Abstract
Keywords
Safety; Electronics; Architecture; Networks; Redundancy;
Abstract Safety is the number one driver demanded capability for new vehicles in Europe. Many of the existing safety measures are passive (providing occupant protection in the event of an accident e.g. airbags), however there are a significant number of new sensors systems and actuators under development to provide active safety measures (which help to prevent accidents occurring e.g. external environment monitoring, collision avoidance sensing). Also, improvements in the overall vehicle dynamic handling and control are being sought through integrating chassis control functions (for steering, suspension etc.) together with the ABS/ESP systems today.
The enabler to these systems is advanced electronics (and corresponding reductions in cost) combined with suitable control systems and vehicle networks. The common thread within these areas is the need for safety resulting in fail-safe and fault tolerant systems and the implementation of these features must permeate into many areas of the vehicles architecture and implementation.
This paper describes the impact of safety critical requirements at both a network architecture and ECU level. At a network level, the approach is to be able to provide robust, scalable and predictable behaviour through fail-safe and fault-tolerant functionality. At the ECU level, both the hardware and software must provide the required level of fault tolerance in a cost effective way. To demonstrate how these problems may be resolved, a relatively simple braking system will be reviewed. The impact on the electrical architecture, vehicle networks and ECU will be investigated. A bench-top implementation, using a prototype ECU with the required functionality will highlight realistic implementation issues.