Motion Plan of a Parallel Kinematic Machine Based on Stiffness Control

2010 ◽  
Author(s):  
Zhongzhe Chi ◽  
Dan Zhang ◽  
Qiaokang Liang
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Tool Path ◽  
Parallel Kinematic Machine ◽  
Tool Path Planning ◽  
Parallel Kinematic ◽  
Stiffness Control ◽  
Three Degrees Of Freedom

This paper proposes a design for a machine tool based on a parallel kinematic manipulator with three degrees of freedom, including rotations about x and y axis and translation along z axe. Based on the investigated displacement and inverse kinematics, the system stiffness of the parallel manipulator is conducted. Then in order to observe the highest system stiffness single and multi objective optimizations are performed in terms of rotation angles about x and y axis and translation displacement along z axe. Finally, a case study of tool path planning is presented to demonstrate the application of stiffness mapping.

Kinematic Analysis of a New 3-DOF Translational Parallel Manipulator

2005 ◽  
Author(s):  
Yangmin Li ◽  
Qingsong Xu
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Industrial Applications ◽  
Forward Kinematics ◽  
Physical Constraints ◽  
Mechanical Joints ◽  
Reachable Workspace ◽  
Three Degrees Of Freedom

A novel three-degrees-of-freedom (3-DOF) translational parallel manipulator (TPM) with orthogonally arranged fixed actuators is proposed in this paper. The mobility of the manipulator is analyzed via screw theory. The inverse kinematics, forward kinematics, and velocity analyses are performed and the singularities and isotropic configurations are investigated in details afterwards. Under different cases of physical constraints imposed by mechanical joints, the reachable workspace of the manipulator is geometrically generated and compared. Especially, it is illustrated that the manipulator in principle possesses a fairly regular like workspace with a maximum cuboid defined as the usable workspace inscribed and one isotropic configuration involved. Furthermore, the singularity within the usable workspace is verified, and simulation results show that there exist no any singular configurations within the specified workspace. Therefore, the presented new manipulator has a great potential for high precision industrial applications such as assembly, machining, etc.

Design and Experimental Investigation of a New 2R1T Overconstrained Parallel Kinematic Machine With Actuation Redundancy

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Lingmin Xu ◽  
Xinxue Chai ◽  
Qinchuan Li ◽  
Liangan Zhang ◽  
Wei Ye
Keyword(s):  
Inverse Kinematics ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Curved Surfaces ◽  
Parallel Kinematic Machine ◽  
Actuation Redundancy ◽  
Dimensional Parameters ◽  
Force Transmissibility ◽  
Parallel Kinematic

Two rotations and one translation (2R1T) parallel kinematic machines (PKMs) are suitable for the machining of complex curved surfaces, which requires high speed and precision. To further improve rigidity, precision, and avoid singularity, actuation redundancy, and overconstrained PKMs with fixed actuators and limited-degrees of freedom (DOF) limbs are preferred. However, there are few 2R1T PKMs with these features. This paper introduces a new 2R1T overconstrained PKM with actuation redundancy, which is called Tex4. The Tex4 PKM consists of four limited-DOF limbs; that is, two PUR limbs and two 2PRU limbs (where P denotes an actuated prismatic joint, U denotes a universal joint, and R denotes a revolute joint). The kinematic model of the proposed 2PUR-2PRU machine is presented along with the results of mobility, inverse kinematics, and velocity analysis. By considering the motion/force transmissibility, the dimensional parameters of the Tex4 PKM were optimized to obtain an improved satisfactory transmission workspace without singular configurations. Finally, a prototype based on the optimized parameters was fabricated, and its feasibility and accuracy were validated by motion and position error experiments. The Tex4 PKM has the advantages of high rigidity, simple kinematic model, and zero singularity in the workspace, which suggests that it has potential for use in the high-speed machining of curved surfaces.

A Novel Three-DOF 3-RRRRR Parallel Platform Mechanism and Its Position Analysis

2005 ◽  
Author(s):  
Shihua Li ◽  
Zhen Huang ◽  
Jianguang Wu
Keyword(s):  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Initial Configuration ◽  
Parallel Platform ◽  
Moving Platform ◽  
General Configuration ◽  
Novel Model ◽  
Three Degrees Of Freedom

In order to enrich deficient-DOF parallel mechanism models, a novel model of a 3-DOF platform manipulator is presented and establish its inverse kinematics equation. Here, studies instantaneous motions of 3-RRRRR parallel manipulator at initial configuration and general configuration. Find: it has three degrees of freedom at initial configuration and after translated along the X, Y, Z axis. Secondly, the relation is given between every active input (θ1) and moving platform position by using D-H means, the solution is developed for inverse kinematics, numerical example for the position kinematic is presented, the figure of workspace along the Z-axis is drawn finally. The mechanism can be applied to jiggle mechanism.

Mobility Analysis and Inverse Kinematics of a Novel 2R1T Parallel Manipulator

2011 ◽  
Author(s):  
Enrique Cuan-Urquizo ◽  
Ernesto Rodriguez-Leal ◽  
Jian S. Dai
Keyword(s):  
Software Package ◽  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Parallel Robot ◽  
Mobility Analysis ◽  
Closure Equation ◽  
Inverse Kinematics Problem ◽  
Three Degrees Of Freedom

This paper presents a novel parallel robot constructed with a three-limb CUP architecture. The mobility of the mechanism is obtained using screw theory, showing that the platform has three degrees of freedom, namely: (i) translation along the Z axis; and (ii) two rotations. The position analysis investigates the loop-closure equation resulting in a unique solution for the inverse kinematics problem and the identification of parasitic motions of the platform. The paper validates the analytical solution with a numerical example, where the results are compared with motion simulations of the manipulator using a commercially available software package.

On Performance Enhancement of Parallel Kinematic Machine

2005 ◽  
Author(s):  
Dan Zhang ◽  
Lihui Wang
Keyword(s):  
Remote Control ◽  
Degrees Of Freedom ◽  
Geometric Model ◽  
Kinematic Model ◽  
Parallel Kinematic Machine ◽  
Web Based ◽  
Remote Manipulation ◽  
Parallel Kinematic ◽  
Moving Platform ◽  
Three Degrees Of Freedom

This paper proposes a spatial three degrees of freedom parallel kinematic machine enhanced by a passive leg and a web-based remote control system. First, the geometric model of the three degrees of freedom parallel kinematic machine is addressed; in the mechanism, a fourth kinematic link — a passive link connecting the base center to the moving platform center — is introduced. This last link is used to constrain the motion of the tool (located in the moving platform) to only three degrees of freedom, as well as to enhance the global stiffness of the structure and distribute the torque from machining. With the kinematic model, a web-based remote control approach is then applied. The concept of the web-based remote manipulation approach is introduced and the principles behind the method are explored in detail. Finally, an example of remote manipulation is demonstrated to the proposed 3-DOF structure using web-based remote control concept before conclusions.

A Method to Evaluate and Calculate the Mobility of a General Compliant Parallel Manipulator

2004 ◽  
Author(s):  
Jingjun Yu ◽  
Shusheng Bi ◽  
Guanghua Zong
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Compliant Mechanism ◽  
Parallel Manipulators ◽  
Kinematic Characteristic ◽  
Parallel Kinematic Machine ◽  
Compliance Matrix ◽  
Multiple Degrees Of Freedom ◽  
Parallel Kinematic

A compliant parallel manipulator (CPM), is a kind of compliant mechanism characterizes a complicate topological structure and multiple degrees of freedom. As one of the kinematic characteristics of a CPM, the mobility of a CPM become complicate compared to its rigid-counterpart. In order to describe such a complicate kinematic characteristic of a CPM, “primary mobility of a compliant parallel manipulator” concept is proposed. By means of the screw theory, a method of quantifying the primary mobility of the CPM is investigated under the ground that the compliance matrix of the manipulator should be calculated primarily. By using this method, the primary mobility of two typical compliant parallel manipulators, one is a planar 3-RRR CPM and the other a spatial 3-RRPR CPM, is addressed respectively. This proposed method is also instructive for analyzing the instantaneous mobility of a general degenerate-DOF parallel manipulator or a Parallel Kinematic Machine (PKM).

Kinematic and Singularity Analysis of 3 PRR Parallel Manipulator

2011 ◽  
Vol 403-408 ◽  
pp. 5015-5021 ◽  
Author(s):  
A. Arockia Selvakumar ◽  
K. Karthik ◽  
A.L. Naresh Kumar ◽  
R. Sivaramakrishnan ◽  
K. Kalaichelvan
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Walking Machines ◽  
Adams Simulation ◽  
Movable Platform ◽  
The One ◽  
Machining Operations ◽  
Three Degrees Of Freedom

Three degrees of freedom (DOF) parallel manipulator is used in the applications such as base for various machining operations, drilling inclined holes, airplane and automobile simulators, walking machines, pointing devices, contour milling and machining etc. The 3 DOF parallel manipulator consists of a fixed platform and a movable platform, which are connected by means of three identical links. Pin joints are used to connect the one end of the link and the lead screw pair. This 3 DOF 1R2T parallel manipulator is having one orientation freedom and two translational freedom, which is actuated by means of screw pair, which in turn operated by a stepper motor. The inverse kinematics and velocity equations of this mechanism have been derived mathematically. Based on this inverse kinematics and velocity equations singularity analysis is completed. Two kinds of singularities are compared with ADAMS simulation results and a prototype of the manipulator is developed for further study.

Kinematic Analysis and Design of a New 3-DOF Translational Parallel Manipulator

2005 ◽  
Vol 128 (4) ◽  
pp. 729-737 ◽  
Author(s):  
Yangmin Li ◽  
Qingsong Xu
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Forward Kinematics ◽  
Velocity Analysis ◽  
Analysis And Design ◽  
Reachable Workspace ◽  
Three Degrees Of Freedom ◽  
Real Machine

A new three degrees of freedom (3-DOF) translational parallel manipulator (TPM) with fixed actuators called a 3-PRC TPM is proposed in this paper. The mobility of the manipulator is analyzed via screw theory. The inverse kinematics, forward kinematics, and velocity analysis are performed and the singular and isotropic configurations are identified afterward. Moreover, the mechanism design to eliminate all singularities and generate an isotropic manipulator has been presented. With the variation on architectural parameters, the reachable workspace of the manipulator is generated and compared. Especially, it is illustrated that the manipulator in principle possesses a uniform workspace with a constant hexagon shape cross section. Furthermore, the dexterity characteristics are investigated in the local and global sense, respectively, and some considerations for real machine design have been proposed as well.

Kinematics of a Fully-Decoupled Remote Center-of-Motion Parallel Manipulator for Minimally Invasive Surgery

2012 ◽  
Vol 6 (2) ◽  
Author(s):  
Chin-Hsing Kuo ◽  
Jian S. Dai
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Surgical Instruments ◽  
End Effector ◽  
Minimally Invasive Surgical ◽  
Inverse Kinematics Problem

A crucial design challenge in minimally invasive surgical (MIS) robots is the provision of a fully decoupled four degrees-of-freedom (4-DOF) remote center-of-motion (RCM) for surgical instruments. In this paper, we present a new parallel manipulator that can generate a 4-DOF RCM over its end-effector and these four DOFs are fully decoupled, i.e., each of them can be independently controlled by one corresponding actuated joint. First, we revisit the remote center-of-motion for MIS robots and introduce a projective displacement representation for coping with this special kinematics. Next, we present the proposed new parallel manipulator structure and study its geometry and motion decouplebility. Accordingly, we solve the inverse kinematics problem by taking the advantage of motion decouplebility. Then, via the screw system approach, we carry out the Jacobian analysis for the manipulator, by which the singular configurations are identified. Finally, we analyze the reachable and collision-free workspaces of the proposed manipulator and conclude the feasibility of this manipulator for the application in minimally invasive surgery.

A Model of the Human Spine: Forward and Inverse Kinematics

1992 ◽  
Author(s):  
Sunil Kumar Agrawal ◽  
Siyan Li ◽  
Glen Desmier
Keyword(s):  
Range Of Motion ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Joint Angles ◽  
Human Spine ◽  
Forward And Inverse Kinematics ◽  
Position And Orientation ◽  
Three Degrees Of Freedom ◽  
Adjacent Vertebra

Abstract The human spine is a sophisticated mechanism consisting of 24 vertebrae which are arranged in a series-chain between the pelvis and the skull. By careful articulation of these vertebrae, a human being achieves fine motion of the skull. The spine can be modeled as a series-chain with 24 rigid links, the vertebrae, where each vertebra has three degrees-of-freedom relative to an adjacent vertebra. From the studies in the literature, the vertebral geometry and the range of motion between adjacent vertebrae are well-known. The objectives of this paper are to present a kinematic model of the spine using the available data in the literature and an algorithm to compute the inter vertebral joint angles given the position and orientation of the skull. This algorithm is based on the observation that the backbone can be described analytically by a space curve which is used to find the joint solutions..

Sign in / Sign up

Export Citation Format

Share Document