Top robotic applications and the EOAT that helps them get

TECHNOLOGY REPORT

Top robotic applications and the EOAT that helps them get the job done

SPONSORED BY

TABLE OF CONTENTSThere’s a robot for every job . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Elbow to elbow, into the cobot future . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Who will collaborate with cobots? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Get a handling on grippers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

AD INDEXFesto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

www.controldesign.com

Robotic Tooling 2

Electric linear axes ELGC and mini slides EGSC

One Integrated Platform for All of Your Automation NeedsOne platform for electric automation means seamless connectivity. From electromechanical actuators when joined with servo motors and servo drives to complete positioning systems, motion control solutions as well as entire handling systems and decentralized control solutions - always with the right software and interface.

www.festo.us/ea

http://www.festo.us/ea

In the popular imagination, robots are

large, dumb machines for doing dull,

muscular, repetitive tasks with precision

and accuracy . That’s only part of today’s

robotics world . Robots now come in many

sizes and configurations, with two to seven

axes . They can do simple or complicated

work, even surgery . For both factory and

process automation, there’s one to suit just

about any application or budget—anywhere

productivity can be enhanced by automat-

ing the movement of tooling or payloads,

or performing production tasks better or

faster . Payloads can be anything from com-

puter chips weighing a gram to locomotive

wheelsets weighing over a ton .

There is a vast assortment of end-of-arm

tooling (EAOT) to perform simple or com-

plex tasks, from grippers to multi-tool end

effectors . Robots are easier than ever to

integrate into any manufacturing or pro-

cessing environment, including food zones,

clean rooms and warehouses . All that said,

given this plethora of options, it’s more

important than ever to know which type

of robot best fits a company’s needs from

both a capabilities and cost standpoint . The


Robotic Tooling 4

There’s a robot for every jobHow to choose the right one

By Kevin Tardif, Festo

MULTI-AXIS ROBOTSFigure 1: Handling systems such as these are also classified as one-, two-, and three-axis robots, able to do high speed repetitive tasks with great accuracy.


Robotic Tooling 5

major types of robots—articulated, carte-

sian, SCARA, delta and cobot—each has

strengths and limitations . Understanding

these plusses and minuses is a necessary

starting point for making an initial invest-

ment in robotics (Figure 1) .

For a half century now, robots have been

the centerpiece of Industry 3 .0, which is

typically defined as the age of pre-digital

automation . They will be just as critical

if not more so as the world transitions to

Industry 4 .0, the digital automation age .

Robots have been changing the industrial

landscape since their introduction in the

1970s; they represented a quantum leap in

productivity, flexibility and reliability . Al-

most any repetitive motion involving the

movement of an object, be it tooling like a

welding gun or sheet metal being welded,

can be done faster and with greater preci-

sion and repeatability by a robot .

Early on, the image of the large, six-axis ar-

ticulated robot welding car and truck bod-

ies became fixed in the popular imagination .

Articulated robots have spread throughout

and beyond heavy industry with many im-

provements to the robot itself as well as the

development of more end effectors (end-

of-arm tooling) to address the wider need

for flexible automation . Articulated robots

are used in sectors as diverse as healthcare,

food and beverage, steelmaking, warehous-

ing—wherever there are repetitive or envi-

ronmentally or ergonomically challenging

tasks that can be accomplished faster, more

reliably and/or more cost-effectively . Ro-

bots are even assembling new robots .

NEW CONCEPTS IN ROBOTICSInitially, this robot revolution provided ma-

jor manufacturers like automakers with even

greater economies of scale, but offered

nothing to most small- and medium-sized

businesses . More recent developments in

robotics—cartesian (linear), SCARA and

delta robots, to name the most widely used,

as well the newest commercial innovation,

collaborative robots—have made automa-

tion accessible to businesses of almost

any size . Pneumatics often are integrated

into robots to actuate specific tasks, but

this piece focuses on electrically powered

robots . The BionicCobot is a project of the

Bionic Learning Network, which consists of

a team that investigates what the produc-

tion of the future can learn from nature .

Each type of robot comes with benefits and

limitations . For would-be new adopters of

robotics, it’s important to understand those

possibilities and pitfalls .

Robots come with one to seven axes, each

axis providing a degree of freedom . A two-

axis cartesian gantry typically plots on the

X-Y or Y-Z axes . A three-axis robot has

three degrees of freedom and performs its

functions through the X-Y-Z axes . These

small robots are rigid in form, and cannot

tilt or rotate themselves, although they can

have attached tooling that can swivel or


Robotic Tooling 6

rotate or adapt to the shape of a small pay-

load . Four- and five-axis robots have addi-

tional flexibility to rotate and tilt . A six-axis

articulated robot has six degrees of free-

dom—the flexibility to move objects in any

directions or rotate them in any orientation .

The latter type is generally chosen when an

application requires complex manipulation

of a large or heavy object .

Seven-axis robots are likewise fully free; the

seventh axis can allow additional orienta-

tions to maneuver tooling in tight spaces .

For example, such a robot can weld a car

body frame from the inside of the cabin by

inserting the end effector through the win-

dow opening and rotating it backwards 180

degrees . Seven-axis robots can operate up

closer to the work piece than other articu-

lated robots for potential space savings .

ARTICULATED ROBOTSThe popularity of six- and seven-axis articu-

lated robots reflects the great flexibility that

six degrees of freedom permit . They are

easy to program, come with their own con-

troller, and movement sequences and I/O

activation can be programmed via a user-

friendly teach pendant . In most applications,

only a basic knowledge of programming

is required to activate the robot . On the

hardware side, industrial articulated robots

can be relatively small or massive, capable

of handling loads like locomotive wheelsets

weighing over a ton . They can have sub-

stantial reach, over 3 meters with certain

models . This range of sizes makes articu-

lated robots suitable for a great number of

industries and applications involving making

or moving of materials or finished goods .

The articulated robot also has issues which

can restrict its utility or boost its cost pro-

file . A small-sized articulated robot is easy

to install; its base only need be bolted to a

frame or floor . But it can only lift so much or

reach so far . Where the job requires a larger

robot, civil engineering may be required to

ensure the structure can handle the weight

and torque caused by the load offset . An

articulated robot grows in reach and pay-

load simultaneously . The longer the reach,

the greater the payload it can manage, the

more space and engineering it requires, the

more it costs . Where an application involves

handling a small load over a long reach or a

heavy load over short distances, an articu-

lated robot may not be the most cost-effec-

tive solution .

By design, the articulated robot occupies

space and footprint that can’t be utilized for

other purposes . It also has singularities—lo-

cations and orientations in the surrounding

space it cannot access . These spatial limita-

tions require more complex safety precau-

tions since the robot will often be used in

zones where workers are present, even just

occasionally . Expensive devices, such as

zone scanners or safety mats are often nec-

essary, and more advanced functionalities

are then required, such as Safely-Limited


Robotic Tooling 7

Speed (SLS), or Safe Speed Monitor (SSM) .

The fact it requires its own controller to

handle the inverse kinematics—the conver-

sion of the multiple motor rotary positions

to usable cartesian coordinates and orienta-

tion in space—can also represent a double

dip from a hardware perspective, since in

certain cases the robot controller will need

to communicate with a higher-level PLC

on the production line . The bottom line is

an issue as well . Where the full flexibility of

a six-axis robot is not required, like many

pick-and-place or packaging applications,

other types of robots may do the job just as

well if not better, and at a lower cost .

CARTESIAN ROBOTSOne of those lower-cost alternatives is the

cartesian or linear robot . Its design con-

sists of an assembly of linear actuators

and sometimes a rotary actuator at the

end of arm for 3D applications . It’s easy to

install and maintain . The cartesian robot is

fully adaptable; strokes and sizes of each

axis can be customized to the application

(Figure 2) . Its reach and payload are inde-

pendent of each other, not intertwined . The

linear axis comes in a number of designs

which further adapt it to the function it per-

forms . For example, toothed belt actuators

allow high velocities while ball screw actua-

tors permit high precision and high feed

force, with pick rates up to 100/min fairly

typical of this type .

The adaptability of these handling systems

makes them price-optimized for a wide

range of straightforward applications where

CARTESIAN ROBOTSFigure 2: The cartesian robot is fully adaptable; strokes and sizes of each axis can be customized to the application.


Robotic Tooling 8

the dexterity of an articulated robot isn’t

required . That can involve extremely light

to very heavy parts placement, sorting or

box-loading, device inspection and much

more . Another major advantage and differ-

entiator of the cartesian robot is its excellent

space economy . It allows full access to the

footprint it occupies . There is no dead space

or singularities . Safety requirements are less

stringent and hence less costly since the

robot’s reach is limited to its small working

zone . Fences, door switches or light curtains

are often sufficient to ensure proper safety .

Little space around the robot is wasted .

Programming the cartesian robot doesn’t

usually require a specific motion control-

ler . Since the actuators are moving along

the workspace coordinate system axis,

interpolation of the motor position is not

required to determine the robot end-of-

arm position in space . In other words, no

calculation of inverse kinematics is needed .

The system PLC can often be used to con-

trol each axis directly, without the addi-

tion of a second controller . Also, cartesian

robot designs are readily scalable, and are

more often than not composed entirely of

standard, catalog components from servo

drives/motors and controller to slides and

grippers . That’s part of their affordability

and assures replacement parts are readily

available and quickly installed .

The cartesian robot’s main limitation is com-

parative inflexibility . It will easily accom-

modate linear movement in three axes, and

rotation around a fourth axis . However, one

has to add a motion controller to perform

rotation around more than one axis . Car-

tesian robots are rarely used in washdown

situations; they don’t provide sufficient

Robotic firstsThe first industrial robot was installed at a General Motors factory in New Jersey in 1961 . In 1969,

the Stanford Arm with six degrees of freedom was developed, making robots suitable for an ex-

traordinary range of tasks .

Where the job requires a larger robot, civil engineering may be required to ensure the structure

can handle the weight and torque caused by the load offset . An articulated robot grows in reach

and payload simultaneously . The longer the reach, the greater the payload it can manage, the

more space and engineering it requires, the more it costs .

Where an application involves handling a small load over a long reach or a heavy load over short

distances, an articulated robot may not be the most cost-effective solution .


Robotic Tooling 9

protection against water ingress . Precision

and thoroughness at installation is required .

Each axis must be carefully aligned, and sur-

face flatness must be adequate, especially

in larger systems . Cartesian robots are also

configured uniquely for each application .

While product or packaging format changes

can be performed quickly via the PLC, ad-

ditional reprogramming of the unit may

be required for more extensive changes in

the application . Finally, cartesian robots, if

used without a separate motion controller,

may require more programming time than

other robot types . Teach pendants are not

common, so programming of sequences

must be done in the PLC, with each axis ad-

dressed and commissioned individually .

SCARA ROBOTSSCARA robots have been designed and

optimized for light applications . The SCARA

acronym stands for selective compliance

articulated robot arm, although some use

assembly in place of articulated . They are

a streamlined version of articulated robots .

Their simplicity and small size make it easy

to integrate on assembly lines and they can

achieve quite impressive cycle times, with

high accuracy (Figure 3) . They are very ad-

ept at functions like inserting components

in spaces with tight tolerances while main-

taining their rigidity in such movements,

which makes them a cost-effective choice in

a lot of pick-and-place applications as well

as small parts handling . In performing such

tasks, there are accessories like feeding sys-

tems to maintain a constant supply of parts .

SCARA robots tend to be durable, requiring

little maintenance . Programming and com-

missioning is relatively easy and fast, using

the manufacturer-supplied teach pendant .

But with low cost come limitations . The

SCARA robot requires a dedicated robot

controller and is limited to planar surfaces .

It is generally restricted to three axes .

It may be the optimal solution where its

full capability—three or four degrees of

freedom—can be used, but if the job only

INTEGRATED ROBOTSFigure 3: A small robot, for example, a 2D or 3D gantry or cobot, can be integrated into a functional work station with a minimal footprint to perform functions such as testing or analysis or small parts handling. Such work stations can even be mobile, moved around a facility and plugged in wherever they are required.


Robotic Tooling 10

requires two (horizontal and vertical move-

ment, for example), the SCARA robot

cannot be reduced to a two-axis system,

making it less attractive than a cartesian

gantry-style robot from both the cost and

performance standpoint . Like the articu-

lated robot, the SCARA robot footprint

also extends further than the working zone,

resulting in a loss of functional space in and

around the unit .

DELTA ROBOTSThe delta robot is mainly renowned for its

speed, with pick rates up to 300/min . Its

mounting type puts it above its working

zone, limiting the loss of footprint . It is often

paired with a vision system to pick pieces

randomly placed in more complex sort-

ing and packing applications . Just like the

articulated and SCARA robot, it will gener-

ally be provided with a teach pendant for

easy programming (Figure 4) . Delta robots

are used in food production, but, like carte-

sian robots, in food zones they may require

additional shielding or separation from the

ambient environment .

On the other hand, the delta robot’s pay-

load capacity is generally much lower than

alternative technologies . Its wiry inverse

tripod design makes it less robust than

the other robot options, which reduces its

maximum payload weight . That perfor-

mance limitation is the price for achieving

such a high dynamic capability . The delta

robot has a quite limited working envelope .

Its design does not allow long reaches . Like

cartesian and SCARA robots, delta robots

are generally limited to four axes and can-

not provide the flexibility of an articulated

robot . Its complex assembly makes it more

difficult to maintain and repair . And if used

as a top mount on a large machine, there

may be a need to reinforce the machine

frame to bear the added weight .

COLLABORATIVE ROBOTSCollaborative robots, or cobots, are a rela-

tively recent development with a promis-

ing future in making possible safe human-

machine interaction . By allowing a direct

collaboration between a worker and robot,

they are adding a dimension to our under-

standing of how automation can be inte-

grated into industry . A cobot can be an ar-

ticulated, cartesian, SCARA or Delta robot,

although to date, most would be catego-

rized as articulated (Figure 5) . They come

with payload capacity of 4-35 kg, scaling up

in size and reach (also price) accordingly .

DELTA ROBOTFigure 4: The delta robot will generally be provid-ed with a teach pendant for easy programming.


Robotic Tooling 11

There are models with up to seven axes; the

latter can perform tasks that are particularly

challengingly ergonomically, and are even

being used as independent production line

robots . The difference between cobots and

other robots is their built-in safety features

that allow direct interaction with humans,

without protective shielding, safety curtains

or other safety features . Since they don’t

need fixed external safety barriers, some

cobots can be mounted on mobile plat-

forms to go wherever they are needed . It is

important to note that a safety evaluation

of the application has to be done, and while

the cobot itself might be safe, if the tool

being used on its end of arm is sharp, an ex-

ternal safety barrier likely would be needed .

Cobots are limited in speed and payload,

which disappoints some users looking for

a conventional robot that doesn’t require

expensive and space-consuming safety

protection . The greatest value of cobots

is where they can free a skilled employee

from the menial aspects of their job to

concentrate exclusively on the high value

aspects . For example, in complex device

assembly requiring a deft human touch,

a cobot can perform simple handling or

manufacturing tasks in support of the

worker, who can then focus exclusively on

the part of the job that makes full use of

their skills or knowledge . It’s a valid ap-

Tooling choices aboundFor smaller robot types, there are many styles of grippers – parallel, three-point, angled, radial,

swivel, bellows and increasingly, adaptive as well as vacuum and suction grippers

Another major advantage and differentiator of the cartesian robot is its excellent space economy .

It allows full access to the footprint it occupies . There is no dead space or singularities . Safety

requirements are less stringent and hence less costly .

SCARA robots tend to be durable, requiring little maintenance . Programming and commissioning

is relatively easy and fast, using the manufacturer-supplied teach pendant .

COLLABORATIVE ROBOTFigure 5: BionicCobot is a pneumatic develop-ment of the Bionic Learning Network. It is the result of a project which investigates what the production of the future can learn from nature.


Robotic Tooling 12

proach, providing the productivity boost

provided by the collaboration delivers a

reasonably quick payback of the invest-

ment . Otherwise, it can turn into what

amounts to an expensive vanity project .

Considerations in making your choice:

Understanding the application: In approach-

ing an investment in robotics, one should

consider all aspects of an application prior

to making a final selection . Here are some

factors to consider:

Reach and payload: The reach and payload

should be the first criteria, as it may imme-

diately shorten the list of suitable options .

On technical grounds alone, a large heavy

load would rule out any consideration of

lightweight handling technologies . On the

other hand, if the reach is long but the pay-

load weight is low, a lower cost cartesian

robot might suffice .

Flexibility: In an application requires five or

six degrees of freedom, an articulated robot

may be the only viable solution . If it is, one

option for the price sensitive business requir-

ing one or two robots might be repurposed

(used) units . However, for simpler applica-

tions, like small parts positioning and load-

ing, electronic parts insertion, and box and

machine tool loading—any application where

two or three axes are sufficient—why pay for

more axes than the application calls for?

Grippers mimic natureAdaptive grippers are a promising development that will help spur the growth of small robots,

and in particular, collaborative robots . Grippers like Festo’s DHEF and DHAS mimic nature in the

way they can adapt to objects of almost any shape, even those many times its size, and clasp

them with great sensitivity for smooth and flexible gripping .

The greatest value of cobots is where they can free a skilled employee from the menial aspects of

their job to concentrate exclusively on the high value aspects .

Recent innovations in adaptive gripper tech-

nology are expanding the applications for

small robots in the handling of pliable, fragile,

or irregularly shaped objects in the same way

that complex and multi-tool end effectors are

adding new roles for large articulated robots.


Robotic Tooling 13

Speed: Does the application require a high

pick rate, like that of a delta robot (up to

300/min is fairly common), or would a less-

er pick rate of cartesian gantry or SCARA

robot suffice? Here’s a real world example:

A machine builder constructed two virtu-

ally identical custom box loading/pallet-

izing machines for a dairy to load yoghurt

containers into boxes . Each machine was

intended for a different container format .

For the first machine boxing plastic tubs, a

high pick rate was required, so a top mount-

ed delta robot was installed for maximum

throughput . For the second machine box-

ing four-packs (2x2) of single serve cups,

a lower pick rate was sufficient, and the

machine builder was able to reduce the cost

to the end user by substituting a two-axis

cartesian gantry as the box loader .

Space and footprint: More and more, ma-

chine and production line footprints are key

planning concerns . Floor space is expensive,

and companies want to optimize their shop

floor layout . Cartesian and delta robots

provide a clear advantage over the other

technologies, since only vertical space is

lost, which is generally less critical .

Engineering and project development:

Design, assembly, installation and commis-

sioning time and expense should be fac-

tored into comparative costing, especially

incorporating a robot into a larger machine

or system . Delays in receiving and assem-

bling the robot could hold up the entire

project . There are online and software tools

that can minimize engineering and procure-

ment risks . Festo, for example, created the

Handling Guide Online, where an engineer

can design an application-specific cartesian

handling system like a 2D or 3D gantry in

20 minutes or less by entering just a few

data points, receive the CAD document for

it immediately at no cost, and in most cases

have the finished product delivered preas-

sembled and pre-tested in an average of

three to four weeks (Figure 6) .

Maintainability, repairability and availability:

Unscheduled downtime is every produc-

tion manager’s nightmare . Robots should be

relatively easy to maintain and repair . This is

a particularly important issue for businesses

which don’t have a large robotic fleet with

in-house technical know-how . Who is going

ONLINE GUIDEFigure 6: Festo’s Handling Guide Online simpli-fies and accelerates design of a single-axis, 2D or 3D handling system.


Robotic Tooling 14

to fix the robot? How long

will it take? What is the lead

time for delivery of critical

replacement parts like mo-

tors and controllers? Dur-

ing planning stages, these

issues are often overlooked

at one’s future peril .

Standardization—when

good is good enough:

Standardization within a

company or industry could

be a valid consideration on

business grounds, even if

the robot selected is not

the most ideally adapted

or even the cheapest but

capable of doing the job .

Sometimes, the well-trav-

elled path will prove to be

the one of least resistance

(and risk) .

CONCLUSIONSThe proliferation of robot

technologies has enabled

businesses of all sizes to

access the benefits of au-

tomation (Figure 7) . Which

one’s best? It’s usually the

one that is the best fit—not

just for achieving the pro-

ductivity gains from the

investment and satisfying

the technical requirements

of the application, but

also from the standpoint

of related issues like plant

safety, space utilization, and

of course, the going-in cost

and after-sales support .

Kevin Tardif is business develop-

ment specialist, electric automa-

tion, at Festo . Contact him at

kevin .tardif@festo .com .

BEST FITFigure 7: The proliferation of robot technologies has enabled busi-nesses of all sizes to access the benefits of automation.

Like many manufacturing entities, we find ourselves challenged to provide enough

workforce to run the lines the way we want to .

While the improved economy means fewer people are out of work, the downside is there

aren’t enough people to go around . Companies like ours are forced to look to improved

automation to meet our obligations .

While the general subject matter of trade shows differs from year to year, one common

thread unites them . As my colleagues and I walk through exhibits, the use of collaborative

robots has become the overwhelming theme of operation . This trend makes perfect sense

when faced with the prospect of a long drought in finding suitable candidates to perform

the repetitive tasks of assembly and packaging goods . If you can’t find people, then find

small, people-sized replacements . The biggest drawback to using robots in the workplace in

close proximity to actual people is the people themselves . The robot doesn’t care about the

objects within the workspace, but the people sure do .

Traditional robot applications involved erecting a secure physical barrier around the robot to

ensure that no harm would come to people who happen to wander into range . These earlier

applications would identify the extreme range of motion of the robot and then build a wall

around the possible path to keep automation and people from coming together by accident .


Robotic Tooling 15

Elbow to elbow, into the cobot futureCollaborative robots are here, as predicted

By Rick Rice, contributing editor


Robotic Tooling 16

As technology got more sophisticated, the

work envelope began to shrink with the

use of devices that would limit the reach

of the robot in particular directions . Today,

a robot application eliminates the physical

barrier altogether by relying on proximity-

sensing devices to avoid, slow down or stop

completely in the presence of a person or

other object .

The technology of presence sensing has

improved dramatically in just a few years .

Early versions involved physical contact

devices, such as a safety mat that relies on

pressure exerted by a weight applied to

two conductive plates separated from each

other by nonconducting layers .

When compressed, the conducting layers

will contact, triggering an output . Another

example of a presence-sensing device is a

two-hand operator station . In this arrange-

ment, operation of a device depends on

physical contact on two electronic pads

mounted far enough apart from one anoth-

er so as to prevent incidental contact with

one hand only . This ensures that a person is

far enough away from a moving object so

as to be deemed safe .

Both of the above examples have loopholes,

however . They are both looking for the

presence of a person in a particular posi-

tion . They don’t cover the scenario where

someone is in a position that is unexpected .

To extend this line of thinking, two other

types of safety devices came into play .

The first was a light curtain . The concept

is simple enough . Situate a series of send/

receive light beams across an opening and

completely surround any other means of

entry into the danger zone . Any one beam

broken would immediately disable the ma-

chine beyond the beam .

The beams are mounted in parallel and at a

fixed gap so as to detect any object larger

than the gap between successive beams .

The second approach broadens the scope

of the protected area by the use of an area

or safety zone scanner .

Earlier scanners were two-dimensional and

looked out from the base in a fixed path

that pulses back and forth across the width

of the covered area . Think of it as a light

curtain that rotates through an arc but with

only one beam .

Scanners have expanded to the point of

being three-dimensional and, in some cases,

can see pretty much any direction around

a central point, both up and down, much

like radar would look for aircraft at varying

altitudes .

Software manages the scanned area and

allows for exceptions to permit the scan-

ner to ignore inanimate objects within the

defined area .


Robotic Tooling 17

At this point, the conventional thinking of

a defined safety area with devices used to

monitor any entry/egress points can be

thrown out the window . The demand for

the use of a collaborative robot changes the

perspective from “keep the people out” to

“I know they are there, so let’s avoid them .”

The Automate Show put it this way:

• Past – Separate the human from the robot .

• Present – Improved human access to the

robot .

• Future – Close human/robot interaction .

The future is here, and the expectation

is that robots and humans will be close

enough to physically touch each other .

The challenge for technology developers

was to come up with ways to alter the be-

havior limits of the robot depending on the

degree of proximity to the human counter-

part . Area scanners are used to downgrade

the movement of the robot as the human

gets closer to the operating envelope, but

there comes a point where declining zones

from 100% safe down to 0% safe will still

bring everything to a halt .

This type of interaction is called near-term,

and the method of sensing to still allow

activity within close confines is much like

two humans working in the same space .

The “skin” of the robot becomes the sens-

ing device .

Popular means of sensing the skin of the ro-

bot aren’t that much different than our own

human sensitivities . Robots are designed

using tactile (touch), capacitive, proximity,

force, torque and ultrasonic sensors, as well

as pads with compression sensors .

This idea of “force field” sensing has dra-

matically changed the deployment of

robots and our conception of what humans

can do with robots as a means to produce .

One of the more intriguing developments

has been the force sensor . Force-sensing

resistors are polymer-thick films that reduce

in resistance with the more force applied to

the active surface .

The robot reacts to the reduced resistance

in much the same fashion that a person

would react to you if you were working in

very close proximity to each other and one

of you made accidental contact . Instinctive-

ly, we would pull back from the contact .

The collaborative robot works in much the

same manner . Once the sensation (presence

sensor) has ceased to be triggered, the ro-

bot will resume activity at a slow pace until

the normal work path can be ascertained .

Another interesting use of technology

is in torque sensors . When applied to a

robot, the torque used to carry out its

normal work path is monitored for any


Robotic Tooling 18

torque that is contrary to the known op-

erating parameters .

The contrary impulse could come from acci-

dental contact with the human in the oper-

ating area and could be as blunt as a direct

opposition to the travel path but might

come as an ever-so-slight brushing against

the robot appendage (axis) while on its way

to the destination .

Capacitive sensing comes in the use of mi-

croscopic level “paint” skins on the robot it-

self . The skin of the robot is a capacitor, and

touch by any object to the skin will result in

a change in the charge of the skin .

By monitoring this ambient capacitance, the

robot controller can respond to a change in

that status quo and slow down or stop, ac-

cording to the programmed algorithm .

While at the show with my colleague, I was

both impressed by the vast number of uses

of collaborative robots and cautiously opti-

mistic of their use .

For every collaborating exhibit, lurking

nearby was a well-dressed, non-descript

person whose job it was to quietly di-

rect people out of harm’s way from these

emerging technologies . For me, the fu-

ture is exciting, and the ability to enhance

our workforce with robotic technology is

encouraging as the struggle to keep lines

running in a booming economy is a bur-

den we share with many other producers .

However, perhaps it is old age talking,

but I am also a little leery yet of the space

around me and my complete confidence

in an inanimate object sharing the same

workspace as me .

The technology is advancing at a rapid

rate . However, whatever trepidation I

might have, my recollection of trade

shows are recent as only two years ago

is that vendors were talking of a future

where robots would be rubbing elbows

with humans, and, here we are, watching

demonstrations of exactly that premoni-

tion . Elbow to elbow, forward into the

battle we must go .

If you can’t find people, then find small, people-sized replacements .

The robots are coming . The robots are coming . Remember the charge that manufac-

turing will disappear because of this level of automation?

While a lot of the fears had been realized in the early years of robotics—welding comes to

mind in the automotive industry—the current state of economics in robotic functionality has

taken a turn .

Technology in this space has advanced tremendously over the past 20 years . The end ef-

fectors, which truly define the robot’s ability to perform tasks, are light years ahead of the

welder grips and high pressure tongs of yesteryear .

The main issue with a robot is based in the name: a robot that performs the same repetitive

task with eerie precision . The what-ifs have been dealt with using artificial intelligence (AI)

to some degree, but, by and large, if the robot encounters an anomaly, it stops, unable to

figure out what to do .

The original application of welding robots was to create a reduced-cost automobile frame

with repeatability and take the perceived inconsistencies of manual welding out of the

equation . GE Fanuc and the Karel programming language took the market by storm many

years ago .


Robotic Tooling 19

Who will collaborate with cobots?Employees are essential, as robots enter the workforce

By Jeremy Pollard, CET


Robotic Tooling 20

Today robotics looks so different, and they

also have a different purpose . Many stud-

ies have been done on the use of robotics

and their effects on manufacturing in recent

years . The outcome of these studies has

produced some interesting results .

Manual welding jobs have not in fact been

decimated . Welding jobs are plentiful with

not enough welders to fill the positions, but

that goes for a lot of hands-on positions . It

has been debated that the lack of versatility

in a robotic welding application creates the

market for an actual person .

The addition of vision however could

change that metric . Robot applications have

penetrated the commercial marketplace,

as well, with brick-laying robots, window-

washing applications and remote-controlled

heavy equipment . Drones are being called

robots as such, as well .

Robots are used in various aspects of man-

ufacturing, including packaging, palletizing,

sorting and the like, as well as more esoteric

functions such as farming . Anywhere there

is a repetitive task, a robot can be used .

However, companies are realizing that

robots can work together with people with

very profitable results . These are called col-

laborative robots, or “cobots .”

In a recent study, Statistics Canada (www .

statcan .gc .ca) has said companies that have

an increasing number of robots are also em-

ploying an increasing number of employees .

It suggests that robotics have not been

apocalyptic for labor overall (www .contr-

oldesign .com/roboteffects) . Where em-

ployees used to do the work, they have

been replaced by robots, but the number of

people to support the use of robotics has

increased, which can also be said of most

technology applied in industry .

So, the types of jobs that have been lost are

where the focus has been . Even managerial

jobs have been lost due to robotics since

more decision-making requirements have

been dropped down to the people doing

the work .

This is where cobots come in . They can

work in the same space as a person and

have safety devices as part of their environ-

ment, so the person working with the robot

is protected .

Cobots don’t operate on their own; they are

collaborative . The payback on using cobots

is typically less than a year, according to

the Robotic Industries Association (www .

robotics .org), which also states the level

of employee satisfaction with their jobs is

higher when a cobot is used .

The cobot becomes a friend, as such . It

performs the tasks that are perhaps dif-

ficult for the employee but really easy


Robotic Tooling 21

to implement with a cobot . The level of

sophistication and articulation in the cobot

space is very striking .

A big advancement is in torque and force

control . We have seen TV commercials

where a robot picks up a small item with

precision and without squashing it . Very

cool and very practical .

Robots are expensive, and there is a busi-

ness model out there that allows users to

rent robots . Robots as a service (RaaS) has

gained acceptance and market share in re-

cent years . The pandemic has really spurred

growth due to social distancing, so employ-

ees need that space, which has been taken

up by cobots .

This model lowers the cost of entry for

many, which would have been prohibitive

for most, but the hidden gem here is that

the vendor supports the hardware and

software, so the user doesn’t have to . It be-

comes an expense on the balance sheet .

Robot technology and applications have

come a long way since the first heavy-duty

robots of the 1970s and 1980s . The appli-

cations of today are so varied that what is

called a robot has blurred the lines of what

a robot looks like .

Their functionality, however, regardless of

the costumes they wear, cannot be under-

estimated .

Here come the robots .

Robots as a service (RaaS) has gained acceptance and market share in recent years .

From electronics manufacturing to automotive assembly, grippers have become

an important part of material handling processes in many industries . Their recent

growth is tied to the rise of robotics, including the need for robots to take on spe-

cial tasks and handle increasingly complex workpieces . The result is you now have more

grippers to choose from than ever . In North America alone, the gripper market is worth

roughly $100 million; and that number is expected to climb up to 5% each year .

With all the recent developments in robotics and gripping technology, it can be difficult to

know which gripper is best for your application . This piece will provide an overview of com-

mon gripper types, including mechanical, soft, adaptive, vacuum and magnetic . It will also

explore their key design features, as well as the benefits they offer in various applications .

UNDERSTAND WHAT YOUR APPLICATION DEMANDSTo help you select the right gripper, it’s important to first consider the nature of your task,

operating environment and workpiece, including its size, mass and material . Some key con-

siderations and questions to ask yourself include:

• Environmental . What temperature range will your gripper operate in? Will your gripper be

exposed to dirt, dust, oil or moisture?

• Industry . Does your application involve food or other hygienic workpieces? Will your grip-

per be exposed to cleaning processes? Does your application require antistatic materials?


Robotic Tooling 22

Get a handling on grippersExplore the key facts and features behind several gripping technologies, ensuring you select the best one for your industrial automation application

By Michael Guelker and Darren O’Driscoll, Festo


Robotic Tooling 23

• Design constraints . What direction of mo-

tion do you need? What is your applica-

tion’s maximum operating speed? How

large is your work space? Will your opera-

tors be sharing the space with collabora-

tive robots?

Other factors to keep in mind include up-

front, operating and maintenance costs, as

well as energy consumption . Grippers fall

into several categories, and your answers to

the above questions will help you determine

which type you need to get the job done as

safely and efficiently as possible .

MECHANICAL GRIPPERS— PROVEN RELIABILITY, FLEXIBILITY AND DURABILITYWhen it comes to handling applications,

pneumatic or electric mechanical grippers

are the most common . Pneumatic grippers,

which make up 90 percent of the market,

tend to be more lightweight and cost-effec-

tive than their electric counterparts . They

also feature higher grip forces, can handle

faster cycle rates and are more suitable

for harsh environments . Electric grippers,

on the other hand, offer greater precision,

affording end users with force and travel

control . At the same time, they tend to be

heavier due to the presence of a motor

and other internal components, which also

drives up their upfront costs .

Whether electric or pneumatic, mechani-

cal grippers fall into several design classes .

Pneumatic vs . electric grippers

Pneumatic Grippers (90% of market)

High grip force

Faster cycle rates

Basic control (open/close)

Lighter weight (end of arm)

Harsher environments (machining, welding)

Less expensive

Electric Grippers (10% of market)

Less grip force

Slower cycle rates

Flexible control (position, speed, force)

Heavier weight (motor)

Cleaner environments (medical, electronics)

More expensive


Robotic Tooling 24

Parallel grippers, for example, incorporate

fingers that pull directly apart . Two-finger

designs are the most common, making up

85 percent of the mechanical gripper mar-

ket, while three-finger designs are suitable

for handling round objects or performing

centering functions . Other examples include

radial and angular grippers, which feature

fingers that open at an angle . Radial grip-

pers open to 180 degrees, making them

suitable for applications involving varying

or inconsistent workpiece sizes . Angular

grippers tend to be faster than 180° designs

and open to roughly 30° .

Other important considerations when se-

lecting your mechanical gripper include the

gripping force, the guiding strength of the

jaws and the design of the gripper itself—

all of which depend on the nature of your

workpiece . In general, the longer the grip-

per fingers, the longer the lever arm, which

exerts more torque on the jaws . In addition,

flat finger designs provide a friction-based

grip for bulky or robust parts, while encap-

sulated designs work best for slippery parts

requiring more precision (Figure 1) .

We can apply many of these principles to a

recent application example, which involved

selecting a gripper for a food processing

application . The grippers had to pick up

large trays with dried pasta, rotate the trays

to dump the pasta onto a conveyor belt

and then return the trays to their stack . The

trays were large, roughly 4 x 2 feet . They

were also made of metal and weighed 15

pounds each . Other important consider-

ations included:

• Environmental . The grippers would oper-

ate at room temperature . The air was dry

but contained some dust from the pasta .

• Design constraints . The gripper had to be

able to handle high forces, as heavy trays

had to be rotated and shaken frequently .

To meet these requirements, we recom-

mended four heavy-duty HGPT mechanical

grippers . Thanks to their oval-shaped piston,

they provide up to 30-percent more grip-

FRICTION VS. SLIPPERYFigure 1: Flat finger designs provide a friction-based grip for bulky or robust parts, while encapsulated designs work best for slippery parts requiring more precision.


Robotic Tooling 25

ping force for heavy objects . They also in-

clude sealing air ports, preventing pasta par-

ticles from entering the gripper jaw guide .

ENABLING NEW AUTOMATION WITH SOFT AND ADAPTIVE GRIPPERSSoft and adaptive grippers can handle

workpieces of various shapes, sizes and

orientations, enabling automation in areas

where it previously didn’t exist . Because

they don’t have any sharp edges, these

types can handle food, glass and other deli-

cate objects without damaging or marking

the surface . They’re also ideal for small work

areas . Compared to mechanical variants,

however, soft and mechanical grippers are

less precise and operate at slower speeds .

They are also more susceptible to dirt, oil

and other contaminants .

Oftentimes, soft and adaptive grippers

incorporate innovative, tweezer-like designs

that can adapt to the contours of various

workpieces . For example, the Festo DHAS

features our Fin Ray structure, derived from

the movement of a fish tail . Two flexible

bands, which meet at the top like a triangle,

are connected by ribs . Using flex hinges,

these ribs are spaced at regular intervals,

creating a flexible, yet sturdy joint con-

nection . Available in lengths of 60, 80 and

120 millimeters, this series is ideal for pick-

and-place applications involving fragile or

irregularly shaped parts . It also incorporates

materials that comply with FDA standards,

making them a good fit for the food and

beverage industry .

REAP THE BENEFITS OF COMPRESSED AIR WITH VACUUM GRIPPERSAnother gripper technology is the vacuum

gripper, which combines suction cups and

vacuum generators . Compact and flexible,

these grippers are ideal for limited work

spaces and can handle a variety of objects

at high speeds . At the same time, however,

vacuum grippers can run up your mainte-

nance and operating costs; suction cups are

susceptible to quick wear, while generators

The parallel HGPT mechanical gripperOne example of a robust mechanical grip-

per is the Festo HGPT . Ideal for dynamic

motion applications involving medium-size

workpieces, this

series incorpo-

rates a T-slot

guiding design

that resists

torque . It also

incorporates

a sealing air

port to prevent

particles, dust and other contaminants from

entering the gripper jaws . And thanks to its

oval piston, the HGPT gripper maximizes

gripping force, providing double the force

for half the stroke length .


Robotic Tooling 26

consume high rates of compressed air and

can easily clog in the presence of dust and

other contaminants .

When it comes to suction cups, it’s impor-

tant to consider the nature of your work-

piece when selecting a material . Buna suc-

tion cups, for example, are ideal for oily or

plain workpieces, while silicon is suitable for

food, as well as hot or cold objects . In addi-

tion, polyurethane is a good choice for oily,

plain and rough workpieces; viton is suitable

for oily, plain and hot workpieces; and anti-

static buna is ideal for electronics .

Cup shape is also an important factor, es-

pecially when it comes to gripping objects

that are flat versus round, slim versus large

and sturdy versus delicate (Figure 2):

• Standard cups—for flat or slightly undulat-

ing surfaces .

• Bellows type—for pliable workpieces, as

well as surfaces that are beveled, domed

or round . This type is also suitable for

glass bottles, lightbulbs and other delicate

objects .

• Oval type—for slim or oblong workpieces .

• Extra deep—for round and domed work-

pieces .

Vacuum sources fall into two catego-

ries: electro-mechanical vacuum pumps/

blowers, as well as compressed air-driven

vacuum generators/ejectors . In general,

electromechanical pumps and blowers can

achieve high vacuum and suction rates—up

CUP SHAPEFigure 2: Cup shape is also an important factor, especially when it comes to gripping objects that are flat versus round, slim versus large and sturdy versus delicate.


Robotic Tooling 27

to 99 .99% and 1,200 cubic meters per hour,

respectively . At the same time, however,

these machines tend to be heavy and large,

requiring a reservoir with a complex pip-

ing system . Because they run continuously,

they also consume a lot of current, which

generates heat .

Compressed-air driven generators, espe-

cially single-stage units, overcome many

of these challenges . Compared to electro-

mechanical pumps and blowers, they are

more compact, lightweight and easier to

install . They include simpler piping systems,

require lower upfront costs and incorporate

no electrical connections, eliminating harm-

ful heat buildup . Although these units can

run up your air consumption rates, many

machines now come with energy-saving

functions, minimizing these effects .

In general, vacuum grippers are ideal for:

material handling applications, such as steel

fabricators, conveyors, electronic assem-

bly, industrial robotics; food and packaging

tasks, including canning, bottling, capping,

tray making, filling, bagging and sealing,

conveying, box making and labeling; and

printing applications, such as sheet feeding

and handling .

MAGNETIC GRIPPERS OFFER UNIQUE BENEFITSLastly, magnetic grippers from Magswitch

can handle metallic objects like sheets of

metal and are ideal for tasks like de-stacking,

fixture tooling and bin picking . Although

these grippers are limited to applications in-

volving ferrous metals, they require minimal

air consumption to actuate, achieving energy

savings up to 90% compared to suction cup

grippers . Other benefits include:

• Strong gripping . Magswitch magnetic

grippers use a shallow magnetic field that

enables material de-stacking .

• True ON/OFF . Magnets can be switched

completely off and stay clean; any metal

fillings left behind from production pro-

cesses instantly fall away .

• Fast . Magswitch magnetic grippers can

actuate in 250 milliseconds, saving valu-

able cycle time .

Making integration easy with gripper kits and software tools Many suppliers of automation and gripper

technologies offer gripper kits that can in-

terface directly with collaborative robots . A

true plug-and-play solution, these kits come

with sensors, accessories and software that

facilitate the commissioning and program-

ming processes .

Many suppliers also offer product sizing

and selection tools—all online . Simply enter

in some basic information about your work-

piece, including its weight and location, as

well as details about your gripper design,

motion requirements and mounting posi-

tion . The software tool will then output vari-

ous grippers that meet your requirements .


Robotic Tooling 28

• Safe . They also provide fail-safe perfor-

mance and will not drop parts in the event

of a power or air loss .

GETTING STARTEDNo matter your application, there’s an ideal

gripper for you . Ultimately, the right choice

depends on a number of variables, includ-

ing workpiece size and shape, operating

conditions, industry, energy requirements

and cost . In some cases, unique handling

applications may even require a custom

gripping device . If that’s the case, our engi-

neering team is here to help .

Michael Guelker and Darren O’Driscoll are in product

management, pneumatic drives, at Festo .

Documents

Top robotic applications and the EOAT that helps them get