Melnikov-Based Open-Loop Control of Escape for a Class of Nonlinear Systems

1995 ◽  
Author(s):  
Emil Simiu ◽  
Marek Franaszek
Keyword(s):  
Stochastic Systems ◽  
Control Method ◽  
Open Loop ◽  
Heteroclinic Orbits ◽  
Time Interval ◽  
Control Force ◽  
Open Loop Control ◽  
Loop Control ◽  
Random Forcing ◽  
Scale Factors

Abstract The performance of certain nonlinear stochastic systems is deemed acceptable if, during a specified time interval, the systems have sufficiently low probabilities of escape from a preferred region of phase space. We propose an open-loop control method for reducing these probabilities. The method is applicable to stochastic systems whose dissipation- and excitation-free counterparts have homoclinic or heteroclinic orbits. The Melnikov relative scale factors are system properties containing information on the frequencies of the random forcing spectral components that are most effective in inducing escapes. This information is useful in practice even if the dissipation and excitation terms are relatively large. An ideal open-loop control force applied to the system would be equal to the negative of a fraction of the exciting force from which the ineffective components have been filtered out. Limitations inherent in any practical control system make it impossible to achieve such an ideal control. Nevertheless, numerical simulations show that substantial advantages can be achieved in some cases by designing control systems that take into account the information contained in the Melnikov scale factors.

Melnikov-Based Open-Loop Control of Escape for a Class of Nonlinear Systems

1997 ◽  
Vol 119 (3) ◽  
pp. 590-594 ◽  
Author(s):  
Emil Simiu ◽  
Marek Franaszek
Keyword(s):  
Stochastic Systems ◽  
Control Method ◽  
Open Loop ◽  
Heteroclinic Orbits ◽  
Time Interval ◽  
Open Loop Control ◽  
Loop Control ◽  
Random Forcing ◽  
Scale Factors ◽  
System Properties

The performance of certain nonlinear stochastic systems is deemed acceptable if during a specified time interval, the systems have sufficiently low probabilities of escape from a preferred region of phase space. We propose an open-loop control method for reducing these probabilities. The method is applicable to stochastic systems whose dissipation- and excitation-free counterparts have homoclinic or heteroclinic orbits. The Melnikov relative scale factors are system properties containing information on the frequencies of the random forcing spectral components that are most effective in inducing escapes. Numerical simulations show that substantial advantages can be achieved in some cases by designing control systems that take into account the information contained in the Melnikov scale factors.

Positioning of Pneumatic Actuator Using Open-Loop System

2015 ◽  
Vol 816 ◽  
pp. 160-164
Author(s):  
Ivan Virgala ◽  
Michal Kelemen ◽  
Erik Prada ◽  
Tomáš Lipták
Keyword(s):  
Mathematical Model ◽  
Control Method ◽  
Open Loop ◽  
Pneumatic Actuator ◽  
Open Loop Control ◽  
Open Loop System ◽  
Precise Positioning ◽  
Loop Control ◽  
Experimental Stand ◽  
Loop Control System

In the paper, we experimentally analyze a pneumatic actuator and possibilities of piston positioning. Paper shows mathematical model of pneumatic actuator. Actuator is experimentally tested and therefor experimental stand is assembled for the purposes of positioning of actuator piston. The changing parameters during the experiment are weight of load and pneumatic pressure. The results show how these parameters can have influence on precise positioning of pneumatic actuator. For experiment there is purposely used open loop control system. The aim of the study is not to show control method for positioning but to show influence of mentioned parameters.

Asymptotic Solution and Trajectory Planning for Open-Loop Control of Mobile Robots

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Alan Whitman ◽  
Garrett Clayton ◽  
Alexander Poultney ◽  
Hashem Ashrafiuon
Keyword(s):  
Mobile Robots ◽  
Trajectory Planning ◽  
Control Method ◽  
Open Loop ◽  
Order Correction ◽  
Reference Trajectory ◽  
Open Loop Control ◽  
Loop Control ◽  
First Order ◽  
First Order Correction

A novel open-loop control method is presented for mobile robots based on an asymptotic inverse dynamic solution and trajectory planning. The method is based on quantification of sliding by a small nondimensional parameter. Asymptotic expansion of the equations yields the dominant nonslip solution along with a first-order correction for sliding. A trajectory planning is then introduced based on transitional circles between the robot initial states and target reference trajectory. The transitional trajectory ensures smooth convergence of the robot states to the target reference trajectory, which is essential for open-loop control. Experimental results with a differential drive mobile robot demonstrate the significant improvement of the controller performance when the first-order correction is included.

scholarly journals Research on system modeling and motion control simulation of automatic power trowel

2021 ◽  
Vol 2125 (1) ◽  
pp. 012031
Author(s):  
Hao Xu ◽  
Yutian Zhu ◽  
Mo Chen ◽  
Zhao Liu
Keyword(s):  
Control Algorithm ◽  
Control Method ◽  
System Modeling ◽  
Open Loop ◽  
State Feedback Control ◽  
Open Loop Control ◽  
Loop Control ◽  
Point Motion ◽  
Point To Point ◽  
The Relationship

Abstract Aiming at the problems that the existing control researches on the power trowel are limited to the analysis of the motion principle and the open-loop control of some mechanisms, taking a hydraulically-driven ride-on power trowel as the research object, the closed-loop control method of the point-to-point motion of the power trowel is studied. After analyzing the motion principle of the power trowel, based on the assumption of elastic deformation of concrete, the dynamic model of a single trowel is established, and the relationship between the driving force, driving moment and hydraulic moment, velocity, and angular velocity of the trowel is obtained. The whole machine motion equation of the power trowel is deduced, the point-to-point state feedback control algorithm of the power trowel is studied, and a simulation model is built to verify the accuracy of the system model of the power trowel and the effectiveness of the control algorithm. This research can provide reference for the control method design of other complex motions of the power trowel.

Optimal Control of Restraint Forces in an Automobile Impact

2006 ◽  
Vol 129 (4) ◽  
pp. 415-424 ◽  
Author(s):  
Richard W. Kent ◽  
Dmitry V. Balandin ◽  
Nikolai N. Bolotnik ◽  
Walter D. Pilkey ◽  
Sergey V. Purtsezov
Keyword(s):  
Optimal Control ◽  
Seat Belt ◽  
Open Loop ◽  
Control Law ◽  
Continuous Control ◽  
Control Force ◽  
Restraint System ◽  
Open Loop Control ◽  
Loop Control ◽  
Linear Spring

This study concerns a concept for an optimal control of the force developed in an automotive restraint system during a frontal impact. The concept is close to that of “smart” restraint systems and involves continuous control of the restraint force by moving the point of attachment of the restraint system to the vehicle or retracting and releasing the seat belts. The analytical foundation for the control of the restraining force does not appear to have been formulated prior to this study. The control design involves the limiting performance analysis of the isolation of an occupant from the crash impact and the formation of a feedback to sustain the open-loop control law that provides the limiting performance. Initially, the problem is outlined using a single-degree-of-freedom system and solved for optimal isolator characteristics. This exercise shows that the optimal force is constant and that the performance of a restraint system behaving as a linear spring is half as effective as the optimal. The methodology is then applied to a published thoracic model having multiple degrees of freedom. A set of functionals is defined as constraints corresponding to injury criteria and the displacement of the occupant relative to the vehicle. The characteristics of the optimal isolator force are then determined. It is shown that this force has a short-duration period of high magnitude early in the profile, followed by an interval of nearly constant force. Next it is shown that a restraint behaving as a linear spring can generate the optimal control force if its attachment point in the vehicle is allowed to move. The design of the control law for this motion involves the determination of an optimal open-loop control and the formation of a feedback to sustain this control. Forms for both of these are presented. A substantial improvement in the behavior of an automobile occupant’s restraint systems can be anticipated from an active control of the seat belt retraction.

Enhancement of dynamic performance of wave energy converter by introducing a flow control

2022 ◽  
pp. 014233122110699
Author(s):  
Dazhou Geng ◽  
Qijuan Chen ◽  
Yang Zheng ◽  
Xuhui Yue ◽  
Donglin Yan
Keyword(s):  
Flow Control ◽  
Transient Process ◽  
Closed Loop ◽  
Control Method ◽  
Control Valve ◽  
Open Loop ◽  
Closed Loop Control ◽  
Flow Control Valve ◽  
Open Loop Control ◽  
Loop Control

The stabilization of power take-off (PTO) is imperative especially under circumstances of fluctuating input wave energy. In this paper, a flow control valve is introduced to optimize the transient process of the hydraulic PTO, which can contribute to a quicker adjustment and a stronger stability. Under variations of input power and load torque in transient process, an open-loop control method and a closed-loop control method are proposed as the opening law of the above valve, and the hydraulic motor speed, the pressure at the accumulator inlet and the generated power are chosen as indicators to examine the regulation performance. Then, the synergic effect of the flow control valve and the accumulator in the transient process is discussed. The effectiveness of the two presented control methods on the fluctuation suppression is respectively tested and compared in both regular wave and irregular wave situations via simulation. To validate the practical effectiveness of the proposed methods, field experiments are conducted. The results demonstrate that the open-loop control can only improve the damping ability of the hydraulic PTO in the speed raising stage, while the closed-loop control can improve the stability both in the speed raising stage and in the load increasing stage.

Optimum Pulse Control of Flexible Structures

1981 ◽  
Vol 48 (3) ◽  
pp. 619-626 ◽  
Author(s):  
S. F. Masri ◽  
G. A. Bekey ◽  
T. K. Caughey
Keyword(s):  
Control Method ◽  
Flexible Structures ◽  
Open Loop ◽  
Response Threshold ◽  
Distributed Parameter ◽  
Open Loop Control ◽  
Pulse Control ◽  
Loop Control ◽  
Pulse Characteristics ◽  
Active Control Method

A simple yet efficient active control method is presented for reducing the oscillations of distributed parameter systems subjected to arbitrary dynamic environments. Following determination that some specified response threshold has been exceeded, an open-loop control pulse is applied. The optimum pulse characteristics are determined analytically so as to minimize a non-negative cost function related to the structure energy. The proposed control method is shown to be reliable in consistently mitigating the response of realistic multidegree-of-freedom systems, whether linear or nonlinear, subject to arbitrary stochastic or deterministic excitation.

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