Development and Validation of the Wheel Speed Sensor Interface Based on V-model Method

Abstract

Hardware development and testing in automotive industry is strongly influenced by safety requirements. Key hardware components, such as the interface of wheel speed sensors (WSS), are subject of functional safety methodology for activities during hardware development. The functional safety of electrical, electronic and software components is addressed by the ISO26262 series of standards, and the proposed methodology follows its recommendations. The WSS are key electrical components of road vehicle brake systems, which is a safety system, rated as ASIL D, therefore the development of hardware interface for these sensors must fully comply with the ISO26262 recommendations [1]. The WSS are physically mounted at each wheel of the car and wired to an Electronic Control Unit (ECU). The data collected from WSS is used for calculating the vehicle velocity and for various function of the braking system, such as ABS (Anti-lock brake system), TCS (Traction control system) and ESC (Electronic stability control) [2], and a plurality of other systems in the car are using the vehicle velocity as an input for performing their various functions. The WSS are working in a harsh environment, exposed to mechanical, environmental, and electrical hazards. Failure of any WSS must be detected and addressed accordingly, in the shortest time and with best possible accuracy.