Internal tyre sensors tell drivers a vehicle’s weight
As a driver, there are times when every seat is taken and the boot is crammed full. Aside from a generally reduced performance and the need to drive slightly differently with a heavier load, this is not something to which one typically gives much thought.
Maybe there will be fewer miles to the gallon and stopping distances will be increased, but the thought that one might actually be overloading the car or need to change tyre pressures is not something that crosses most drivers' minds.
It should. In fact, it's rather obvious when you think about it. While commercial vans and vehicles have strict loading weights that are noted somewhere prominent on the vehicle, day-to-day consumer cars do not. Do you know your car maximum load and how would you go about measuring it?
This is the issue that engineers at international automotive supplier Continental have been mulling over for some time and it now believes it has a solution. As part of ongoing developments it is developing and widening the range of functions available to its tyre pressure sensors.
The future generation of Continental tyre sensors will be fitted directly underneath the tread of the tyre and will accurately be able to detect the size of the contact area on the road as well as vehicle load. Most current car sensors are not capable of checking axle loads, yet Continental believes future vehicles fitted with its tyres will be able to calculate this information automatically from tyre pressure sensors.
"In the past, it was more or less up to drivers to 'guesstimate' to the best of their abilities whether or not the maximum permitted payload of a car had already been reached," says Andreas Wolf, head of the body and security business unit at Continental. "In the future, the vehicle will be able to tell the driver after just a few hundred metres whether the payload has already exceeded the maximum permitted limit, or whether the tyre pressure would simply need to be adjusted accordingly. In this way, our tyre pressure sensors will not only help to save fuel, but also offer active assistance in terms of vehicle safety."
The sensors can be used to collate a number of variables about the tyre and its behaviour to form the basis of automatic load detection system. Its future generation of sensors will be able to accurately detect the size of the contact patch of the tyre, which increases as a result of the weight bearing down on the tyre.
Additionally, with every revolution of the tyre the sensor registers its rolling characteristics on the road. Based on the existing tyre pressure and precise data about the tyres fitted, the system is also able to inform the driver if the current tyre pressure is appropriate for the payload onboard.
Although some innovative systems could make automatic tyre pressure adjustments on the move possible, it is thought Continental's automatic load detection system will still need drivers to stop and make the necessary adjustments themselves.
The load detection system will be integrated and assist with other onboard systems, however, and will be the basis for some other vehicle improvements. Assistance systems relating to vehicle dynamics are designed to always work with the assumption of a maximum payload to provide occupants with the highest level of comfort and safety. Other systems like electronic stability control, emergency steer assist and autonomous emergency braking assistant can incorporate information about the actual vehicle weight into the responses to enable improved response and support for drivers.
Continental has also introduced a 'Filling Assistant' app that specifies the exact inflation pressure of each tyre via a smartphone. Accurate tyre pressures for a given load improve rolling resistance and tyres perform to their maximum capability in terms of safety and comfort.
