Physics-of-failure assessment of a cruise control module

摘要

The purpose of a cruise control system is to accurately maintain the driver's desired set speed, without intervention from the driver, by actuating the throttle-accelerator pedal linkage. Over the past five years, owners of a particular cruise control have complained that it did not operate properly. Complaints ranged from not engaging upon command, to the cruise unexpectedly accelerating past the desired speed. A common thread among all the complaints was the intermittent nature of the problems. More than 96 of the reported failed modules removed from vehicles and returned to th ecompany, passed bench test. This paper presents a physics-of-failure process to identify, induce and analyze failure mechanismms causing intermittent failures, high warranty returns and cannot duplicate (CND) problems of the digital electronic cruise control module (CCM). In addition, we explain why the manufacturer's tests were not representative of th eactual automotive environments, nor were they conducted in a manner to access actual failures. We conclude with a recommendation for a physics-of-failure approach for future product development.