SMART Sensors in tyres or on rims

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Since the 1970’s the Anti-Lock Braking system, now almost ubiquitous, has been helping drivers retain control during heavy braking on wet or slippery roads. The wheel rotation sensors, at the heart of ABS, have been co-opted into traction and stability control systems. Drivers do not consciously rely on these systems to save them from a mistake but seasoned drivers (code of older people) will have noticed that they appear to be much better drivers now than when they were in their 20’s. Which is surprising as reaction times increase with age.

What has been happening over the last thirty years is that vehicle safety systems have become more intelligent and tyres have more grip resulting in minor driver errors being recoverable by a combination of driver input, ABS, ESC and ATC. This list of potentially lifesaving innovations will soon include ‘look-ahead systems’ preventing us from tailgating the car in front or straying out of our motorway lane. None of these worthwhile advances has relied upon sensors embedded in the tyre because such sensors were not needed. Will embedded tyre sensors be capable of delivering worthwhile improvements to safety and/or vehicle dynamics without causing service and support problems for vehicle owners.

Quiet tyres

To develop tyres that run more quietly, with better grip and with lower rolling resistance knowledge of what is happening to the tyre as inputs change is vitally important. There will always be a need for tyre sensors that can provide real operating data that supports the predictions made by the analytic tyre models that are increasingly at the centre of our tyre development. Bay Systems responded to this need in 2006 by developing the Tyre Cavity Microphone (TCM) and other measurement modules that are used to study the behaviour of tyres in the laboratory and more importantly on the road, the environment where they are used. When comparing laboratory and road measurement it was clear that road data contains random variations not seen in the laboratory, see figures 1a & b.

The sound pressure level (SPL) inside a tyre is usually dominated by cavity resonance modes, the primary mode being strongest. The rms level of the noise inside the tyre’s cavity, at any given speed, responds to the texture of the road surface, the coarser the texture the higher the rms level. With a little signal processing the signal from the TCM’s microphone can be processed to give an indication of the road surface condition as can the signal from the TCA’s accelerometer mounted or embedded in the tyre liner, see figures 2 a & b.

The microphone positioned on the rim and integrated into the TPMS housing is potentially in a much safer location than a sensor buried in the tyre’s structure. Tyre fitters are used to remove and install TPMS modules making maintenance easier and more affordable than repairing sensors buried in a tyre’s structure. Inevitably sensors and systems will fail and any sensor mounted in the tyre is destined to have a stressful life. Tyre liner temperatures can exceed 120 degrees C depending on; speed, ambient temperatures and tyre type. Elevated temperatures (>50 degrees C) degrade batteries and semi-conductors. Most semi-conductors fail or suffer dramatically shorter service lives if their ambient temperature regularly reaches 80-100-degree C.

For many drivers the prospect of warning lights burning on their dashboards due to tyre mounted transducers failing will be very unwelcome, particularly if the recommended cure is to buy a new tyre. If the only way to pass the annual vehicle inspection, common in many countries, is for the tyre safety system to be working or not fitted then the not fitted option will be preferred by most buyers of used vehicles. If SMART wheel sensors can be shown to deliver genuine benefits then integrating them into a rim mounted package might be the lowest risk approach, at least from the customer’s perception.

Universal TMS

A Universal Tyre Monitoring System (UTMS) package would therefore appear to be the most attractive option in terms of convenience and minimising the costs associated with maintenance and repair. Essentially the Bay Systems’ TCM system is a UTMS system, albeit for R&D use only. The key question is therefore; ‘Can the data from UTMS be usefully employed to enhance vehicle utility, handling and safety?’ This is a difficult question to answer, for handling and safety, as for these applications the chassis management system (CMS) computer must receive and process signals in real time for the information to be usefully employed. Being informed that road surface icing has occurred some 30 metres after the vehicle has transitioned onto ice is liable to be too late. The signal from a tread liner accelerometer, see figures 3a. shows the transition from wet to flooded road, N.B. the vehicle was not aquaplaning but a slight increase in speed might well have invoked it. This raw time history would need to be processed before it could be used to trigger an intervention, in figure 3b a wavelet transform is used to highlight the differences between wet and flooded road surfaces. Real time responses imply high data rates from sensors, which in turn result in higher power consumption. Getting power to and signals back from the two front wheel sensors, rear wheel road surface information is typically front wheel data delayed by 3 metres, or from all wheels will be a challenge. Vehicles may be parked for days and even weeks, UTMS must shut down completely to conserve battery life. This may be achieved using a motion switch, these are readily available but as always adding complexity increases the risk of failures. The bigger problem is how to maintain and recharge the battery during normal usage. Any form of physical coupling through a connector will certainly be damaged or fail through water ingress making some type of induction coupled charging a more attractive option.

Low power radio transmission has worked well for TCM. However, such a system across the entire vehicle fleet may present problems on densely trafficked roads. On a busy motorway a vehicle might pass within 2 metres of another vehicle at a rate of 10 per second. Should all of these vehicles be using the UTMS radio spectrum then there will be up to 40 channel contentions per second to resolve. It is unlikely that radio spectrum will be made available that allows space for more than 100 channels. Each vehicle’s UTMS radio system must be primed to channel hop to avoid contentions from up to 10 interfering vehicles per second while sustaining a minimum data rate of 100kbytes per second.

Such a work load imposed be an ever-changing mix of vehicles will be difficult to manage without gaps in the data. A possible solution exists if the transmitted power from UTMS is very low, to the point that signals are only detectable inside the transmitting vehicle’s own wheel arch. Very low power radio transmission also brings low power drain at the transmitter making power supply easier. However, it also implies that a high receiver sensitivity might be needed. The extremely weak signals from nearby vehicles may therefore become detectable which returns us to the problem of radio channel contentions. Setting a low transmission power limit is therefore likely to be an area of diminishing returns and the channel contention issue is likely to always exist for high data rates.

To calculate the instantaneous rolling resistance of each wheel the CMS will require only two measurements; the temperature of the tyre and its pressure. A once per second reading rate for these two parameters would be enough, due to the tyre’s relatively high thermal inertia and

the normally slow rate of change of inflation pressure. The liner temperature measurement might be over a single area or across a section of the tyre. In the case of our TCT system (aimed at tyre R&D) the measurement is over 64 pixels and can stretch from bead to bead or be focused on an area if interest e.g. the tyre’s shoulder with an accuracy of 0.1 degrees C and resolution of 0.01 degrees C. A measurement cycle, even at high resolution would require a data packet of less than 200 bytes which with overhead might be 1kbytes. This rate would fit into the radio channels even on a busy motorway making dynamic estimation of rolling resistance possible while real time road surface measurement would be problematic.

Rolling resistance can account for up to 30% of battery energy in an EV making the choice of tire and the way the vehicle is driven very important; potentially being the difference between driving and walking the last few miles home on a cold wet night! There will be, for any journey, an optimum vehicle speed and route where energy consumption will be minimized. The probability of reaching the destination will be increased if this route is followed but it is more important to alert the driver if there is a significant probability of not reaching the destination on the remaining battery charge.

EVs with batteries that are over three years old may have battery capacities of 80% or less of the new capacity. This makes a planned journey of just 100miles (160km) problematic, particularly when air conditioning, heater and windscreen wipers are all operating. This range deficit may increase with traffic conditions such as road works, detours, accidents etc. To increase driver confidence a fully integrated vehicle management and GPS route planning system would need to use environmental data such as ambient temperature, wind speed and direction together with vehicle data such as load and UTMS derived tyre liner temperature and pressure to calculate the projected energy consumption for any proposed route. For this total tyre energy budget to be calculated for the journey the full tyre specification will be needed for each tyre i.e. the rolling efficiency for all temperatures, inflation pressures, loads and temperatures. The GPS navigation system, using these parameters and taking into account traffic updates would then evaluate the probability of reaching the destination without a battery recharge. If the journey was beyond the battery range an alternative route would be suggested that would pass a recharging station.

Data accuracy

The key to all this working reliably will be the accuracy of the tyre specification data entered into the CMS. What will be needed will be the full energy dissipation profile for all conditions, not just the laboratory performance rating, though this would be better than nothing. Tyres are currently rated for energy dissipation (rolling resistance) when operating in a laboratory at 25 +/- 4 degrees C while running on a smooth steel road wheel. The tyre is run for 30 minutes at 80kph before the test, is correctly inflated and is carrying 80% of its maximum load. Our measurements have revealed that the liner temperature across similar tyres from different manufacturers can vary from 50 to 90 degrees C for this test.

Energy dissipation drives the liner temperature higher until thermal equilibrium is reached. On the road, in the real world, the maximum temperature measured on the liner of a Mazda BT50 pickup truck tyre was 45 degrees C when pulling a trailer at a steady 100kph for 6 hours with an air ambient temperature of 22 degrees C. i.e. much lower than would have been expected. Energy efficiency improves with increasing temperature at the rate of 0.6% per degree C, over the temperature range 15-50 degrees C. It is highly likely that most tyres operating in temperate regions are not delivering their labeled energy efficiencies because they are running cool. This applies even in the summer when ambient temperatures are near those specified for the laboratory. In the winter the Mazda truck tyre did not reach 30 degrees C. i.e. half of the lab test result and probably 2 full tyre grades worse performance than the label states, possibly resulting in a 5+ mile shortfall in vehicle range.

While the case for in tyre sensors and even rim-based sensor fitment to vehicles is open to debate the case for their use in R&D is now well proven and accepted. Tyre internal noise and tyre cavity resonance is easily and reliably measured with good accuracy, both on a laboratory road wheel and on the highway. The differences between tyres from different manufacturers can be quickly evaluated, see figures 4 a & 4b, allowing car makers to choose a tyre best suited to their vehicle and the road surfaces it is most likely to be driven over. For the tyre companies their new product development can be steered towards lower levels of noise and cavity resonant modes.

The primary cavity resonance mode if heard in the vehicle cabin is annoying and is often interpreted by the owner as a defect. For auto makers noise complaints are a concern as investigation in the field is costly and if unresolved becomes a barrier to a repeat sale. Tyre companies are encouraged by auto makers to reduce cavity resonant mode levels and reduce road noise. The loss of vehicle control is a much more serious matter and has always been at the top of the priority list for tyre and auto companies. The measurement of tyre liner acceleration provides a great deal of information including early warning that the threshold for aquaplaning is imminent, see figure 3a.

Reductions in pre and post contact patch waves, see them clearly in figure 5, that propagate around the tyre will lead to reductions in radiated noise and lower pass-by noise levels. No improvement in a tyre’s characteristic comes free of charge and this cost is often a trade off with other equally desirable characteristics. Typically, less grip and faster wear rates are what result when a tyre’s energy dissipation is improved. Wet grip performance is featured on the tyre label and who would deliberately choose a tyre with lower wet grip. Leaving the most likely trade off candidate as wear and of course faster wear means more particulates shed into the environment which is undesirable. It seems likely that wear rate will soon appear on the tyre label. There seem to be no unalloyed successes, only the least worst choices to be made!

Toyo Tire Shareholder Change Follows Mitsubishi Exit

Toyo Tire Shareholder Change Follows Mitsubishi Exit

Toyo Tire Corporation said Mitsubishi Corporation has ceased to be a major shareholder after tendering its entire holding through a treasury share buyback, ending its status as the company’s largest shareholder.

The change took effect on 10th August , 2026, following Toyo Tire’s acquisition of its own shares through off-auction trading (ToSTNeT-3). Mitsubishi tendered all its shares, excluding less than one unit, as part of the transaction.

As a result, Mitsubishi is no longer classified as a major shareholder or associated company of Toyo Tire, the company said.

Before the transaction, Mitsubishi held 30,822,206 shares, equivalent to 20.07 percent of total voting rights, and ranked as the largest shareholder. Following the change, its holding has effectively been reduced to zero.

The move follows Toyo Tire’s earlier announcement on August 7, 2026 regarding the termination of its capital and business alliance with Mitsubishi, alongside plans to repurchase its own shares.

Toyo Tire said the change would have no impact on its consolidated financial results.

Linglong Becomes First Chinese Tyre Maker To Join GDSO As Full Member

Linglong Becomes First Chinese Tyre Maker To Join GDSO As Full Member

Linglong Tire has become the first Chinese tyre manufacturer to join the Global Data Service Organization (GDSO) as a full member, marking a step in the industry’s efforts to standardise and exchange tyre-related data globally.

The company joins the non-profit body as its fourteenth member. GDSO was established in January 2022 by Bridgestone, Continental, Goodyear, Michelin and Pirelli to facilitate the digital exchange of tyre data and develop common standards across the sector.

Moh Wahi, Head Of Truck And Bus Tyre Development at Linglong Europe, said: "By joining the GDSO as a Full Member and providing reliable data, we want to be the first Chinese tyre manufacturer to make a positive contribution to the further development of the tire industry and set new standards for the efficient processing of tire data in the digital age."

Riccardo Giovannotti, Secretary General of GDSO, said: "With Linglong Tire as a Full Member, GDSO is gaining one of the leading Chinese tire companies which is committed to digitalization and sustainability in the industry. Together, we will further make progress in developing standards for data processing and future-oriented solutions."

Shandong Linglong Tire Co., Ltd., founded in 1975, operates seven research and development centres globally and employs almost 20,000 people. The company runs nearly 200,000 sales outlets and exports products to 175 countries.

It supplies tyres to more than 200 production bases for over 60 automakers and has manufacturing facilities across China, Thailand and Serbia, with plans to expand further overseas.

TyreSafe And Sussex Police Launch Digital Tyre Safety Tool For Frontline Officers

TyreSafe And Sussex Police Launch Digital Tyre Safety Tool For Frontline Officers

TyreSafe, UK’s charity dedicated to raising tyre safety awareness, has joined forces with Sussex Police’s Road Safety Team to introduce a pioneering digital reference tool for frontline officers. The initiative equips police with immediate, device-accessible tyre safety data during roadside stops.

Developed as a local pilot, the application enables consistent vehicle examinations and improves driver communication regarding tyre dangers. It offers specific checklists for diverse vehicle categories, including motorcycles, cars, heavy goods vehicles, light commercial vans and towed trailers. The system further incorporates guidance on part-worn tyres, common queries and educational talking points.

Following its Sussex trial, the programme holds potential for nationwide adoption across UK police forces. This deployment underscores Sussex Police’s dedication to roadway innovation and reinforces the essential contribution of proper tyre maintenance to overall public safety.

Stuart Lovatt, TyreSafe Chair, said, “This partnership with Sussex Police is a landmark moment for tyre safety enforcement and education. By putting reliable, accessible tyre safety guidance directly into the hands of frontline officers, we can ensure safer vehicles on our roads and help prevent avoidable collisions and breakdowns. Sussex is leading the way, and we hope this model will soon be adopted nationally.”

Superintendent Jo Grantham, Head of Roads Policing, Sussex Police, said, “Our officers are committed to keeping road users safe, and having instant access to this tyre safety resource makes a real difference on the ground. It supports enforcement while also giving us the tools to educate drivers more effectively. We’re proud to be working with TyreSafe on this project and to be the first police force in the country to pilot it.”

Towing Breakdowns Reach Record High As Vehicle Fleet Ages, Says UKTSA

Towing Breakdowns Reach Record High As Vehicle Fleet Ages, Says UKTSA

The UK Towing Safety Alliance (UKTSA) has published a comprehensive four-year analysis of incident data from National Highways’ Strategic Road Network, covering 2022 to 2025. The findings reveal a 23 percent rise in total towing-related incidents, driven primarily by a maintenance crisis affecting utility and commercial trailers. While traffic collisions involving towed vehicles decreased by 17 percent, mechanical breakdowns now constitute 77 percent of all towing-related incidents, highlighting vehicle and trailer condition as the sector's foremost challenge.

The data coincides with SMMT Motorparc 2025 figures showing Britain's vehicle fleet at its oldest recorded level, with average car age reaching 9.7 years. The summer harvest season has also arrived, bringing agricultural trailers back to roads after months of disuse. NFU Mutual research indicates collisions involving agricultural vehicles are 56 percent more likely between May and September, reinforcing the need for pre-journey roadworthiness checks.

Utility and agricultural trailers now account for nearly half of all towing-related callouts, surpassing 3,000 incidents in 2025. Regionally, the North West has overtaken the South East as the most incident-prone area, with trailer failures surging 60 percent since 2022, while the North East recorded a 55 percent increase. A growing divide exists between leisure and commercial towing sectors.

Leisure sector improvements, including fewer horsebox incidents and regional caravan reductions, suggest awareness campaigns are yielding positive results. However, utility trailer failures continue climbing, indicating maintenance standards across commercial and domestic sectors require greater attention. Regular servicing, correct loading and proper coupling remain essential to prevent avoidable incidents.

For working trailers, summer represents peak operational period, with agricultural and utility trailers seeing intensive use while rural roads become busier with tourists and cyclists. The Alliance emphasises that trailers stored for extended periods require thorough inspections before returning to service.

The UKTSA urges all towers to perform three essential checks covering tyres, load and connection before every journey. Tyres must be inspected for pressure, tread and deterioration; loads correctly distributed and couplings and electrical connections verified. The Alliance will place ‘The Working Trailer’ at the centre of safety campaigns, collaborating with industry partners to boost maintenance awareness and reduce preventable breakdowns across the Strategic Road Network.

A spokesperson for the UK Towing Safety Alliance said, “It’s encouraging to see fewer collisions involving towing vehicles, which suggests that drivers are becoming more aware of safe towing practices. However, that progress is being undermined by a growing number of preventable mechanical failures. The challenge is no longer simply about how people tow – it’s increasingly about what they’re towing and the condition it’s in. As both tow vehicles and trailers get older, regular maintenance has never been more important.”

Stuart Lovatt, Chair of TyreSafe, said, “Harvest season places extra demands on both vehicles and trailers, particularly those that may only be used for a few months each year. One of the most common issues we see is tyres that appear to have plenty of tread but have deteriorated through age, weathering or prolonged storage. Whether you’re towing a livestock trailer, plant trailer, horsebox or caravan, tyres should always be inspected for correct pressure, damage, cracking and signs of ageing before every journey. A few minutes spent carrying out these checks can prevent breakdowns and significantly improve safety for everyone using our roads.”

Sarah Smithurst MBE, COO, National Trailer & Towing Association (NTTA), said, “Across the NTTA network, we’re seeing a noticeable increase in enquiries from people looking to refurbish older trailers or source second-hand trailers, including imported models, as a more affordable alternative to buying new. While extending the life of a trailer is often entirely appropriate, it’s essential that owners understand that trailers are not maintenance-free. Many have been in service for years, sometimes decades, and components naturally deteriorate over time, even if the trailer has seen relatively little use. Every trailer should be thoroughly inspected before it returns to the road, with particular attention paid to tyres, brakes, bearings, couplings and lighting. Investing in regular servicing and maintenance is far less costly than experiencing a breakdown – or worse, being involved in an incident. The NTTA continues to help and advice new and old trailer users about safety and many are asking for help when towing, especially the reversing aspect of a trailer, now the B&E test was withdrawn. We are also seeing more trailers being repatriated from North America and Europe rather than purchasing new in the UK.”