Analysis and Application of a 2-DOF Planar Parallel Mechanism

2006 ◽  
Vol 129 (4) ◽  
pp. 434-437 ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Tiemin Li ◽  
Liping Wang
Keyword(s):  
Parallel Mechanism ◽  
Euler Method ◽  
Inertia Force ◽  
Kinematic Parameters ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Inverse Dynamic Model ◽  
Kinematic Design ◽  
Hybrid Machine Tool ◽  
Hybrid Machine

This paper deals with the optimal kinematic design, dynamic analysis, and application of a 2 degree of freedom (2-DOF) planar parallel mechanism. In the optimal kinematic design phase, the singularities and workspace are investigated, and the optimal kinematic parameters of the mechanism are achieved by minimizing a global and comprehensive conditioning index. The Newton–Euler method is employed to derive the inverse dynamic model. Dynamic simulations show that the inertia force of moving parts is an important factor affecting the dynamic characteristics of the mechanism. The parallel mechanism is incorporated into a 4-DOF hybrid machine tool which also includes a 2-DOF worktable to demonstrate its applicability.

Error Comparison and Analysis of Parallel and Constraint Mechanism for 3-TPS Hybrid Machine Tool

2011 ◽  
Vol 127 ◽  
pp. 277-282
Author(s):  
Peng Fei Dang ◽  
Li Jin Fang
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Parallel Robot ◽  
Error Model ◽  
Position Error ◽  
Robot Kinematics ◽  
Motion Error ◽  
Movable Plate ◽  
Hybrid Machine Tool ◽  
Hybrid Machine

This paper establishes position error model based on parallel robot kinematics theory, and analyses position error of the 3-TPS hybrid machine tool. Firstly, to calculate position error of the movable plate caused by the parallel mechanism links, through error model of the parallel mechanism which is established through inverse kinematics of the hybrid machine tool. Then, according to the error model of constraint mechanism established by transformation matrix method, the position error has been simulated and calculated. Finally, this paper compares the effects of both mechanisms. The analysis indicates the link error of constraint mechanism has more influence on movable plate posture than parallel mechanism, and provides help with motion error compensation and kinematic calibration.

Inverse Dynamics of 2UPS-2RPS Parallel Mechanism Based on Virtual Work Principle

2010 ◽  
Vol 29-32 ◽  
pp. 744-749 ◽  
Author(s):  
Wen Hua Wang ◽  
Zhi You Feng ◽  
Ting Li Yang ◽  
Ce Zhang
Keyword(s):  
Computer Simulation ◽  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Inverse Dynamics ◽  
Virtual Work ◽  
Dynamic Equations ◽  
Inverse Dynamic ◽  
Virtual Work Principle ◽  
Inverse Dynamic Model ◽  
Moving Platform

Inverse dynamic equations of the 2UPS-2RPS mechanism are formulated by utilizing the virtual work principle. Kinematic analysis of the mechanism is presented, on the basis of which the Jacobian matrices of the limbs and the mechanism are deduced. By combining the dynamics of the limbs and the moving-platform, the inverse dynamic model of the mechanism is obtained. Finally a computer simulation is carried out to demonstrate the dynamic analysis of the moving platform.

Dynamic Analysis and Counterweight Optimization of the 2-DOF Parallel Manipulator of a Hybrid Machine Tool

2007 ◽  
Vol 2 (4) ◽  
pp. 344-350 ◽  
Author(s):  
Jun Wu ◽  
Jinsong Wang ◽  
Liping Wang ◽  
Tiemin Li ◽  
Yue Liu
Keyword(s):  
Machine Tool ◽  
Parallel Manipulator ◽  
Cutting Tool ◽  
Force Model ◽  
Cutting Force Model ◽  
Dynamic Simulations ◽  
Hybrid Machine Tool ◽  
Planar Parallel Manipulator ◽  
Hybrid Machine ◽  
Two Degree Of Freedom

This paper focuses on the dynamic modeling and counterweight optimization of the two degree of freedom planar parallel manipulator, which is a subpart of a hybrid machine tool. Based on a kinematic analysis, the dynamic equation is derived by using the Newton-Euler approach. Then, three counterweight modes are presented for the parallel manipulator. According to the cutting force model and motion planning of the cutting tool, the dynamic simulations with three counterweight modes are performed, and the mass of counterweight in each counterweight mode is optimized by minimizing the sum of mean square values of actuator forces. The simulations show that the optimal mass of counterweights does not equal the total mass of moving parts of the parallel manipulator, and each counterweight mode has its advantage and disadvantage. Considering the ease in which a counterweight can be implemented, the counterweight mode where two counterweights are connected to two sliders is adopted for the parallel manipulator.

scholarly journals Forward and Inverse Dynamics of a Six-Axis Accelerometer Based on a Parallel Mechanism

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 233
Author(s):  
Linkang Wang ◽  
Jingjing You ◽  
Xiaolong Yang ◽  
Huaxin Chen ◽  
Chenggang Li ◽  
...  
Keyword(s):  
Configuration Space ◽  
Parallel Mechanism ◽  
Inverse Dynamics ◽  
Recursive Algorithm ◽  
Hamiltonian Function ◽  
Euler Method ◽  
Dynamic Equations ◽  
Sensor Calibration ◽  
Inverse Dynamic ◽  
New Strategy

The solution of the dynamic equations of the six-axis accelerometer is a prerequisite for sensor calibration, structural optimization, and practical application. However, the forward dynamic equations (FDEs) and inverse dynamic equations (IDEs) of this type of system have not been completely solved due to the strongly nonlinear coupling relationship between the inputs and outputs. This article presents a comprehensive study of the FDEs and IDEs of the six-axis accelerometer based on a parallel mechanism. Firstly, two sets of dynamic equations of the sensor are constructed based on the Newton–Euler method in the configuration space. Secondly, based on the analytical solution of the sensor branch chain length, the coordination equation between the output signals of the branch chain is constructed. The FDEs of the sensor are established by combining the coordination equations and two sets of dynamic equations. Furthermore, by introducing generalized momentum and Hamiltonian function and using Legendre transformation, the vibration differential equations (VDEs) of the sensor are derived. The VDEs and Newton–Euler equations constitute the IDEs of the system. Finally, the explicit recursive algorithm for solving the quaternion in the equation is given in the phase space. Then the IDEs are solved by substituting the quaternion into the dynamic equations in the configuration space. The predicted numerical results of the established FDEs and IDEs are verified by comparing with virtual and actual experimental data. The actual experiment shows that the relative errors of the FDEs and the IDEs constructed in this article are 2.21% and 7.65%, respectively. This research provides a new strategy for further improving the practicability of the six-axis accelerometer.

The Dynamic Analysis of a 2-PRR Planar Parallel Mechanism

2005 ◽  
Vol 219 (9) ◽  
pp. 901-909 ◽  
Author(s):  
L-P Wang ◽  
J-S Wang ◽  
J Chen
Keyword(s):  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Driving Forces ◽  
Inverse Dynamic ◽  
Inverse Dynamic Model ◽  
Planar Parallel Manipulator ◽  
Euler Approach ◽  
Motion Parameters

The article presents the inverse dynamics of a two-degrees-of-freedom planar parallel manipulator by the Newton-Euler approach. On the basis of the inverse dynamic model, the driving forces of actuators are simulated in different motion parameters. Further, the effects of inertia of each moving component to the driving forces are computed through the numerical method.

Design and workspace analysis of a 3-degree-of-freedom parallel swivel head with large tilting capacity

2015 ◽  
Vol 231 (10) ◽  
pp. 1838-1849 ◽  
Author(s):  
Jiangzhen Guo ◽  
Dan Wang ◽  
Rui Fan ◽  
Wuyi Chen
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Spherical Joint ◽  
Hybrid Machine Tool ◽  
Tilting Angle ◽  
Workspace Analysis ◽  
Hybrid Machine ◽  
Orientation Workspace

Traditional parallel mechanisms are usually characterized by small tilting capability. To overcome this problem, a 3-degree-of-freedom parallel swivel head with large tilting capacity is proposed in this article. The proposed parallel swivel head, which is structurally developed from a conventional 3-PRS parallel mechanism, can achieve a large tilting capability by means of structural improvements. First, a modified spherical joint with a maximum tilting angle of ±120° is devised to diminish the physical restrictions on the orientation workspace. Second, a UPS typed leg is introduced for the sake of singularity elimination. The superiority of the proposed parallel swivel head is theoretically proved by investigations of singularity-free orientation workspace and then is experimentally validated using a prototype fabricated. The theoretical and experimental results illustrate that the proposed parallel swivel head has a large tilting capacity and thus can be used as swivel head for a hybrid machine tool which is designed to be capable of realizing both horizontal and vertical machining.

Design and Experimental Study of a 3-DOF Parallel Swivel Head

2013 ◽  
Vol 418 ◽  
pp. 132-140
Author(s):  
Dan Wang ◽  
Jiang Zhen Guo ◽  
Rui Fan ◽  
Wu Yi Chen
Keyword(s):  
Experimental Study ◽  
Machine Tool ◽  
Parallel Mechanism ◽  
Experimental Results ◽  
Parallel Mechanisms ◽  
Spherical Joint ◽  
Hybrid Machine Tool ◽  
Tilting Angle ◽  
Hybrid Machine ◽  
Orientation Workspace

Traditional parallel mechanisms (PMs) are usually characterized by small tilting capability. To overcome this problem, a 3-DOF parallel swivel head (PSH) with large tilting capacity is proposed in this paper. The proposed PSH, which is structurally developed from a conventional 3-PRS parallel mechanism (PM), can achieve a large tilting capability by means of structural improvements. Firstly, a modified spherical joint with a maximum tilting angle of ±120o is devised to diminish the physical restrictions on the orientation workspace. Secondly, a UPS typed leg is introduced for the sake of singularity elimination. The superiority of the proposed PSH is theoretically proved by investigations of singularity-free orientation workspace and then is experimentally validated using a prototype fabricated. The theoretical and experimental results illustrate that the proposed PSH has a large tilting capacity and thus can be used as swivel head for a hybrid machine tool which is designed to be capable of realizing both horizontal and vertical machining.

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