 Tyre pressure control 3
The tyre pressure sensor on the valve is not entirely problem-free because it is simply a little too close to the point where the bead has to be pressed off the rim and pulled over the rim flange with great force during
disassembly/assembly. The shovel should be placed on the opposite side of the valve from the very first time the pressure is applied. The blade should be placed on the opposite side of the valve when removing for the first
time.
The tyre pressure sensor on the valve is not entirely problem-free because it is simply a little too close to the point where the bead has to be pressed off the rim and pulled over the rim flange with great force during
disassembly/assembly. The shovel should be placed on the opposite side of the valve from the very first time the pressure is applied. The blade should be placed on the opposite side of the valve when removing for the first
time.
When impose it on, you start with the sensor just before the valve so that it is definitely out of the danger zone. This means that the part with the valve is the last to be installed. Another hurdle of the system is the well over 100
different versions, which are unlikely to be in stock in tyre shops given in case of rare vehicles here.
It is even noticeable that these can be significantly more expensive, for example in American vehicles. The sensor and valve are not always one part and both can be installed completely separately, for example the sensor in
the drop center, attached with a steel band around the rim. The sensor can often be used for several vehicle types. There are small groups of sensors, each of which even covers several manufacturers.
Perhaps interesting for the future are completely round sensors, including the battery, that are placed in rubber pockets. If the tyre has a smooth structure on the inside of its tread, these rubber pockets can be glued there. It
is important to pay attention to their direction or that of the sensor, because the is clearly specified. Here, for example, you do not need to worry about possible air loss in the valve sensor unit.
It will be interesting to see when tire manufacturers agree on the size of such pockets and generally include them in the tyre. Perhaps these could then be included in the marking with an assumed sensor weight. Today,
more data than just pressure and temperature are expected, since a sensor close to the tread could also determine driving data such as acceleration or delay and make them usable for chassis settings.
This of course means all possible data about the condition of the road and/or weather conditions, which could be passed on to a network and evaluated there, bypassing the driver. This is where the new 5G wireless
standard comes into play again. However, this is not necessarily necessary, as some of this could also be determined using the suspension travel and ABS sensors.
In any case, a standard for data communication between vehicles from different manufacturers and also fixed facilities within CarToX would first be necessary. So we have to wait, as well as for higher levels of automatic
driving. Owners of all types of trailers do not have to wait. For them, there is a system with sensors as caps that replace valve caps. These send to a fairly inexpensive control unit with a monitor.
You may not even need to pull a cable there. If you stick it to the inside of the windshield, for example, it can even recharge itself. It is doubtful whether such systems have a long battery life. However, they have a very low
sleep current when the trailer is not moving and, unlike the systems in the tyre, they can be easily replaced.
The caps have another disadvantage besides the low battery capacity. They don't really detect the temperature in the tyre, even though they are connected to the air in the tyre by constantly pressing down the valve body. This
can mean that a larger range has to be set for the warning. In any case, tires on trailers are often subjected to much higher loads than those on towing vehicles.
The legislator hopes that the requirement for a tire pressure monitoring system will not only bring benefits for safety, but also for environmental protection. Supposedly, if the tire pressure is 0.6 bar too low, fuel consumption
is around 4 percent higher, although such a difference should be avoided at all costs because of the more bad driving behavior. Incidentally, such a difference in the direction of too much pressure can also lead to a
significant deterioration.
At the beginning of this series, when comparing the passive and active control systems, we also assumed that the costs would be higher, as changing from summer to winter tires and back yourself is not worth it because
of the necessary visit to the workshop. During our research, however, we noticed incredible differences in the calibration of permanently installed sensors. Depending on the system, there are inexpensive devices available
online that you can use to do this yourself.
There are even tire pressure monitoring systems that automatically connect the sensors in the tyres to the relevant control unit. We have also found with our own passive systems that a reset after each wheel change is not
really necessary, even though it is really easy. So if you really want to save money and do something on your car, you could try this once at an active system, too.
Finally, there is a complex system that relieves the driver of all problems. Here, the inside of the tire is permanently connected to an air connection on the vehicle, where the tire pressure can of course also be read. One
important use seems to be for driving in desert sand. You can temporarily release the pressure to e.g. 1 bar.
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