Forward/Reverse Velocity and Acceleration Analysis for a Class of Lower-Mobility Parallel Mechanisms

2006 ◽  
Vol 129 (4) ◽  
pp. 390-396 ◽  
Author(s):  
Si J. Zhu ◽  
Zhen Huang ◽  
Hua F. Ding
Keyword(s):  
Kinematic Analysis ◽  
Jacobian Matrix ◽  
Hessian Matrix ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Analysis Method ◽  
Rear Part ◽  
Lower Mobility ◽  
Acceleration Analysis

This paper proposes a novel kinematic analysis method for a class of lower-mobility mechanisms whose degree-of-freedom (DoF) equal the number of single-DoF kinematic pairs in each kinematic limb if all multi-DoF kinematic pairs are substituted by the single one. For such an N-DoF (N<6) mechanism, this method can build a square (N×N) Jacobian matrix and cubic (N×N×N) Hessian matrix. The formulas in this method for different parallel mechanisms have unified forms and consequently the method is convenient for programming. The more complicated the mechanism is (for instance, the mechanism has more kinematic limbs or pairs), the more effective the method is. In the rear part of the paper, mechanisms 5-DoF 3-R(CRR) and 5-DoF 3-(RRR)(RR) are analyzed as examples.

An application of screw theory to the kinematic analysis of a Delta-type robot

2014 ◽  
Vol 28 (9) ◽  
pp. 3785-3792 ◽  
Author(s):  
Jaime Gallardo-Alvarado ◽  
Albert L. Balmaceda-Santamaría ◽  
Eduardo Castillo-Castaneda
Keyword(s):  
Kinematic Analysis ◽  
Screw Theory ◽  
Delta Type

Analysis and Design of Lower-Mobility Parallel Mechanism of Non-Symmetrical Based on Variable Topology Theory

2011 ◽  
Vol 201-203 ◽  
pp. 1907-1912
Author(s):  
Rong Jiang Cui ◽  
Zong He Guo ◽  
Zi Xun Yin ◽  
Song Song Zhu
Keyword(s):  
Parallel Mechanism ◽  
Screw Theory ◽  
Parallel Mechanisms ◽  
Basic Variable ◽  
Analysis And Design ◽  
And Topology ◽  
Variable Topology ◽  
Lower Mobility ◽  
Branched Chain ◽  
Mechanism Theory

First, the branched-chain of parallel mechanism was Classified according to reciprocal screw theory. Then, the introduction of variable topology mechanism theory, with the characteristics of parallel mechanisms themselves, the definition and basic variable topology means of variable topology parallel mechanism were given. With evolutionary theory, the method to design lower-mobility parallel mechanisms of non-asymmetric was proposed based on variable topology mechanism theory .Taking 3-RPS as ideal mechanism and topology synthesis was carried out, besides 2-RPS mechanism were analyzed. The introduction of variable topology mechanism theory provided a theoretical basis and innovative approaches for the synthesis configuration of Lower-mobility parallel mechanisms of non-asymmetric.

Optimum Design and Trafficability Analysis for an Articulated Wheel-legged Forestry Chassis

2021 ◽  
pp. 1-17
Author(s):  
Zhibo Sun ◽  
Dan Zhang ◽  
Zhilong Li ◽  
Shi Yan ◽  
Na Wang
Keyword(s):  
Parameter Optimization ◽  
Kinematic Analysis ◽  
Screw Theory ◽  
Kinematic Model ◽  
Surface Profile ◽  
Error Rates ◽  
Wheel Slip ◽  
Working Environments ◽  
Rigid Model ◽  
Four Bar Linkage

Abstract High trafficability and stability are the most two significant features of the forestry chassis. In this study, in order to improve surface trafficability, a novel articulated wheel-legged forestry chassis(AWLFC) is presented. To balance the trafficability and stability, a serial suspension system which is a combination with the active four-bar linkage articulated suspension (AFLAS) and passive V shape rocker-bogie is proposed. Then, parameter optimization with a comprehensive object function is implemented not only to enhance the trafficability and stability benefit of the structure but also to reduce the wheel slip. After that, through the flexible kinematic model based on screw theory, characteristics such as leveling ability and surface profile accessibility of the chassis are analyzed. The minimum accessible radius is obtained as 3088mm, and the longitudinal and lateral leveling angle reaches to 22° and 28.7° separately. The new chassis performs better on leveling ability and surface profile accessibility than the forestry chassis in the current literature. Finally, compared with the simulation and prototype experiment, error rates of the flexible kinematic analysis are reduced by 12.2% and 8.6% related to the rigid model. Previously inaccessible forestry working environments can be available with the development of AWLFC.

Geometry Modeling for Indexing Cams Based on Screw Theory and Product of Exponential Formula

2006 ◽  
Vol 505-507 ◽  
pp. 991-996
Author(s):  
Zong Yu Chang ◽  
Yu Hu Yang ◽  
Ce Zhang ◽  
Shou Bin Ding ◽  
Bin Zhang ◽  
...  
Keyword(s):  
Kinematic Analysis ◽  
Screw Theory ◽  
Product Formula ◽  
Coordinate Systems ◽  
Model Surface ◽  
Cam Mechanism ◽  
Geometry Modeling ◽  
Exponential Formula ◽  
Indexing Mechanism ◽  
Systems Transformation

This paper proposes a method of geometry modeling for indexing cam mechanism by using screw theory and exponential product formula. Kinematic analysis based on screw theory is introduced firstly. Then, method to model surface of indexing cams is presented when screw theory and exponential product formula are applied. The paper gives examples to obtain the geometry models of roller gear cam, barrel indexing cam and parallel indexing cam. Our work suggests that this method can avoid the burdensome work on building coordinate systems, transformation matrixes and understanding on the mechanism. Moreover, this method can be used to innovate and design new types of indexing mechanism.

Kinematic Analysis of a Novel Manual Medical Instrument for Minimally Invasive Surgery

2011 ◽  
Vol 308-310 ◽  
pp. 1969-1974 ◽  
Author(s):  
Xiao Fei Wang ◽  
Jian Min Li ◽  
Guo Kai Zhang
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Kinematic Analysis ◽  
Screw Theory ◽  
Medical Instrument ◽  
Low Friction ◽  
Calculation Results ◽  
High Flexibility ◽  
Basic Configuration

This paper presents a novel compact manual instrument for minimally invasive surgery (MIS). The instrument possesses several good features, such as large workspace, high flexibility, low friction and comfortable operability. The structure of the instrument is a basic configuration of some manual instruments. Besides basic operations, it can be applied to accomplish some more difficult processes, e.g. suturing and knotting. Based on screw theory and product-of-exponentials (POE) formula, the degree of freedom (DoF) and kinematics of the instrument are analyzed in the paper. The calculation results are verified by the simulation.

Kinematics and mobility analysis of carton folds in packing manipulation based on the mechanism equivalent

2002 ◽  
Vol 216 (10) ◽  
pp. 959-970 ◽  
Author(s):  
J S Dai ◽  
J Rees Jones
Keyword(s):  
Graph Theory ◽  
Closed Form ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Mobility Analysis ◽  
Mathematical Basis ◽  
Packaging Process ◽  
Kinematic Geometry ◽  
Position And Orientation

The process of erecting and closing a carton in packing manipulation is seen as a succession of folds in position and orientation from one distinct configuration to another. Permitted manipulations and changes in shape are governed by the geometry of crease lines, dimensions and profiles of the panels. The possibility for panels to fold into successive distinct configurations is determined by the kinematic geometry. This paper presents a mathematical basis which determines the mobility of distinct configurations of a carton to include the degrees of freedom dominating the manipulation and the overconstraint configurations in an erected and closed form, and proposes the kinematic analysis of a carton during packing manipulation. Use is made of the concept of line vectors and screw theory associated with graph theory. The analysis helps to explain some configurations which show how a carton can fold and opens up the way of describing manipulation in the packaging process.

Motion/Force Transmission Analysis of Parallel Mechanisms With Planar Closed-Loop Subchains

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kristan Marlow ◽  
Mats Isaksson ◽  
Jian S. Dai ◽  
Saeid Nahavandi
Keyword(s):  
Performance Measures ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Screw Theory ◽  
Parallel Mechanisms ◽  
Force Transmission ◽  
Six Degrees Of Freedom ◽  
Lower Mobility ◽  
Transmission Ability

Singularities are one of the most important issues affecting the performance of parallel mechanisms. A parallel mechanism with less than six degrees of freedom (6DOF) is classed as having lower mobility. In addition to input–output singularities, such mechanisms potentially suffer from singularities among their constraints. Furthermore, the utilization of closed-loop subchains (CLSCs) may introduce additional singularities, which can strongly affect the motion/force transmission ability of the entire mechanism. In this paper, we propose a technique for the analysis of singularities occurring within planar CLSCs, along with a finite, dimensionless, frame invariant index, based on screw theory, for examining the closeness to these singularities. The integration of the proposed index with existing performance measures is discussed in detail and exemplified on a prototype industrial parallel mechanism.

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