A desktop NC machine tool with a position/force controller using a fine-velocity pulse converter

Fusaomi Nagata, Tetsuo Hase, Zenku Haga, Masaaki Omoto, Keigo Watanabe

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

In this paper, a new desktop NC machine tool with the ability of compliance control is presented for finishing of metallic molds with small curved surface. The NC machine tool consists of a three-axis robot whose single one has a high position accuracy of 1 μm, which means that it can perform higher resolutions of position and force, compared to general industrial robots. A ball-end abrasive tool is attached to the tip of z-axis through a force sensor. In order to first confirm the application limit of an industrial robot to a finishing task, we evaluate the backlash that causes inaccuracy in position at the tip of the abrasive tool, by simply measuring the position and force. The basic resolution of the proposed NC machine tool is shown through the similar position and force measurement to one used in the conventional robot. Next, a CAD/CAM-based position/force control method with a fine-velocity pulse converter is proposed for a pulse-based servo controller that actuates the single-axis of the robot. We further introduce a systematic method for tuning a desired damping, which is coming from the critically damped condition used in a static force control system. The desired damping is the most important factor when an impedance model following force control is applied. Finally, to evaluate the characteristics of the NC machine tool, a profiling control experiment is conducted along a spiral path for a plastic lens mold with axis-symmetric concave areas. Consequently, it is confirmed that the proposed NC machine tool has a good performance, which can be applied to the finishing process of plastic lens molds.

Original languageEnglish
Pages (from-to)671-679
Number of pages9
JournalMechatronics
Volume19
Issue number5
DOIs
Publication statusPublished - Aug 2009
Externally publishedYes

Fingerprint

Machine tools
Force control
Plastic lenses
Controllers
Industrial robots
Molds
Robots
Abrasives
Damping
Compliance control
Position measurement
Force measurement
Position control
Computer aided manufacturing
Computer aided design
Tuning
Control systems
Sensors
Experiments

Keywords

  • CL data
  • Desktop NC machine tool
  • Fine-velocity pulse converter
  • Force control
  • Mold finishing
  • Small curved surface
  • Weak coupling control

ASJC Scopus subject areas

  • Mechanical Engineering
  • Electrical and Electronic Engineering
  • Computer Science Applications

Cite this

A desktop NC machine tool with a position/force controller using a fine-velocity pulse converter. / Nagata, Fusaomi; Hase, Tetsuo; Haga, Zenku; Omoto, Masaaki; Watanabe, Keigo.

In: Mechatronics, Vol. 19, No. 5, 08.2009, p. 671-679.

Research output: Contribution to journalArticle

Nagata, Fusaomi ; Hase, Tetsuo ; Haga, Zenku ; Omoto, Masaaki ; Watanabe, Keigo. / A desktop NC machine tool with a position/force controller using a fine-velocity pulse converter. In: Mechatronics. 2009 ; Vol. 19, No. 5. pp. 671-679.
@article{edcd6dc829e847fea9bc18edf1e2312c,
title = "A desktop NC machine tool with a position/force controller using a fine-velocity pulse converter",
abstract = "In this paper, a new desktop NC machine tool with the ability of compliance control is presented for finishing of metallic molds with small curved surface. The NC machine tool consists of a three-axis robot whose single one has a high position accuracy of 1 μm, which means that it can perform higher resolutions of position and force, compared to general industrial robots. A ball-end abrasive tool is attached to the tip of z-axis through a force sensor. In order to first confirm the application limit of an industrial robot to a finishing task, we evaluate the backlash that causes inaccuracy in position at the tip of the abrasive tool, by simply measuring the position and force. The basic resolution of the proposed NC machine tool is shown through the similar position and force measurement to one used in the conventional robot. Next, a CAD/CAM-based position/force control method with a fine-velocity pulse converter is proposed for a pulse-based servo controller that actuates the single-axis of the robot. We further introduce a systematic method for tuning a desired damping, which is coming from the critically damped condition used in a static force control system. The desired damping is the most important factor when an impedance model following force control is applied. Finally, to evaluate the characteristics of the NC machine tool, a profiling control experiment is conducted along a spiral path for a plastic lens mold with axis-symmetric concave areas. Consequently, it is confirmed that the proposed NC machine tool has a good performance, which can be applied to the finishing process of plastic lens molds.",
keywords = "CL data, Desktop NC machine tool, Fine-velocity pulse converter, Force control, Mold finishing, Small curved surface, Weak coupling control",
author = "Fusaomi Nagata and Tetsuo Hase and Zenku Haga and Masaaki Omoto and Keigo Watanabe",
year = "2009",
month = "8",
doi = "10.1016/j.mechatronics.2009.02.004",
language = "English",
volume = "19",
pages = "671--679",
journal = "Mechatronics",
issn = "0957-4158",
publisher = "Elsevier Limited",
number = "5",

}

TY - JOUR

T1 - A desktop NC machine tool with a position/force controller using a fine-velocity pulse converter

AU - Nagata, Fusaomi

AU - Hase, Tetsuo

AU - Haga, Zenku

AU - Omoto, Masaaki

AU - Watanabe, Keigo

PY - 2009/8

Y1 - 2009/8

N2 - In this paper, a new desktop NC machine tool with the ability of compliance control is presented for finishing of metallic molds with small curved surface. The NC machine tool consists of a three-axis robot whose single one has a high position accuracy of 1 μm, which means that it can perform higher resolutions of position and force, compared to general industrial robots. A ball-end abrasive tool is attached to the tip of z-axis through a force sensor. In order to first confirm the application limit of an industrial robot to a finishing task, we evaluate the backlash that causes inaccuracy in position at the tip of the abrasive tool, by simply measuring the position and force. The basic resolution of the proposed NC machine tool is shown through the similar position and force measurement to one used in the conventional robot. Next, a CAD/CAM-based position/force control method with a fine-velocity pulse converter is proposed for a pulse-based servo controller that actuates the single-axis of the robot. We further introduce a systematic method for tuning a desired damping, which is coming from the critically damped condition used in a static force control system. The desired damping is the most important factor when an impedance model following force control is applied. Finally, to evaluate the characteristics of the NC machine tool, a profiling control experiment is conducted along a spiral path for a plastic lens mold with axis-symmetric concave areas. Consequently, it is confirmed that the proposed NC machine tool has a good performance, which can be applied to the finishing process of plastic lens molds.

AB - In this paper, a new desktop NC machine tool with the ability of compliance control is presented for finishing of metallic molds with small curved surface. The NC machine tool consists of a three-axis robot whose single one has a high position accuracy of 1 μm, which means that it can perform higher resolutions of position and force, compared to general industrial robots. A ball-end abrasive tool is attached to the tip of z-axis through a force sensor. In order to first confirm the application limit of an industrial robot to a finishing task, we evaluate the backlash that causes inaccuracy in position at the tip of the abrasive tool, by simply measuring the position and force. The basic resolution of the proposed NC machine tool is shown through the similar position and force measurement to one used in the conventional robot. Next, a CAD/CAM-based position/force control method with a fine-velocity pulse converter is proposed for a pulse-based servo controller that actuates the single-axis of the robot. We further introduce a systematic method for tuning a desired damping, which is coming from the critically damped condition used in a static force control system. The desired damping is the most important factor when an impedance model following force control is applied. Finally, to evaluate the characteristics of the NC machine tool, a profiling control experiment is conducted along a spiral path for a plastic lens mold with axis-symmetric concave areas. Consequently, it is confirmed that the proposed NC machine tool has a good performance, which can be applied to the finishing process of plastic lens molds.

KW - CL data

KW - Desktop NC machine tool

KW - Fine-velocity pulse converter

KW - Force control

KW - Mold finishing

KW - Small curved surface

KW - Weak coupling control

UR - http://www.scopus.com/inward/record.url?scp=67349256370&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67349256370&partnerID=8YFLogxK

U2 - 10.1016/j.mechatronics.2009.02.004

DO - 10.1016/j.mechatronics.2009.02.004

M3 - Article

AN - SCOPUS:67349256370

VL - 19

SP - 671

EP - 679

JO - Mechatronics

JF - Mechatronics

SN - 0957-4158

IS - 5

ER -