Yaz
Keyword(s):  
Discrete Time ◽  
Estimation Error ◽  
Finite Energy ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Performance Criteria ◽  
Linear Matrix ◽  
Computational Errors ◽  
Simple Estimation ◽  
Measurement Equations

A class of discrete-time nonlinear system and measurement equations having incrementally conic nonlinearities and finite energy disturbances is considered. A linear matrix inequality based nonlinear observer design approach is presented, which guarantees the satisfaction of a variety of performance criteria ranging from simple estimation error boundedness to dissipativity in the presence of random perturbations, due possibly to computational errors or changes during operation, on the observer gain. Some simulation examples are included to illustrate the proposed design methodology.

Trajectory tracking control of hypersonic vehicle considering modeling uncertainty

2019 ◽  
Vol 233 (13) ◽  
pp. 4779-4787
Author(s):  
Yuxiao Wang ◽  
Tao Chao ◽  
Songyan Wang ◽  
Ming Yang
Keyword(s):  
Disturbance Observer ◽  
Hypersonic Vehicle ◽  
Design Parameters ◽  
Differential Flatness ◽  
Differential Flatness Theory ◽  
Trajectory Tracking Control ◽  
Nonlinear Disturbance Observer ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Nonlinear Disturbance

The tightly coupled, highly nonlinear, and notoriously uncertain nature of hypersonic vehicle dynamics brings a great challenge to the control system design. In this paper, an integrated controller based on Differential flatness theory and L1 adaptive theory is designed, and a nonlinear disturbance observer is added to solve the problem of model uncertainty. Differential flatness is applied to the outer loop to linearize the nonlinear model, and L1 adaptive control is applied to the inner loop to stabilize the attitude. The combination realizes the complementarity of their shortcomings. It can not only retain the advantages of L1 adaptive controller, but also avoid wide range of state changes and makes it easy to design parameters satisfying global convergence. The computational order of differential flatness is also reduced and the design of nonlinear disturbance observer becomes feasible. Simulation results for the hypersonic vehicle are presented to demonstrate the effectiveness and robustness of the proposed control scheme.

Sliding Mode Nonlinear Observer Design for Underwater Vehicle Control System

2013 ◽  
Vol 706-708 ◽  
pp. 1000-1007 ◽  
Author(s):  
Chun Nan Deng ◽  
Tong Ge
Keyword(s):  
Sliding Mode ◽  
Estimation Error ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Ocean Current ◽  
Remotely Operated Vehicle ◽  
Sea Current ◽  
Underwater Vehicle Control ◽  
Lyapunov Stability Criterion ◽  
Umbilical Cable

The ocean current and cable will affect the ROV(remotely operated vehicle) when ROV is working under the sea. Current velocity and umbilical cable disturbing are hard to measure by sensors, which has to be estimated by observer. In order to improve the precision of observer, we present reasonable models for ocean current and umbilical cable disturbance, and design a sliding mode observer which has the same robustness as sliding mode controller. An upper bound of estimation error is derived by using Lyapunov stability criterion. Performance of the observer is verified using numerical simulation.Algorithm is very easy to complie,could meet the engineering needs.

scholarly journals Experimental Design and Verification of Extended State Observers for Magnetic Levitation System Based on PSO

2018 ◽  
Vol 12 (1) ◽  
pp. 110-120 ◽  
Author(s):  
Amjad J. Humaidi
Keyword(s):  
Magnetic Levitation ◽  
Estimation Error ◽  
Observer Design ◽  
Design Parameters ◽  
Extended State ◽  
State Observers ◽  
Observation Process ◽  
Levitation System ◽  
Magnetic Levitation System ◽  
Set Up

Introduction: This work presents analysis, design and implementation of two schemes of Extended State Observer (ESO) to estimate the position, velocity and unmeasurable states for magnetic levitation systems, Linear ESO (LESO) and Nonlinear ESO (NESO). The multiplicity of design parameters for both LESO and NESO made it difficult to find appropriate setting of these parameters such that to reach satisfactory performance of observation process. Methods: Particle Swarm Optimization (PSO) technique is used to improve performance of observation process by finding optimal tuned parameters of observer design parameter subjected to specified performance index. Theoretical results of both observers are firstly implemented in the environment of MATLAB/SIMULINK. Then, experimental state estimation of observers is set up based on feedback instrument (33-942S) to verify the simulated results. Results and Conclusion: Root Mean Square (RMS) of estimation error has been used as an indicator to assess the performance of observers. The simulated and practical results showed that LESO could give better estimation performance than NESO.

Track Following Control for Large Capacity Flexible Disk Drives -Disturbance Observer Design using Two Position Sensors-

2003 ◽  
Vol 15 (4) ◽  
pp. 458-468
Author(s):  
Jun Ueda ◽  
◽  
Akihiko Imagi ◽  
Hitoshi Tamayama ◽  
Tsuneo Yoshikawa ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
Design Method ◽  
Open Loop ◽  
Observer Design ◽  
Large Capacity ◽  
Storage Devices ◽  
Loop Design ◽  
Backward Compatibility ◽  
Flexible Disk ◽  
Two Degree Of Freedom

Storage devices require highly accurate positioning performance to cope with disturbance friction force and vibration. In this paper, a novel configuration of realizing a two-degree-of-freedom (2DOF) track following controller with a disturbance observer is proposed for large capacity FDDs with backward compatibility. The controller is designed using two position sensors, one of them is used to handle low density disks. Furthermore, a new open loop design method is applied to choose the stable parameter against unmodeled dynamics. The validity of the proposed scheme has been confirmed by experiments.

Improved disturbance observer-based control for multivariable processes with time delays based on modified inverse model

2019 ◽  
Vol 42 (3) ◽  
pp. 339-350 ◽  
Author(s):  
Qibing Jin ◽  
Wu Cai ◽  
Xinghan Du
Keyword(s):  
Disturbance Rejection ◽  
Time Delays ◽  
Disturbance Observer ◽  
Design Method ◽  
Estimation Error ◽  
Multiple Input Multiple Output ◽  
Inverse Model ◽  
Multiple Time ◽  
Input Multiple Output ◽  
Delay Matrix

In this paper, a modified multivariable disturbance observer-based (MDOB) design method is proposed to improve disturbance rejection performance for multiple-input-multiple-output (MIMO) processes with multiple time delays. Two important issues in MDOB control are studied here: computation of the inverse model and design of the filter. First, to reduce the influence of time delays, the nominal process is factorized as a diagonal time delay matrix and a remaining transfer function matrix, and the remaining part is used to design the inverse model in MDOB. Considering the difficulty of matrix inversion, the Nyquist set is used to describe the dynamic of the inverse model, and accordingly, the simplified inverse model is obtained by the curve fitting technique. In addition, to guarantee the properness and stability of the simplified inverse model, a compensator is introduced. Rules for selecting compensator parameters are given. Finally, with the proposed inverse model and compensator, the filter [Formula: see text] is optimized by minimizing the H∞ norm of the disturbance estimation error. The filter constants are determined by fully consider the disturbance rejection performance and robustness of the system. Simulation examples are presented to illustrate the effectiveness and merits of the proposed method.

Sign in / Sign up

Export Citation Format

Share Document