Tyre Pressure Monitoring System (TPMS)

  • by 0
  • June 24, 2020
Tyre Pressure Monitoring System (TPMS)

Tyres do not typically carry the weight of our vehicles but it is only the air inside them does. There are three basic elements which determine the load capacity of a tyre namely, the size of the air chamber formed between the tyre and wheel, the strength provided by the engineering construction of tyre to hold air pressure, and the amount of air pressure actually in the tyre.

Fig No 1

Most flat tyres or zero pressure air  are the result of slow leaks that go unnoticed and allow the tyre's air pressure to escape over time (Fig.1). Therefore, monitoring tyre air pressure in real-time is extremely important. Fortunately, in these days we practically have such devices inbuilt in tyre, called, Tyre Pressure Monitoring System or TPMS, Fig.2. Run Flat Tyres (RFT) are typically designed passenger car tyre or light truck tyres or SUVs to run even when they are flat  or when there is zero inflation pressure. It is more of a safety issue - it's design allows you to continue driving in deflated condition to a point were you can safely get the tyre changed or repaired. To all RFT, therefore, it is was required to fit in TPMS system (Fig.2) to indicate driver that the tyre is running with low pressure or tyre is failed and is under zero pressure now.

Fig No 2

Tyre pressure sensor (pressure transmitter) converts the physical quantity 'tyre pressure' into an industry-standard signal , that enables the driver if the tyre pressure is becoming low or the tyre has already failed during driving (Fig.2). Mandates for TPMS technology in new cars have been continued to proliferate in the 21st century in Russia, the EU, Japan, South Korea and many other Asian countries. As of November 2014, the above fitment rate stands had been to ~ 54% of passenger cars.

 

Tyre pressure has profound influence on vehicle safety and efficiency. Tyre-pressure monitoring (TPM) was first adopted by the European market as an optional feature for luxury passenger vehicles in the 1980s. The first passenger vehicle to adopt TPM was the Porsche 959 in 1986, using a hollow spoke wheel system. In 1996 Renault used the Michelin PAX system. In the United States, TPM was introduced by General Motors for the 1991 model year for the Corvette in conjunction with Goodyear run-flat tyres. The system uses sensors in the wheels and a driver display which can show tyre pressure at any wheel, plus warnings for both high and low pressure (Fig.2). It has been standard on Corvettes ever since.

The dynamic behavior of a pneumatic tyre is closely connected to its inflation pressure. Key factors like braking distance and lateral stability require the inflation pressures to be adjusted and kept as specified by the vehicle manufacturer. Extreme under-inflation can even lead to thermal and mechanical overload caused by overheating and subsequent, sudden destruction of the tyre itself. Additionally, fuel efficiency and tyre wear are severely affected by under-inflation. Tyres do not only leak air if punctured, they also leak air naturally (air permeability), and over a year, even a typical new, properly mounted tyre can lose from 3 to 9 psi, roughly 10% or even more of its initial pressure.

Fig No 3

Maintaining proper tyre inflation is essential to vehicle handling, overall tyre performance, and load carrying capability. A properly inflated tyre will reduce tread movement, reduce rolling resistance, and increase water dispersion. Reduced tread movement gives the tyre a longer tread life. Reduced rolling resistance, the force required to roll a loaded tyre, results in increased fuel efficiency. Increased water dispersion decreases the possibility of hydroplaning. Both over-inflation and under-inflation can cause premature tread wear and possible tyre failure. Over-inflation can result in decreased traction and the inability to absorb road impact. Overinflated tyres will show premature wear in the centre of the tread. On the other hand, under inflation will cause sluggish tyre response, decrease fuel economy, excessive heat buildup, and tyre overload. An under inflated  tyre will show premature wear on both outside shoulders (Fig.3).

 

The European Union reports that an average under-inflation of ~ 6psi ,  produces an increase of fuel consumption of 2% and a decrease of tyre life of 25%. The European Union concludes that tyre under-inflation today is responsible for over 20 million liters of unnecessarily-burned fuel, dumping over 2 million tones of CO2 into the atmosphere, and for 200 million tyres being prematurely wasted worldwide. In 2018, a field study on TPMS shows that TPMS fitment reliably prevents severe and dangerous under-inflation and hence yields the desired effects for traffic safety, fuel consumption and emissions. The above study also showed that there is no difference in effectiveness between dTPMS and iTPMS and that the TPMS reset function does not present a safety risk.

The Tyre Pressure Monitoring System (TMPS) is an electronic system in the vehicle that monitors tyre air pressure and alerts the driver when it falls dangerously low. This system involves a pressure sensor (Fig.4) fitted in tyre air filling valve. However, a given TPMS system can only work with compatible sensors in the tyres.  

 

Fig No 4

TPMS notifies on vehicle dash board when vehicle’s tyre pressure is low or is going flat and this help to maintain proper tyre pressure (Fig.2). TPMS can directly or indirectly, increase vehicle safety on the road by improving your vehicle’s handling, decreasing tyre wear, reducing braking distance and bettering fuel economy. The significant advantages of TPMS are summarized as follows:

  • Fuel savings: For every 10% of under-inflation on each tyre on a vehicle, a 1% reduction in fuel economy will occur. In the United States alone, the Department of Transportation estimates that under inflated tyres waste 2 billion US gallons (7,600,000 m3) of fuel each year.
  • Extended tyre life: Under inflated tyres are the major cause of tyre failure and contribute to tyre disintegration, heat buildup, ply separation and sidewall/casing break downs. Further, a difference of 10 psi in pressure on a set of duals literally drags the lower pressured tyre 2.5 metres per kilometre (13 feet per mile). Moreover, running a tyre even briefly on inadequate pressure breaks down the casing and prevents the ability to retread. It is important to note that not all sudden tyre failures are caused by under-inflation. Structural damages caused, for example, by hitting sharp curbs or potholes, can also lead to sudden tyre failures, even a certain time after the damaging incident. These cannot be proactively detected by any TPMS.
  • Improved safety: Under-inflated tyres lead to tread separation and tyre failure, resulting in 40,000 accidents, 33,000 injuries and over 650 deaths per year only in USA. Further, tyres properly inflated add greater stability, handling and braking efficiencies and provide greater safety for the driver, the vehicle, the loads and others on the road.

 

  • Environmental efficiency: Under-inflated tyres, as estimated by the Department of Transportation, release over 26 billion kilograms (57.5 billion pounds) of unnecessary carbon-monoxide (CO) pollutants into the atmosphere each year in the United States alone.
Fig No 5

A TPMS reports real-time tyre-pressure information to the driver of the vehicle, either via a gauge, a pictogram display, or a simple low-pressure warning light (Fig.2).  

TPMS can be divided into two different types – direct (dTPMS) and indirect (iTPMS). TPMS are provided both at an OEM (factory) level as well as an aftermarket solution (replacement market). TPMS is increasing consumer demand for avoiding traffic accidents, poor fuel economy, and increased tyre wear due to under-inflated tyres through early recognition of a hazardous state of the tyres.

A sensor based TPMS has a pressure monitoring sensor fixed inside the wheel and tyre  assembly(Fig.5). This is usually clamped to the wheel and constantly monitors the internal pressure of the tyre . This information is relayed to a receiving unit on the vehicle body which is connected to a processing unit in the electronics system of the vehicle. This alerts the driver to a loss in tyre pressure.

 

Fig No 6

There are two different types of systems being used today: Direct TPMS and Indirect TPMS. Direct (dTPMS) uses a sensor mounted in the wheel to measure air pressure in each tyre. When air pressure drops 25% below the manufacturer’s recommended level, the sensor transmits that information to the computer system of car and triggers your dashboard indicator light (Fig.2).

 

Indirect (iTPMS) works with Antilock Braking System’s (ABS) wheel speed sensors. If a tyre’s pressure is low, it will roll at a different wheel speed than the other tyres. This information is detected by the computer system of car , which triggers the dashboard indicator light (Fig.2). The purpose of the TPMS is to alert you when tyre pressure is too low and could to create unsafe driving conditions. If the light is illuminated, it means your tyres could be underinflated, which can lead to undue tyre wear and possible tyre failure.

Direct TPMS

Direct TPMS (dTPMS), is a directly measuring hardware-based systems. They could be fitted in each wheel, most often on the inside of the valve (Fig.6), there is a battery-driven pressure sensor which transfers pressure information to a central control unit which reports it to the vehicle's instrument cluster or a corresponding monitor. Some units also measure and alert temperatures of the tyre as well.

These systems can identify under-inflation in any combination, be it one tyre or all, simultaneously. Although the systems vary in transmitting options, many TPMS products (both OEM and aftermarket) can display real time tyre pressures at each location monitored whether the vehicle is moving or parked. There are many different solutions, but all of them have to face the problems of exposure to hostile environments. The majority are powered by batteries which limit their useful life.  A direct TPMS sensor consists of the following main functions requiring only a few external components, that is mounted to the valve stem inside the tyre:

 

  • Pressure sensor
  • Analog-digital converter
  • Microcontroller
  • System controller
  • Oscillator
  • Radio frequency transmitter
  • Low frequency receiver
  • Voltage regulator (battery management)

 

InDirect TPMS

Fig No 7

Indirect TPMS (iTPMS)  uses to detect the differing speed of revolution of a wheel with a reduced circumference, caused by a reduction in tyre pressure . There may be  dashboard icons for low pressure warning icon  or system failure icon (Fig.2). This system uses the ABS  or the Antilock Braking System of the vehicle to monitor the rotation speed of the individual wheels. If a deflation of a tyre occurs the resulting increase in wheel speed triggers the TPMS and advises the driver accordingly (Fig.7).

Advantages of the ABS based system include the fact that the system uses technology and equipment that is already fitted to the vehicle. Also there are no sensors fitted inside the wheel/tyre assembly which makes the tyre fitting process easier than the sensor based systems.

Dr Samir Majumdar, Rubber Consultant (India & Asia pacific), has served in leading tyre companies like JK Tyre, Kyoto Japan Tire, among others. He was technical and R&D head (Asia Pacific) in ExxonMobil. He has authored several research papers and technical books. smajumdar501234@yahoo.co.in

Comments (0)

ADD COMMENT

    Black Swan Graphene Retains DS Market Solutions

    Black Swan Graphene Retains DS Market Solutions

    Black Swan Graphene Inc. (Black Swan) has formally stated that it has retained DS Market Solutions Inc. (DS Market) to offer market making services in compliance with TSXV standards, subject to the TSXV's approval.

    With the aim of improving market depth and raising the liquidity of the company's common shares, DS Market will supply Black Swan with liquidity services in accordance with the terms of TSXV Policy 3.4. In addition to using its own funds to provide the services, DS Market has no direct or indirect stake in Black Swan's securities and no entitlement to purchase them, with the exception of assets required for liquidity. The services are offered by DS Market via Canaccord Direct DMA. DS Market has no direct or indirect stake in the firm or its securities, and Black Swan and DS Market are independent, unaffiliated, and unconnected businesses, reads the statement.

    The statement further states that Black Swan will pay DS Market USD 5,000 per month from its available funds in exchange for the services for a minimum of one month, with the agreement being renewed for successive one-month durations. Thirty days before the end of the then-current term, either party may discontinue the agreement by giving writing notice to that effect. On 1 May 2025, DS Market will start offering its services.

    Comments (0)

    ADD COMMENT

      Rubber Board Showcases Innovative Method For Recovering High-Quality Rubber From Skim Latex

      Rubber Board Showcases Innovative Method For Recovering High-Quality Rubber From Skim Latex

      The Rubber Board, which is observing its 77th anniversary this year, organised a press conference to showcase a novel method developed by the Rubber Research Institute of India (RRII) for recovering high-quality rubber from skim latex.

      The new technique creates rubber lumps by treating the skim latex with a specific chemical mixture for 24 hours, then allowing the acid to coagulate. After that, these lumps may be dried and turned straight into skim crepe. About 3–4 percent of the rubber used to make Centrifuged Latex (Cenex) is skim latex, a by-product of the process. Cenex is frequently used in the production of goods including balloons, condoms, and gloves. About 10 percent of the natural rubber produced in India is converted into Cenex via centrifugation, which is accomplished at more than 40 centrifuging facilities.

      The current method for recovering skim rubber is the acid coagulation of skim latex, which produces a slurry of skim rubber. After being packed into many plastic sacks, this slurry is allowed to solidify and dewater for two weeks. Skim crepe is made by further processing the resultant skim powder. But this traditional approach is labour-intensive, unrefined and results in bad odours, and it only generates rubber of poor grade. It has also caused public outcry and legal conflicts in the vicinity of Cenex enterprises, and it presents difficulties for wastewater treatment facilities. With the innovative method created by RRII, plastic bags are no longer used and processing takes only twenty-four hours. In addition to improving environmental sustainability and guaranteeing full recovery of premium rubber from skim latex, it drastically reduces offensive odours.

      The Federation of Latex Processors (FLP), a group of owners of centrifuged latex factories, has been granted access to this technology on a fee basis. Other organizations and Cenex units can also purchase it. The product is marketed as Indian Purified Skim Rubber (IPSR) by the Rubber Board, which is also working on a patent for the concept. Rubber companies nationwide have expressed a strong interest in employing IPSR in product manufacture as it provides a competitive edge because of its improved quality and reduced cost.

      Several efforts to solve various problems that exist in the rubber value chain were also addressed at the press conference. At the press conference, it was revealed that a nationwide celebration of the Silver Jubilee of the National Institute for Rubber Training (previously the Rubber Training Institute) would be organised, with participation from all relevant parties. M Vasanthagesan IRS (Executive Director, Rubber Board), Dr T Siju (Rubber Production Commissioner), Dr M D Jessy (Director-in-Charge, Rubber Research Institute of India) and representatives of the Federation of Latex Processors were in attendance.

      Comments (0)

      ADD COMMENT

        Kraton Launches CirKular+ Paving Circularity Series

        Kraton Launches CirKular+ Paving Circularity Series

        Kraton Corporation, a leading global sustainable producer of speciality polymers and high-value bio-based products derived from pine wood pulping co-products, has expanded its CirKular+ product line with the launch of CirKular+ Paving Circularity Series C5000 in line with its long-term vision to create innovative solutions for a sustainable tomorrow.

        The CirKular+ Paving Circularity Series addresses the changing demands of the paving industry to use more reclaimed asphalt and lower greenhouse gas (GHG) emissions. It allows for the addition of up to 50 percent or more reclaimed asphalt to the asphalt mix in surface layers while enhancing performance and processability. It increases the modified asphalt's resilience while maintaining resistance to permanent deformation and lowering the pavement's lifetime carbon footprint.  C5000 satisfies requirements for asphalt surface materials and is compatible with Warm Mix Asphalt technology.

        Pedro Lopes, Kraton Global VP of Strategic Marketing, Product Management and Supply Chain, said, “Launching the Paving Circularity Series is a testament to our commitment to sustainability and innovation. In Europe, the paving industry is actively working to increase circularity and reduce GHG emissions in alignment with the European Green Deal and the EU’s 2050 climate neutrality goals. The new series helps unlock value-added circularity by enabling polymer-modified bitumen (PMB) producers and contractors to increase the reuse of reclaimed asphalt, thereby reintegrating it back into the road surface layer.”

        Comments (0)

        ADD COMMENT

          CTS Tyre Recycling Reshaping Western Australia’s End-of-Life Tyre Disposal

          CTS Tyre Recycling Reshaping Western Australia’s End-of-Life Tyre Disposal

          Perth-based CTS Tyre Recycling is forging ahead with its plans to reshape the options for disposal of end-of-life tyres in Western Australia.

          The company, a part of the wider Cometti Group, a family-owned business with more than 40 years of experience in the tyre industry, has invested more than USD 40 million in a state-of-the-art recycling plant at Neerabup, north of Perth, that processes waste tyres into crumb rubber, tyre derived products, reusable high tensile steel wire and reusable textile. The company also made some additions to its management ranks and expanded its links with industry associations as it moves forward with its strategy. These tyres, along with all other sizes, will be remanufactured in the new Neerabup factory into new, high-value goods like load-restraining matting, gym matting, equestrian and farm matting and acoustic underlay.

          Leigh Cometti, the company’s Managing Director, identified a potential to diversify into the recycling of end-of-life tyres, concentrating on some of the huge off-the-road tyres utilised in the mining services and agricultural industries. Over 90 percent of the bigger OTR tyres now in use in Western Australia are thought to end up in landfills. Tyres are commonly buried in pits left behind during excavation, which results in the greatest landfill disposals in the Pilbara area. The recycling programmes will lessen the need for more virgin products in addition to decreasing landfill discharge.

          Cometti has brought on two seasoned senior level managers to support him as the company grows. Joseph Jeevaraj has joined as Chief Financial Officer, while Darren Rodwell has been named Chief Operating Officer. Both positions work for the Cometti Group, which also owns the Bunbury Trucks Sales and Service dealership, CTS People and Mechanics Recruitment.

          Comments (0)

          ADD COMMENT