文档介绍：Available online at hanism
and
Machine Theory
Mechanism and Machine Theory 43 (2008) 104–114
ate/mechmt
Improving path accuracy of a crank-type 6-dof
parallel mechanism by pensation
E. Castillo-Castan˜eda a,*, Y. Takeda b
a Autonomous University of Queretaro, Faculty of Engineering, Cerro de las Campanas, 76010 Queretaro, Mexico
b Tokyo Institute of Technology, Department of Mechanical Sciences and Engineering, 2-12-1, O-okayama,
Meguro-ku, Tokyo 152-8552, Japan
Received 7 March 2006; received in revised form 1 November 2006; accepted 10 December 2006
Available online 24 January 2007
Abstract
The path accuracy of parallel mechanisms depends on both the mechanical design and the motion control algorithm
that minimizes the following error. The PID control algorithm is not suitable for very precise motion control since it can-
pensate non-linear phenomena such as backlash and static friction or stiction. This work proposes a -
pensation algorithm to improve path accuracy of a crank-type 6-dof parallel mechanism. The stiction has been modeled as
a dead-zone and has been experimentally identified. The results pared with those of the classical PID including
velocity and acceleration feed forward.
Ó 2006 Elsevier Ltd. All rights reserved.
Keywords: Parallel mechanisms; Path accuracy; Precision motion; pensation
1. Introduction
In 1990, the anization for Standardization (ISO) published what is known as the ISO 9283
standard of Performance Criteria and Related Test Methods for industrial manipulators. Many robot suppli-
ers use this standard to determine the performance of their products and publish specifications based on at
least a subset of the tests mended in ISO 9283. This standard establishes that pose accuracy, repeatabil-
ity, overshoot, settling time, as well as path accuracy, should be taken into account to evaluate the perfor-
mances of industrial robots. The accuracy is one of the most important requirements of panies
of e