scholarly journals Observer Design for a Variable Moment of Inertia System

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5850
Author(s):  
Jerzy Baranowski
Keyword(s):  
Observer Design ◽  
Moment Of Inertia ◽  
Nonlinear Observer ◽  
Laboratory System ◽  
Systematic Testing ◽  
State Observers ◽  
Full State ◽  
Efficient Control ◽  
Linear Observer ◽  
Variable Moment

Variable moment of inertia systems are common, and a popular laboratory system of this type is the “ball-and-beam”. Such systems are, however, nonlinear and often unstable. Efficient control requires full state information (or at least partial velocities), which are generally difficult to measure. That is why the design of state observers is a relevant problem. In this paper, a new design of an observer is proposed. This new nonlinear observer uses partial output injection and the circle criterion to ensure semiglobal stability. Moreover, we present a complete modeling of the system and systematic testing of the observer in comparison to a baseline in the form of a linear observer. The results show that the designed observer outperforms its linear counterpart and does not impede control.

Observer Design for State Estimation of UV Curing Processes

2014 ◽  
Author(s):  
Adamu Yebi ◽  
Beshah Ayalew ◽  
Satadru Dey
Keyword(s):  
State Estimation ◽  
Online Monitoring ◽  
Uv Curing ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Advanced Manufacturing ◽  
Monitoring And Control ◽  
State Observers ◽  
State Measurement ◽  
And Control

This article discusses the challenges of non-intrusive state measurement for the purposes of online monitoring and control of Ultraviolet (UV) curing processes. It then proposes a two-step observer design scheme involving the estimation of distributed temperature from boundary sensing cascaded with nonlinear cure state observers. For the temperature observer, backstepping techniques are applied to derive the observer partial differential equations along with the gain kernels. For subsequent cure state estimation, a nonlinear observer is derived along with analysis of its convergence characteristics. While illustrative simulation results are included for a composite laminate curing application, it is apparent that the approach can also be adopted for other UV processing applications in advanced manufacturing.

Importance of Chaos Synchronization on Technology and Science

2011 ◽  
pp. 210-246 ◽  
Author(s):  
Ricardo Aguilar-López ◽  
Ricardo Femat ◽  
Rafael Martínez-Guerra
Keyword(s):  
Feedback Control ◽  
Chaos Synchronization ◽  
Biological Systems ◽  
Chaotic Signal ◽  
External Input ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Control Laws ◽  
State Observers ◽  
The Subject

In this chapter the authors talk about importance of chaos synchronization on technology and science. This chapter is developed in three sections. In the former the authors tackle the subject related with the so-called the synchronized state in the sense of identical synchronization. It is done via robust nonlinear observer design, considering corrupted measurements and model uncertainties, coupling uncertainty estimators with nonlinear state observers. The second part treats the subject related to the applications to chaos communications, that is to say, an application of chaos theory which is aimed to provide security in the transmission of information performed through telecommunications technologies, speaking roughly at the transmitter, a message is added on to a chaotic signal and then, the message is masked in the chaotic signal. As it carries the information, the chaotic signal is also called chaotic carrier. This is done via control theory and is a particular case of chaos synchronization. Finally, in the latter section the authors talk about application to synchronization of biological systems that is to say, the intercellular Ca²+ waves have been seen like a mechanism by means of which a group of cells can communicate with one another and coordinate a multicellular response to a local event. Recently, it has been observed in a variety of systems that calcium signals can also propagate from one cell to another and thereby serve as a means of intercellular communication. The desire to understand the biophysical mechanisms of cellular dynamics has lead to introduce feedback control laws in some biological systems. Departing from the above ideas, this section explores links between feedback control schemes, with an external input, and intracellular calcium functions for coordination and control.

scholarly journals Observer Design for Estimation of Nonobservable States in Buildings

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
M. Długosz ◽  
J. Baranowski
Keyword(s):  
Temperature Control ◽  
Contraction Semigroup ◽  
Observer Design ◽  
State Variables ◽  
Control Applications ◽  
Fast Estimation ◽  
State Observers ◽  
Standard Observer ◽  
Efficient Control ◽  
Relevant Variables

Efficient temperature control requires more than air temperature measurements. Relevant variables, such as wall, ceiling, and other construction temperature evolution are usually unmeasured. Estimation of such quantities is often difficult because they are not observable with respect to available data. Their availability however would allow efficient control design. In this paper, we propose a method for designing state observers that efficiently estimate not only observable but also nonobservable (but detectable) state variables. Our method uses contraction semigroup, to obtain observer with a monotonic error reduction. Proposed approach gives twice as fast estimation as pure simulation and avoids transitional error standard observer would have. Problem of state estimation in building control applications is an important one. Attractiveness of obtaining values of physically unmeasurable variables is easily visible, as it would allow more efficient methods of temperature control. In this paper, authors discuss the problem of such estimation using a lumped capacitance model. This type of model is usually only detectable but not observable. Methods of observer tuning for such systems are not discussed properly in the literature and require special consideration. In this paper, three approaches for estimation are compared: pure model, eigenvalue shifting, and contraction semigroup observer. Results are illustrated with numerical experiments.

A nonlinear fractional-order H∞ observer for SOC estimation of battery pack of electric vehicles

2021 ◽  
pp. 095440702199434
Author(s):  
Wei Yue ◽  
Cong-zhi Liu ◽  
Liang Li ◽  
Xiang Chen ◽  
Fahad Muhammad
Keyword(s):  
Fractional Order ◽  
Estimation Method ◽  
Equivalent Circuit Model ◽  
Lithium Ion ◽  
Open Circuit ◽  
Design Criterion ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Battery Pack ◽  
Soc Estimation

This work is focused on designing a fractional-order [Formula: see text] observer and applying it into the state of charge (SOC) estimation for lithium-ion battery pack system. Firstly, a fractional order equivalent circuit model based on the fractional capacitor is established and identified. Secondly, the SOC estimation method based on the fractional-order [Formula: see text] observer is proposed. The nonlinear intrinsic relationship between the open-circuit voltage and SOC is described as a polynomial function, and its Lipschitz proposition has been discussed. Then, the nonlinear observer design criterion is established based on the Lyapunov method. Finally, the effectiveness of the proposed method is verified with high accuracy and robustness by the experiment results.

scholarly journals Reduced-order Nonlinear Observer Design for Two-time-scale Systems

2020 ◽  
Vol 53 (2) ◽  
pp. 5922-5927
Author(s):  
Zhaoyang Duan ◽  
Costas Kravaris
Keyword(s):  
Time Scale ◽  
Observer Design ◽  
Nonlinear Observer ◽  
Reduced Order

Application of Practical Observer to Semi-Active Suspensions

1998 ◽  
Vol 122 (2) ◽  
pp. 284-289 ◽  
Author(s):  
H. Nakai ◽  
S. Oosaku ◽  
Y. Motozono
Keyword(s):  
Ride Comfort ◽  
Difficult Problem ◽  
Nonlinear Observer ◽  
Vertical Acceleration ◽  
Acceleration Sensor ◽  
Active Suspensions ◽  
Linear Observer ◽  
Gain Scheduled

This paper presents the development of gain-scheduled observers for semi-active suspensions. The states of the semi-active suspensions must be accurately obtained because the accuracy directly affects system performances such as ride comfort. Nonlinearity in the absorber of the semi-active suspensions is a difficult problem for estimating the accurate states using conventional linear observer theories. To solve this problem, we have designed a new gain-scheduled observer by introducing two improvements. The validity of this nonlinear observer was confirmed by simulations and experiments. The results indicate that the present observer can accurately estimate the suspension stroke velocity using the vertical acceleration sensor on the sprung mass. [S0022-0434(00)02302-9]

Average Modeling and Nonlinear Observer Design For Pneumatic Actuators With On/Off Solenoid Valves

2021 ◽  
Author(s):  
Khaled Laib ◽  
Minh Tu Pham ◽  
Xuefang LIN-SHI ◽  
Redha Meghnous
Keyword(s):  
Closed Loop ◽  
Sliding Mode ◽  
High Gain ◽  
Observer Design ◽  
Nonlinear Observer ◽  
State Model ◽  
Pressure Measurements ◽  
Pneumatic Actuators ◽  
Nonlinear Observers ◽  
Piston Position

Abstract This paper presents an averaged state model and the design of nonlinear observers for an on/off pneumatic actuator. The actuator is composed of two chambers and four on/off solenoid valves. The elaborated averaged state model has the advantage of using only one continuous input instead of four binary inputs. Based on this new model, a high gain observer and a sliding mode observer are designed using the piston position and the pressure measurements in one of the chambers. Finally, their closed-loop performances are verified and compared on an experimental benchmark.

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