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The paper will present the results and analysis of high resolution pressure measurements in car tires. The measurements have been logged under real traffic conditions like city tours, overland driving or highway rides. Additionally special situations like stop and go, curving and load changes have been tested. Conclusion on the usability of pressure measurements for power saving algorithms of tire pressure measurements transponders will be drawn. Finally algorithms to determine the timing of RF transmission in dependence on the dynamic of pressure signals are suggested and power estimates for systems using these algorithms are given based on existing hardware.

The signal delivery and quality of sensor data is of growing importance for modern automotive control applications. Sensors tend to be calibrated subsystems that are designed to stay in a defined tolerance and thus can easily be modeled. Compared to this deterministic behavior the transmission channel is time variant due to EMC and aging of contacts for example. The use of analog signaling, which is the actual state of realization in many cases, is sensitive to the time variant effects mentioned before. This time variance is hard to consider for the control system development. In this paper we will analyze the role of the sensor in the signal supply chain and discuss approaches for digital sensor-ECU communication and their potential to establish a link, which allows neglecting low level effects of the channel.

The paper will give an introduction to the principle of the giant magneto resistive - GMR - effect and the silicon system integration of GMR sensors. The two main applications of a GMR as a magnetic field strength sensor and as an angular field direction sensor will be discussed under consideration of automotive requirements. The typical applications of a magnetic field strength GMR sensor in incremental position and speed sensing and those of GMR angular field sensors in position sensing will be summarized. Finally advantages of GMR in those applications will be discussed and conclusions on the use of GMR in automotive sensing will be drawn.