Actuators in IoT

"The type of actuator you need is dependent on the work you need it to
do,"
• Actuators, which predate the digital era, are hardware
components at the heart of many IoT deployments.

• At the most basic level, an actuator is a device that

converts energy into movement.

In short, it is the part of any machine that makes

movement possible.
• An IoT device is made up of a Physical object (“thing”) + Controller
(“brain”) + Sensors + Actuators + Networks (Internet).

• An actuator is a machine component or system that moves or

controls the mechanism of the system.

• Sensors in the device sense the environment, then control signals are
generated for the actuators according to the actions needed to
perform.
Example
• An IoT deployment that regulates a refrigerator unit has sensors
to read the temperature.
• The sensors send the temperature data to the control system as
scheduled.
• The control system compares those temperature readings to the
programmed desired temperature range.
• If the temperature moves outside that preprogrammed range, the
control system sends a signal to an actuator to either turn on or off
the refrigeration.
• In many IoT deployments, the sensor, controller and actuator are
physically different components that communicate via wireless or
wired communication networks and an internet protocol.
• In other builds, a single physical device houses all three components.
A smart valve, for example, generally contains a sensor, controller and
actuator.

• Some IoT deployments center around the actuators themselves. In

such use cases, sensors monitor actuator performance, said Preston
Johnson, senior solution manager for asset integrity and reliability at
the intelligent edge at domain expert integrator CBT.
• "In the old world, you would have to have someone inspect the
actuators," Johnson said. “
• But, with the advent of IoT, we don't have to send inspectors in.
• We can get reports on how actuators are performing or whether they
need mitigation."
• Sensors can monitor, for example, the speed at which actuators open
and close valves in pipes, with controllers that analyze the
measurements to ensure the actuators properly work and to send an
alert when there is a malfunction.
How actuators are used in IoT
• In IoT, actuators enable a physical action based on data that originates
with one or more sensors.
• The conversion of sensor data to activity follows this sequence:
1. Sensors detect an event in the physical environment.
2. The sensors convert that information about the event into
electronic signals that travel to a control system, which has a
scheme to determine when and what movement is needed.
3. The controller tells the actuator to take the desired action.
4. The actuator takes the action by turning energy into a physical
force.
• A servo motor is an example of an actuator. They are linear or rotatory
actuators, can move to a given specified angular or linear position. We can use
servo motors for IoT applications and make the motor rotate to 90 degrees, 180
degrees, etc., as per our need.
• The following diagram shows what actuators do, the controller directs the
actuator based on the sensor data to do the work.

• The control system acts upon an environment through the actuator.

• It requires a source of energy and a control signal. When it receives a control signal, it
converts the source of energy to a mechanical operation.
• On this basis, on which form of energy it uses, it has different types given below.

Types of Actuators : Other actuators are –

Thermal/Magnetic Actuators
1. Hydraulic Actuators Mechanical Actuators
2. Pneumatic Actuators
3. Electrical Actuators
 Linear actuators
• Tools that generate movement along a straight line are known as
linear actuators.
• They typically appear in hydraulic or pneumatic equipment and might
be mechanical or electrical.
• A linear actuator is usually present in any device that needs to move
in a straight line.
This simple device is the basis for straight movement, while other
sophisticated linear actuators will include additional elements.
Rotary actuators
• Rotary actuators generate a circular motion as
opposed to linear actuators.
• Since most machines use these rotating components to
complete a turning movement, they are referred to as
"rotary" machines.
• Electric fans, windscreen wipers, and industrial
equipment moving products from one location to another
use rotational actuators.

• If a machine needs to move up, down, forward, or

backward, they are frequently employed in tandem with a
linear actuator motor.
• Hydraulic or pneumatic systems power several rotational
actuators in addition to the majority powered by
electricity.
Source of energy

• We may also arrange actuators by the system or power source that

drives it to separate various types of actuators further.
The most popular actuators categorized according to energy
sources are listed below: Types of Actuators :
1. Hydraulic Actuators
2. Pneumatic Actuators
3. Electrical Actuators
Hydraulic Actuators
Hydraulic Actuators
• With the help of a cylinder or fluid motor,
hydraulic actuators can provide mechanical
motion, producing linear or rotatory.
• A hydraulic actuator can make a significant
amount of force since liquids are essentially
challenging to compress.
Hydraulic actuators can exert a large amount
of force and move at a high speed.
• These characteristics suit use in construction
and manufacturing equipment.
• But they have high maintenance
requirements. For example, they can need
noise mitigation, and fluid leaks can reduce
their performance.
• A force is applied to the bottom of the piston, which is also inside the
hydraulic cylinder of the actuator, when the fluid enters the lower
chamber of the cylinder.
• The sliding piston is moved upward, and the valve is opened by the
pressure, which carries the piston in the opposite direction of the
force produced by the upper chamber's spring.
• The disadvantage of these actuators is the requirement for several
auxiliary components and the potential for fluid leakage.
Advantages

• It is helpful for clamping, welding, and similar activities.

• It is best utilized to raise or lower autos in car transport vans.
• A hydraulic actuator is capable of producing a lot of force and speed.

In the context of raising or

lowering autos in car transport
vans, hydraulic actuators are
used to lift and lower the
platform
Disadvantages

• The cost of hydraulic actuators is high.

• Leaks in the hydraulic fluid can reduce performance and create
cleaning problems.
• Heat exchangers, noise reduction technology, and high maintenance
systems are needed to complement its functioning.
Pneumatic actuators

• A pneumatic actuator uses energy formed by vacuum or compressed

air at high pressure to convert into either linear or rotary motion.
• Example- Used in robotics, use sensors that work like human fingers
by using compressed air.
• Compressed air energy is transformed into mechanical motion by pneumatic
actuators. In this instance, compressed air or gas is introduced into a chamber to
increase pressure.
• A straight or circular mechanical motion results when this pressure rises above
the necessary pressure levels compared to the atmospheric pressure outside the
chamber. This happens when the piston or gear is moved kinetically in a
controlled manner.
• Air cylinders, pneumatic cylinders, and air actuators are some examples. Since no
power source needs to be kept in reserve for operation, they are less expensive
and frequently more powerful than other actuators and can start or stop quickly.
• These actuators are commonly used in conjunction with valves to regulate the
amount of air that passes through the valve. They provide a significant amount of
force with only modest pressure changes.
• Advantages
• A pneumatic actuator is a cheap alternative and best utilized in high-
temperature situations - where using air is safer than chemicals.
• It is dependable, has a long working life, and requires little
maintenance.
• The motion starts and stops very quickly, making the actuator
reliable.
• Disadvantages
• The pressure loss could reduce its effectiveness.
• The air compressor ought to be operating nonstop.
• Air requires upkeep and is subject to pollution.
Electric actuators
Such actuators need electricity to function.
Famous examples include robotics equipment,
manufacturing gear, and electric vehicles. Since
the flow of electrical power is steady, electric
actuators produce accurate motion like pneumatic
actuators do.
Electric actuators
• a common option for IoT devices, convert energy into mechanical.
• Electric energy is less noisy in operation than other actuator types.
These actuators don't require fluid to run.
• Additionally, electric actuators offer high-control precision positioning
due to programmability.
• But these actuators can be expensive. They also may not be suitable
for extreme operating environments found in some manufacturing,
aerospace and military use cases.
• Advantages
• Due to an electric actuator's ability to automate industrial valves, it
has many uses across numerous sectors.
• Since there are no fluid leaks, it is safer to operate and makes less
noise.
• It offers the highest control and precise positioning and may be
reprogrammed.
• Disadvantages
• An electric actuator is costly to deploy and maintain.
• The type of environment has a significant impact on its working.
The two types of electric actuators are:
• i. Electromechanical actuators: When an
electric motor replaces the control knob or
handles on a mechanical actuator, the device is
called an electromechanical actuator. The
motor's rotating motion causes linear
displacement.
• ii. Electrohydraulic actuators: Electrohydraulic
actuators are self-contained actuators that
only use electrical power, unlike hydraulic
systems. In essence, they are utilized to
operate tools like multi-turn valves or electric-
powered construction and excavation
machinery.
• The electrical actuators were initially created
for the aerospace sector. However, today they
are used in many other industries - wherever
hydraulic power is employed.
 Thermal actuators
• A non-electric motor known as a thermal actuator produces linear
motion in reaction to temperature variations. A piston and a
thermally sensitive substance make up its essential parts. The
thermally sensitive materials start to expand in response to a rise in
temperature, which forces the piston out of the actuator.
• Similarly, when the temperature drops, the thermally sensitive
components within the contract cause the piston to withdraw.
• Besides operating latches, switches, and open or close valves, these
actuators can be utilized for other functions. They have a wide range
of uses, mainly in the solar, automotive, agricultural, and aerospace
sectors.
 Magnetic actuators

• Actuators that use magnetic effects to move a component are known

as magnetic actuators. The movement in magnetic actuators is
brought around by the magnetic field. It is known as the Joule effect
and sometimes occurs simply with a coil's placement in a static
magnetic field. The Laplace-Lorentz force causes constant motion of
the actuator.
• They often fall into the following groups: electromagnetic actuator,
moving coil actuator, magnet actuator, and moving iron actuator.
They are lightweight yet capable of making powerful movements.
 Mechanical actuators

• Mechanical actuators move by transforming one type of motion, such

as rotary motion, into another, such as linear motion. Consider a rack
and pinion as an example. A chain block hoisting weight is another
illustration in which a load is raised using the mechanical motion of
the chain.
• Mechanical actuators depend on the interactions of the structural
elements that make them up, such as gears and rails or pulleys and
chains. Among the benefits are high dependability, ease of use, more
straightforward maintenance, and improved positioning precision.
Actuators can be classified as hydraulic, pneumatic, or electronic.
Supercoiled polymer actuators

• Actuators made of supercoiled polymer are a relatively recent

addition to the various forms of actuators.
• Because they can mimic the motion of human muscle using a coil that
contracts and expands when heated or cooled, they are employed
in robotics and prosthetic limbs.
The anatomy of actuators in IoT

• An actuator is a machine or part of a machine used to convert

externally-available energy into motion based on the control signals.
• It is similar to how hands and legs enable humans to move around
and perform tasks.
• Actuators allow IoT devices to undertake various mechanical
movements.
• Typically, an actuator comprises:
Real-life examples of actuators in IoT

• Actuators are an integral part of the IoT ecosystem and have been
used long before IoT became a buzzword. Perhaps, these real-life
examples of actuators will ring a bell:
Escalators
• Originally known as "revolving stairs," the escalators' motion is
because of the actuating mechanism, which obtains its input from the
motion sensor.
• Once the sensor detects the movement, it activates the actuator that
kickstarts the movement of the escalator belt.
Sliding doors
• These are one of the most popular examples where one can
experience the functioning of a real-life actuator.
• The actuators used here get their input from motion sensors.
Whenever a sensor detects a movement, it activates the actuator,
resulting in the panels of the sliding doors moving sideways -
basically, open and shut.
 The advanced braking
Braking system systems used for
stopping moving
vehicles (e.g., cars,
buses, trucks) comprise
pneumatic actuators.

Such brakes are also

known as air brakes as
they improve the
optimal use of the
allocated space and
promote power
conservation.
Car seat adjustments
wonder how easily you can move
a car seat forward and backward
with the help of electrically-
powered motors?

Whenever you turn on the switch

placed on the side, an electrical
signal flows through the circuit
wires to power the motor, which,
in turn, acts as the actuator and
controls the seat's movement as
long as the circuit is complete.
Windshield wipers

• These use linear actuators. The vehicle's battery is connected to the

wiper switch, which works in sync with the wiper motor.
• On the other hand, the motor is attached to the actuator and the
wiper blade. The entire arrangement forms an electrical circuit that
operates the movement of the windshield wipers. When the wiper
gets switched on, that activates the actuator, inducing linear and
periodic motion of the wiper blades.
Over to you

• In a nutshell, actuators are devices that manipulate the physical

environment, such as the temperature control switches used in smart
homes.
• Actuators take the electrical input and convert it into tangible action.
• Naturally, actuators collect an enormous amount of data, which can
be valuable and useful to a business once it has been organized and
appropriately processed.