scholarly journals Anti-Swing Control of Gantry and Tower Cranes Using Fuzzy and Time-Delayed Feedback with Friction Compensation

2005 ◽  
Vol 12 (2) ◽  
pp. 73-89 ◽  
Author(s):  
H.M. Omar ◽  
A.H. Nayfeh
Keyword(s):  
Fuzzy Logic Controller ◽  
Mapping Method ◽  
Delayed Feedback ◽  
Feedback Controller ◽  
Delayed Feedback Controller ◽  
Identification Technique ◽  
Rotational Motions ◽  
Load Swing ◽  
Gantry Cranes ◽  
Time Delayed Feedback

We designed a feedback controller to automate crane operations by controlling the load position and its swing. First, a PD tracking controller is designed to follow a prescribed trajectory. Then, another controller is added to the control loop to damp the load swing. The anti-swing controller is designed based on two techniques: a time-delayed feedback of the load swing angle and an anti-swing fuzzy logic controller (FLC). The rules of the FLC are generated by mapping the performance of the time-delayed feedback controller. The same mapping method used for generating the rules can be applied to mimic the performance of an expert operator. The control algorithms were designed for gantry cranes and then extended to tower cranes by considering the coupling between the translational and rotational motions. Experimental results show that the controller is effective in reducing load oscillations and transferring the load in a reasonable time. To experimentally validate the theory, we had to compensate for friction. To this end, we estimated the friction and then applied a control action to cancel it. The friction force was estimated by assuming a mathematical model and then estimating the model coefficients using an off-line identification technique, the method of least squares (LS).

Gain Scheduling Feedback Control of Tower Cranes with Friction Compensation

2004 ◽  
Vol 10 (2) ◽  
pp. 269-289 ◽  
Author(s):  
Hanafy M Omar ◽  
Ali H Nayfeh
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Gain Scheduling ◽  
Gantry Crane ◽  
Friction Coefficients ◽  
Identification Technique ◽  
Rotational Motions ◽  
Point To Point ◽  
Gantry Cranes ◽  
Load Weight

We have designed a controller based on gain-scheduling feedback to move a load from point to point within one oscillation cycle and without inducing large swings. The settling time of the system is taken to be equal to the period of oscillation of the load. This criterion enables us to calculate the controller feedback gains for varying load weight and cable length. First, we designed the controller for gantry cranes and then extended it to tower cranes by considering the coupling between the translational and rotational motions. Numerical simulations show that the controller is effective for reducing load oscillations and transferring the load in a reasonable time compared with that of optimal control. To experimentally validate the theory, we had to compensate for friction. To this end, we estimated the friction, then applied an opposite control action to cancel it. To estimate the friction force, we assumed a mathematical model, then we estimated the model coefficients using an off-line identification technique, the least-squares method. First, the process of identification was applied to a theoretical model of a dc motor with known friction coefficients. From this example, some guidelines and rules were deduced for the choice of the least-squares parameters. Then, the friction coefficients of the gantry crane model were estimated and validated.

Integrity Analysis of Electrically Actuated Resonators With Delayed Feedback Controller

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Fadi Alsaleem ◽  
Mohammad I. Younis
Keyword(s):  
Microelectromechanical Systems ◽  
Initial Conditions ◽  
Basin Of Attraction ◽  
Capacitive Sensor ◽  
Delayed Feedback ◽  
Feedback Controller ◽  
Positive Gain ◽  
Delayed Feedback Controller ◽  
The Stability ◽  
Integrity Analysis

In this work, we investigate the stability and integrity of parallel-plate microelectromechanical systems resonators using a delayed feedback controller. Two case studies are investigated: a capacitive sensor made of cantilever beams with a proof mass at their tip and a clamped-clamped microbeam. Dover-cliff integrity curves and basin-of-attraction analysis are used for the stability assessment of the frequency response of the resonators for several scenarios of positive and negative gain in the controller. It is found that in the case of a positive gain, a velocity or a displacement feedback controller can be used to effectively enhance the stability of the resonators. This is confirmed by an increase in the area of the basin of attraction of the resonator and in shifting the Dover-cliff curve to higher values. On the other hand, it is shown that a negative gain can significantly weaken the stability and integrity of the resonators. This can be of useful use in MEMS for actuation applications, such as in the case of capacitive switches, to lower the activation voltage of these devices and to ensure their trigger under all initial conditions.

MASTER-SLAVE SYNCHRONIZATION OF NONAUTONOMOUS CHAOTIC SYSTEMS AND ITS APPLICATION TO ROTATING PENDULUMS

2012 ◽  
Vol 22 (06) ◽  
pp. 1250147 ◽  
Author(s):  
KE DING ◽  
QING-LONG HAN
Keyword(s):  
Chaotic Systems ◽  
Design Method ◽  
Sufficient Conditions ◽  
Delayed Feedback ◽  
Delayed Feedback Control ◽  
Phase Locked Loops ◽  
Linear Matrix ◽  
Delayed Feedback Controller ◽  
Delay Dependent ◽  
Time Delayed Feedback

Some mathematical models in engineering and physics, such as rotating pendulums, governors and phase locked loops in circuits, can be described as nonautonomous systems in which there exist chaotic attractors. This paper investigates master-slave synchronization for two nonautonomous chaotic systems by using time-delayed feedback control. Firstly, three delay-dependent synchronization criteria, which are formulated in the form of linear matrix inequalities (LMIs), are established for complete synchronization, lag synchronization and anticipating synchronization, respectively. Secondly, sufficient conditions on the existence of a time-delayed feedback controller are derived by employing these newly-obtained synchronization criteria. The controller gain can be obtained by solving a set of LMIs. Finally, the synchronization criteria and the design method are applied to master-slave synchronization for rotating pendulum systems.

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