ABSTRACT
Since the s, one observes an exponential increase in the number of electronic systems that have gradually replaced those that are purely mechanical or hydraulic. The growing performance and reliability of hardware components and the possibilities brought by software technologies enabled implementing complex functions that improve the comfort of the vehicle’s occupants as well as their safety. In particular, one of themain purposes of electronic systems is to assist the driver to control the vehicle through functions related to the steering, traction (i.e., control of the driving torque), or braking such as the anti-lock braking system (ABS), electronic stability program (ESP), Electric Power Steering, active suspensions, or engine control. Another reason for using electronic systems is to control devices in the body of a vehicle such as lights, wipers, doors, windows, and, recently, entertainment and communication equipments (e.g., radio, DVD, hand-free phones, and navigation systems). In the early days of automotive electronics, each new function was implemented as a stand-alone
electronic control unit (ECU), which is a subsystem composed of a microcontroller and a set of sensors and actuators. This approach quickly proved to be insufficient with the need for functions to be
distributed over several ECUs and the need for information exchanges among functions. For example, the vehicle speed estimated by the engine controller or by wheel rotation sensors has to be known to adapt the steering effort, to control the suspension, or simply to choose the right wiping speed.
