Under-inflated tires are a major problem, wasting over 1 billion gallons of fuel per year in the US alone. Self-inflating tire systems aim to address this by automatically maintaining proper tire pressure levels. These systems use sensors to detect pressure drops and pneumatic components like compressors, valves, and distribution lines to re-inflate tires. When implemented widely, self-inflating tire systems could save significant amounts of fuel, reduce emissions, and prevent injuries from under-inflated tire-related accidents each year.

2.  27% of passenger cars and 32% of light trucks have at least one tire under
pressured by more than 25%. This results in 1.24 billion gallons of wasted fuel per
year (costing 3.7 billion USD).
 38% of cars in the EU drive on under-inflated tires. This results in 5.3 billon liters
of wasted fuel worth of 7 billion EUR, and an extra 12.3 million tons of CO2
released into the atmosphere.
 87% of all flat tires have a history of under-inflation.
 Every year, 4.5 million tires need to be replaced before their designed lifespan.

3.  A statistics showed that tires which are under inflated by as little as 2 psi reduce
fuel efficiency by 10 percent. Over a year of driving, that can amount to several
hundred dollars in extra fuel purchases.
 One of the reasons for Road Accident to occur is less or Insufficient Tire
Pressure. In the United States, 660 persons die and 33,000 are injured every year
due to this reason.
 Near about 10,000 injuries could be prevented per year if all vehicles were
equipped with tire pressure monitoring systems.
So, we can say that we require a system that is easy
and inexpensive to produce and would bring enormous
savings in fuel, pollution, and human lives when
implemented on a large scale.

5. Self-inflating tires allow a vehicle to adjust to the current
terrain for ideal performance and safety in those conditions.
Self-inflating tires are designed to constantly maintain tire
pressure at the proper level.
Self-inflating systems are designed more for slow leaks and
for optimizing performance and safety.
Self-inflation systems helps in re-inflation of tires to proper
level

6. Detect when the air pressure in a particular tire has dropped
Notify the driver of the problem.
Inflate that tire back to the proper level

7. Valve to isolate individual tires
Sensors for sensing the tire pressures
Air source, which is usually an existing onboard source
Getting the air from the air source to the tires, which is usually
through the axle Systems either use a sealed-hub axle with a hose from the
hub to the tire valve or else they run tubes through the axle with the axle
acting as a conduit.
 A pressure relief vent to vent air from the tire without risking damage
to the hub or rear-axle seals.

8. 1.Semi Tire Inflation System (STIS)
2.The Central Tire Inflation System (CTIS)
3.Tire Maintenance System and AIRGO
4.Automatic Central Tire Inflation System

9. The idea behind the CTIS is to provide
control over the air pressure in
each tire as a way to improve
performance on different surfaces.
By giving the driver direct control over
the air pressure in each tire,
maneuverability is greatly improved.
Another function of the CTIS is to
maintain pressure in the tires if there is a
slow leak or puncture. In this case, the
system controls inflation automatically
based on the selected pressure the
driver has set.

10. 1. A wheel valve
2. Electronic control unit
3. Pneumatic control unit
4. Operator control panel
5. Speed sensor
6. Pressure switch

12. A wheel valve is located at each wheel end.
Part of the wheel valve's job is to isolate the tire from the system when it's not
in use in order to let the pressure off of the seal and extend its life.
The wheel valve also enables on-demand inflation and deflation of the tires.
An electronic control unit (ECU) mounted behind the passenger seat is the brain
of the system.
It processes driver commands, monitors all signals through out the system and
tells the system to check tire pressures every 10 minutes.

13. The ECU sends commands to the pneumatic control unit, which directly
controls the wheel valves and air system.
The pneumatic control unit also contains a sensor that transmits tire
pressure readings to ECU.
An operator control panel allows the driver to select tire-pressure modes to
match current conditions.
This dash-mounted panel displays current tire pressures, selected modes and
system status.
When the driver selects a tire-pressure setting, signals from the control panel
travel to the electronic control unit and from there it goes to the pneumatic
control unit and finally reaches the wheel valves.

14. The CTIS includes a speed sensor that sends vehicle speed information to the
electronic control unit.
If the vehicle continues moving at a higher speed for a set period of times,
the system automatically inflates the tires to an appropriate pressure for that
speed.
This type of system uses air from the same compressor that supplies air to the
brakes.
A pressure switch makes sure the brake system gets priority, preventing the
CTIS from taking air from the supply tank until the brake system is fully charged.

15. The electronic control unit tells the
pneumatic control unit to check current
pressure and either inflate or deflate the
tire to the pressure selected by the
driver.
If the system determines that inflation
is needed, it first checks to make sure
that brake pressure reserves are where
they should be
If they are, it applies a slight pressure
to the wheel valve to allow inflation.
If the tires are over inflated, the
system applies a slight vacuum to the
wheel valve.
When the pneumatic control unit
reads that the appropriate pressure is
reached, the valve closes.

17. Air tank
Pressure Protection Valve
Shut-off valve
Filter
Control Box
Air-supply line
The overall system is made up of a
wheel-end assembly and a control
module

18. The wheel-end assembly includes
A flexible hose with check valves.
The check valves only allow air to flow
into each tire and ensure that while one tire
is being inflated, the other tires doesn’t lose
air pressure.
A stator (a non-rotating part) inside the
axle spindle
A flow-through tee that is attached to the
hubcap.
 A deflector shield keeps contaminants
such as dirt and water from entering the
wheel end.

19. The system control module includes
A shut-off valve to stop air from being sent to the
system.
A filter to remove moisture and contaminants.
The petcock releases system pressure so
maintenance can be performed.
A pressure protection valve so that it won't pull air
if the air supply is below 80 psi.
A system pressure adjustment knob allows for
adjustments to the overall system air pressure.
 A flow-sensing switch activates the indicator
light to let the driver knows if a significant amount
of air is being pumped into a tire, which would
indicate a potential puncture.

20. When a tire loses pressure, due to
a puncture or other seepage, a series
of check valves automatically detects
it.
The System then immediately
draws air from the vehicle’s
pneumatic system and directs it to
each tire requiring air.
The air pressure is delivered via the
trailer’s hollow axle housing.
The air then goes through the hub
assembly and into the tires. It is
completely isolated from the brake
system

21. The Self inflating system allows the users to adjust tire pressure to
suit prevailing conditions when traveling either on- or off-road.
This allows for an optimized tire pressure setting depending on
terrain type, and provides enhanced tire preservation, better tractive
performance, reduced soil compaction, improved fuel consumption,
and reduced overall operating cost.
Additionally, the system reduces downtimes associated with tire
malfunctions, such as minor punctures, leaks, or immobilization in
muddy terrain.

23. Michelin is working with several other companies to develop an active pressure-
management system called TIPM (Tire Intelligent Pressure Management).
This system has a compressor that automatically adjusts the pressure in each tire
while the vehicle is in operation to compensate for leaks and slow-leak punctures.
There are two systems in the early development stages that are oriented toward the
consumer market
 The EnTire system
 The Cycloid Air Pump system(Auto Pump).
The EnTire Self-Inflating Tire system uses a valve that pulls in air from
the atmosphere. It then pumps the air into the under-inflated tire using a peristaltic-
pump action. The goal is to constantly maintain a specific pressure.
The Cycloid Air Pump system has a small, wheel-hub-mounted pump that is powered
by the turning of the wheels. When the system's monitor detects a drop in pressure of
2 to 3 psi, it pumps air into the underinflated tire. Auto Pump has a warning system
that is activated when there is a puncture.

24. Improved Mobility
 Increased traction
 Higher Vehicle speeds
 Continuous vehicle operation in the presence of minor tire leaks
Longer tire life
Reduced fuel consumption
Protection against soil compaction
Increased driving stability
Enhanced productivity for field work
Improved pulling performance
Convenient push-button operation

25. Increases safety, comfort and fuel efficiency
Flexibility for drivers
Better option to reduce road accidents
Field programmable
Maintains appropriate pressure at higher speeds
Allows accurate selection of tire pressure for different terrains
and load conditions
Alerts driver of potential tire problems and system status