Satisfying Design Constraints for Automotive Safety-Critical Systems 2007-01-1483
Leading automotive researchers are currently attempting to develop safety-critical automotive systems such as Steer-by-Wire (SBW), Brake-by-Wire (BBW) and Collision Avoidance Systems. These systems require a sound fault management infrastructure and a high reliability. However, this must be achieved at a low cost and with reduced lead time, while meeting other requirements such as for performance, size, weight, etc.
The traditional system design methodology that follows a preliminary design, analysis, appraisal and redesign pattern for automotive systems makes balancing contradicting design constraints difficult. Often all of the constraints are not met, and projects run over budget and time.
This paper describes a software tool that has been developed to assist engineers design safety-critical systems that satisfy constraints such as reliability and cost. Once fault management requirements are defined, the tool assists the user to design suitable fault detection and recovery schemes for their system by finding fault detection methods for components that will provide the required reliability within a given cost using constraint satisfaction methods.
The paper begins with the motivation behind the research and theory of constraint satisfaction. Next, the structure of the tool and the embedded design process is explained. The tool and the process are demonstrated using an Electronic Power Assisted Steering (EPAS) example.