The technological leader for tractors - AGCO GmbH with their premium brand Fendt – now also uses pressure sensors from the M01 module kit by Sensor-Technik Wiedemann GmbH (STW) in the pneumatic and hydraulic brake systems of their large tractors.
The technical requirements are high, and, particularly in brake systems, a loss of accuracy, functional failure of the pressure sensor or even breakage of the pressure sensor is not acceptable. From a functional safety point of view, the requirement is at least Performance Level c (Pl c). This also includes a pronounced capability for self-diagnosis, which is expressed in the so-called “Diagnostic Coverage”. The M01 sensor used in the Fendt tractors recognizes more than 70 % of the possible errors and reaches an MTTFd of more than 250 years.
The pressure sensor is installed in the pressure lines of the brake system, and as a result is permanently exposed to soiling, salt water, large temperature fluctuations and strong vibrations – but in spite of this, it measures the pressure with an accuracy of +/-1 % or better.
Reliability and availability, even under extreme conditions, are indispensable and characterize both the pressure sensor as a component, and also the complete product: The tractor.
Due to its use in various tractor models - with pneumatic and hydraulic brake systems – differing pressure ranges, pressure connections, output plugs and signals are necessary, and identical components cannot be used for this reason. This fact, and additional economic factors, were the main reason why AGCO Fendt GmbH decided on the M01 modular system. Here, and with other safety-critical and demanding applications, modular-based sensors provide significant advantages.