On-Line Control of Nonlinear Flexible Structures

1982 ◽  
Vol 49 (4) ◽  
pp. 877-884 ◽  
Author(s):  
S. F. Masri ◽  
G. A. Bekey ◽  
T. K. Caughey
Keyword(s):  
Control Method ◽  
Direct Method ◽  
Flexible Structures ◽  
Tall Buildings ◽  
Pulse Amplitude ◽  
Random Excitation ◽  
Control Procedure ◽  
Pulse Generators ◽  
On Line ◽  
Reliability And Robustness

A simple yet efficient method is presented for the on-line control of nonlinear, multidegree-of-freedom systems responding to arbitrary dynamic environments. The control procedure uses pulse generators located at selected positions throughout a given system. The degree of system oscillation near each controller determines the controller’s activation time and pulse amplitude. The direct method of Liapunov is used to establish that the response of the controlled nonlinear system is Lagrange stable. Simulation studies of three example systems (conducted with digital and analog computers) demonstrate the feasibility, reliability, and robustness of the proposed active-control method. These systems, which include one with a hysteretic nonlinearity, are structures representative of modern tall buildings; they are subjected to nonstationary random excitation representative of earthquake ground motions.

Active Parameter Control of Nonlinear Vibrating Structures

1989 ◽  
Vol 56 (3) ◽  
pp. 658-666 ◽  
Author(s):  
S. F. Masri ◽  
R. K. Miller ◽  
T. J. Dehghanyar ◽  
T. K. Caughey
Keyword(s):  
Vibration Control ◽  
Primary Structure ◽  
Control Method ◽  
Direct Method ◽  
Primary System ◽  
System A ◽  
On Line ◽  
Reliability And Robustness ◽  
Related Paper ◽  
Active Control Method

A simple, yet efficient method is presented for the on-line vibration control of nonlinear, multidegree-of-freedom systems responding to arbitrary dynamic environments. The procedure uses nonlinear auxiliary mass dampers with adjustable motion-limiting stops located at selected positions throughout a given nonlinear system. A mathematical model of the system to be controlled is not needed for implementing the control algorithm. The degree of the primary structure oscillation near each vibration damper determines the damper’s actively-controlled gap size and activation time. By using control energy to adjust the damper parameters instead of directly attenuating the motion of the primary system, a significant improvement is achieved in the total amount of energy expended to accomplish a given level of vibration control. In a related paper, the direct method of Lyapunov is used to establish that the response of the controlled nonlinear primary structure is Lagrange stable. Numerical simulation studies of several example systems, as well as an experimental study with a mechanical model, demonstrate the feasibility, reliability, and robustness of the proposed semi-active control method.

Active Vibration Control of Flexible Structures Arranged in Parallel

1994 ◽  
Vol 6 (3) ◽  
pp. 243-248
Author(s):  
Katsuhiko Ezure ◽  
◽  
Kazuto Seto ◽  
Sinji Mitsuta ◽  
Katsumi Sawatari ◽  
...  
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Low Frequency ◽  
Tall Buildings ◽  
Control Force ◽  
Active Vibration ◽  
Strong Winds ◽  
Lq Control

This paper proposes a vibration control method for flexible structures arranged in parallel. In recent years, tall buildings equipped with active dynamic absorbers have been popularized to maintain living comfort by reducing the vibration of higher floors by strong winds. The higher a tall building the lower its natural frequency. It will be difficult to control the vibration of ultra-tall buildings using active dynamic absorbers because of difficulties in obtaining enough control force under the lower frequency. According to the proposed method, a pair of flexible buildings are controlled actively by controlling each other by means of actuators placed between them. Therefore, it is able to obtain enough control force under the low frequency. In this paper, a reduced-order model expressed by 2DOF systems is proposed for preventing spillover instability. The LQ control theory is applied to the design of the control system. The effectiveness of this method is demonstrated theoretically as well as experimentally.

scholarly journals Task-space regulation of rigid-link electrically-driven robots with uncertain kinematics using neural networks

2021 ◽  
Vol 54 (1-2) ◽  
pp. 102-115
Author(s):  
Wenhui Si ◽  
Lingyan Zhao ◽  
Jianping Wei ◽  
Zhiguang Guan
Keyword(s):  
Neural Networks ◽  
Asymptotic Stability ◽  
Control Method ◽  
Joint Space ◽  
Robot Kinematics ◽  
Rbf Neural Networks ◽  
Task Space ◽  
Actuator Dynamics ◽  
Rigid Link ◽  
On Line

Extensive research efforts have been made to address the motion control of rigid-link electrically-driven (RLED) robots in literature. However, most existing results were designed in joint space and need to be converted to task space as more and more control tasks are defined in their operational space. In this work, the direct task-space regulation of RLED robots with uncertain kinematics is studied by using neural networks (NN) technique. Radial basis function (RBF) neural networks are used to estimate complicated and calibration heavy robot kinematics and dynamics. The NN weights are updated on-line through two adaptation laws without the necessity of off-line training. Compared with most existing NN-based robot control results, the novelty of the proposed method lies in that asymptotic stability of the overall system can be achieved instead of just uniformly ultimately bounded (UUB) stability. Moreover, the proposed control method can tolerate not only the actuator dynamics uncertainty but also the uncertainty in robot kinematics by adopting an adaptive Jacobian matrix. The asymptotic stability of the overall system is proven rigorously through Lyapunov analysis. Numerical studies have been carried out to verify efficiency of the proposed method.

A compliant control method for disassembly of non-elastic parts using realised motion

Robotica ◽  
1995 ◽  
Vol 13 (6) ◽  
pp. 591-598 ◽  
Author(s):  
Yagmur Denizhan
Keyword(s):  
Control Method ◽  
Recognition System ◽  
Automatic Recognition ◽  
Human Operator ◽  
Control Methods ◽  
Compliant Control ◽  
On Line

SummaryIn disassembly tasks, due to the large variety of objects and the different positions and orientations in which they appear, the disassembly trajectories supplied on-line by a human operator or an automatic recognition system can contain large errors. The classical compliant control methods turn out to be insufficient to eliminate sticking which is due to these errors. This paper presents a compliant control method for disassembly of non-elastic parts in non-elastic environments which adopts the trajectories according to realised motion. In case of sticking a new direction of motion is searched for until the manipulated part is set into motion.

Robust Control Method Based on Machine Learning for Boiler Combustion System

2014 ◽  
Vol 685 ◽  
pp. 368-372 ◽  
Author(s):  
Hao Zhang ◽  
Ya Jie Zhang ◽  
Yan Gu Zhang
Keyword(s):  
Robust Control ◽  
Intelligent Control ◽  
Pid Control ◽  
Control Algorithm ◽  
Control Method ◽  
Support Vector ◽  
Control Performance ◽  
Fuzzy Pid Control ◽  
On Line ◽  
Control Output

In this study, we presented a boiler combustion robust control method under load changes based on the least squares support vector machine, PID parameters are on-line adjusted and identified by LSSVM, optimum control output is obtained. The simulation result shows control performance of the intelligent control algorithm is superior to traditional control algorithm and fuzzy PID control algorithm, the study provides a new control method for strong non-linear boiler combustion control system.

scholarly journals A Control Method Switching from Vibration Reduction to Positioning for Power Assisted Moving Flexible Structures

2012 ◽  
Vol 48 (1) ◽  
pp. 27-36
Author(s):  
Isao FUJIMOTO ◽  
Susumu HARA ◽  
Yoji YAMADA ◽  
Yoshifumi MORITA ◽  
Kiyoshi SESHIMO ◽  
...  
Keyword(s):  
Control Method ◽  
Vibration Reduction ◽  
Flexible Structures

scholarly journals Plantwide Control: A New Design Procedure and Its Application at Liquefied Petroleum Gas Facility (LPGF) Plant

2020 ◽  
Vol 190 ◽  
pp. 00039
Author(s):  
Toto Haksoro ◽  
Safira Firdaus Mujiyanti ◽  
Aulia Siti Aisjah ◽  
Totok Ruki Biyanto
Keyword(s):  
Supervisory Control ◽  
Energy Use ◽  
Control Method ◽  
Design Procedure ◽  
Regulatory Control ◽  
System Response ◽  
Control Procedure ◽  
Liquefied Petroleum Gas ◽  
Fractionation Process ◽  
Plantwide Control

Natural Gas is the cleanest source of fossil energy, resulting in lower carbon emissions from coal and oil. In gas processing, the process done to separate the product composition is the fractionation process. In the gas industry, facilities/parts that are specifically to perform the process are called liquefied petroleum gas Facility plant (LPGF). Process Control is the key to a safe and profitable process industry. The Plantwide control is a structural design and control strategy for the factory as a whole. The preferred control method on this final task is the PID for regulatory control as well as the decentralized supervisory control for supervisory control and the real time optimizer for its optimization. The new plantwide control procedure can increase the profit in the process liquefied petroleum gas facility plant up to USD 643 h–1 (3 %) and decreased energy use by USD 5 h–1 (5.16 %). The application of the Plantwide control on the liquefied petroleum gas facility is also able to produce a stable system response when the interruption of the feed flow rate changes. This is demonstrated by decreasing slurries time and maximum overshoot as well as eliminating steady-state errors.

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