PRODUCT

Tire Grip Indicator

Revolutionizing driver awareness - enabling car autonomy

Here’s a fact: awareness changes driver behavior. On dry asphalt, for instance, most drivers tend to drive more dynamically than on gravel, knowing that the tire grip is better. However, when that dry asphalt road suddenly and unexpectedly becomes slippery, the driver may not be aware – until going too fast.

Had the driver known, he would of course have adopted his driving style accordingly. The solution? Tire Grip Indicator, TGI by NIRA. A software solution, TGI by NIRA requires no additional sensors. Continuously monitoring the friction between the tire and the road by analyzing the wheel speed signals and other automotive grade sensors, TGI provides accurate friction values, taking both road and tire properties into account.

Continuously monitoring the friction between the tire and the road by analyzing the wheel speed signals and other automotive grade sensors, TGI provides accurate friction values, taking both road and tire properties into account.

TGI is especially innovative as it works even under normal driving conditions when slip control functions such as the ABS, traction control or ESC are still far from becoming active.

Offering both driver support and vehicle assistance, TGI boosts not only safety but performance as well – using software only.

Increasing driver awareness. And enabling autonomy while we’re at it.

TGI is especially innovative as it works even under normal defensive driving conditions when slip control functions such as the ABS, traction control or ESC are still far from becoming active. Although TGI could well be integrated with advanced vehicle systems such as Automatic Emergency Braking or Adaptive Cruise Control, at the core it’s a true driver awareness device. That’s not to say the driver has to be a person. In fact, solving what is widely considered to be a key issue when it comes to autonomous driving – that’s tire grip prediction – TGI is a real enabler for the self-driving cars of the future. And it’s ready for series implementation today.

Having driven “to the moon and back” – thirty times – from the desert heat of Death Valley to the blistering cold of northern Sweden, using more than 20 000 different tires, we’ve learnt a thing or two about road friction. With Tire Grip Indicator, all that experience will be yours – in a cost efficient, easy-to-implement software solution.

TGI estimates the friction between the tire and the road under normal driving conditions – long before ABS, ESC or traction control are activated. This means that the tire grip is monitored at all times.

TGI is able to accurately estimate the total available friction by using only a part of the friction potential – thus being able to foresee the available friction before a critical situation occurs.

Use case examples

Torque Distribution in 4WD electric vehicles

Pre-set the torque distribution way to decide when the secondary engine shall be used. Improving performance and comfort by not reaching the slip limit before activating 4WD.

The torque control function shall use the most efficient engine and the most efficient operating point as possible in order to optimize range.
The second engine shall be applied when necessary due to high torque request or low tire grip.
TGI can provide the torque distribution function with valuable information concerning friction in order to decide when the secondary engine shall be used.

“Pre-set the torque distribution way before reaching the slip limit toimprove performance and comfort”

Dynamic ACC

Pre-set the torque distribution way to decide when the secondary engine shall be used. Improving performance and comfort by not reaching the slip limit before activating 4WD.

Dynamic ACC adjust the cruise control to the curvature of the road and slows down in curves when the lateral accelerations become larger.
Friction information can further increase the safety by also adopting the distance to the vehicle in the front with respect to the road conditions and brake distance.

“Restrict the shortest time gaps to the car in front during slipperiness to avoid unsafe settings”

Breake blending in electric and hybrid vehicles

In order to extend the range, the electric engine should do as much regenerative braking as possible. Most electrical vehicles are limiting the regeneration, but friction information can extend the operating envelope of the recuperation without compromising with safety.

In order to extend the range, the electric engine should do as much regenerative braking as possible
Most electrical vehicles are limiting the regeneration at 3 m/s², far from what electrical system can handle
Friction information can extend the operating envelope of the recuperation without compromising with safety

The grip indicator – in less than a minute

A high-performance software solution, Tire Grip Indicator detects monitors the slip of the road surface continously. Here’s how it works.