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18 EE|Times EUROPE

OPINION | SMART FACTORY

Tactile Cobots for a

Smart Factory

By Neil Bellinger, EU Automation automation and realizing smart factories.
Automating every process on the production
Small, lightweight, and designed to operate safely line has the potential to replace outdated
alongside humans, cobots are ideal for the modern work processes with smart robotic systems
and generate business growth for companies
smart factory. Some of the newest models include state- regardless of their size.
of-the-art sensors and software that allow them to feel PREVENTING COLLISION
and identify the objects being touched, increasing their There are currently several tactile sensors
dexterity and their suitability to a variety of applications. used in cobots, including piezoelectric,
piezoresistive, capacitive, and elastoresistive
types. Piezoelectric technologies are used for
The first cobot was invented in 1996 and was defined as “a gathering data from the cobot’s joints and
device and method for direct physical interaction between a person transmitting it to the controller. On the other
and a computer-controlled manipulator.” It was mainly designed hand, capacitive sensors can act as proximity
for basic pick-and-place applications and used motion resistance to sensors, allowing the cobot to slow down
communicate with the operator. when it detects the presence of an obstacle.
A recent study by the Massachusetts Institute of Technology Most detection sensors, such as area sen-
(MIT) found that human-robot cooperation reduced human idle time sors, are placed outside of the cobot, enabling
by 85%. At the same time, cobots have become more versatile and it to slow down or stop when human workers
can be used not only by big manufacturers looking to optimize the are close by. Although collisions might still
workflows for their complex production lines but also by SMEs who require flexible automation happen, these technologies ensure that the
solutions but may not have the resources to invest in large systems. impact is minimized. Tactile sensors are gen-
Modern cobots are also more technologically advanced. They can detect objects and people in erally embedded at the end of the cobot arm
their environment using vision sensors and slow down or stop to avoid an unintended contact. to make navigation more reliable, just as in a
Their touch-sensing technologies are evolving, too, increasing their applicability and safety in human arm, and are equipped with artificial
demanding applications that require handling delicate materials safely and precisely, such as in intelligence to avoid collision and allow the
health care. cobot to move more efficiently.
Regardless of the size of the business or the application, tactile cobots can provide benefits in In a 2021 research paper from Frontiers in
a variety of Industry 4.0 scenarios. Neurorobotics, Andrea Cherubini and David
Navarro-Alarcon found that robot skins
DELICATE OBJECT HANDLING equipped with tactile sensors will be most
Touch is essential for the effective manipulation of objects and for regulating the pressure suitable for ensuring safety, cooperation,
applied to an object to avoid damaging the product. With a more effective sense of touch, cobots and coexistence. Robot skin can be modeled
can be used in applications in which they interact with soft, fragile, or deformable objects. after the human central nervous system and
Tactile sensors can also be used to identify the features of objects and recognize defects and use feedback from detection sensors to infer
changes. For example, early research from the USC Viterbi School of Engineering used embedded motion commands. Robot skins could be used
tactile sensors with conductive fluid to simulate human touch, resulting in a robot able to differ- in surgical operations but also in smart facto-
entiate between the texture of wool and that of cotton. ries to avoid unwanted collisions, giving cobots
an enhanced ability to perceive their surround-
QUALITY ASSURANCE ings and facilitating interactions with humans.
Similarly, modern touch-sensing systems use tactile sensors to gather different information After the most recent advances in
about an object, such as shape, size, and texture, and transmit an electrical signal to the machine-vision technology, cobots are now
controller. They then measure the real characteristics of the objects, producing accurate infor- closer to gaining another sense that has
mation and spotting inaccuracies in products. been denied to them thus far: the sense of
This is particularly helpful in detecting defects on industrial production lines while cooper- touch. Advancements in tactile sensors allow
ating with quality inspectors. Because they are lightweight and easily deployable, cobots can be humans and machines to perform increasingly
moved to different points on the line and can inspect multiple products at once. They are also complex tasks in a collaborative environ-
more cost-effective than employing a team of highly trained inspectors or investing in conven- ment to achieve increased productivity and
tional machine-vision systems that lack precise detection technologies. accuracy. An agile work environment that
plays on the strengths of automation is key to
MACHINE TENDING a successful business but is also essential for
Tactile cobots are also valuable for precise object placement when loading parts into a fixture for achieving a smart and modern factory. ■
machine tending. Their sensing technology can find the exact part location and correct changes
in the position or size of the raw stock material by measuring the insertion force. Neil Bellinger is head of EMEA at EU
These various applications make cobots highly advantageous for achieving end-to-end Automation.

NOVEMBER 2021 | www.eetimes.eu