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Safety certifying automotive components
March 13, 2010
In response to a Pillar to Post blog entry on Toyota’s speed controller woes, one reader asked: For electronics to make their way onto commercial airliners, extensive testing and failure modes must be determined before they are certified for flight. Is there a similar requirement for automobile fly by wire systems?
One of the most widely used safety standards is IEC 61508, the international standard for “Functional Safety of Electrical, Electronic, and Programmable Electronic Safety-Related Systems.” It defines SIL (safety integrity level) classifications and how to develop products to achieve a SIL rating. It is the standard that all agencies (TÜV, Exida, SIRA/CSA, FM, etc.) use to evaluate and certify products to SIL requirements. It is a generic specification for functional safety and is not specific to any particular industry or application. There are also sector specific IEC functional safety standards, including IEC 61511 (a.k.a. ISA S84) for the process industry sector and IEC 62061 for the machinery sector. There are also IEC functional safety standards for nuclear (IEC 61513), rail (IEC 62278), and medical (IEC 62304) applications. There is a standard under development, ISO 26262, entitled “Road Vehicles–Functional Safety,” which is an adaptation of the functional safety standard IEC 61508. However, in the meantime, IEC 61508 can be and is applied to automotive electronics. Exida does a lot of work for German auto manufacturers who pioneered the use of “drive-by-wire” technology and did it with a very high level of safety.
Globally, the topic of failsafe designs has not been applied as broadly as it should be. The North American transportation industry, in general, seems to have avoided coming to terms with it, but European companies have applied it much more effectively. While still under investigation by the NTSB, early indications suggest that recent rail incidents (e.g., DC Metro, Disney World Monorail) were a result of electronic controls that are not functionally safe, at least by today’s standards.
–John Cusimano, CFSE
Director of Security Services
Read Control Engineering’s Machine Safety blog with J.B. Titus.
Posted by Ask Control Engineering on March 13, 2010