Kinematic Analysis of a Planar Mechanism Driven by Two Orthogonal Layout Actuators

2012 ◽  
Vol 490-495 ◽  
pp. 2305-2309
Author(s):  
Xiao Rong Zhu ◽  
Yi Lu ◽  
Hui Ping Shen
Keyword(s):  
Closed Form ◽  
Kinematic Analysis ◽  
Machine Tools ◽  
Jacobi Matrix ◽  
The Other ◽  
Stiffness Index ◽  
Forward Kinematics ◽  
Performance Indices ◽  
Hand Dexterity ◽  
Mobile Base

In this paper, a planar five-bar mechanism driven by two orthogonal layout actuators is proposed. The inverse and forward kinematics can be described in closed form. The Jacobi matrix, singularity and workspace of the mechanism are investigated. In addition, charts of some performance indices, such as dexterity, velocity, payload capability and stiffness index, are plotted. The results show that the mechanism has a flatter singularity-free workspace, which is usually our research object. On the other hand, Dexterity, Payload capability and stiffness index of the mechanism are basically the same distribution on the workspace, which are axis symmetric. But, the trend of velocity index is opposite. The proposed mechanism can be applied to the field of machine tools or used as the mobile base for a spatial manipulator. The results of the paper are very useful for the design and application of the new mechanism

Performance Evaluation of a 2-DOF Planar Parallel Manipulator

2011 ◽  
Vol 121-126 ◽  
pp. 2829-2833
Author(s):  
Xiao Rong Zhu ◽  
Hui Ping Shen
Keyword(s):  
Machine Tools ◽  
Parallel Manipulator ◽  
Inverse Dynamics ◽  
Forward Kinematics ◽  
Planar Parallel Manipulator ◽  
Velocity Equation ◽  
Force Transmissibility ◽  
Inverse Dynamics Problem ◽  
Linear Actuators ◽  
Mobile Base

In this paper, a 2-DOF planar parallel manipulator actuated horizontally by linear actuators is proposed. The inverse and forward kinematics can be described in closed form. The velocity equation, singularity of the manipulator and the conditioning index is investigated. In addition, the inverse dynamics problem of the device is investigated employing the Lagrange approach. The dynamic simulation is carried out. The results show that the kinematics performance and the force transmissibility are worse when the end-effecter moves near the singularity. The proposed manipulator can be applied to the field of machine tools or used as the mobile base for a spatial manipulator. The results of the paper are very useful for the design and application of the new manipulator.

scholarly journals Forward kinematic analysis of Dobot using closed-loop method

2020 ◽  
Vol 9 (3) ◽  
pp. 153
Author(s):  
Javier Dario Sanjuan De Caro ◽  
Mohammad Rahman ◽  
Ivan Rulik
Keyword(s):  
Analytical Solution ◽  
Kinematic Analysis ◽  
Closed Loop ◽  
Dynamical Model ◽  
Forward Kinematics ◽  
Loop Method ◽  
Serial Robots ◽  
Forward Kinematic

Dobot is a hybrid robot that combines features from parallel and serial robots. Because of this characteristic, the robot excels for is reliability, allowing its implementation in diverse applications. Therefore, researchers have studied its kinematics to improve its capabilities. However, to the extent of our knowledge, no analysis has been reported taking into consideration the closed-loop configuration of Dobot. Thus, this article presents the complete analytical solution for the forward kinematics of Dobot, considering each link. The results are expected to be utilized in the development of a dynamical model that contemplates the dynamics of each element of the robot.

Closed-Form Synthesis of Force-Generating Planar Four-Bar Linkages

1995 ◽  
Author(s):  
R. Randall Soper ◽  
Michael Scardina ◽  
Paul Tidwell ◽  
Charles Reinholtz ◽  
Michael A. Lo Presti
Keyword(s):  
Closed Form ◽  
The Other ◽  
Design Parameters ◽  
Synthesis Methods ◽  
Function Generator ◽  
Mechanical Advantage ◽  
Nonlinear Mechanical ◽  
Two Parameters ◽  
Selection Of ◽  
Weight Force

Abstract This paper presents a technique for synthesizing four-bar linkages to produce a specified resisting force or torque. The resisting energy is provided by a weight acting on the other grounded link. The linkage serves as a nonlinear mechanical advantage function generator. Force and velocity synthesis methods have been extensively discussed in the literature. The general approach, however, has been to assume that the specified force or velocity occurs at a prescribed position. This results in the loss of design parameters that are being used unnecessarily to control position. In this application, force input to the linkage is specified as a function of only the input link position and the magnitude and direction of the weight force. Mechanical advantage synthesis can be achieved at as many as seven precision points. The method presented in this paper allows free selection of two parameters and viewing one infinity of solutions.

An Automated Inversion Apporach to Closed-Form Kinematic Analysis of Planar Mechanisms

1992 ◽  
Author(s):  
Arunava Biswas ◽  
Gary L. Kinzel
Keyword(s):  
Closed Form ◽  
Iterative Methods ◽  
Kinematic Analysis ◽  
Equation Approach ◽  
Planar Mechanisms ◽  
Loop Equation ◽  
Closed Form Solutions

Abstract In this paper an inversion approach is developed for the analysis of planar mechanisms using closed-form equations. The vector loop equation approach is used, and the occurrence matrices of the variables in the position equations are obtained. After the loop equations are formed, dependency checking of the unknowns is performed to determine if it is possible to solve for any two equations in two unknowns. For the cases where the closed-form solutions cannot be implemented directly, possible inversions of the mechanism are studied. If the vector loop equations for an inversion can be solved in closed-form, they are identified and solved, and the solutions are transformed back to the original linkage. The method developed in this paper eliminates the uncertainties involved, and the large number of computations required in solving the equations by iterative methods.

scholarly journals Equation Based New Methods for Residential Load Forecasting

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6378
Author(s):  
S. M. Mahfuz Alam ◽  
Mohd. Hasan Ali
Keyword(s):  
Root Mean Square ◽  
Load Forecasting ◽  
Residential Building ◽  
The Other ◽  
Support Vector ◽  
Linear Regression Method ◽  
Mean Square ◽  
Performance Indices ◽  
Degree Days ◽  
Average Percentage

This work proposes two non-linear and one linear equation-based system for residential load forecasting considering heating degree days, cooling degree days, occupancy, and day type, which are applicable to any residential building with small sets of smart meter data. The coefficients of the proposed nonlinear and linear equations are tuned by particle swarm optimization (PSO) and the multiple linear regression method, respectively. For the purpose of comparison, a subtractive clustering based adaptive neuro fuzzy inference system (ANFIS), random forests, gradient boosting trees, and long-term short memory neural network, conventional and modified support vector regression methods were considered. Simulations have been performed in MATLAB environment, and all the methods were tested with randomly chosen 30 days data of a residential building in Memphis City for energy consumption prediction. The absolute average error, root mean square error, and mean average percentage errors are tabulated and considered as performance indices. The efficacy of the proposed systems for residential load forecasting over the other systems have been validated by both simulation results and performance indices, which indicate that the proposed equation-based systems have the lowest absolute average errors, root mean square errors, and mean average percentage errors compared to the other methods. In addition, the proposed systems can be easily practically implemented.

Development of Flexible Worktable for Endmilling Based on Parallel Mechanism

2010 ◽  
Vol 447-448 ◽  
pp. 826-830 ◽  
Author(s):  
Tomohisa Tanaka ◽  
Masahiro Komori ◽  
Jiang Zhu ◽  
Yoshio Saito
Keyword(s):  
Machine Tools ◽  
Parallel Mechanism ◽  
High Accuracy ◽  
The Other ◽  
Geometrical Parameters ◽  
Basic Design ◽  
Positioning Accuracy ◽  
Accuracy Measurement ◽  
High Degree ◽  
Work Table

Parallel mechanism has many advantages, such as high stiffness, high accuracy, high degree of freedom (DOF), etc. These fine features are suitable for work table of machine tools for production of recent complicated designs. In this study, six axes linear-actuated parallel mechanism was chosen as the basic design for work table. First, geometrical parameters of the table were designed to satisfy the required movable range with minimum cutting load. Then, the work table was actually constructed and its performance was evaluated. From positioning accuracy measurement, it was found that the table is suitable to be used for machining of complicated products. On the other hand, from actual cutting tests of primitive shapes using chemical wood and measurement of the machined shapes, potential of the table for real cutting application was confirmed.

Kinematic Analysis of Mechanisms by the Complex Conjugate Exponential Method

1975 ◽  
Vol 97 (3) ◽  
pp. 795-799 ◽  
Author(s):  
J. A. Smith
Keyword(s):  
Angular Velocity ◽  
Closed Form ◽  
Kinematic Analysis ◽  
Angular Position ◽  
Angular Acceleration ◽  
Dynamic State ◽  
Complex Conjugate ◽  
Iterative Techniques ◽  
Numerical Example ◽  
Exponential Method

Generalized closed-form expressions are presented for the analysis of angular and path position and dynamic state properties of an n link mechanism with single or multiple prescribed input specifications. The complex conjugate concept is extensively used to formulate these explicit expressions. A numerical example of a six-bar mechanism is presented, and the closed-form expressions are used to calculate—without graphical, numerical, or iterative techniques—the angular position, angular velocity, and angular acceleration of each link.

A Double-Faced 6R Single-Loop Overconstrained Spatial Mechanism

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Xianwen Kong ◽  
Xiuyun He ◽  
Duanling Li
Keyword(s):  
Kinematic Analysis ◽  
Isosceles Triangle ◽  
The Other ◽  
Dual Quaternion ◽  
Single Loop ◽  
Plane Symmetric ◽  
Spatial Mechanism ◽  
Revolute Joints ◽  
Full Turn ◽  
Overconstrained Mechanisms

This paper deals with a 6R single-loop overconstrained spatial mechanism that has two pairs of revolute joints with intersecting axes and one pair of revolute joints with parallel axes. The 6R mechanism is first constructed from an isosceles triangle and a pair of identical circles. The kinematic analysis of the 6R mechanism is then dealt with using a dual quaternion approach. The analysis shows that the 6R mechanism usually has two solutions to the kinematic analysis for a given input and may have two circuits (closure modes or branches) with one or two pairs of full-turn revolute joints. In two configurations in each circuit of the 6R mechanism, the axes of four revolute joints are coplanar, and the axes of the other two revolute joints are perpendicular to the plane defined by the above four revolute joints. Considering that from one configuration of the 6R mechanism, one can obtain another configuration of the mechanism by simply renumbering the joints, the concept of two-faced mechanism is introduced. The formulas for the analysis of plane symmetric spatial triangle are also presented in this paper. These formulas will be useful for the design and analysis of multiloop overconstrained mechanisms involving plane symmetric spatial RRR triads.

Design and Kinematic Analysis of a Novel Machine Tool With Four Rotational Axes and One Translational Axis

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Song Gao ◽  
Jihong Chen ◽  
Shusheng Liu ◽  
Xiukun Yuan ◽  
Pengcheng Hu ◽  
...  
Keyword(s):  
Machine Tool ◽  
Kinematic Analysis ◽  
Machine Tools ◽  
Inverse Kinematics ◽  
Kinematics Analysis ◽  
Rotary Axes ◽  
Machining Quality ◽  
New Type ◽  
Kinematic Performance ◽  
Five Axis

Abstract Due to their superior machining quality, efficiency, and availability, five-axis machine tools are important for the manufacturing of complicated parts of freeform surfaces. In this study, a new type of the five-axis machine tool was designed that is composed of four rotary axes as well as one translational axis. Given the structure of the proposed machine tool, an inverse kinematics analysis was conducted analytically, and a set of methods was then proposed to address the issues in the kinematic analysis, e.g., the singularity and multi-solution problems. Compared with traditional five-axis machine tools, which are typically composed of three linear axes and two rotary axes, the proposed machine tool exhibited better kinematic performance with machining parts with hub features, such as impellers, which was validated by simulations and real cuttings.

Identifying Sets of Four and Five Positions That Generate Distinctive Center-Point Curves

2009 ◽  
Author(s):  
David H. Myszka ◽  
Andrew P. Murray
Keyword(s):  
Closed Form ◽  
The Other ◽  
Specific Design ◽  
Opposite Pole ◽  
Center Point ◽  
Point Curve ◽  
Position Synthesis ◽  
Two Sides ◽  
Cubic Function

The fixed pivots of a planar 4R linkage that can achieve four design positions are constrained to a center-point curve. The curve is a circular cubic function and plots can take one of five different forms. The center-point curve can be generated with a compatibility linkage obtained from an opposite pole quadrilateral of the four design positions. This paper presents a method to identify design positions that generate distinctive shapes of the center-point curves. The form of the center-point curve is dependent on whether the shape of the opposite pole quadrilateral is an open or closed form of a rhombus, kite, parallelogram, or when the sum of two sides equals the other two. Interesting cases of three and five position synthesis are also explored. Four and five position cases are generated that have center points at infinity allowing a PR dyad with line of slide in any direction to achieve the design positions. Further, a center-point curve for five specific design positions is revealed.

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