Movatterモバイル変換


[0]ホーム

URL:


Jump to content
WikipediaThe Free Encyclopedia
Search

Talk:Parallel manipulator

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia
This article is ratedStart-class on Wikipedia'scontent assessment scale.
It is of interest to the followingWikiProjects:
WikiProject iconRoboticsMid‑importance
WikiProject iconThis article is within the scope ofWikiProject Robotics, a collaborative effort to improve the coverage ofRobotics on Wikipedia. If you would like to participate, please visit the project page, where you can jointhe discussion and see a list of open tasks.RoboticsWikipedia:WikiProject RoboticsTemplate:WikiProject RoboticsRobotics
MidThis article has been rated asMid-importance on theproject's importance scale.

high bandwidth motion capability?

[edit]

This article contains the phrasehigh bandwidth motion capability. I am in the process of disambiguating links to the wordbandwidth. I found this term a bit odd, because in context it seems to mean motion capable of very agile adjustments, but it is an unusual usage ofbandwidth. Is this a term commonly used this way? It does not seem to fit well with any of the existing definitions of that word, most of which fall into one of two categories: a range of frequencies, or a bit rate. If this is a common phrase used by mechanical engineers or robotics experts, perhaps an article likeBandwidth (robotics) needs to be created. Any help from an expert would be appreciated!CosineKitty (talk)22:03, 30 June 2008 (UTC)[reply]

I agree with your argument. I think the term "bandwith" is not appropriately well used here. I work in robotics and I never used the term "bandwith" regarding motion, only in data transmission. I think this sentence is better: "wide range of motion capability". Anonymous 08:45, 22 September 2008 (UTC)—Precedingunsigned comment added by147.83.48.86 (talk)
A range of frequencies. I suspect this iscontrol theory jargon, inserted by acontrol engineer. But I agree there is a better way of saying it.
By "high bandwidth", I'm pretty sure the original author is trying to say that the device has a high mechanical "natural frequency". The lower moving mass and higher stiffness of parallel configuration -- compared to a serial arm configuration using the same actuators -- allows us to drive the end effector in a square wave -- from point A to point B (rise time), stop there, and then move it back to point A (fall time) -- at a higher frequency, with lessovershoot.
This is useful when we want the robot to move lots of parts, one at a time, from some fixed location A to some other fixed location B.
But the original author, like myself, finds it all too easy to accidentally throw in technical jargon which makes it sound far more complicated than it really is. --68.0.124.33 (talk)21:14, 14 December 2008 (UTC)[reply]

Merge

[edit]

I vote for the merge intoparallel robot. ---BAxelrod (talk)03:58, 23 November 2008 (UTC)[reply]

Done. I merged the other way, fromparallel robot intoparallel manipulator. Mainly because I think this configuration is closer to the definition of amanipulator than the definition of arobot. Although it's even more like amechanical linkage. --68.0.124.33 (talk)21:22, 14 December 2008 (UTC)[reply]

Merge

[edit]

this page should me merged withDelta robotBatsu (talk)20:21, 20 October 2009 (UTC)[reply]

Oppose. Delta robots are a later development and although they are certainly related, they're sufficiently distinct in their own right.Andy Dingley (talk)10:29, 5 August 2010 (UTC)[reply]

Attention needed

[edit]

* Tidyup after merge - opening sentence in the lead seems in the wrong place* Expand - if possibleChaosdruid (talk)01:50, 8 August 2010 (UTC)[reply]

Problem in statement 1

[edit]

"Errors in one chain's positioning are averaged in conjunction with the others, rather than being cumulative."

This assumpiion is wide spread in the scientific community. It seems to be self-evident at a first sight. But..


Ilian Bonev sais:

ARE PARALLEL ROBOTS MORE ACCURATE THAN SERIAL ROBOTS?Sébastien Briot and Ilian A. BonevDépartement de génie de la production automatisée, École de technologie supérieure (ÉTS),1100, rue Notre-Dame Ouest, Montréal, Québec, H3C 1K3, Canadae-mail: ilian.bonev@etsmtl.ca

"ABSTRACTIt is widely claimed that parallel robots are intrinsically more accurate than serial robots because their errors are averaged instead of added cumulatively, an assertion which has not been properly addressed in the literature....."

"...So, in this example, one might indeed say that there is an averaging of errors in the parallel robot.However, when its end-effector is close to certain singularities, then the maximal position errorcould be several times larger than the input error (in the case of prismatic actuators). We therefore believe that this is, in general, too strong a statement and should be avoided. ..."— Precedingunsigned comment added byJoachimLlambiCorrectness (talkcontribs)18:45, 23 June 2016 (UTC)[reply]

Problem in statement 2

[edit]

"Because of the difficulty of such a non-linear command, the parallel manipulators are not yet used in high precision machining, despite their excellent mechanical properties (speed and precision)."

There is no lack in computer horsepower today that might be a problem here. Therefore, another issue should be stressed, please have a look at ciations below. The main problems are accuracy issues.

FIRST CITATION

ANNALS OF FACULTY  ENGINEERING HUNEDOARA – INTERNATIONAL JOURNAL OF ENGINEERING Tome X (Year 2012) – Fascicule 2(ISSN 1584 -2665)Zoran PANDILOV , Vladimir DUKOVSKI PARALLEL KINEMATICS MACHINE TOOLS: OVERVIEW‐ FROMHISTORY TO THE FUTURE

"Although more than 15 years passed since the firstcommercial kinematics machine tools were introduced, they are not widely accepted in the industry.From the beginning of their appearance it became obvious that implementation of their theoreticalcapabilities in practice introduces many new problems. Accuracy of the parallel kinematics machinetools has become one of their main weaknesses."


SECOND CITATION


Parallel Robots: Open ProblemsJean-Pierre MERLETINRIA, BP 93, 06902 Sophia-Antipolis, FranceE-mail: Jean-Pierre.Merlet@sophia.inria.fr


"4 CalibrationPractical use of the inverse and direct kinematicsrequires a perfect knowledge of certain geometric el-ements of the robot, particularly for accurate robots.Thus, position control of a Gough platform needs thelocations of the passive joints (a full model requires 132parameters [35]). Even if a quite accurate estimates ofthese parameters are available, a calibration may benecessary. Although this problem has been solved forserial robots, this is not the case for parallel robot."— Precedingunsigned comment added byJoachimLlambiCorrectness (talkcontribs)18:47, 23 June 2016 (UTC)[reply]

Rewrote section, Concomitant motion

[edit]

Rewrote section, Concomitant motion. This is an important topic. Thanks to the author for introducing the topic into this Wikipedia page and for providing the framework for its contents. This edit attempts to reword the main concepts introduced in this section. Changed title from `Concomitant motion’ to `Lower mobility’. This change emphasizes the causal relationship between ‘lower mobility’ and ‘concomitant motion’, i.e. concomitant motion is a consequence of lower mobility. Reorganized the section. Introduced the concept of `degrees of freedom’, to provide more background for people unfamiliar with the field of study. Motivated the importance of lower mobility manipulators. Talked about their advantages. Talked about their disadvantages, in terms of parasitic motion. Pointed out the importance of designing lower mobility manipulators, while being cognizant of the possible disadvantages of parasitic motion. Repeatedly refered to the successful Delta robot as an example, to elucidate the characteristics and significance of lower mobility manipulators in general. Fixed some obvious typos like, ` the mechanism may contain dependent and dependent motion’. Eliminated mathematical notation such as `∈ℝ^6’. Added more citations.— Precedingunsigned comment added byPjwiktor (talkcontribs)20:27, 3 December 2020 (UTC)[reply]

Retrieved from "https://en.wikipedia.org/w/index.php?title=Talk:Parallel_manipulator&oldid=1217068169"
Categories:

[8]ページ先頭

©2009-2025 Movatter.jp