In the eighties of the last century, a revolution began, which aimed to increase driving safety. Bosch engineers have developed an ABS system that they have been working on for fourteen years to prevent the wheels from locking when braking. Its essential part was speed sensors placed on each wheel.
ABS made its debut in 1978. The system took up a lot of space and was very expensive. Therefore, at the very beginning, it was fitted out for the equipment of luxury cars – S-class and BMW 7-series. Engineers did not idle and introduced new versions of the system: smaller, less complicated (fewer cables), cheaper and with more functions (eg with braking force distribution) ). The production of ABS and sensors was also taken up by other companies from the automotive industry, which had an impact on the price drop and the popularization of this solution. For many years ABS has been a standard feature of every new car, regardless of its class.
However, the role of wheel speed sensors (ABS sensors) does not end there.
In 1986, Bosch engineers invented the ASR system (traction control system), preventing the driving wheels from slipping (especially when starting), and in 1995 the ESP system – an advanced anti-slip system that facilitates curves and turns, preventing oversteering and skidding. understeering. ASR and ESP, as well as ABS, use wheel speed sensors (as well as their own). History repeated itself – first, the systems were expensive and available only on the most expensive vehicles. Currently, they can be found even with low-cost city cars.
Modern ABS, ASR and ESP systems are modular. All of them, in their specific way, deal with the regulation of the braking force. And they all need four wheel speed sensors to work properly.
Wheel speed sensor and … tire pressure measuring system
Wheel speed sensors (sensors ABS) y ZnAl pounds another application. The tire pressure monitoring system has been an obligatory element of car equipment for several years. Two solutions are used – more expensive, with transmitters at each valve and cheaper, operating on the basis of an indirect system using wheel speed sensors.
How can an ABS sensor be useful when measuring tire pressure? The tire, in which there is less pressure, performs a lower number of revolutions than the other, properly inflated wheels. And it is captured by the system. We have to admit it honestly – an imperfect system. But this is not the topic of our article.