scholarly journals Vibration Response and Power Flow Characteristics of a Flexible Manipulator with a Moving Base

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yufei Liu ◽  
Wei Li ◽  
Xuefeng Yang ◽  
Mengbao Fan ◽  
Yuqiao Wang ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Power Flow ◽  
Flow Characteristics ◽  
Flexible Manipulator ◽  
Rigid Base ◽  
Flexible Beam ◽  
Noticeable Effect ◽  
Moving Base ◽  
Vibration Responses ◽  
Motion Characteristics

Flexible manipulator generally can be modeled as a coupling system with a flexible beam and a rigid moving base. This paper investigates the vibration responses and power flow of a flexible manipulator with a moving base (FMMB). Considering the motion characteristics of the rigid base, the moving base is modeled to have a motion with disturbances, and the dynamic model of the FMMB is established. With the dynamic model, vibration responses of the FMMB for the rigid base having disturbance velocities and accelerations are specifically presented. Subsequently, to investigate the effect of the disturbances on the vibration energy distributions of the FMMB, power flow of the FMMB is exhibited. To verify the dynamic model, an ADAMS physical model of the FMMB is constructed. It reveals that the motion characteristics of the rigid base have a noticeable effect on the vibration responses and power flow of the FMMB and should be considered. The results are significant and contribute to the vibration control of flexible manipulators.

scholarly journals The Study of Dynamic Modeling and Multivariable Feedback Control for Flexible Manipulators with Friction Effect and Terminal Load

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1522
Author(s):  
Fuli Zhang ◽  
Zhaohui Yuan
Keyword(s):  
Dynamic Model ◽  
Vibration Suppression ◽  
Control Method ◽  
Coupling Effect ◽  
Flexible Manipulator ◽  
Flexible Beam ◽  
Robot Dynamics ◽  
Joint Friction ◽  
Balance Principle ◽  
Multivariable Feedback

The flexible manipulato is widely used in the aerospace industry and various other special fields. Control accuracy is affected by the flexibility, joint friction, and terminal load. Therefore, this paper establishes a robot dynamics model under the coupling effect of flexibility, friction, and terminal load, and analyzes and studies its control. First of all, taking the structure of the central rigid body, the flexible beam, and load as the research object, the dynamic model of a flexible manipulator with terminal load is established by using the hypothesis mode and the Lagrange method. Based on the balance principle of the force and moment, the friction under the influence of flexibility and load is recalculated, and the dynamic model of the manipulator is further improved. Secondly, the coupled dynamic system is decomposed and the controller is designed by the multivariable feedback controller. Finally, using MATLAB as the simulation platform, the feasibility of dynamic simulation is verified through simulation comparison. The results show that the vibration amplitude can be reduced with the increase of friction coefficient. As the load increases, the vibration can increase further. The trajectory tracking and vibration suppression of the manipulator are effective under the control method of multi-feedback moment calculation. The research is of great significance to the control of flexible robots under the influence of multiple factors.

scholarly journals Coupled dynamic model and vibration responses characteristic of a motor-driven flexible manipulator system

2015 ◽  
Vol 6 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Y. F. Liu ◽  
W. Li ◽  
X. F. Yang ◽  
Y. Q. Wang ◽  
M. B. Fan ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
High Speed ◽  
Dynamic Effect ◽  
Structure Design ◽  
Integrated System ◽  
Flexible Manipulator ◽  
Effect Mechanism ◽  
Motion Optimization ◽  
Vibration Responses

Abstract. Motor-driven flexible manipulator systems (MDFMSs) are widely used in industry robot fields. During the dynamic modeling, the separate investigation method which neglects the dynamic behavior of the driving motor will cause an error in the dynamic analysis of the flexible manipulator, especially with high-speed operations. This paper proposes a coupled dynamic model of the MDFMS in which the driving motor and flexible manipulator are considered as an integrated system, which can clearly reflect the influence of the dynamic effect of the driving motor. Based on the proposed dynamic model, the vibration responses of the flexible manipulator under different velocities, accelerations and structure parameters, as well as the effect mechanism of the driving motor on the vibration responses, are investigated. The results obtained in this paper contribute to the structure design, motion optimization and dynamic analysis of flexible manipulators.

scholarly journals Planetary Gearbox Dynamic Modeling Considering Bearing Clearance and Sun Gear Tooth Crack

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2638
Author(s):  
Xianhua Chen ◽  
Xingkai Yang ◽  
Ming J. Zuo ◽  
Zhigang Tian
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Failure Modes ◽  
Gear Tooth ◽  
Working Environment ◽  
The Sun ◽  
Planetary Gearbox ◽  
Bearing Clearance ◽  
Vibration Responses ◽  
Planet Gear

Planetary gearbox systems are critical mechanical components in heavy machinery such as wind turbines. They may suffer from various failure modes, due to the harsh working environment. Dynamic modeling is a useful method to support early fault detection for enhancing reliability and reducing maintenance costs. However, reported studies have not considered the sun gear tooth crack and bearing clearance simultaneously to analyze their combined effect on vibration characteristics of planetary gearboxes. In this paper, a dynamic model is developed for planetary gearboxes considering the clearance of planet gear, sun gear, and carrier bearings, as well as sun gear tooth crack levels. Bearing forces are calculated considering bearing clearance, and the dynamic model equations are updated accordingly. The results reveal that the combination of bearing clearances can affect the vibration response with sun gear tooth crack by increasing the kurtosis. It is found that the effect of planet gear bearing clearance is very small, while the sun gear and carrier bearing clearance has clear impact on the vibration responses. These findings suggest that the incorporation of bearing clearance is important for planetary gearbox dynamic modeling.

Effect of Feedback Control on the Power Consumption of Induced-Strain Actuators

2000 ◽  
Author(s):  
Sriram Chandrasekaran ◽  
Douglas K. Lindner ◽  
Don Leo
Keyword(s):  
Structural Control ◽  
Power Flow ◽  
Reactive Power ◽  
Flow Characteristics ◽  
Control Laws ◽  
The Real ◽  
Reactive Power Flow ◽  
Flow Through ◽  
Sinusoidal Disturbance ◽  
A Current

Abstract In this paper we study the closed loop power flow characteristics between a controlled piezoelectric actuator and a current controlled drive amplifier for two different structural control laws. We determine the real and reactive power flow through the structure and actuator into the amplifier when the structure is excited with a sinusoidal disturbance force under both control laws. The dependence of the real and reactive components of the power on the material properties of the actuator, structure and the configuration of the controller is presented. These real and reactive power estimates are useful for sizing the drive amplifier for the actuator.

Energy flow and performance evaluation of inerter-based vibration isolators mounted on finite and infinite flexible foundation structures

2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110704
Author(s):  
Zhuang Dong ◽  
Jian Yang ◽  
Chendi Zhu ◽  
Dimitrios Chronopoulos ◽  
Tianyun Li
Keyword(s):  
Power Flow ◽  
Vibration Isolation ◽  
Vibration Suppression ◽  
Flow Behavior ◽  
Flexible Beam ◽  
Vibration Isolators ◽  
Force Transmissibility ◽  
And Performance ◽  
Flexible Foundation ◽  
Isolation Performance

This study investigates the vibration power flow behavior and performance of inerter-based vibration isolators mounted on finite and infinite flexible beam structures. Two configurations of vibration isolators with spring, damper, and inerter as well as different rigidities of finite and infinite foundation structures are considered. Both the time-averaged power flow transmission and the force transmissibility are studied and used as indices to evaluate the isolation performance. Comparisons are made between the two proposed configurations of inerter-based isolators and the conventional spring-damper isolators to show potential performance benefits of including inerter for effective vibration isolation. It is shown that by configuring the inerter, spring, and damper in parallel in the isolator, anti-peaks are introduced in the time-averaged transmitted power and force transmissibility at specific frequencies such that the vibration transmission to the foundation can be greatly suppressed. When the inerter is connected in series with a spring-damper unit and then in-parallel with a spring, considerable improvement in vibration isolation can be achieved near the original peak frequency while maintaining good high-frequency isolation performance. The study provides better understanding of the effects of adding inerters to vibration isolators mounted on a flexible foundation, and benefits enhanced designs of inerter-based vibration suppression systems.

On the Properties of a Dynamic Model of Flexible Robot Manipulators

1998 ◽  
Vol 120 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Marco A. Arteaga
Keyword(s):  
Dynamic Model ◽  
Structural Properties ◽  
Robot Manipulators ◽  
Equations Of Motion ◽  
Mechanical Systems ◽  
Control Design ◽  
Flexible Manipulator ◽  
Robot Dynamics ◽  
Flexible Link ◽  
Flexible Robot

Control design of flexible robot manipulators can take advantage of the structural properties of the model used to describe the robot dynamics. Many of these properties are physical characteristics of mechanical systems whereas others arise from the method employed to model the flexible manipulator. In this paper, the modeling of flexible-link robot manipulators on the basis of the Lagrange’s equations of motion combined with the assumed modes method is briefly discussed. Several notable properties of the dynamic model are presented and their impact on control design is underlined.

Wave Propagation and Power Flow Analysis of Sandwich Structures With Internal Absorbers

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
J. S. Chen ◽  
R. T. Wang
Keyword(s):  
Wave Propagation ◽  
Power Flow ◽  
Wave Attenuation ◽  
Sandwich Structures ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Continuum Models ◽  
Sandwich Beams ◽  
The Core ◽  
In Series

This study examines wave attenuation and power flow characteristics of sandwich beams with internal absorbers. Two types of absorbing systems embedded in the core are considered, namely, a conventional spring-mass-dashpot system having a mass with a spring and a dashpot in parallel, and a relaxation system containing an additional relaxation spring added in series with the dashpot. Analytical continuum models used for interpreting the attenuation behavior of sandwich structures are presented. Through the analysis of the power flowing into the structure, the correlation of wave attenuation and energy blockage is revealed. The reduction in the power flow indicates that some amount of energy produced by the external force can be effectively obstructed by internal absorbers. The effects of parameters on peak attenuation, bandwidth, and power flow are also studied.

A new Fourier series method and displacement function for in-plane vibration and power flow characteristics analysis of isotropic rectangular plates

2019 ◽  
Vol 50 (6) ◽  
pp. 176-194
Author(s):  
Kavikant Mahapatra ◽  
SK Panigrahi
Keyword(s):  
Fourier Series ◽  
Boundary Conditions ◽  
Power Flow ◽  
Flow Characteristics ◽  
Displacement Function ◽  
Rectangular Plates ◽  
Series Method ◽  
Plane Vibration ◽  
Fourier Series Method ◽  
Beam Displacement

The generation of in-plane vibration in plates is an important issue and frequently occurs due to the presence of excitations in the ship’s hull due to turbulent fluid flows, turbulent airflow excitation on aerospace structures, gear system subjected to axial excitation, assemblies housing piezoelectric crystals and sandwiched plates, and so on. The present analysis aims to establish a universal and numerically efficient method for determination of in-plane vibration characteristics of isotropic rectangular plates both for conventional and general boundary conditions. The new in-plane Fourier series and displacement function of the plate have been developed using beam displacement functions in x and y directions, respectively, under in-plane condition. A modified Fourier series assumption for the in-plane beam displacement has been utilised and further developed as plate displacement function. The computational efficiency of the present method is compared in terms of convergence of natural frequency parameter, speed of execution and manual convenience to reduce human errors with the frequently used Fourier series method by various researchers. Rayleigh–Ritz procedure has been applied to determine the in-plane natural frequencies. The mode shapes for few conventional and generally varying boundary conditions have been presented and analysed. The dynamic response has been obtained and analysed in terms of the in-plane mobility and power flow characteristics of the plate under varying boundary conditions. The validity of results obtained by the current method has shown excellent accuracy and faster convergence with the existing results. The present results can provide a benchmark to analyse the dynamic in-plane response of plate systems being used for built-up structures in real engineering applications.

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