Cartesian coordinate robot: Difference between revisions

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Revision as of 20:37, 28 December 2020

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{{short description|Industrial robot whose three principal axes of control are linear and are at right angles to each other}}

[[Image:Descartes configuration.png|thumb|right|[[Kinematic diagram]] of Cartesian (coordinate) robot]]

[[File:Hp 9862a.jpg|thumb|A plotter is an implementation of the Cartesian coordinate robot.]]A C'''artesianCartesian coordinate robot''' (also called '''linear robot''') is an [[industrial robot]] whose three [[principal axis (mechanics)|principal axes]] of control are linear (i.e. they move in a straight line rather than rotate) and are at [[right angle]]s to each other.<ref>{{Cite book|title=Mechatronics and Robotics Engineering for Advanced and Intelligent Manufacturing|last=Zhang|first=Dan|last2=Wei|first2=Bin|date=2016|publisher=Springer|isbn=978-3-319-33580-3|___location=Cham|pages=31}}</ref> The three sliding joints correspond to moving the wrist up-down, in-out, back-forth. Among other advantages, this mechanical arrangement simplifies the [[Robot control]] [[arm solution]]. It has high reliability and precision when operating in three-dimensional space.<ref>{{Cite book|title=Advanced High Strength Steel And Press Hardening - Proceedings Of The 4th International Conference On Advanced High Strength Steel And Press Hardening (Ichsu2018)|last=Mingtu|first=Ma|last2=Yisheng|first2=Zhang|date=2018|publisher=World Scientific|isbn=978-981-327-797-7|___location=Singapore|pages=526}}</ref> As a robot coordinate system, it is also effective for horizontal travel and for stacking bins.<ref>{{Cite book|title=Fundamentals of Robotics Engineering|last=Poole|first=Harry H.|date=2012|publisher=Van Nostrand Reinhold|isbn=978-94-011-7052-9|___location=New York|pages=35}}</ref>

[[File:Hp 9862a.jpg|thumb|A plotter is an implementation of the Cartesian coordinate robot.]]

== Configurations ==

{{refimprove|date=April 2017}}

[[File:Zaber motorized linear stage.jpg|thumb|Linear stage]]

A C'''artesian coordinate robot''' (also called '''linear robot''') is an [[industrial robot]] whose three [[principal axis (mechanics)|principal axes]] of control are linear (i.e. they move in a straight line rather than rotate) and are at [[right angle]]s to each other.<ref>{{Cite book|title=Mechatronics and Robotics Engineering for Advanced and Intelligent Manufacturing|last=Zhang|first=Dan|last2=Wei|first2=Bin|date=2016|publisher=Springer|isbn=978-3-319-33580-3|___location=Cham|pages=31}}</ref> The three sliding joints correspond to moving the wrist up-down, in-out, back-forth. Among other advantages, this mechanical arrangement simplifies the [[Robot control]] [[arm solution]]. It has high reliability and precision when operating in three-dimensional space.<ref>{{Cite book|title=Advanced High Strength Steel And Press Hardening - Proceedings Of The 4th International Conference On Advanced High Strength Steel And Press Hardening (Ichsu2018)|last=Mingtu|first=Ma|last2=Yisheng|first2=Zhang|date=2018|publisher=World Scientific|isbn=978-981-327-797-7|___location=Singapore|pages=526}}</ref> As a robot coordinate system, it is also effective for horizontal travel and for stacking bins.<ref>{{Cite book|title=Fundamentals of Robotics Engineering|last=Poole|first=Harry H.|date=2012|publisher=Van Nostrand Reinhold|isbn=978-94-011-7052-9|___location=New York|pages=35}}</ref>

[[File:Robot Portico tecno-840.jpg|thumb|Gantry robot]]

[[Robot|Robots]]<ref>{{Cite book|last=Craig|first=John|title=Introduction to Robotics. Mechanics and Control|publisher=Addison-Wesley|year=1989|isbn=978-0-201-09528-9|___location=|pages=}}</ref><ref>{{Citation|last=Dagalakis|first=Nicholas G.|title=Industrial Robotics Standards|url=http://dx.doi.org/10.1002/9780470172506.ch24|work=Handbook of Industrial Robotics|pages=447–459|place=Hoboken, NJ, USA|publisher=John Wiley & Sons, Inc.|isbn=978-0-470-17250-6|access-date=2020-12-28}}</ref> have [[Mechanism (engineering)|mechanisms]] consisting of rigid links connected together by [[Kinematic pair|joints]] with either linear (prismatic ''P'') or rotary (revolute ''R'') motion, or combinations of the two.  Active prismatic ''P'' and active revolute ''R'' joints are driven by motors under programmable control to manipulate objects to perform complex automated tasks. The linear motion of active prismatic ''P'' joints may be driven by rotary motors through gears or pulleys. Cartesian coordinate robots are controlled by mutually [[Perpendicular#:~:text%3DIn%20elementary%20geometry%2C%20the%20property%2Cintersect%20at%20a%20right%20angle.|perpendicular]] active prismatic ''P'' joints that are aligned with the ''X, Y, Z'' axes of a [[Cartesian coordinate system]]<ref>{{Cite journal|last=Descartes|first=Rene|date=2009-01-01|title=Discourse on the method of rightly conducting the reason, and seeking truth in the sciences|url=http://dx.doi.org/10.5214/ans.0972.7531.2009.160108|journal=Annals of Neurosciences|volume=16|issue=01|pages=17–21|doi=10.5214/ans.0972.7531.2009.160108|issn=0972-7531}}</ref><ref>{{Cite journal|last=Klubertanz|first=George P.|date=1969|title=Discourse on Method, Optics, Geometry, and Meteorology. By Rene Descartes. Trans, with Introd. Paul J. Olscamp|url=http://dx.doi.org/10.5840/schoolman196946493|journal=The Modern Schoolman|volume=46|issue=4|pages=370–371|doi=10.5840/schoolman196946493|issn=0026-8402}}</ref>.  Although not strictly `robots’, other types of [[Manipulator (device)|manipulators]], such as computer [[Numerical control|numerically controlled]] (CNC) machines, [[3D printing#Processes%20and%20printers|3D printers]] or [[Plotter|pen plotters]], also have the same  mechanical arrangement of mutually perpendicular active prismatic ''P'' joints.

'''Joint topology''' A single kinematic linkage of links and joints connects a moving object to a base of [[Serial manipulator|serial manipulators]]. Multiple kinematic linkages (limbs) connect the moving object to the base of [[Parallel manipulator|parallel manipulators]]<ref>Z. Pandilov, V. Dukovski, Comparison of the characteristics between serial and parallel robots, Acta Technica Corviniensis-Bulletin of Engineering, Volume 7, Issue 1, Pages 143-160</ref>.  Most Cartesian coordinate robots are fully serial or a combination of serial and parallel connected linkages.  However, there are [[Cartesian parallel manipulators|some]] Cartesian coordinate robots that are fully parallel-connected<ref>{{Cite journal|last=Gosselin|first=Clement M.|last2=Masouleh|first2=Mehdi Tale|last3=Duchaine|first3=Vincent|last4=Richard|first4=Pierre-Luc|last5=Foucault|first5=Simon|last6=Kong|first6=Xianwen|date=2007|title=Parallel Mechanisms of the Multipteron Family: Kinematic Architectures and Benchmarking|url=http://dx.doi.org/10.1109/robot.2007.363045|journal=Proceedings 2007 IEEE International Conference on Robotics and Automation|publisher=IEEE|volume=|pages=|doi=10.1109/robot.2007.363045|isbn=1-4244-0602-1|via=}}</ref><ref>{{Cite journal|last=Gogu|first=Grigore|date=2004|title=Structural synthesis of fully-isotropic translational parallel robots via theory of linear transformations|url=http://dx.doi.org/10.1016/j.euromechsol.2004.08.006|journal=European Journal of Mechanics - A/Solids|volume=23|issue=6|pages=1021–1039|doi=10.1016/j.euromechsol.2004.08.006|issn=0997-7538|via=}}</ref><ref>{{Cite journal|last=Wiktor|first=Peter|date=2020|title=Coupled Cartesian Manipulators|url=http://dx.doi.org/10.1016/j.mechmachtheory.2020.103903|journal=Mechanism and Machine Theory|volume=|pages=103903|doi=10.1016/j.mechmachtheory.2020.103903|issn=0094-114X|via=}}</ref>.

[[Cartesian coordinate]] robots with the horizontal member supported at both ends are sometimes called Gantry robots; mechanically, they resemble [[gantry crane]]s, although the latter are not generally robots. Gantry robots are often quite large.

'''Degrees of freedom''' Since they are driven by linear active prismatic ''P'' joints, Cartesian coordinate robots typically manipulate objects with only translation ''T'' [[Degrees of freedom (mechanics)|degrees of freedom]].  However, [[Cartesian parallel manipulators|some]] Cartesian coordinate robots also have rotational ''R'' degrees of freedom.

'''Construction''' Each axis of a Cartesian coordinate robot typically is a [[linear stage]] consisting of a linear [[actuator]] geometrically parallel with [[Linear-motion bearing|linear bearings]]. The linear actuator is typically between two linear bearings spaced apart from each other to support [[Moment (physics)|moment]] loads.  Two perpendicular linear stages stacked on top of each other form an [[X-Y table|XY table]].  Examples of XY tables include the XY axes of [[Milling (machining)|milling machines]] or precision positioning stages.   At least one of the linear stages of [[Cantilever|cantilevered]] Cartesian coordinate robots is supported at only one end. Cantilevered construction provides accessibility to parts for pick-and-place applications such as [[laboratory automation]] for example. Cartesian coordinate robots with the horizontal member supported at both ends are sometimes called Gantry robots; mechanically, they resemble [[Gantry crane|gantry cranes]], although the latter are not generally robots. Gantry robots are often quite large and may support heavy loads.

==Applications==