Control of Two-Link Flexible Structures

Volume 1 ◽  
2004 ◽  
Author(s):  
Clarice Wagner-Nachshoni ◽  
Yoram Halevi
Keyword(s):  
Transfer Function ◽  
Time Delays ◽  
Wave Motion ◽  
Controller Design ◽  
Flexible Structures ◽  
Infinite Dimensional ◽  
Second Stage ◽  
Finite Dimensional ◽  
Control Scheme ◽  
Two Stages

A method of noncollocated controller design for non-uniform flexible structures, governed by the wave equation, is proposed. An exact, infinite dimensional, transfer function, relating the actuation and measurement points, with general boundary conditions, is derived for the multi-link case. Three modeling methods are presented and discussed. A key element of the model is the existence of time delays, due to the wave motion, which play a major role in the controller design. The design consists of two stages. First an inner rate loop is closed in order to improve the system dynamic behavior. It leads to a finite dimensional plus delay inner closed loop, which is the equivalent plant for the outer loop. In the second stage an outer noncollocated position loop is closed. It has the structure of an observer–predictor control scheme to compensate for the response delay. The resulting overall transfer function is second order, with arbitrarily assigned dynamics, plus delay.

Control of Flexible Structures Governed by the Wave Equation Using Infinite Dimensional Transfer Functions

2004 ◽  
Vol 127 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Yoram Halevi
Keyword(s):  
Wave Equation ◽  
Transfer Function ◽  
Transfer Functions ◽  
Controller Design ◽  
Flexible Structures ◽  
Infinite Dimensional ◽  
Second Stage ◽  
Finite Dimensional ◽  
Control Scheme ◽  
Two Stages

A method of noncollocated controller design for flexible structures, governed by the wave equation, is proposed. First an exact, infinite dimension, transfer function is derived and its properties are investigated. A key element in that part is the existence of time delays due to the wave motion. The controller design consists of two stages. The first one is an inner collocated rate loop. It is shown that there exists a controller that leads to a finite dimensional plus delay inner closed loop, which is the equivalent plant for the outer loop. In the second stage an outer noncollocated position loop is closed. It has the structure of an observer-predictor control scheme to compensate for the response delay. The resulting overall transfer function is second order, with arbitrarily assigned dynamics, plus delay.

An adaptive PID-like controller for vibration suppression of piezo-actuated flexible beams

2017 ◽  
Vol 24 (12) ◽  
pp. 2656-2670 ◽  
Author(s):  
Teerawat Sangpet ◽  
Suwat Kuntanapreeda ◽  
Rüdiger Schmidt
Keyword(s):  
Vibration Suppression ◽  
Flexible Structures ◽  
Flexible Beam ◽  
Flexible Beams ◽  
Present Scheme ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems ◽  
Finite Dimensional ◽  
Control Scheme ◽  
The Stability

Flexible structures have been increasingly utilized in many applications because of their light-weight and low production cost. However, being flexible leads to vibration problems. Vibration suppression of flexible structures is a challenging control problem because the structures are actually infinite-dimensional systems. In this paper, an adaptive control scheme is proposed for the vibration suppression of a piezo-actuated flexible beam. The controller makes use of the configuration of the prominent proportional-integral-derivative controller and is derived using an infinite-dimensional Lyapunov method. In contrast to existing schemes, the present scheme does not require any approximated finite-dimensional model of the beam. Thus, the stability of the closed loop system is guaranteed for all vibration modes. Experimental results have illustrated the feasibility of the proposed control scheme.

scholarly journals Boundary Control for a Certain Class of Reaction-Advection-Diffusion System

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1854
Author(s):  
Eduardo Cruz-Quintero ◽  
Francisco Jurado
Keyword(s):  
Boundary Conditions ◽  
Boundary Control ◽  
Distribution Systems ◽  
Controller Design ◽  
Neumann Boundary ◽  
Neumann Boundary Conditions ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems ◽  
Finite Dimensional ◽  
Advection Diffusion

There are physical phenomena, involving diffusion and structural vibrations, modeled by partial differential equations (PDEs) whose solution reflects their spatial distribution. Systems whose dynamics evolve on an infinite-dimensional Hilbert space, i.e., infinite-dimensional systems, are modeled by PDEs. The aim when designing a controller for infinite-dimensional systems is similar to that for finite-dimensional systems, i.e., the control system must be stable. Another common goal is to design the controller in such a way that the response of the system does not be affected by external disturbances. The controller design for finite-dimensional systems is not an easy task, so, the controller design for infinite-dimensional systems is even more challenging. The backstepping control approach is a dominant methodology for boundary feedback design. In this work, we try with the backstepping design for the boundary control of a reaction-advection-diffusion (R-A-D) equation, namely, a type parabolic PDE, but with constant coefficients and Neumann boundary conditions, with actuation in one of these latter. The heat equation with Neumann boundary conditions is considered as the target system. Dynamics of the open- and closed-loop solution of the PDE system are validated via numerical simulation. The MATLAB®-based numerical algorithm related with the implementation of the control scheme is here included.

Active Control of Flexible Structures Subject to Distributed and Seismic Disturbances

1993 ◽  
Vol 115 (4) ◽  
pp. 649-657 ◽  
Author(s):  
Akira Ohsumi ◽  
Yuichi Sawada
Keyword(s):  
Active Control ◽  
Flexible Structures ◽  
Distributed Parameter ◽  
Dimensional System ◽  
Random Disturbance ◽  
Modal Expansion ◽  
Infinite Dimensional ◽  
Finite Dimensional ◽  
Real Earthquake ◽  
The Mathematical Model

The purpose of this paper is to present a method of active control for suppressing the vibration of a mechanically flexible cantilever beam which is subject to a distributed random disturbance and also a seismic input at the clamped end. First, the mathematical model of the flexible structure is established by a stochastic partial differential equation which describes the Euler-Bernoulli type distributed parameter system with internal viscous damping and subject to the seismic and distributed random inputs. Second, the distributed parameter model, which is considered as an infinite-dimensional system, is reduced to a finite-dimensional one by using the modal expansion, and split into the controlled part and the uncontrolled (residual) one. The principal approach is to regard the observation spillover due to uncontrolled part as a colored observation noise and construct an estimator, and then we construct the optimal control system. Finally, simulation studies are presented by using a real earthquake accelerogram data.

Modeling and control of flexible link manipulators for unmodeled dynamics effect

2018 ◽  
Vol 233 (3) ◽  
pp. 245-263 ◽  
Author(s):  
Berk Altıner ◽  
Akın Delibaşı ◽  
Bilal Erol
Keyword(s):  
Controller Design ◽  
Flexible Structures ◽  
Lumped Parameter Model ◽  
Unmodeled Dynamics ◽  
Experimental Setup ◽  
Flexible Link ◽  
Linear Quadratic ◽  
Partial Differential ◽  
Infinite Dimensional ◽  
Infinite Dimensional Systems

Flexible link manipulators are mostly prefered in applications where energy consumption and faster operation are critically important. Since distributed nature of flexibility makes the system depend on not only time variable but also a spatial variable, the dynamics of flexible structures are expressed by partial differential equations. In the virtue of this kind of modeling, the designers encounter with infinite dimensional systems which means that the system has an infinite number of degrees of freedom. To cope with infinite dimensional systems, one of the most relevant techniques is to truncate the model into a definite order. However, this may yield the unmodeled dynamics that cause performance degradation and even instability. In this paper, the main motivation is to propose control techniques to compensate unwanted effects of unmodeled dynamics which may occur in truncation process. In order to achieve this goal, the linear quadratic Gaussian and the weighted [Formula: see text] controller design are adopted. The performances of the designed controllers are demonstrated on the experimental setup. Besides this motivation, traditional lumped parameter model of the flexible link manipulator which is widely seen in the literature is considered and the superiority of the partial differential equation model is shown on the experimental setup.

Modeling and Control of Acoustic Ducts

2000 ◽  
Vol 123 (1) ◽  
pp. 2-10 ◽  
Author(s):  
H. R. Pota ◽  
A. G. Kelkar
Keyword(s):  
Controller Design ◽  
Parametric Uncertainty ◽  
Theoretical Models ◽  
Unmodeled Dynamics ◽  
Modeling And Control ◽  
Infinite Dimensional ◽  
Finite Dimensional ◽  
Dimensional Models ◽  
And Control ◽  
Acoustic Ducts

This paper presents closed-form mathematical models for an acoustic duct with general boundary conditions. These infinite-dimensional models are derived using symbolic computations. A new method to obtain finite dimensional approximations of infinite-dimensional models using quartic functions is presented. The theoretical models are compared with the experimental data obtained for the KSU duct. The experimental results of a new robust broadband feedback controller, designed using passivity-based techniques, are presented. The controller design is shown to be robust to the unmodeled dynamics and parametric uncertainty.

Nonlinear stabilizing control of a rotary double inverted pendulum: a modified backstepping approach

2016 ◽  
Vol 39 (11) ◽  
pp. 1721-1734 ◽  
Author(s):  
Abdul Jabbar ◽  
Fahad Mumtaz Malik ◽  
Shahzad Amin Sheikh
Keyword(s):  
Inverted Pendulum ◽  
Coupled System ◽  
System Model ◽  
Control Law ◽  
Second Stage ◽  
Backstepping Approach ◽  
Stabilizing Control ◽  
Control Scheme ◽  
Backstepping Controller ◽  
Two Stages

Modified backstepping control is proposed for an under-actuated rotary double inverted pendulum. The system has actuated rotary base joint with which two unactuated links are attached. The proposed control design is a three step process for de-coupled system model. In the first stage, a backstepping controller is designed for each of the active and passive joints. In the second stage, compensation is introduced in the respective control efforts to cater for uncertain terms based on Lyapunov function for each joint. Finally, the controllers obtained in the two stages are combined to form a total control law. The performance of the proposed control scheme is evaluated by convergence analysis and simulations.

Sign in / Sign up

Export Citation Format

Share Document