日付2019-10-28
タイトルA paper by Atsushi Sakurai, the representative of FS Micro, which provides functional safety consulting, has been accepted by the IEEE conference.
内容A paper by Atsushi Sakurai, CTO & CEO of FS Micro Corporation. (Head Office: Nagoya City), which provides ISO 26262 functional safety (Note 1) consulting, was accepted by the 66th RAMS (RAMS 2020: Note 2) hosted by IEEE (Note 3) Reliability Society on October 19, 2019. RAMS 2020 will be held from January 27th to 30th 2020 at Marriott Renaissance, Palm Springs, California, USA.

The title of the paper is “Generic Equations for a Probabilistic Metric for Random Hardware Failures According to ISO 26262”, which makes it possible to accurately evaluate the stochastic metrics for random hardware failures (PMHF: Note 4) of a vehicle.

In 2011, the first edition of ISO 26262, the international standard for functional safety in in-vehicle electronic devices, was issued, and in 2018, a revised version was issued. In the revised version of the standard, the PMHF formula has been changed, but the mathematical definition of PMHF values ​​and the prerequisites of the element (Note 5) were not clear. In this paper, we clarified these points and clarified the unavailability formula for the first time for elements that are periodically inspected according to the standard. Based on this formula, a new PMHF formula for general subsystems (Note 6) was derived. This paper makes it possible to evaluate PMHF values accurately, so it is possible to implement appropriate safety designs in a wide range of in-vehicle ECUs. In addition, since excessive design constraints related to the emergency operation allowable time interval (EOTTI: Note 7) can be reduced, it is possible to shorten the design period and reduce the product cost in fault-tolerant systems (Note 8) typified by autonomous driving systems.

Note 1: The concept of improving safety at the system level by taking various safety measures. ISO 26262 is the international standard for functional safety for in-vehicle electrical and electronic equipment.
Note 2: The 66th Annual Reliability & Maintainability Symposium. The world's highest-level international conference on reliability engineering, organized every year by the IEEE Reliability Society. http://rams.org/
Note 3: The world's largest academic institute on electrical and electronics engineering headquartered in the United States.
Note 4: Probabilistic Metric for Random Hardware Failures. In-vehicle electrical/electronic systems, hardware design target value that averages the probability of system failure during the vehicle lifetime.
Note 5: In ISO 26262, it is a unit of function that constitutes a system, and consists of hardware parts and software parts.
Note 6: Subsystem composed of elements, where both the mission function that controls the intended function and the safety mechanism that ensures its safety are repairable.
Note 7: Emergency Operation Tolerant Time Interval. The time interval during which the safety target is not violated if repair or switching to alternative processing is performed within this period.
Note 8: A system that can perform its original function to some extent without losing its function immediately in the event of a failure.