scholarly journals Research on Control of Stewart Platform Integrating Small Attitude Maneuver and Vibration Isolation for High-Precision Payloads on Spacecraft

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 333
Author(s):  
Weichao Chi ◽  
He Ma ◽  
Caihua Wang ◽  
Tianyu Zhao
Keyword(s):  
High Precision ◽  
Attitude Control ◽  
Vibration Isolation ◽  
Stewart Platform ◽  
Control Force ◽  
Parallel Operation ◽  
Disturbance Rejection Control ◽  
Attitude Maneuver ◽  
Vibration Isolation Performance ◽  
Isolation Performance

The Stewart platform, a classical mechanism proposed as the parallel operation apparatus of robots, is widely used for vibration isolation in various fields. In this paper, a design integrating both small attitude control and vibration isolation for high-precision payloads on board satellites is proposed. Our design is based on a Stewart platform equipped with voice-coil motors (VCM) to provide control force over the mechanism. The coupling terms in the dynamic equations of the legs are removed as the total disturbance by the linear active disturbance rejection control (LADRC). Attitude maneuver and vibration isolation performance is verified by numerical simulations.

scholarly journals Dynamics and control of a bio-inspired Stewart platform

2021 ◽  
Vol 39 (2) ◽  
pp. 258-266
Author(s):  
Yuansheng Peng ◽  
Honghua Dai ◽  
Hao Zhang ◽  
Xiaokui Yue
Keyword(s):  
Dynamic Model ◽  
Feedback Linearization ◽  
Vibration Isolation ◽  
Control Method ◽  
Stewart Platform ◽  
The Novel ◽  
Isolation System ◽  
Theoretical Simulation ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Collision and strong impacts take place in mission of the on orbit capture of non-cooperative spacecraft. So, it is necessary to design a vibration isolation system with efficient vibration isolation performance. A Stewart vibration isolation platform based on the bio-inspired isolation system is proposed in this paper. The characteristics of the novel bio-inspired Stewart platform realizes the vibration isolation protection of the serving spacecraft during the capture mission. The dynamic model of the vibration isolation platform is established by Lagrange's equations. The fidelity of the established dynamic model is verified via a comparison of the theoretical simulation and the ADAMS simulation. Comparisons between the presently proposed vibration isolation platform and the traditional spring-mass-damper type Stewart vibration isolation platform demonstrates the advantages of the present platform. The effects of system parameters on the isolation performance of the present platform are thoroughly investigated. The feedback linearization control method is used to control the present platform which overcomes the drift motion that occurs in the passive isolation case. The results show that the novel bio-inspired Stewart platform has excellent vibration isolation performance, which provides a promising way for the vibration isolation of the non-orbit capture mission.

scholarly journals Dynamic modeling and experimental analyses of Stewart platform with flexible hinges

2018 ◽  
Vol 25 (1) ◽  
pp. 151-171 ◽  
Author(s):  
Jian Jiao ◽  
Ying Wu ◽  
Kaiping Yu ◽  
Rui Zhao
Keyword(s):  
Vibration Control ◽  
Dynamic Modeling ◽  
Vibration Amplitude ◽  
Vibration Isolation ◽  
Stewart Platform ◽  
Microgravity Environment ◽  
Kinematics Analysis ◽  
Balance Equations ◽  
Vibration Isolation Performance ◽  
Isolation Performance

A new dynamic model of the Stewart platform with flexible hinges is proposed based on the Kane equation combined with the principle of virtual powers. Firstly, the model and coordinates introduced are described. Specifically, the velocity and acceleration of each part are obtained through kinematics analysis. Secondly, balance equations are subsequently formulated using the principle of virtual powers. Noting that the vibration amplitude of satellites is very small in the space microgravity environment, a linearly simplified form of the dynamic equation of the Stewart platform with flexible hinges is obtained. Finally, the validity of the equations is experimentally and numerically verified, and it is also demonstrated that the proposed platform possesses a good vibration isolation performance. All the results presented in this paper lay the foundation for further study on vibration control using a Stewart platform.

On vibration isolation of sandwich plate with periodic hollow tube core

2017 ◽  
Vol 21 (3) ◽  
pp. 1119-1132 ◽  
Author(s):  
Gui-Lan Yu ◽  
Hong-Wei Miao
Keyword(s):  
Vibration Isolation ◽  
Sandwich Plate ◽  
Experimental Studies ◽  
Low Frequency ◽  
Dispersion Relations ◽  
Frequency Responses ◽  
Vibration Attenuation ◽  
Potential Applications ◽  
Vibration Isolation Performance ◽  
Isolation Performance

The vibration isolation performance of a PC sandwich plate with periodic hollow tube core is investigated experimentally and numerically. The experiment results reveal that there exist vibration attenuation zones in acceleration frequency responses which can be improved by increasing the number of periods or tuning some structure parameters. The presence of soft fillers shifts the attenuation zone to lower frequencies and enhances the capability of vibration isolation to some extent. Dispersion relations and acceleration frequency responses are calculated by finite element method using COMSOL MULTIPHYSICS. The attenuation zones obtained by experiments fit well with that by simulations, and both are consistent with the band gap in dispersion relations. The numerical and experimental studies in the present paper show that this PC sandwich plate exhibits a good performance on vibration isolation in low frequency ranges, which will provide some useful references for relevant research and potential applications in vibration propagation manipulations.

Vibration isolation performance of nonobstructive particle damping in a machine rack

2018 ◽  
Vol 25 (5) ◽  
pp. 1122-1130 ◽  
Author(s):  
Zhanpeng Zheng ◽  
Chengjun Wu ◽  
Hengliang Wu ◽  
Jianyong Wang ◽  
Xiaofei Lei
Keyword(s):  
Theoretical Model ◽  
Dynamic Response ◽  
Vibration Isolation ◽  
Passive Control ◽  
Vibration Energy ◽  
Damping Force ◽  
Damping Effect ◽  
Particle Damping ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Nonobstructive particle damping (NOPD) is a novel passive control technology with strong nonlinear-damping. Many scholars put effort into the research on the internal mechanism of NOPD. In contrast, the application of NOPD to engineering has not received much research effort. A theoretical model based on the principle of gas–solid flows, which is employed to evaluate damping effect of NOPD and to predict dynamic response of a machine rack by a co-simulation approach, is established in this paper. In view of the difference between damping effect acting on the lateral and bottom of NOPD holes directly, total damping force is divided into lateral damping force and bottom damping force according to the Janssen theory of stress changed direction. Moreover, NOPD technology is applied to a machine rack for discussing its vibration isolation performance. The results indicate that NOPD technology can suppress the intense vibration, especially between 4000 Hz and 8000 Hz. It is noted that the theoretical model of NOPD can accurately predict the dynamic response of the machine rack with NOPD. The 1/3 Octave vibration energy spectrum indicates that NOPD technics can dissipate the vibration energy of the machine rack at full frequency, especially in 31.5 Hz, and attenuation up to 39.75 dB.

scholarly journals Vibration isolation performance of an elevator motor using Nitrile-Butadiene Rubber /Multi-Walled Carbon Nanotube composite machine mounts

2020 ◽  
Vol 318 ◽  
pp. 01050
Author(s):  
Konstantinos Tsongas ◽  
Gabriel Mansour
Keyword(s):  
Vibration Isolation ◽  
Element Model ◽  
Test System ◽  
Damping Capacity ◽  
Butadiene Rubber ◽  
Motor Test ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Vibration Isolation Performance ◽  
Isolation Performance

The objective of this paper is to evaluate the vibration isolation performance of an elevator motor mounted on elastomeric nanocomposite mounts. A series of conventional acrylonitrile-butadiene rubber (NBR) mounts have been reinforced with 20wt% concentration of multi-walled carbon nanotubes (MWCNTs). The vibration isolation capacity of the machine mounts was calculated through the transmissibility of an elevator motor test system. A Finite Element Model (FEM) was introduced and a harmonic analysis based on the ANSYS code has been utilized to investigate the modal behavior of the nanocomposite machine mount/elevator motor system and extract a representative model of the vibrational behavior. The cyclic compression results have revealed that the stiffness and damping capacity of the conventional elastomers can be modified by adjusting the proportion of MWCNTs. Elastomers’ vibration isolation performance of the motor was ameliorated with the inclusion of MWCNTs, signifying that the enhancement of the elastomers with MWCNTs was rather effective. The vibration level of the elevator motor was decreased to 90% by incorporating the optimal concentration of MWCNTs in NBR mounts.

Optimization of Vehicle Powertrain Mounting System and its Performance

2013 ◽  
Vol 441 ◽  
pp. 580-583
Author(s):  
Gong Yu Pan ◽  
Xin Yang ◽  
You Yan
Keyword(s):  
Vibration Isolation ◽  
Dynamics Model ◽  
Acceleration Response ◽  
Idle State ◽  
Decoupling Method ◽  
Before And After ◽  
Vibration Transmissibility ◽  
Six Degree Of Freedom ◽  
Vibration Isolation Performance ◽  
Isolation Performance

In order to solve the vibration problem of diesel engine powertrain assembly at its idle state, a six degree-of-freedom dynamics model of the powertrain mounting system is established and a optimization based on Adams/View is applied to simulation and analysis on the powertrain mounting system with energy decoupling method. The results show that the optimized repositioning mounts installation position can effectively improve decoupling rate in main vibration directions of mounting system. Based on this, the vibration transmissibility and acceleration response before and after optimization are simulated. The results show that the optimized engine mounting system makes a great improvement of vibration isolation performance.

The Experimental Research of Vibration Isolation Performance of MR Isolator at High Temperature

2012 ◽  
Vol 184-185 ◽  
pp. 525-528 ◽  
Author(s):  
Hui Yan ◽  
Liang Chen ◽  
Hong Rui Ao ◽  
Hong Yuan Jiang
Keyword(s):  
Vibration Isolation ◽  
Evaluation Index ◽  
Structural Parameter ◽  
Sweep Frequency ◽  
Frequency Test ◽  
Metal Rubber ◽  
Performance Evaluation Index ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Sine Sweep

Transmissibility is the main performance evaluation index of Metal Rubber (MR) isolator, which can be got by sine sweep frequency test. At different temperature, the sine sweep frequency test is done with different structural parameter MR isolator. The influence that relative density and pre-deformation have on transmissibility and natural frequency when temperature changed is analyzed. The changing regularity of MR isolator’s transmissibility at different temperature is explored. Research results provide the basis for designing MR isolator.

Vibration and Shock Isolation Performance of a Semi-Active “On-Off” Damper

1985 ◽  
Vol 107 (4) ◽  
pp. 398-403 ◽  
Author(s):  
S. Rakheja ◽  
S. Sankar
Keyword(s):  
Relative Position ◽  
Relative Velocity ◽  
Vibration Isolation ◽  
Performance Characteristics ◽  
Orifice Area ◽  
Hydraulic Damper ◽  
Control Scheme ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Command Signal

The concept of an “on-off” damper employing the feedback signals from directly measurable variables is proposed. A control scheme utilizing the directly measurable relative position and relative velocity signals to produce the command signal is configured. The on-off damping mechanism can be achieved through the modulation of orifice area in a conventional hydraulic damper, using a two position on-off valve driven by the command signal. The shock and vibration isolation characteristics of the proposed on-off damper are evaluated through computer simulations. The shock and vibration isolation performance characteristics of the proposed damper are compared to the performance characteristics of a passive and an on-off damper utilizing the feedback from absolute and relative velocity signals.

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