Kinematics, dynamics and control of high precision parallel manipulators

2007 ◽  
Author(s):  
Wing-fung, Jacob Cheung
Keyword(s):  
High Precision ◽  
Parallel Manipulators ◽  
Dynamics And Control ◽  
And Control

Forward and Inverse Acceleration Analyses of In-Parallel Manipulators

1998 ◽  
Vol 122 (3) ◽  
pp. 299-303 ◽  
Author(s):  
Jose´ Marı´a Rico Martı´nez ◽  
Joseph Duffy
Keyword(s):  
Parallel Manipulator ◽  
Computing Time ◽  
Parallel Manipulators ◽  
Simple Expression ◽  
Intermediate Step ◽  
Simple Method ◽  
Dynamics And Control ◽  
Klein Form ◽  
Six Degree Of Freedom ◽  
And Control

Simple expressions for the forward and inverse acceleration analyses of a six degree of freedom in-parallel manipulator are derived. The expressions are obtained by firstly computing the “accelerator” for a single Hooke-Prismatic-Spheric, HPS for short, connector chain in terms of the joint velocities and accelerations. The accelerator is a function of the line coordinates of the joint axes and of a sequence of Lie products of the same line coordinates. A simple expression for the acceleration of the prismatic actuator is obtained by forming the Klein form, or reciprocal product, with the accelerator and the coordinates of the line of the connector chain. Since the Klein form is invariant, the resulting expression can be applied directly to the six HPS connector chains of an in-parallel manipulator. As a required intermediate step, this contribution also derives the corresponding solutions for the forward and inverse velocity analyses. The authors believe that this simple method has applications in the dynamics and control of these in-parallel manipulators where the computing time must be minimized to improve the behavior of parallel manipulators. [S1050-0472(00)01303-9]

An Efficient Inverse Acceleration Analysis of In-Parallel Manipulators

1996 ◽  
Author(s):  
José María Rico Martínez ◽  
Joseph Duffy
Keyword(s):  
Parallel Manipulator ◽  
Computing Time ◽  
Parallel Manipulators ◽  
Simple Expression ◽  
Degree Of Freedom ◽  
Simple Method ◽  
Dynamics And Control ◽  
Acceleration Analysis ◽  
Klein Form ◽  
And Control

Abstract A very simple novel expression for the accelerations of the six prismatic actuators, of the HPS connector chains, of a 6 degree of freedom in-parallel manipulator is derived. The expression is obtained by firstly computing the “accelerator” for a single HPS connector chain in terms of the joint velocities and accelerations. The accelerator is a function of the line coordinates of the joint axes and of a sequence of Lie products of the same line coordinates. A simple expression for the acceleration of the prismatic actuator is obtained by forming the Klein form, or reciprocal product, with the accelerator and the coordinates of the line of the connector chain. Since the Klein form is invariant, the resulting expression can be applied directly to the six HPS connector chains of an in-parallel manipulator. The authors believe that this simple method has important applications in the dynamics and control of these in-parallel manipulators where the computing time must be minimized to improve the behavior of parallel manipulators.

Design of the Virtual Machine System for High Precision Centerless Grinding and its Implementation Perspectives

2016 ◽  
Author(s):  
Qi Cui ◽  
Kai Cheng ◽  
Hui Ding ◽  
Shijin Chen
Keyword(s):  
Virtual Machine ◽  
High Precision ◽  
Machine System ◽  
Virtual Machining ◽  
Machine Performance ◽  
Dynamics And Control ◽  
Intrinsic Correlation ◽  
Centerless Grinding ◽  
High Level ◽  
And Control

In order to investigate the rounding process of high precision centerless grinding in time domain reliably and predictably, a virtual machine design approach is essential particularly towards 0.1–0.3μm roundness precision. The virtual machine system presented in this paper is developed through high-level integration of the machine characteristics, workpiece rounding mechanism and their intrinsic correlation. In this system, the primary elements affecting the workpiece roundness regeneration, including kinematics, dynamics and control of the machine, grinding dynamics and machining conditions, are integrated into the high precision virtual centerless grinding to render the rounding process, evaluate the machine performance and optimize grinding strategies accordingly. An application case study on virtual machining of the targeted workpiece roundness 0.1μm is provided to present the implementation perspectives of the virtual machine system for high precision centerless grinding.

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