Control of a Buckled Beam Subjected to a Compressive Force

2001 ◽  
Author(s):  
Hiroshi Yabuno ◽  
Kazuya Ando ◽  
Nobuharu Aoshima
Keyword(s):  
Steady State ◽  
Disturbance Observer ◽  
Coulomb Friction ◽  
Control Method ◽  
Compressive Force ◽  
Restoring Force ◽  
Velocity Feedback ◽  
Stabilization Control ◽  
Buckled Beam ◽  
Position Feedback

Abstract In this paper, we deal with a stabilization control for the buckled beam subjected to a compressive force. It is easily predicted that by applying a restoring force to the beam (P control), which is proportional to the deflection, the critical compressive force for the buckling is increased. However it is theoretically and experimentally clarified in our former study that in the neighborhood of the critical point, the effect of Coulomb friction at the supporting points is relatively increased even if it is very slight. It follows that the beam cannot be stabilized to the trivial steady state only by using the position feedback control and also velocity feedback. In this paper, we propose a stabilization control method of the beam to the trivial steady state by the aid of disturbance observer. Furthermore, the validity of the theoretically proposed method is experimentally confirmed.

Stabilization Control of a Simply Supported Buckled Beam

2003 ◽  
Vol 9 (3-4) ◽  
pp. 449-473 ◽  
Author(s):  
Hiroshi Yabuno ◽  
Kazuya Ando ◽  
Nobuharu Aoshima
Keyword(s):  
Steady State ◽  
Coulomb Friction ◽  
Control Method ◽  
Compressive Force ◽  
Control Force ◽  
Lateral Direction ◽  
Simply Supported ◽  
Stabilization Control ◽  
Straight Position ◽  
Buckled Beam

A stabilization control scheme for a simply supported buckled beam subjected to a compressive force is proposed theoretically and experimentally. It is easily predicted that the application of a control force based on P-control (control force is proportional to the deflection) increases the stiffness of the beam as well as the critical compressive force for the buckling. However, P-control cannot stabilize the buckled beam into the trivial steady state (straight position) for the following reason. Because the simply supported point is composed of rotatingequipment such as radial bearing, there is Coulomb friction in the circumferential direction around the rotatingaxis at that point and this friction causes the bendingmoment at the supporting point. As theoretically and experimentally clarified in our former study, in the neighborhood of the critical point, this effect of Coulomb friction produces an infinite number of fixed points for a compressive force. Then because the sum of the equivalent destabilization force in the lateral direction owing to the compressive force, originally existing stiffness of the beam, and the control force is spontaneously balanced with the effect of the bendingmoment due to the Coulomb friction, the beam cannot be stabilized to the trivial steady state by using the P-control. Also, in the same manner, the beam cannot be stabilized to the trivial steady state even by proportional derivative (PD) control. In this paper, we regard the effect of the Coulomb friction as a disturbance, and by estimating the disturbance with the aid of a disturbance observer, we stabilize the simply supported buckled beam to the trivial steady state. Furthermore, we conduct experiments using simple apparatus and we confirm the validity of the theoretically proposed control method.

Stabilization of a Buckled Beam by High-Frequency Excitation: Linear Analysis and Experiments

2005 ◽  
Author(s):  
Koji Tsumoto ◽  
Hiroshi Yabuno ◽  
Nobuharu Aoshima
Keyword(s):  
High Frequency ◽  
Control Method ◽  
Compressive Force ◽  
Pitchfork Bifurcation ◽  
Complex Structures ◽  
Stabilization Control ◽  
Buckled Beam ◽  
High Frequency Excitation ◽  
Frequency Excitation ◽  
The Stability

Beam is one of the fundamental elements in complex structures. It is very significant to clarify its stability under the various circumstances. In particular, the buckling phenomenon, which is characterized as a pitchfork bifurcation, has accepted much interest by many researchers. In this paper, we propose a stabilization control method for the first-mode buckling phenomenon in the clamped-clamped beam without feedback control. We analyze the stability of a buckled beam under high frequency excitation in linear theory. It is theoretically clarified and experimentally that the high-frequency excitation shifts the bifurcation point (the critical compressive force) and prevents the beam buckling.

Stabilization of Self-Excited Oscillation in a Flexible Fluid-Conveying-Pipe by Position Feedback Control

2012 ◽  
Author(s):  
Hideaki Kosaki ◽  
Hiroshi Yabuno
Keyword(s):  
Control Method ◽  
Unstable Mode ◽  
Adjoint System ◽  
The Self ◽  
Flexible Pipe ◽  
Stabilization Control ◽  
Position Feedback ◽  
Excited Oscillation ◽  
Excitation Mechanisms ◽  
Points Of View

Resonances in flexible fluid-conveying-pipes have been theoretically and experimentally analyzed from the practical and physical points of view. The excitation mechanisms for the resonances have been given considerable attention. In contrast with the analysis of the resonance phenomena, there are few studies on the stabilization control method for the self-excited oscillation of a flexible fluid-conveying-pipe. In this paper, we propose a control method for the self-excited oscillation in a fluid-conveying-pipe theoretically and experimentally. The unstable mode of the fluid-conveying-pipe is not any eigenmodes of the flexible pipe without flow because it is non-self adjoint system. In this paper, by not using the eigenmodes of the flexible pipe without flow deriving the unstable mode shape exactly, we propose a stabilization control method which actuates the unstable mode directly. Therefore, under the proposed control method, the spillover is avoidable and only one sensor is required.

Robust finite-time trajectory tracking control for a space manipulator with parametric uncertainties and external disturbances

2021 ◽  
pp. 095441002110147
Author(s):  
Qijia Yao
Keyword(s):  
Trajectory Tracking ◽  
Finite Time ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Control Method ◽  
Parametric Uncertainties ◽  
External Disturbances ◽  
Trajectory Tracking Control ◽  
Space Manipulator ◽  
Tracking Controller

Space manipulator is considered as one of the most promising technologies for future space activities owing to its important role in various on-orbit serving missions. In this study, a robust finite-time tracking control method is proposed for the rapid and accurate trajectory tracking control of an attitude-controlled free-flying space manipulator in the presence of parametric uncertainties and external disturbances. First, a baseline finite-time tracking controller is designed to track the desired position of the space manipulator based on the homogeneous method. Then, a finite-time disturbance observer is designed to accurately estimate the lumped uncertainties. Finally, a robust finite-time tracking controller is developed by integrating the baseline finite-time tracking controller with the finite-time disturbance observer. Rigorous theoretical analysis for the global finite-time stability of the whole closed-loop system is provided. The proposed robust finite-time tracking controller has a relatively simple structure and can guarantee the position and velocity tracking errors converge to zero in finite time even subject to lumped uncertainties. To the best of the authors’ knowledge, there are really limited existing controllers can achieve such excellent performance under the same conditions. Numerical simulations illustrate the effectiveness and superiority of the proposed control method.

scholarly journals A novel sliding mode single-loop speed control method based on disturbance observer for permanent magnet synchronous motor drives

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881527 ◽  
Author(s):  
Xudong Liu ◽  
Ke Li
Keyword(s):  
Permanent Magnet ◽  
Disturbance Observer ◽  
Control Structure ◽  
Control Method ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Speed Control ◽  
Synchronous Motor ◽  
Motor Drives ◽  
Sliding Mode Controller

A novel speed control method based on sliding mode control and disturbance observer is studied for permanent magnet synchronous motor drives. Different from the conventional speed and current cascade control structure in the field-oriented vector control, the new controller adopts the single-loop control structure, in which the speed and quadrate axes current controllers are combined together. First, a multiple-surface sliding mode controller is designed for the speed control system of permanent magnet synchronous motor. Although the sliding mode controller has the strong robustness for the matched disturbance in the system, it still cannot deal with mismatched disturbance effectively, such as external load disturbance and some parameter variations. Thus, the disturbance observer is introduced to estimate the disturbance in the motor, which is designed by combining the proposed sliding mode controller. Finally, the effectiveness is tested under various conditions by both simulation and experiment. The results show that the designed controller has the fast transient response and robustness under different operating conditions.

scholarly journals Stabilization Control of Inverted Two-Wheeled Luggage Transport Vehicle Using a Kalman Filter-Based Disturbance Observer

2021 ◽  
Vol 33 (3) ◽  
pp. 643-652
Author(s):  
Hironori Matsubara ◽  
◽  
Yuki Nagatsu ◽  
Hideki Hashimoto
Keyword(s):  
Kalman Filter ◽  
Disturbance Observer ◽  
Service Industry ◽  
High Mobility ◽  
Least Mean Square ◽  
Transport Costs ◽  
Turning Angle ◽  
Stabilization Control ◽  
Translational Movement ◽  
Transport Vehicle

In addition to the declining birthrate and aging population in Japan, there has been a recent decrease in its total population. This threatens to exacerbate a shortage in labor force, which could trigger an increase in the luggage transport costs of transportation companies or the service industry. The demand for inverted two-wheeled luggage transport vehicles has been increasing steadily owing to their high mobility, compactness, affordability, and pivotal turnability. However, owing to their statical instability, these vehicles are limited. Accordingly, stability can be improved in these systems by configuring a spreading system and applying a disturbance observer based on a Kalman filter. The application of a Kalman filter enables us to estimate the disturbance in which the error between the true and estimated values is the least mean square. Furthermore, we validated the efficiency of the proposed method via its translational movement, turning angle control, and load-loading/unloading experiments using various loads.

Balancing Control of a Mobile Manipulator with Two Wheels by an Acceleration-Based Disturbance Observer

2018 ◽  
Vol 15 (03) ◽  
pp. 1850005 ◽  
Author(s):  
Yeong-Geol Bae ◽  
Seul Jung
Keyword(s):  
Disturbance Observer ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Experimental Studies ◽  
Service Robot ◽  
Mobile Manipulator ◽  
Control Performance ◽  
Six Degrees Of Freedom ◽  
Inertia Model ◽  
Balancing Control

This paper presents the balancing control performance of a mobile manipulator built in the laboratory as a service robot called Korean robot worker (KOBOKER). The robot is designed and implemented with two wheels as a mobile base and two arms with six degrees-of-freedom each. Kinematics and dynamics of the robot are analyzed. For the balancing control performance, two wheels are controlled independently by the time-delayed control method based on the inertia model of the robot. The acceleration information obtained directly from the sensor is used for the modified disturbance observer structure called an acceleration-based disturbance observer (AbDOB). Experimental studies of the balancing control of the robot are conducted to compare the control performances by both a PID control method and an AbDOB.

Comparison of Active and Hybrid Vibration Confinement With Conventional Active Vibration Control

1999 ◽  
Author(s):  
Lawrence R. Corr ◽  
William W. Clark
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Numerical Study ◽  
Active Vibration Control ◽  
Piezoelectric Actuators ◽  
Control Technique ◽  
Flexible Beam ◽  
Velocity Feedback ◽  
Active Vibration ◽  
Piezoelectric Actuators And Sensors

Abstract This paper presents a numerical study in which active and hybrid vibration confinement is compared with a conventional active vibration control method. Vibration confinement is a vibration control technique that is based on reshaping structural modes to produce “quiet areas” in a structure as opposed to adding damping as in conventional active or passive methods. In this paper, active and hybrid confinement is achieved in a flexible beam with two pairs of piezoelectric actuators and sensors and with two vibration absorbers. For comparison purposes, active damping is achieved also with two pairs of piezoelectric actuators and sensors using direct velocity feedback. The results show that both approaches are effective in controlling vibrations in the targeted area of the beam, with direct velocity feedback being slightly more cost effective in terms of required power. When combined with passive confinement, however, each method is improved with a significant reduction in required power.

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