Solutions to Point-to-Point Control Problems Using Laplace Transform Technique

1991 ◽  
Vol 113 (3) ◽  
pp. 425-431 ◽  
Author(s):  
S. P. Bhat ◽  
D. K. Miu
Keyword(s):  
Laplace Transform ◽  
Linear Time ◽  
Open Loop ◽  
Control Problems ◽  
Algebraic Equations ◽  
Programming Technique ◽  
Linear Algebraic Equations ◽  
Laplace Transform Technique ◽  
Point Control ◽  
Point To Point

Using finite-time Laplace transform, the governing differential equations of linear, time invariant point-to-point control problems are converted into an equivalent set of linear algebraic equations embedded with the desired boundary conditions, characterizing the entire set of optimal and sub-optimal solutions. A linear programming technique for synthesizing the control inputs using selected sets of basis functions is presented. A new concept of feedback control which involves a recursive evaluation of the open-loop input is also developed.

Experiments on Point-to-Point Control of a Flexible Beam Using Laplace Transform Technique: Part II—Closed-Loop

1991 ◽  
Vol 113 (3) ◽  
pp. 438-443 ◽  
Author(s):  
S. P. Bhat ◽  
D. K. Miu
Keyword(s):  
Closed Loop ◽  
Position Control ◽  
Open Loop ◽  
Flexible Beam ◽  
Laplace Domain ◽  
Loop Control ◽  
Feed Forward Control ◽  
Laplace Transform Technique ◽  
Point Control ◽  
Point To Point

Using the Laplace domain synthesis technique documented in earlier publications, experiments on the closed-loop point-to-point position control of a flexible beam are presented. Two different approaches are described, a feed-forward control and an iterative open-loop control. Solution to the robustness problems encountered during actual implementation is also demonstrated.

scholarly journals Flexible Link End-Point Control Based on Exact Dynamic Inversion: Experimental Results

2001 ◽  
Author(s):  
Aurelio Piazzi ◽  
Antonio Visioli
Keyword(s):  
Open Loop ◽  
Experimental Results ◽  
Flexible Link ◽  
End Point ◽  
Point Motion ◽  
Inversion Procedure ◽  
System Inversion ◽  
Point Control ◽  
Tip Position ◽  
Point To Point

Abstract In this paper we present a new method for the point-to-point motion control of the end-point of a single flexible link manipulator. The technique is based on an exact system inversion procedure, that allows to define a suitable motion law for the hub in order to reduce the residual vibration at the end of the tip motion. Thus, the end-point control is actually performed in open-loop, therefore avoiding the use of a sensor to measure the actual tip position. Experimental results demonstrate the effectiveness of the approach and that the overall control system is inherently robust to modelling errors.

Hilbert Transform Generalization of a Classical Random Vibration Integral

1993 ◽  
Author(s):  
Pol D. Spanos ◽  
Scott M. Miller
Keyword(s):  
Hilbert Transform ◽  
Linear Time ◽  
Applied Mathematics ◽  
Classical Problem ◽  
Random Excitation ◽  
System Response ◽  
Algebraic Equations ◽  
Spectral Moments ◽  
Linear Time Invariant ◽  
Linear Algebraic Equations

Abstract Integrals which represent the spectral moments of the stationary response of a linear, time-invariant system under random excitation are considered. It is shown that these integrals can be determined through the solution of linear algebraic equations. These equations are derived by considering differential equations for both the autocorrelation function of the system response and its Hilbert transform. The method can be applied to determine both even order and odd order spectral moments. Furthermore, it provides a potent generalization of a classical formula used in control engineering and applied mathematics. The applicability of the derived formula is demonstrated by considering random excitations with, among others, the white noise, “Gaussian”, and Kanai-Tajimi seismic spectra. The results for the classical problem of a randomly excited single-degree-of-freedom oscillator are given in a concise and readily applicable format.

A Laplace Transform Technique for Direct Determination of Density of Electronic States in Disordered Semiconductors from Transient Photocurrent Data

2000 ◽  
Vol 609 ◽  
Author(s):  
Mariana J. Gueorguieva ◽  
Charles Main ◽  
Steve Reynolds
Keyword(s):  
Electronic States ◽  
Direct Determination ◽  
Algebraic Equations ◽  
Density Of Electronic States ◽  
Transient Photocurrent ◽  
Linear Algebraic Equations ◽  
Laplace Transform Technique ◽  
A New Technique ◽  
Disordered Semiconductors

ABSTRACTA new technique for direct determination of the density of electronic states (DOS) in disordered semiconductors is described. It involves Laplace transformation of transient photocurrent data I(t) followed by the numerical solution of the system of linear algebraic equations obtained from the Fredholm integral of the first kind, for a DOS represented by a series of discrete levels. No approximations are used in the solution, and no prior assumptions as to the form of the DOS are made. The fidelity of this method is assessed and compared with existing techniques by application to computer-simulated I(t) data generated from single-level and continuous DOS profiles, and to experimental data.

Parameter Estimation of Delay Systems Via Block Pulse Functions

1980 ◽  
Vol 102 (3) ◽  
pp. 159-162 ◽  
Author(s):  
Yen-Ping Shin ◽  
Chyi Hwang ◽  
Wei-Kong Chia
Keyword(s):  
Linear Time ◽  
Delay Systems ◽  
Algebraic Equations ◽  
Unknown Parameters ◽  
Linear Time Invariant ◽  
Least Squares Estimate ◽  
Block Pulse Functions ◽  
Linear Algebraic Equations ◽  
Delay Differential ◽  
Time Invariant

Linear time-invariant delay-differential equation systems are approximately represented by a set of linear algebraic equations with the block pulse functions. A least squares estimate is then used to determine the unknown parameters. Examples with satisfactory results are given.

scholarly journals MODELING AND PERFORMANCE ASSESSMENT OF INVERTED INTERMITTENT GAS LIFT

2007 ◽  
Vol 6 (1) ◽  
pp. 96 ◽  
Author(s):  
S. N. Bordalo ◽  
C. O. Carvalho Filho
Keyword(s):  
Oil And Gas ◽  
Linear Time ◽  
Dynamical Behavior ◽  
Algebraic Equations ◽  
Practical Applications ◽  
Well Production ◽  
Artificial Lift ◽  
Linear Algebraic Equations ◽  
Non Linear ◽  
Gas Lift

The Intermittent Gas Lift (IGL) is an artificial lift method for petroleum production suitable for producing wells from depleted or low productivity reservoirs. In order to enhance the well production, many variants of the conventional IGL have been developed and used worldwide. One of these variants, the Inverted IGL (IGL-I), consists of removing the gas lift valve and reversing the flow paths inside the well: gas is injected through the tubing whereas liquid is lifted through the casing annulus. The oil production is believed to increase with the IGL-I due to the larger annulus storage capacity, at the expense of higher injected gas volumes. Despite of its potential for practical applications, the IGL-I has not been covered by the literature. Aiming to surmount such  gap in the literature, this paper presents a model for the dynamical behavior of the IGL-I wells. The complexity emerged from the IGL-I cyclic operation is assessed through a simultaneous and coupled simulation scheme, comprising a variable set of non-linear algebraic equations and non-linear time-differential equations for the flow of oil and gas throughout the injection, transfer, elevation, production, decompression and loading stages of each cycle. The simulator provides the engineer with a valuable tool to investigate the well behavior of several IGL cycles. Based on the observed results, the designer may propose practical recommendations regarding the IGL-I design and operation.

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