Dynamics Decomposition for Stewart Platforms

1994 ◽  
Vol 116 (1) ◽  
pp. 67-69 ◽  
Author(s):  
Zhiming Ji
Keyword(s):  
Dynamic Analysis ◽  
Driving Forces ◽  
Stewart Platform ◽  
Inertia Effect ◽  
Moving Plate ◽  
Stewart Platforms

This paper shows that special features of the Stewart platform can lead to the decomposition of the moving plate and the legs in the dynamic analysis. Formulas for evaluating, separately, the driving forces needed for the movement of the legs are developed for studying the combined inertia effect of all the leg rotations in a Stewart platform. The proposed formulation is easy to implement for Stewart platforms with nonnegligible leg inertia.

Dynamic Analysis on a Cable-Driven Interventional Active Catheter Using Kane's Method Combined with Screw Theory

2014 ◽  
Vol 527 ◽  
pp. 140-145
Author(s):  
Da Xu Zhao ◽  
Bai Chen ◽  
Guo Zhong Shou ◽  
Yu Qi Gu
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Motion Control ◽  
Screw Theory ◽  
Driving Forces ◽  
Structure Design ◽  
Kinematics And Dynamics ◽  
Existing Problems ◽  
Blind Area ◽  
The Mathematical Model

In view of the existing problems of traditional interventional catheters, particularly poor activity, operation difficulty and mass blind area, a novel interventional catheter with a cable-driven active head-end is proposed, and a prototype was built to verify the performance. This paper deals with the kinematics and dynamics of the cable-driven prototype, a dynamic model based on Kanes method combined with screw theory was presented in this paper. According the mathematical model and the prototypes structure, the analysis of kinematics and dynamics of active head-end-end is done in the environment of Mathematica. The needed driving forces of every joint when the system moving along planned trajectory are calculated. The results can provide a basis for the structure design and motion control of the interventional active catheter.

Workspace Evaluation of Stewart Platforms

1992 ◽  
Author(s):  
Oren Masory ◽  
Jian Wang
Keyword(s):  
Stewart Platform ◽  
Design Tool ◽  
Kinematic Constraints ◽  
Stewart Platforms ◽  
Selection Of

Abstract The workspace and the dexterity of a Stewart Platform are effected by the choice of its major dimensions, actuators’ stroke and the kinematic constraints of its joints. An investigation of the effects of these parameters on workspace volume of the platform is presented. The obtained results were normalized so that these can be used as a design tool for the selection of dimensions, joints and actuators.

scholarly journals A Unified Method for Computing Position and Orientation Workspaces of General Stewart Platforms

2011 ◽  
Author(s):  
Oriol Bohigas ◽  
Llui´s Ros ◽  
Montserrat Manubens
Keyword(s):  
Complex Shape ◽  
Three Dimensional ◽  
Stewart Platform ◽  
Large Dimension ◽  
Connected Components ◽  
Cartesian Space ◽  
Position And Orientation ◽  
Stewart Platforms ◽  
Orientation Workspace ◽  
Unified Method

The workspace of a Stewart platform is a complex six-dimensional volume embedded in the Cartesian space defined by six pose parameters. Because of its large dimension and complex shape, such workspace is difficult to compute and represent, so that comprehension on its structure is being gained by studying its three-dimensional slices. While successful methods have been given to determine the constant-orientation slice, the computation and appropriate visualization of the constant-position slice (also known as the orientation workspace) has proved to be a challenging task. This paper presents a unified method for computing both of such slices, and any other ones defined by fixing three pose parameters, on general Stewart platforms involving mechanical limits on the active and passive joints. Additional advantages over previous methods include the ability to determine all connected components of the workspace, and any motion barriers present in its interior.

Research on Inverse Kinematic Design of a Certain Hydraulic Stewart Platform

2011 ◽  
Vol 58-60 ◽  
pp. 2442-2445
Author(s):  
Zhi Yong Qu ◽  
Zheng Mao Ye
Keyword(s):  
Machine Tools ◽  
Stewart Platform ◽  
Inverse Kinematic ◽  
Design And Optimization ◽  
Kinematic Design ◽  
Structural Rigidity ◽  
The Future ◽  
Stewart Platforms ◽  
Kinematic Loop ◽  
Motion Dynamics

Stewart platforms have recently attracted attention as simulator and machine tools because of their conceptual potentials in high motion dynamics and accuracy combined with high structural rigidity due to their closed kinematic loop. This paper, composed of inverse kinematic design and optimization, attempts to ground the foundation on dynamics design and choice in the future.

scholarly journals Dynamic Analysis of Stewart Platform by Bond Graphs

2015 ◽  
Vol 100 ◽  
pp. 226-233 ◽  
Author(s):  
Vjekoslav Damic ◽  
Maida Cohodar
Keyword(s):  
Dynamic Analysis ◽  
Stewart Platform ◽  
Bond Graphs

Dynamic analysis and control of a stewart platform manipulator

1993 ◽  
Vol 10 (5) ◽  
pp. 629-655 ◽  
Author(s):  
G. Lebret ◽  
K. Liu ◽  
F. L. Lewis
Keyword(s):  
Dynamic Analysis ◽  
Stewart Platform ◽  
And Control

Dynamic modeling of the Stewart platform for the NanShan Radio Telescope

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094007
Author(s):  
Guljaina Kazezkhan ◽  
Binbin Xiang ◽  
Na Wang ◽  
Aili Yusup
Keyword(s):  
Radio Telescope ◽  
Driving Forces ◽  
Virtual Work ◽  
Dynamic Performance ◽  
Stewart Platform ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Passive Rotation ◽  
Precise Analysis ◽  
And Control

The NanShan Radio Telescope is a 26-m fully steerable radio telescope, and it adopts a 6-UPU Stewart platform with electric motors to adjust and align the position of the subreflector. In order to analyze the actual dynamic performance and control the Stewart platform of the NanShan Radio Telescope, this article models the inverse dynamic of the Stewart platform using the virtual work approach. The model improves the accuracy of the dynamic equations and considered the pitching motion of the base platform in the practical application of the radio telescope. Dynamic simulations of the Stewart platform are implemented, the conditions of the passive rotation of the piston of actuators are considered, and the results show that the effect of the passive rotation of the pistons of the actuators is important to obtain more accurate result. The conditions of the system under the different elevation angles of the radio telescope are also considered, and the results show that the change of the elevation angles of the radio telescope has a great impact on the driving forces of the Stewart platform. It is known from the analysis that the passive rotation of pistons of actuators and the elevation movement of the primary reflector of the radio telescope are not ignorable for the precise analysis and control of the Stewart platform of the NanShan Radio Telescope.

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