Survey of Software Failsafe Techniques for Safety-Critical Automotive Applications

A requirement of many modern safety-critical automotive applications is to provide failsafe operation. Several analysis methods are available to help confirm that automotive safety-critical systems are designed properly and operate as intended to prevent potential hazards from occurring in the event of system failures. One element of safety-critical system design is to help verify that the software and microcontroller are operating correctly. The task of incorporating failsafe capability within an embedded microcontroller design may be achieved via hardware or software techniques. This paper surveys software failsafe techniques that are available for application within a microcontroller design suitable for use with safety-critical automotive systems. Safety analysis techniques are discussed in terms of how to identify adequate failsafe coverage. Software failsafe techniques are surveyed relative to their targeted failure detection, architecture dependencies, and implementation tradeoffs. Lastly, certain failsafe strategies for a Delphi Brake Controls application are presented as examples.