0
Research Papers

A Control Strategy of a Two Degrees-of-Freedom Heavy Duty Parallel Manipulator

[+] Author and Article Information
Jun Wu

Institute of Manufacturing Engineering,
Department of Mechanical Engineering,
Tsinghua University;
Beijing Key Lab of Precision/Ultra-Precision Manufacturing Equipment and Control,
Beijing 100084, China
e-mail: jhwu@mail.tsinghua.edu.cn

Dong Wang, Liping Wang

Institute of Manufacturing Engineering,
Department of Mechanical Engineering,
Tsinghua University;
Beijing Key Lab of Precision/Ultra-Precision Manufacturing Equipment and Control,
Beijing 100084, China

1Corresponding author.

Contributed by the Dynamic Systems Division of ASME for publication in the JOURNAL OF DYNAMIC SYSTEMS, MEASUREMENT, AND CONTROL. Manuscript received May 21, 2014; final manuscript received November 20, 2014; published online January 27, 2015. Assoc. Editor: M. Porfiri.

J. Dyn. Sys., Meas., Control 137(6), 061007 (Jun 01, 2015) (10 pages) Paper No: DS-14-1213; doi: 10.1115/1.4029244 History: Received May 21, 2014; Revised November 20, 2014; Online January 27, 2015

The motion accuracy of a heavy duty parallel manipulator is usually low due to time lag and the difficulty to real-time measure the position of the end-effector. In this paper, a dynamic modeling of this system with consideration of the link flexible deformation is proposed, and a double-feedforward control is presented. The link deformation is considered in the kinematic model. Taking link deformation into account, the dynamic model is derived for real-time application, and the inverse dynamic compensator is designed. The zero phase error tracking controller (ZPETC) is introduced as the second compensator. The system stability is investigated by simulations. The control method is compared with the kinematic-based control without consideration of link deformation. The results show that the maximum contouring error reduces from 7.5mm to 10μm. Thus, the tracking performance is improved when using the method proposed in this paper.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 3

Free-body diagram of link AiBi

Grahic Jump Location
Fig. 2

Kinematic model of the redundant manipulator

Grahic Jump Location
Fig. 1

3D model of the 5DOF hybrid machine tool

Grahic Jump Location
Fig. 5

Schematic diagram of control system

Grahic Jump Location
Fig. 4

Position error of the moving platform caused by link deformation

Grahic Jump Location
Fig. 6

Principle of dual channel compensation

Grahic Jump Location
Fig. 7

Relationship between contouring error and tracking error

Grahic Jump Location
Fig. 8

Simulation trajectory

Grahic Jump Location
Fig. 9

Kinematic-based control under ideal conditions. (a) x direction tracking error, (b) y direction tracking error, and (c) contouring error.

Grahic Jump Location
Fig. 10

Double-feedforward control under ideal conditions. (a) x direction tracking error, (b) y direction tracking error, and (c) contouring error.

Grahic Jump Location
Fig. 12

Tracking error and contouring error with kinematic-based control. (a) x direction tracking error, (b) y direction tracking error, and (c) contouring error.

Grahic Jump Location
Fig. 13

Tracking error and contouring error with double-feedforward control. (a) x direction tracking error, (b) y direction tracking error, and (c) contouring error.

Grahic Jump Location
Fig. 14

Driving force: (a) without cutting force and (b) with cutting force

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In