We are Apogeeweb Semiconductor Electronic

WELCOME TO OUR BLOG

Home arrow Sensors arrow Operating Principle of Tire Pressure Sensors

arrow left

arrow right

Operating Principle of Tire Pressure Sensors

Author: Apogeeweb
Date: 26 Aug 2021
 304
tire pressure monitoring systems

Introduction

With the advancement of automobile technology, an increasing number of cars are equipped with car tire pressure monitoring systems, which provide us with a quick and real-time understanding of the car tire pressure, and we no longer have to worry about insufficient and excessive tire pressure before driving, and the car tire pressure monitoring system has brought great convenience to our car. Currently, most car tires are equipped with pressure sensors to detect pressure changes in order to ensure the safety of car driving. According to relevant statistics, tire pressure reaches a reasonable value, which can not only improve driving safety but also reduce fuel consumption. So, how does a car tire pressure sensor work? This article will introduce in detail.

Video: Tire Pressure Sensors

 

Catalog

Introduction

Ⅰ Principles of Tire Pressure Sensors in Automobiles

Ⅱ Design Background of TPMS

Ⅲ Tire Pressure Sensors in a Tire Pressure Monitoring System

Ⅳ Details of Tire Pressure Sensors in Direct Tire Pressure Monitoring System

Ⅴ Summary

Ⅵ Frequently Asked Questions about Tire Pressure Sensors

 

Ⅰ Principles of Tire Pressure Sensors in Automobiles

1.Strain Sensors in Automobiles

The principle of a strain sensor is primarily based on the resistive strain effect,when the conductor undergoes mechanical deformation due to external action, a corresponding change in resistance value occurs. Calculate the required pressure by first calculating the magnitude of strain using the relationship between the change in resistance value and the change in output electrical signal. The strain gauge pressure sensor is primarily used to measure the dynamic or static pressure of a flowing medium, such as the inlet and outlet gas or liquid pressure of power pipeline equipment, engine pressure, internal combustion engine pipeline pressure, and so on.

The most widely used strain gauge is the paste strain gauge (strain gauge). Its main disadvantages are small output signal, narrow linear range, and poor dynamic response (see resistance strain gauge, semiconductor strain gauge). However, due to the small size of strain gauge, many specifications of commercial strain gauge can be selected, and the form of elastic sensor can be flexibly designed to adapt to various applications, strain type pressure sensor made by strain gauge is still widely used. According to the different structure of elastic sensor, strain type pressure sensor can be roughly divided into strain tube type, diaphragm type, strain beam type and combined type.

Strain-Sensors-in-Automobiles

Figure:Strain Sensors in Automobiles

 

2.Piezoresistive Pressure Sensors in Automobiles
The piezoresistive pressure sensor's pressure sensitive element is a piezoresistive element that operates on the piezoresistive effect. The term "piezoresistive element" actually refers to the diffusion resistance created by integrated circuit technology on a semiconductor substrate. When subjected to external force, its resistance changes due to resistivity change. During normal operation, diffusion resistors must be attached to elastic elements, and monocrystalline silicon diaphragms are commonly used.

The piezoresistive pressure sensor's main advantages are its small size, relatively simple structure, good dynamic response, high sensitivity, and ability to measure micro pressures of more than ten Pascals. It is a relatively ideal one, and it is currently being developed and applied at a rapid pace. Sensor of pressure. Non-linearity and temperature affect the measurement accuracy of this sensor, affecting the size of the piezoresistive coefficient. Microprocessors are used in today's intelligent piezoresistive pressure sensor to compensate for nonlinearity and temperature. It integrates the sensor and computer on the same silicon chip using large-scale integrated circuit technology, and it has functions such as signal detection, processing, and memory. As a result, the sensor's stability and measurement accuracy are greatly improved.

Piezoresistive-Pressure-Sensors

Figure:Piezoresistive Pressure Sensor

 

3.Other Automotive Pressure Sensors

Furthermore, differential transformer type pressure sensors (LVDT) and surface elastic wave pressure sensors are available (SAW). SAW type pressure sensors have small size, light weight, low power consumption, high reliability, high sensitivity, high resolution, digital output, and so on. LVDT type pressure sensors have larger output, easy to digital output, but poor anti-interference. It is used to detect the pressure of an automobile suction valve and can operate reliably in high temperatures.

 

Ⅱ Design Background of TPMS

The tire pressure influences both the car's excellent performance and the length of the tire's service life. According to SAE (Society of Automotive Engineers) data, there are more than 260,000 traffic accidents caused by tire failure in the United States each year, with flat tires accounting for 70% of highway accidents. Furthermore, natural tire leakage or under-inflation is the leading cause of tire failure. Every year, approximately 75% of tire failures occur. The data also shows that in high-speed driving, punctures caused by tire failure are a major cause of traffic accidents.

Flat tires, the unseen killer, have caused numerous human tragedies and incalculable economic losses to the country and businesses. As a result, in order to reduce the number of traffic accidents caused by flat tires, the US federal government has mandated that automakers accelerate the development of TPMS ( Tire Pressure Monitoring System).

Figure-tire-pressure-sensor

Figure:Tire Pressure Monitoring System

 

Ⅲ Tire Pressure Sensors in a Tire Pressure Monitoring System

There are two main tire pressure monitoring system solutions: direct system and indirect system.

The direct tire pressure monitoring system measures tire pressure directly using the pressure sensor installed in each tire and displays and monitors the tire pressure. The system will automatically alert if the tire pressure is too low or if there is a leak.To monitor tire pressure, the indirect tire pressure monitoring system compares the speed difference between tires using the wheel speed sensor of the automobile abs system.The main disadvantages of this type of system are as follows: 1. The accurate instantaneous air pressure value of each tire cannot be displayed; 2. It is not possible to alarm when the pressure of the same axle, same side wheel, or all tires drops at the same time; and 3. Factors such as vehicle speed and detection accuracy cannot be taken into account simultaneously.

Figure-tire-pressure-sensor-system

Figure:Tire Pressure Sensors in a TPMS

 

Ⅳ Details of Tire Pressure Sensors in Direct Tire Pressure Monitoring System

There are two types of direct tire pressure monitoring systems: active and passive.

The active system makes capacitive or piezoresistive pressure sensors on silicon using mems technology. Each rim has a pressure sensor, and the signal is transmitted via radio frequency. It is set up in the wireless cab. The pressure sensitive signal is received by the receiving device, which then displays the current tire pressure after some signal processing.

The advantage of active technology is that it is relatively mature, and the modules developed can be applied to tires of various brands, but the disadvantages are also more noticeable. Its induction module requires battery power, posing a problem with system service life.

The passive tire pressure monitoring system's sensor is based on surface acoustic waves. A radio frequency electric field is used to generate a surface acoustic wave in this sensor. The surface acoustic wave changes as it passes through the surface of the piezoelectric substrate material. The change in the surface acoustic wave can indicate tire pressure. Although this technology does not require battery power, it does necessitate the integration of the transponder into the tire, and it can only be implemented if tire manufacturers agree on a common standard. The tire pressure monitoring system must detect abnormal tire pressure conditions, and it can only do so with high resolution and accuracy. Battery life is limited, and capacity is affected by temperature as well. It is best for the sensor to perform passive detection in order to improve system reliability. According to studies, the information collected by tire pressure sensors can be used to monitor vehicle suspension failures and correct navigation systems. As a result, the future automotive pressure sensor should be a passive intelligent sensor with multiple functions.

 

Ⅴ Summary

In recent years, automotive sensors have been the fastest growing and most widely used sensor category. The growth of the automotive industry encourages the rapid development of automotive pressure sensors. Sensor performance is improving as a result of advances in manufacturing and process technology, and tire pressure monitoring is becoming increasingly important.

 

Ⅵ Frequently Asked Questions about Tire Pressure Sensors

1.When should a tire pressure sensor be replaced?

TPMS sensors are designed to last for many years.5-10 years is a likely lifespan. Given their cost, most drivers will be inclined to replace TPMS sensors on an “as needed” basis.In other words, only once their batteries have expired, or other TPMS components have failed.

 

2.Is it safe to drive with tire pressure sensor fault?

No, driving with the TPMS Light on is not safe. It means one of your tires is underinflated or overinflated. This can cause undue wear on the tire, potentially lead to a tire failure, and cause a blowout dangerous to you and other drivers on the road.

 

3.How much does it cost to replace a tire pressure sensor?

The average cost for TPMS sensor replacement is between $207 and $257. Labor costs are estimated between $53 and $67 while parts are priced between $154 and $190. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.

 

4.How do you fix a tire pressure sensor?

Without starting the car, turn the key to the “On” position. Press the TPMS reset button and hold it until the light blinks three times, then release it. Start the car and let it run for 20 minutes to reset the sensor. You'll usually find the tire pressure monitor reset button beneath the steering wheel.

 

5.How do I know if my tire pressure sensor is bad?

A small light illuminates at the dashboard's display panel whenever there is a problem with the tire pressure sensors. It appears as a vivid yellow exclamation point inside of a U symbol; you'd be easily able to spot it. As soon as it turns on, the driver must check the tire for less or no air.

 

 

Best Sales of diode

Photo Part Company Description Pricing (USD)
A3977SLPTR-T A3977SLPTR-T Company:Allegro MicroSystems Remark:IC MTR DRV BIPOLR 3-5.5V 28TSSOP Price:
4000+: $2.25280
Inquiry
ACS724LLCTR-50AB-T ACS724LLCTR-50AB-T Company:Allegro MicroSystems Remark:SENSOR CURRENT HALL Price:
3000+: $2.01460
Inquiry
AS7C4096-15JI AS7C4096-15JI Company:Alliance Semiconductor Corporation Remark:Standard SRAM, 512KX8, 15ns, CMOS, PDSO36, 0.400 INCH, SOJ-36 Price:
Call
Inquiry
AM29LV160DT-70EC AM29LV160DT-70EC Company:AMD Remark:1MX16 FLASH 3V PROM, 70ns, PDSO48, MO-142DD, TSOP-48 Price:
Call
Inquiry
DAC8413BT-883C DAC8413BT-883C Company:Analog Devices Inc. Remark:IC DAC 12BIT QUAD V-OUT 28CDIP Price:
1+: $465.32000
Inquiry
AD5724AREZ AD5724AREZ Company:Analog Devices Inc. Remark:IC DAC 12BIT V-OUT 24TSSOP Price:
1+: $13.67000
10+: $12.56400
25+: $12.04360
100+: $10.09050
250+: $9.43952
Inquiry

Alternative Models

Part Compare Manufacturers Category Description
Mfr.Part#:UCC284DP-ADJ Compare: Current Part Manufacturers:TI Category:Voltage Regulators Description: TEXAS INSTRUMENTS UCC284DP-ADJ LDO Voltage Regulator, Adjustable, -15V to -3.2V in, 250mV drop, -1.25V to -15V/500mA out, SOIC-8
Mfr.Part#:UCC384DP-ADJG4 Compare: UCC284DP-ADJ VS UCC384DP-ADJG4 Manufacturers:TI Category:Voltage Regulators Description: TEXAS INSTRUMENTS UCC384DP-ADJG4 LDO Voltage Regulator, Adjustable, -15V to -3.2V in, 250mV drop, -1.2V to -15V/500mA out, SOIC-8
Mfr.Part#:UCC384DPTR-ADJ Compare: UCC284DP-ADJ VS UCC384DPTR-ADJ Manufacturers:TI Category:Voltage Regulators Description: LDO Regulator Neg -1.25V to -15V 0.5A 8Pin SOIC T/R
Mfr.Part#:UCC284DPTR-ADJ Compare: UCC284DP-ADJ VS UCC284DPTR-ADJ Manufacturers:TI Category:Voltage Regulators Description: LDO Regulator Neg -1.25V to -15V 0.5A 8Pin SOIC T/R

Ordering & Quality

Image Mfr. Part # Company Description Package PDF Qty Pricing (USD)
AD7798BRUZ AD7798BRUZ Company:Analog Devices Inc. Remark:IC ADC 16BIT SIGMA-DELTA 16TSSOP Package:16-TSSOP (0.173", 4.40mm Width)
DataSheet
In Stock:204
Inquiry
Price:
1+: $9.64000
10+: $8.70800
25+: $8.30240
100+: $6.88500
250+: $6.27752
500+: $5.87250
Inquiry
AD8009ARZ-REEL7 AD8009ARZ-REEL7 Company:Analog Devices Inc. Remark:IC OPAMP CFA 1 CIRCUIT 8SOIC Package:8-SOIC (0.154", 3.90mm Width)
DataSheet
In Stock:On Order
Inquiry
Price:
750+: $2.89600
1500+: $2.62450
Inquiry
AD8615AUJZ-R2 AD8615AUJZ-R2 Company:Analog Devices Inc. Remark:IC OPAMP GP 1 CIRCUIT TSOT5 Package:SOT-23-5 Thin, TSOT-23-5
DataSheet
In Stock:6500
Inquiry
Price:
250+: $2.04180
500+: $1.96800
1250+: $1.78350
Inquiry
ADA4898-2YRDZ-R7 ADA4898-2YRDZ-R7 Company:Analog Devices Inc. Remark:IC OPAMP VFB 2 CIRCUIT 8SOIC Package:8-SOIC (0.154", 3.90mm Width) Exposed Pad
DataSheet
In Stock:3000
Inquiry
Price:
1000+: $4.87200
Inquiry
ADATE305BSVZ ADATE305BSVZ Company:Analog Devices Inc. Remark:IC DCL 100TQFP Package:100-TQFP Exposed Pad
DataSheet
In Stock:136
Inquiry
Price:
1+: $52.84000
10+: $49.29800
25+: $47.23200
100+: $42.80400
Inquiry
ADF4113BRUZ-REEL7 ADF4113BRUZ-REEL7 Company:Analog Devices Inc. Remark:IC SYNTHESZR FREQ PLL RF 16TSSOP Package:16-TSSOP (0.173", 4.40mm Width)
DataSheet
In Stock:On Order
Inquiry
Price:
Call
Inquiry
ADUM261N0BRIZ ADUM261N0BRIZ Company:Analog Devices Inc. Remark:DGTL ISO 5000VRMS 6CH GP 16SOIC Package:16-SOIC (0.295", 7.50mm Width)
DataSheet
In Stock:On Order
Inquiry
Price:
1+: $5.57000
10+: $4.99800
25+: $4.72520
100+: $3.88500
250+: $3.48600
500+: $3.36000
1000+: $3.04500
Inquiry
AD586LQ AD586LQ Company:Analog Devices Inc. Remark:Series Voltage Reference IC ±0.05% 8-CERDIP Package:8-CDIP (0.300"", 7.62mm)
N/A
In Stock:On Order
Inquiry
Price:
Call
Inquiry

Related Articles

pinglun 0 comment

Leave a Reply

Your email address will not be published.

 
 
   
 
code image
Rating: poor fair good very good excellent

# 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z