Video Exclusives


Inside Nexen's Changnyeong plant

Sentury

Visit the highly automated facility in South Korea, outfitted with the most advanced production technologies and systems.

Click here to watch the video


Nokian tire testing

Sentury

Indoor analysis underway at the Nokia R&D facility​

Click here to watch the video


Do you feel you spend too much time acquiring, retrieving and handling data than you do analyzing and interpreting it?

Industry Opinion

« back to blog listings

A sense of purpose

Gregory Smith considers how multi-axis accelerometers could be beneficial in testing

My last column ended with a mention of smart tires. Most eyes reading this column are likely owned by people who already know what smart tires are; nevertheless, here is my version of smart tires 101. Firstly, the term ‘smart tires’ is about as precisely defined as a tire’s ‘capacity’, or ‘linearity’, by which I mean most people in the industry seem to roughly understand what it refers to, although actually the term can mean almost anything. That said, it usually centers around the emerging technology of adding various sensors into the tire, which feed data to the car. Smart tires are often associated with autonomous vehicles and those are often linked with electric drivetrains; although in fact none of these technologies are intrinsically linked and all can be used independently.

The basic idea of a smart tire is to mount an accelerometer to the innerliner. While the tire is rotating, this sensor detects a bump as it hits the ground at the front of the contact patch and then another bump as it leaves the ground at the end of the contact patch. With the speed of the car being known, the time between these bumps can be used to determine the distance, which is the length of the contact patch. Meanwhile, a TPMS sensor can be used to monitor the tire’s inflation pressure. Then a look-up table can be used (based on a known relationship between load, pressure and contact patch length) to determine the vertical load on that tire at that time. This is very useful information for the car’s active safety systems, which can use this for µ (grip) estimation, among many other things.

Furthermore, the accelerometer could be used to identify changes in the tire itself, such as the wheel and tire assembly suddenly becoming unbalanced. This could be used to alert the driver that a wheel weight has fallen off, or that the tire has picked up a nail, or similar.

Additionally, the smart tire could be used to communicate more general information to the car, such as how old the tire is, and to alert the driver if the tire is starting to perish. Or the tire could communicate to the car how good or otherwise its wet grip is likely to be, based on testing conducted prior to selling the tire.

With this information, the car could switch to an appropriate stability management setup that is suited to that particular tire. If the owner mounts a low-quality aftermarket tire, the car could switch to a more intrusive traction control system. If the owner then mounts a high-quality tire with more grip, the car could switch to a less intrusive system.

This is all well and good and lots of research is being conducted in this area. However, what I think is missing is the fact that smart tire technology could also be used in the engineering and design phase. Currently, we test tires on a rig and take measurements from the hub; these measurements are then used to parameterize tire models. Assuming a stiff wheel, this means we know everything that’s happening up to the wheel rim, but aside from temperature there is no information coming directly from the tire itself. This is not ideal as the tire is the very thing we are trying to measure.

Inspired by smart tires, high-quality multi-axis accelerometers could be mounted to the tire’s innerliner during rig testing. This will provide data as to exactly how the tire itself moves, vibrates and flexes while under known test conditions. With this new information, the tire’s stiffnesses, damping characteristics and other attributes could be calculated more accurately. Furthermore, additional parameters that are not currently available, such as the magnitude of the belt’s lateral movement while corning, could be measured.

With this new and more accurate information, comparisons between tires could be carried out more thoroughly. This additional data could also be used to improve the parameterization of physical and semi-physical tire models such as FTire, CDTire and RMOD-K, as well as being used in finite element models. Of course, the parameterization software and processes will need to be updated, but this information could significantly improve the accuracy of the resulting models. This sounds to me like the basis of a very interesting PhD proposal. Let me know if you’re interested…

January 16, 2018

 

Comments:

There are currently no comments.

If you would like to post a comment about this blog, please click here.
RECEIVE THE
LATEST NEWS


Your email address:



Read Latest Issue

Read Latest Issue

Read Latest Issue

Web Exclusives

Bridgestone Americas and Versalis in partnership
The two companies have revealed their plans to develop a technology package with the aim of commercializing guayule
Read Now

Yokohama launches revolutionary concept tire
Incorporating new mixing technology, the BluEarth-air EF21 is rated AAA for rolling resistance and an A for wet grip – the highest graded on the market according to the Japanese tire label
Read Now

Nokian unveils images of new Spain facility
More conceptual renderings have been released showing the layout of the new 300ha facility, currently being built south of the Spanish capital of Madrid
Read Now

Snow Academy project
Luleå University of Technology initiates project to develop methods of measuring snow quality in order to improve preparation of test tracks  
Read Now

Drivers in Europe reveal they do not change their tires to suit conditions
A study conducted by Nokian Tyres has shown that a significant amount of European motorists drive on unsuitable tires for the conditions
Read Now


Supplier Spotlight

Supplier SpotlightWe are building a list of leading suppliers covering all aspects of the tire industry. Want to see your company included? Contact olivia.campbell@ukimediaevents.com for more details.

Submit your industry opinion

Industry BlogDo you have an opinion you'd like to share with the tire technology community? We'd like to hear your views and opinions on the leading issues shaping the industry. Share your comments by sending up to 500 words to rachel.evans@ukimediaevents.com

Submit Your Recruitment Ad

Recruitment AdTo send us your recruitment advertising or to receive information on placing a banner please email olivia.campbell@ukimediaevents.com