Midway fault diagnosis system and electric power steering apparatus incorporating it

摘要

[Problem] An object of the present invention is to provide an intermittent failure diagnostic system that in addition to a failure detection of a conventional failure threshold, sets an intermittent diagnostic threshold inside of the failure threshold or sets the intermittent diagnostic threshold in an arbitrary scope with a detection resolving-power unit, securely detects the intermittent failure in a wide region by using a statistics way, suppresses an unprepared system down and improves the reliability and to an electric power steering apparatus provided with the same. [Means for solving the problem] The present invention is an intermittent failure diagnostic system comprising: wherein the intermittent failure diagnostic system sets an intermittent failure diagnostic threshold for an intermittent failure diagnosis between the mean value and the failure threshold, and the fail-counter measures a number or a time that the measured values exceed the intermittent failure diagnostic threshold; and wherein the intermittent failure diagnostic system sets a counting value or a time to failure-settle 2 on the fail-counter so as to coincide a false-failure probability of the ordinary diagnosis with a false-failure probability of the intermittent failure diagnosis.