Industrial Robot basic

8/20/2019 Industrial Robot basic

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What is an Industrial Robot

• An industrial robot isa programmable,

multi-functionalmanipulator designedto move materials,parts, tools, or specialdevices throughvariable programmedmotions for theperformance of avariety of tasks.

• The robot, therefore,represents eibleautomation and so it!ts "ell in the frameof #I$


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Robot #onstruction

• The manipulator of an industrial robot consists of anumber of rigid links connected by %oints of di&erenttypes, controlled and monitored by a computer.

• The link assembly is connected to the body, "hich isusually mounted on a base.

• To a large etend, the physical construction of a robotresembles a human arm.

• A "rist is attached to the arm.

• To facilitate gripping or handling, a hand is attached atthe end of the "rist, this hand is called an end-e&ector.

• The complete motion of the end-e&ector is

accomplished through a series of motions andpositions of the links, %oints, and "rist.

• Robot construction is concerned "ith the types andsi'es of %oints, links and other aspects of themanipulator.


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(oints and )inks or Robots

• A joint of an industrial robot is similar to a %oint in thehuman body* It provides relative motion bet"een t"oparts of the body.

• +ach %oint, or axis as it is sometimes called, provides therobot "ith a so-called degree-of-freedom ../0 ofmotion.

• In nearly all cases, only one degree-of-freedom isassociated "ith a %oint.

• #onnected to each %oint aret"o links, an input link andoutput link.

• Links are the rigidcomponents of the robotmanipulator.

• The purpose of the %oint is toprovide controlled relativemovement bet"een the input


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(oints and )inks or Robots

• $ost of robots are mounted on a stationary base on the oor.

• The base and its connection to the !rst %oint is )ink 1.

• )ink 1 is the input link of %oint 2, the !rst %oint of a series of %oints used in the construction of the robot.

• The output link of %oint 2 is the link 2.

• )ink 2 is the input lint to %oint 3, "hose output link is link 3, andso forth.


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#lassi!cation of Robot (oints

• 4early all industrial robots have mechanical %oints that can beclassi!ed into one of the !ve types*

T"o types that provide translational motion. Three types that provide rotary motion

2. )inear (oint type ) %oint0

The relative movement bet"een the input link and theoutput link is a translational sliding motion, "ith the aesof the t"o links being parallel.


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3. rthogonal %oint type %oint0

This is also a translational sliding motion, but the inputlink and output links are perpendicular to each otherduring the move.


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5. Rotational (oint type R %oint0

This type provides rotational relative motion, "ith theais of rotation perpendicular to the aes of the input andoutput links.


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6. T"isting (oint type T %oint0

This %oint also involves rotary motion, but the ais ofrotation is parallel to the aes of the t"o links.


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7. Revolving (oint type 8 %oint, 8 from the “v” in revolving0

In this %oint type, the ais of the input link is parallel tothe ais of rotation of the %oint, and the ais of the outputlink is perpendicular to the ais of rotation


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#ommon Robot #on!gurations

• A robot manipulator can be divided into t"o sections*

A 9ody-and-arm assembly.

Wrist assembly.

• There are usually three degree-of-freedom associated "ith thebody-and-arm , and either t"o or three degrees-of-freedom "iththe "rist.

• At the end of the manipulator’s "rist is a device related to thetask that must be accomplished by the robot. The device, calledan end eector , is usually either*

2. A gripper for holding a "orkpart, or

3. A tool for performing some process.

• The body-and-arm of the robot is used to position the ende&ector, and the robot’s "rist is used to orient the end e&ector.


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9ody-and-Arm #on!gurations

• There are !ve basic con!gurations commonly available incommercial industrial robots*

2. :pherical ;olar0 #on!guration

This con!guration consists of a sliding arm ) %oint0 actuatedrelative to the body, that can rotate about a vertical ais T %oint0 and a hori'ontal ais R %oint0


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3. #ylindrical #on!guration

• This robot con!guration consists of a vertical column,relative to "hich an arm assembly is moved up and do"n.The arm can be moved in and out relative to the ais of thecolumn.

• A T joint to rotate the column about its ais. An L joint isused to move the arm assembly vertically along the column.An O joint is used to achieve radial movement of the arm.


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9ody-and-Arm #on!gurations9ody-and-Arm #on!gurations

5. #artesian Rectangular0 #on!guration

• It is composed of three sliding %oints, t"o of "hich are

orthogonal.


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9ody-and-Arm #on!gurations9ody-and-Arm #on!gurations9ody-and-Arm #on!gurations

6. (ointed-arm robot articulated0 #on!guration

• This robot manipulator has the general con!guration of a

human arm. The %oined arm consists of a vertical columnthat s"ivels about the base using a T %oint.

• At the top of the column is a shoulder %oint R %oint0, "hoseabout link connects to an elbo" %oint R %oint0


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7. :#ARA :elective #omplains Assembly Robot Arm0

• This con!guration is similar to the %ointed robot ecept that

the shoulder and elbo" rotational aes are vertical, "hichmeans that the arm is very rigid in the vertical direction, butcomplaint in the hori'ontal direction.


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Wrist #on!gurations

• The robot’s "rist is used to establish the orientation of theend e&ector. Robot "rists usually consists of t"o or threedegrees-of-freedom. The three %oints are de!ned as*

1. Roll , using a T %oint to accomplish rotation about the robot ’sarm ais.

2. Pitch, "hich involves up-and-do"n rotation, typically a R %oint.

3. a!, "hich involves right-and-left rotation, also accomplishedby means of an R-(oint.

• A t"o --/ "rist typically includes only roll and pitch %ointsT and R %oints0


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(oint 4otation :ystem

• The letter symbols for the !ve %oint types ), , R, T, and 80 canbe used to de!ne a %oint notation system for the robot

manipulator.• In this notation system, the manipulator is described by the

%oints that make up the body-and-arm assembly, follo"ed by the %oint symbols that make up the "rist.

• /or eample, the notation T)R*TR represents a !ve degree-of-

freedom manipulator "hose body-and-arm is made up of *2. A t"isting %oint (oint 2 < T0

3. A linear %oint %oint 3 < )0

5. A rotational %oint %oint 5 < R0

• The "rist consists of t"o %oints*

6. A t"isting %oint %oint 6 < T0

7. A rotational %oint %oint 7 < R0

• A colon separates the bod-and-arm notation from the "rist notati


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(oint 4otation :ystem - +ample

• esignate the robot con!gurations sho"n belo", using the %ointnotation scheme.

• :olution

2. This con!guration has t"o linear %oints, =ence, it is designated )).

3. This con!guration has three rotational %oints, =ence, it is

designated RRR.

5. This con!guration has one t"siting %oint and one linear %oint. This is

indicated by T)

( i t 4 t ti : t + l


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(oint 4otation :ystem - +ample• The robots sho"n belo" are e>uipped "ith a "rist that has

t"isting, rotary, and t"isting %oints in se>uence from the arm to theend-e&ector. ?ive the designation for the complete con!guration ofeach robot

• /or the robots sho"n above, the complete designation is as

follo"s*

W k 8 l


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Work 8olume

• The "ork volume "ork envelope0 of the manipulator is de!nedas the envelope or space "ithin "hich the robot can manipulate

the end of its "rist.

• Work volume is determined by*

2. the number and types of %oints in the manipulator body-

and-arm and "rist0,3. the ranges of the various %oints, and

5. the physical si'es of the links

• The shape of the "ork volume depends largely on the robot ’scon!guration

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Work 8olume

• A #artesian robot has a rectangular "ork volume

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Work 8olume• A cylindrical robot has a cylindrical "ork volume

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Work 8olume• A spherical robot tends to have a sphere as its "ork

volume

(oint ri e : stem


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(oint rive :ystem• A robot %oints are actuated using any of three possible

types of drive systems*

2. +lectric drive.

3. =ydraulic drive.

5. ;neumatic drive

• "lectric dri#e systems use electric motors as %ointactuators.

• $%dra&lic and 'ne&matic dri#e systems use devices suchas linear pistons and rotary vane actuators to accomplishthe motion of the %oint.

• ;neumatic drive is typically limited to smaller robots used in

simple material transfer applications.• +lectric drive and hydraulic drive are used on more-

sophisticated industrial robots.

• +lectric drive robots are relatively accurate compared "ithhydraulically po"ered robots. 9y contrast, the advantages of

hydraulic drive include greater speed and strength.

+nd +&ectors


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+nd +&ectors

• The end e&ector enables the robot to accomplish aspeci!c task. 9ecause of the "ide variety of tasks

performed by industrial robots, the end e&ector mustusually be custom-engineered and fabricated for eachdi&erent application.

• T"o categories of end e&ectors are

2. ?rippers.

3. Tools.• Tools are used in applications "here the robot must perform

some processing operation on the part. +amples of the toolsare*

2. :pot "elding gun.3. Arc "elding tool.

5. :pray painting gun.

6. Rotating spindle for drilling, grinding, and so forth.

7. Assembly tool e.g. automatic scre" driver0

+nd +&ectors


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+nd +&ectors

• ?rippers are end e&ectors used to grasp and manipulateob%ects during the "ork cycle

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Industrial Robot basic