Nonlinear Modeling and Partial Linearizing Control of a Slewing Timoshenko-Beam

1996 ◽  
Vol 118 (1) ◽  
pp. 75-83 ◽  
Author(s):  
King Yuan ◽  
Chen-Meng Hu
Keyword(s):  
Timoshenko Beam ◽  
Slenderness Ratio ◽  
Nonlinear Modeling ◽  
Equations Of Motion ◽  
Nonlinear Controller ◽  
Elastic Mode ◽  
Modeling And Control ◽  
Centrifugal Stiffening ◽  
Orthogonality Conditions ◽  
And Control

The modeling and control of a horizontally slewing inextensible Timoshenko beam, taking into account the centrifugal stiffening effect and a tip payload, are considered. Partial differential equations of motion and orthogonality conditions for the constrained modes are derived. A finite dimensional dynamic model simplified by using the orthogonality conditions is obtained. To achieve the joint angle trajectory tracking with simultaneous suppression of elastic vibrations, a nonlinear controller is designed using input-output linearization and elastic-mode stabilization. A sufficient condition for asymptotic stability of the closed-loop system is established. Numerical examples with the role of slenderness ratio of the slewing beam highlighted are presented to demonstrate the effectiveness of the proposed control strategy.

Nonlinear Modeling and Control of Hysteresis in Active Material Systems

1999 ◽  
Author(s):  
Glenn V. Webb ◽  
Dimitris C. Lagoudas ◽  
Andrew J. Kurdila
Keyword(s):  
Shape Memory ◽  
Nonlinear Modeling ◽  
Active Material ◽  
Electrorheological Fluids ◽  
Adaptive Model ◽  
Structural System ◽  
Modeling And Control ◽  
Significant Challenge ◽  
Hysteresis Nonlinearity ◽  
And Control

Abstract Active material actuators present a significant challenge to researchers interested in applying them to aerospace structures. Materials such as shape memory alloys, piezo-ceramcs and electrorheological fluids exhibit hysteresis to varying degrees. Not only do they exhibit hysteresis, but in some cases the hysteresis is non-stationary. We present a methodology that allows for design of controllers for the structural system from linear system theory. This is accomplished by compensating, or linearizing, the hysteresis nonlinearity using an adaptive model of hysteresis. Experimental results for adaptive control of shape memory alloy actuators with non-stationary hysteresis are provided.

Nonlinear Modeling and Control of Overhead Crane Load Sway

1988 ◽  
Vol 110 (3) ◽  
pp. 266-271 ◽  
Author(s):  
Kamal A. F. Moustafa ◽  
A. M. Ebeid
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Digital Computer ◽  
Nonlinear Modeling ◽  
Overhead Crane ◽  
Nonlinear Dynamical ◽  
Modeling And Control ◽  
Control Scheme ◽  
Rate Of Decay ◽  
And Control

In this paper, we derive a nonlinear dynamical model for an overhead crane. The model takes into account simultaneous travel and transverse motions of the crane. The aim is to transport an object along a specified transport route in such a way that the swing angles are suppressed as quickly as possible. We develop an antiswing control system which adopts a feedback control to specify the crane speed at every moment. The gain matrix is chosen such that a desired rate of decay of the swing angles is obtained. The model and control scheme are simulated on a digital computer and the results prove that the feedback control works well.

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