Analysis of Dynamic Performance Indices of 4RR(RR)R Parallel Mechanism

2008 ◽  
Vol 44 (07) ◽  
pp. 63 ◽  
Author(s):  
Shuang LIU
Keyword(s):  
Parallel Mechanism ◽  
Dynamic Performance ◽  
Performance Indices

Dynamic Performance Study of Stewart Parallel Mechanism Based on Natural Frequency

2014 ◽  
Vol 635-637 ◽  
pp. 1246-1250 ◽  
Author(s):  
Bang Jun Lv ◽  
Li Kun Peng ◽  
Jia Chen
Keyword(s):  
Natural Frequency ◽  
Parallel Mechanism ◽  
Dynamic Performance ◽  
Transmission Mechanism ◽  
Local Dynamic ◽  
Performance Study ◽  
Performance Indices ◽  
Inertia Parameters ◽  
Moving Platform ◽  
Variation Trends

The stiffness of transmission mechanism, assembled joints and moving platform, the compressibility of oil, and the load inertia of hydraulic Stewart mechanism will cause synthetically mechanical and hydraulic resonance problems, which will directly influence the system dynamic performance. The natural frequency and local dynamic isotropy index are adopted to evaluate dynamic performance. The variation trends of performance indices with configuration and inertia parameters are analyzed, and general optimal design rules and conclusions are obtained.

Optimal Design of a 4-DOF SCARA Type Parallel Robot Using Dynamic Performance Indices and Angular Constraints

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Songtao Liu ◽  
Tian Huang ◽  
Jiangping Mei ◽  
Xueman Zhao ◽  
Panfeng Wang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Rigid Body Dynamics ◽  
Performance Indices ◽  
Global Dynamic ◽  
Transmission Angle ◽  
Body Dynamics ◽  
Rigid Design

This paper deals with the optimal design of a 4-DOF SCARA type (three translations and one rotation) parallel robot using dynamic performance indices and angular constraints within and amongst limbs. The architecture of the robot is briefly addressed with emphasis on the mechanical realization of the articulated traveling plate for achieving a lightweight yet rigid design. On the basis of the kinematic singularity analysis, two types of transmission angle constraints are considered to ensure the kinematic performance. A simplified model of rigid body dynamics is then formulated, with which two global dynamic performance indices are proposed for minimization by taking into account both inertial and centrifugal/Coriolis effects. In addition, the servomotor specifications are estimated using the Extended Adept Cycle. The proposed approach has successfully been employed to develop a prototype machine.

Acceleration and Dexterity Performance Indices for 6-DOF and Lower-Mobility Parallel Mechanism

2004 ◽  
Author(s):  
X. J. Guo ◽  
F. Q. Chang ◽  
S. J. Zhu
Keyword(s):  
Parallel Mechanism ◽  
Robot Manipulator ◽  
Coefficient Matrix ◽  
Second Order ◽  
Influence Coefficient ◽  
Global Index ◽  
Performance Indices ◽  
First Order ◽  
Lower Mobility

On the basis of first-order and second-order kinematic influence coefficient matrices, dynamics characteristics indices for robot manipulator are presented in the paper. Different from indices before, these indices include not only the first-order kinematics influence coefficient matrix G, but also the second-order kinematic influence coefficient matrix H. Then with the global index, these indices can be used to guide the dynamics design.

Evaluation of the Kinematic Performance of a 3-RRS Parallel Mechanism

Robotica ◽  
2020 ◽  
pp. 1-12
Author(s):  
Manxin Wang ◽  
Qiusheng Chen ◽  
Haitao Liu ◽  
Tian Huang ◽  
Hutian Feng ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Parallel Mechanism ◽  
Jacobian Matrix ◽  
Mean Value ◽  
Spherical Joint ◽  
Performance Indices ◽  
Active Joint ◽  
Strongly Coupled ◽  
The Mean ◽  
Kinematic Performance

SUMMARY This paper proposes a set of novel indices for evaluating the kinematic performance of a 3-RRS (R and S denote revolute and spherical joint respectively, R denotes active joint.), parallel mechanism whose translational and rotational movements are strongly coupled. First, the indices are formulated using the decoupled overall Jacobian matrix, which is developed using coordinate transformation. Then, the influences of the homogeneous dimensionless parameters on these indices are investigated. In addition, the dimension synthesis of the 3-RRS parallel mechanism is carried out by minimizing the mean value of the kinematic performance indices and their standard deviation. The results demonstrate that the established approach facilitates good global kinematic performance of the parallel mechanism.

scholarly journals Dynamic Intelligent Feedback Scheduling in Networked Control Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hui-ying Chen ◽  
Zu-xin Li ◽  
Pei-liang Wang
Keyword(s):  
Networked Control Systems ◽  
Dynamic Performance ◽  
Networked Control System ◽  
Networked Control ◽  
Performance Indices ◽  
Available Bandwidth ◽  
Control Loops ◽  
Limited Bandwidth ◽  
Network Bandwidth ◽  
Feedback Scheduling

For the networked control system with limited bandwidth and flexible workload, a dynamic intelligent feedback scheduling strategy is proposed. Firstly, a monitor is used to acquire the current available network bandwidth. Then, the new available bandwidth in the next interval is predicted by using LS_SVM approach. At the same time, the dynamic performance indices of all control loops are obtained with a two-dimensional fuzzy logic modulator. Finally, the predicted network bandwidth is dynamically allocated by the bandwidth manager and the priority allocator in terms of the loops' dynamic performance indices. Simulation results show that the sampling periods and priorities of control loops are adjusted timely according to the network workload condition and the dynamic performance of control loops, which make the system running in the optimal state all the time.

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