A dependable anisotropic magnetoresistance sensor system for automotive applications

The increasing usage of electronic systems in automotive applications aims to enhance passenger safety as well as the performance of the cars. In modern vehicles, the mechanical and hydraulic systems traditionally used have been replaced by X-by-wire systems in which the functions are performed by electronic components. However, the components required should be reliable, have a high-performance, low-cost and capable of operating for a long time in a highly dependable manner despite the harsh operating conditions in automotive applications. Dependability represents the reliance that a user justifiably poses on the service offered by a system, being this especially important in safety-critical applications in which a failure can constitute a threat to people or the environment.

An Anisotropic Magnetoresistance (AMR) sensor is a type of magnetic sensor often used for angle measurements in cars. This sensor is affected by performance degradation and catastrophic faults that in principle cause the sensor to stop working suddenly. Therefore, the sensor dependability should be improved in order to guarantee that it will satisfy the continuous increasing dependability as well as accuracy requirements demanded by automotive applications. This research proposes an AMR sensor system that includes a fault-tolerant approach to handle catastrophic faults and self-X properties to maintain the performance of the sensor during its lifetime. Additionally, an interface with the IEEE 1687 standard has been considered, so the sensor is able to communicate with other components of the system in which it is integrated.