Theoretical and Experimental Investigation of Elevator Cable Dynamics and Control

2005 ◽  
Vol 128 (1) ◽  
pp. 66-78 ◽  
Author(s):  
W. D. Zhu ◽  
Y. Chen
Keyword(s):  
Control Method ◽  
Upward Movement ◽  
High Rise ◽  
Cable Dynamics ◽  
Theoretical Predictions ◽  
Dynamics And Control ◽  
And Control ◽  
Elevator Cable ◽  
Parameter Estimation Techniques ◽  
Good Agreement

The vibratory energy of a moving cable in an elevator increases in general during upward movement. A control method is presented to dissipate the energy associated with the lateral vibration of the cable. A novel experimental method is developed to validate the theoretical predictions for the uncontrolled and controlled lateral responses of a moving cable in a high-rise elevator. This includes the design and fabrication of a scaled elevator, experimental setup, and development of measurement and parameter estimation techniques. Experimental results show good agreement with the theoretical predictions.

Dynamics and control of a 6-DOF space robot with flexible panels

2016 ◽  
Vol 231 (6) ◽  
pp. 1022-1034 ◽  
Author(s):  
Yu Zhang-Wei ◽  
Liu Xiao-Feng ◽  
Li Hai-Quan ◽  
Cai Guo-Ping
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Torque Control ◽  
Space Robot ◽  
Velocity Variation ◽  
Variation Principle ◽  
Dynamics Modeling ◽  
Dynamics And Control ◽  
Flexible Panels ◽  
And Control

With the development of space exploration, researches on space robot will cause more attentions. However, most existing researches about dynamics and control of space robot concern planar problem, and the effect of flexible panel on dynamics of the system is not considered. In this article, dynamics modeling and active control of a 6-DOF space robot with flexible panels are investigated. Dynamic model of the system is established based on the Jourdain's velocity variation principle and the single direction recursive construction method. The computed torque control method is used to design point-to-point active controller of the space robot. The validity of the dynamic model is verified through the comparison with ADAMS software; the effects of panel flexibility on the system performance and the active controller design are studied in detail. Simulation results indicate that the proposed model is effective to describe the dynamics of space robot; panel flexibility has large influence on the dynamic behavior of space robot; the designed controller can effectively make the robot reach a specified position and the elastic vibration of the panels may be suppressed simultaneously.

Dynamics and Control of a Helicopter Carrying a Payload Using a Cable-Suspended Robot

2005 ◽  
Author(s):  
So-Ryeok Oh ◽  
Ji-Chul Ryu ◽  
Sunil K. Agrawal
Keyword(s):  
Control Method ◽  
Dual System ◽  
Robust Controller ◽  
Robot System ◽  
Control Approach ◽  
Cable Robot ◽  
Dynamics And Control ◽  
Position And Orientation ◽  
And Control ◽  
Scale Control

This paper presents a study of the dynamics and control of a helicopter carrying a payload through a cable-suspended robot. The helicopter can perform gross motion, while the cable suspended robot underneath the helicopter can modulate a platform in position and orientation. Due to the under-actuated nature of the helicopter, the operation of this dual system consisting of the helicopter and the cable robot is challenging. We propose here a two time scale control method, which makes it possible to control the helicopter and the cable robot independently. In addition, this method provides an effective estimation on the bound of the motion of the helicopter. Therefore, even in the case where the helicopter motion is unknown, the cable robot can be stabilized by implementing a robust controller. Simulation results of the dual system show that the proposed control approach is effective for such a helicopter-robot system.

scholarly journals A self-oscillating h.f. power generator with a Class E resonant amplifier

2013 ◽  
Vol 61 (2) ◽  
pp. 527-534 ◽  
Author(s):  
M. Mikołajewski
Keyword(s):  
High Efficiency ◽  
Control Method ◽  
Power Sources ◽  
Power Generator ◽  
Power Generators ◽  
Theoretical Predictions ◽  
Proposed Modification ◽  
Generator Design ◽  
Good Agreement ◽  
Class E

Abstract Self-oscillating h.f. power generators with a Class E amplifier are used as industrial high-efficiency h.f. power sources. In the paper a modification of the classic Class E generator by applying an additional capacitor in the matching and feedback circuit is presented. The proposed solution increases the degree of freedom in the generator design and can noticeably reduce its cost by eliminating the need for the use of high-value h.f. capacitors in the feedback loop divider. The self-oscillating Class E generator (150 W/6.78 MHz) with the proposed modification has been designed, built and its parameters were measured. Theoretical predictions were in a good agreement with experimental results. Moreover, the burst control method of the output power in the generator has also been presented

On Nonlinear Dynamics and Control of an Inverted Flexible Pendulum System With Chaos

2019 ◽  
Author(s):  
Hartiny Kahar ◽  
Dirk Söffker
Keyword(s):  
Control Method ◽  
Impulsive Control ◽  
Chaotic Behavior ◽  
Energy Content ◽  
Dynamical Behavior ◽  
Pendulum System ◽  
Time Frequency ◽  
Dynamics And Control ◽  
Specific Frequency ◽  
And Control

Abstract In this paper, the dynamical behavior of a nonlinear mechanical system is considered, namely an inverted flexible pendulum excited in its base by a cart driven by a motor. In this experimental procedure, the chaotic motion of the pendulum tip was identified, in combination with a specific range of parameters. Time-frequency energy analysis is performed to be used for modeling the transition between the equilibria of the chaotic systems. Controlling the chaotic behavior of the system is realized using impulsive control method, where additive impulses are injected into the system, designed with specific impulses energy content at a specific frequency band. The experimental results are presented and discussed in detail, concentrating on how the designed impulses have to be injected to affect the system, specifically the transition between states of equilibria. The results from this experimental modeling procedure show that both additive impulse design and frequency filtering of the injected additive impulses are able to stimulate the equilibrium shift and therefore to control the chaotic behavior of the system.

High-Frequency Vibration of Leg Masses for Improving Gait Stability of Compass Walking on Slippery Downhill

2019 ◽  
Vol 31 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Longchuan Li ◽  
Fumihiko Asano ◽  
Isao Tokuda ◽  
◽  
Keyword(s):  
High Frequency ◽  
Control Method ◽  
Frictional Coefficient ◽  
Biped Robot ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Dynamics And Control ◽  
Entrainment Effect ◽  
The Stability ◽  
And Control

Towards improving the stability of point-foot biped robot on slippery downhill, a novel and indirect control method is introduced in this paper using active wobbling masses attached to both legs. The whole dynamics which contains walking, sliding and wobbling, can be dominated by high-frequency oscillation via entrainment effect. Stable gaits are therefore achieved by controlling only 1% of the whole system where the original passive dynamic walking fails. First, we derive the equations of dynamics and control for this indirectly controlled biped walking on slippery downhill. Second, we numerically show the possibility of improving the stability with high-frequency oscillation. We also find the main effect of wobbling motion on walking via phase-plane plot. Third, we prove that the range of stable walking with respect to frictional coefficient can be enlarged by employing suitable high-frequency oscillation via parametric study. Our method will be further applied to more general conditions in real tasks which contain different locomotion types, where the whole dynamics could be dominated by high-frequency oscillation and the phase properties of the dynamics will be positively utilized.

Modeling and control of a flapping wing robot

2018 ◽  
Vol 233 (1) ◽  
pp. 174-181 ◽  
Author(s):  
Abdolbaghi Bakhtiari ◽  
Shahram Ehtemadi Haghighi ◽  
Adel Maghsoudpour
Keyword(s):  
Aerodynamic Force ◽  
Leading Edge ◽  
Flapping Wing ◽  
Inversion Method ◽  
Force Model ◽  
Modeling And Control ◽  
Theoretical Predictions ◽  
Dynamics And Control ◽  
Convergence Performance ◽  
And Control

The dynamics and control of a flapping wing robot are studied in this paper which helps to develop a complete dynamic model for the robot consisting of tail effects and also enhance the path tracking control of the robot. In the first part of the paper, the aerodynamic model of the wings is presented, and an aerodynamic force model for the tail is introduced which includes the leading edge suction effects. An experiment is also carried out on a flapping wing robot in a laboratory environment to evaluate the forces on the tail and its result will be compared with the results of the model presented for the tail. In the second part, a controller is designed for the robot. This controller uses the nonlinear dynamic inversion method to solve the nonlinear equations of the control system. The experimental results of the tail forces agree well with the theoretical predictions and reveal that the tail aerodynamics are affected by leading edge suction. Also, simulation results show that the competence performance and convergence performance of the designed controller are obtained.

scholarly journals Improving Interactions between a Power-Assist Robot System and Its Human User in Horizontal Transfer of Objects Using a Novel Adaptive Control Method

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
S. M. Mizanoor Rahman ◽  
Ryojun Ikeura
Keyword(s):  
Adaptive Control ◽  
Horizontal Transfer ◽  
Control Method ◽  
Weight Perception ◽  
The Novel ◽  
Robot System ◽  
Control Scheme ◽  
Dynamics And Control ◽  
Motion Features ◽  
And Control

Power assist systems are usually used for rehabilitation, healthcare, and so forth.This paper puts emphasis on the use of power assist systems for object transfer and thus brings a novelty in the power-assist applications. However, the interactions between the systems and the human users are usually not satisfactory because human features are not included in the control design. In this paper, we present the development of a 1-DOF power assist system for horizontal transfer of objects. We included human features such as weight perception in the system dynamics and control. We then simulated the system using MATLAB/Simulink for transferring objects with it and (i) determined the optimum maneuverability conditions for object transfer, (ii) determined psychophysical relationships between actual and perceived weights, and (iii) analyzed load forces and motion features. We then used the findings to design a novel adaptive control scheme to improve the interactions between the user and the system. We implemented the novel control (simulated the system again using the novel control), the subjects evaluated the system, and the results showed that the novel control reduced the excessive load forces and accelerations and thus improved the human-system interactions in terms of maneuverability, safety, and so forth. Finally, we proposed to use the findings to develop power assist systems for manipulating heavy objects in industries that may improve interactions between the systems and the users.

Dynamics and Control of a Helicopter Carrying a Payload Using a Cable-Suspended Robot

2005 ◽  
Vol 128 (5) ◽  
pp. 1113-1121 ◽  
Author(s):  
So-Ryeok Oh ◽  
Ji-Chul Ryu ◽  
Sunil K. Agrawal
Keyword(s):  
Control Method ◽  
Dual System ◽  
Robust Controller ◽  
Robot System ◽  
Control Approach ◽  
Cable Robot ◽  
Dynamics And Control ◽  
Position And Orientation ◽  
And Control ◽  
Scale Control

In this paper we present a study of the dynamics and control of a helicopter carrying a payload through a cable-suspended robot. The helicopter can perform gross motion, while the cable suspended robot underneath the helicopter can modulate a platform in position and orientation. Due to the underactuated nature of the helicopter, the operation of this dual system consisting of the helicopter and the cable robot is challenging. We propose here a two time scale control method, which makes it possible to control the helicopter and the cable robot independently. In addition, this method provides an effective estimation on the bound of the motion of the helicopter. Therefore, even in the case where the helicopter motion is unknown, the cable robot can be stabilized by implementing a robust controller. Simulation results of the dual system show that the proposed control approach is effective for such a helicopter-robot system.

Dynamics and control of three-dimensional dual cranes transporting a bulky payload

2020 ◽  
pp. 095440622094957
Author(s):  
Jie Huang ◽  
Kuo Zhu
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Model ◽  
Control Method ◽  
Three Dimensional ◽  
Structural Flexibility ◽  
Positioning Accuracy ◽  
Modeling And Control ◽  
Input Shaper ◽  
Dynamics And Control ◽  
And Control

The inevitable oscillations of the payload decrease the positioning accuracy and lessen the safety in dual cranes carrying a large payload. In the presence of the structural flexibility, the dynamics of dual cranes are governed by the payload swing, pitch, and twisting after considering three-dimensional motions. However, little research has been directed at the modeling and control of three-dimensional dual cranes. A dynamic model of three-dimensional dual cranes including the payload swing, pitch and twisting is described. Moreover, a combined modified extra-insensitive input shaper and four-pieces smoother method is proposed to control the swing, pitch, and twisting of the payload. The dynamic behavior of the nonlinear model and the effectiveness of the new control method are verified experimentally on dual cranes carrying a slender beam.

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