29-11-2012, 05:08 PM
Tire pressure monitoring systems
[attachment=41729]
INTRODUCTION
A tire pressure monitoring system (TPMS) is an electronic system designed to monitor the air pressure inside the pneumatic tires on various types of vehicles.
TPMS can be divided into two different types — direct (dTPMS) and indirect (iTPMS)
TPMS Reduces CO2 emission and reducing tire abrasion by an optimal inflation
working
The system contains a tire pressure monitoring system inside each tire, and an INITIATOR under each wheel well.
Anytime the engine is running, the TPMS control unit monitors wireless signals on all four tires and the system continuously.
If it detects low pressure, it alerts the driver by turning on the LOW PRESSURE INDICATOR for the appropriate tire on the multi-information TPMS INDICATOR display.
When the vehicle is running, a radio frequency band wave signal is transmitted continuously from the tire pressure sensor to the initiator to the control unit in the vehicle.
Direct TPMS
Direct TPMS employ pressure sensors on each tire, either internal or external.
The sensors physically measure the tire pressure in each tire and report it to the vehicle's instrument cluster or a corresponding monitor, sometimes also the temperature inside the tire.
These systems can identify under-inflation in any combination, be it one tire or all four, simultaneously.
dTPMS have the sensors mounted on the inside of the rims and the batteries are not exchangeable
Indirect tpms
Indirect TPMS do not use physical pressure sensors but measure air pressures by monitoring individual wheel rotational speeds and other signals available outside of the tire itself.
First generation iTPMS systems utilize the effect that an under-inflated tire has a slightly smaller diameter (and hence higher angular velocity) than a correctly inflated one.
These differences are measurable through the wheel speed sensors of ABS systems.
For heavy duty vehicles
For heavy-duty vehicles (Classes 7 and 8, gross vehicle weight greater than 26,000 pounds), most of the above-mentioned systems don't work well, requiring the development of other systems
The main issues on a large vehicle are
Lack of standardization: Tires are often purchased in bulk and moved between tractors over time, so a given TPMS system can only work with compatible sensors in the tires, creating logistic problems
Second, it usually should have the ability to cover dual sets of tires in some fashion.
it needs to have a wireless communication system that has an appropriate range and battery life
Benefits of TPMS
Fuel savings
Extended tire life: Under inflated tires are the #1 cause of tire failure and contribute to tire disintegration, heat buildup, ply separation and sidewall/casing breakdowns
Decreased downtime and maintenance: Under-inflated tires lead to costly hours of downtime and maintenance.
Improved safety: Under-inflated tires lead to tread separation and tire failure, resulting in 40,000 accidents, 33,000 injuries and over 650 deaths per year.
[attachment=41729]
INTRODUCTION
A tire pressure monitoring system (TPMS) is an electronic system designed to monitor the air pressure inside the pneumatic tires on various types of vehicles.
TPMS can be divided into two different types — direct (dTPMS) and indirect (iTPMS)
TPMS Reduces CO2 emission and reducing tire abrasion by an optimal inflation
working
The system contains a tire pressure monitoring system inside each tire, and an INITIATOR under each wheel well.
Anytime the engine is running, the TPMS control unit monitors wireless signals on all four tires and the system continuously.
If it detects low pressure, it alerts the driver by turning on the LOW PRESSURE INDICATOR for the appropriate tire on the multi-information TPMS INDICATOR display.
When the vehicle is running, a radio frequency band wave signal is transmitted continuously from the tire pressure sensor to the initiator to the control unit in the vehicle.
Direct TPMS
Direct TPMS employ pressure sensors on each tire, either internal or external.
The sensors physically measure the tire pressure in each tire and report it to the vehicle's instrument cluster or a corresponding monitor, sometimes also the temperature inside the tire.
These systems can identify under-inflation in any combination, be it one tire or all four, simultaneously.
dTPMS have the sensors mounted on the inside of the rims and the batteries are not exchangeable
Indirect tpms
Indirect TPMS do not use physical pressure sensors but measure air pressures by monitoring individual wheel rotational speeds and other signals available outside of the tire itself.
First generation iTPMS systems utilize the effect that an under-inflated tire has a slightly smaller diameter (and hence higher angular velocity) than a correctly inflated one.
These differences are measurable through the wheel speed sensors of ABS systems.
For heavy duty vehicles
For heavy-duty vehicles (Classes 7 and 8, gross vehicle weight greater than 26,000 pounds), most of the above-mentioned systems don't work well, requiring the development of other systems
The main issues on a large vehicle are
Lack of standardization: Tires are often purchased in bulk and moved between tractors over time, so a given TPMS system can only work with compatible sensors in the tires, creating logistic problems
Second, it usually should have the ability to cover dual sets of tires in some fashion.
it needs to have a wireless communication system that has an appropriate range and battery life
Benefits of TPMS
Fuel savings
Extended tire life: Under inflated tires are the #1 cause of tire failure and contribute to tire disintegration, heat buildup, ply separation and sidewall/casing breakdowns
Decreased downtime and maintenance: Under-inflated tires lead to costly hours of downtime and maintenance.
Improved safety: Under-inflated tires lead to tread separation and tire failure, resulting in 40,000 accidents, 33,000 injuries and over 650 deaths per year.