INTERMITTENT FAILURE DIAGNOSTIC SYSTEM AND ELECTRIC POWER STEERING APPARATUS PROVIDED WITH THE SAME
1 Assignment
0 Petitions
Accused Products
Abstract
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.
-
Citations
18 Claims
-
1-9. -9. (canceled)
-
10. An intermittent failure diagnostic system comprising a fail-counter to failure-settle 1 on an ordinary diagnosis by calculating a normal distribution based on a mean value and a standard deviation of measured values at a normal state of an electrical apparatus, by setting at least one failure threshold as a diagnostic threshold of said measured values, and by measuring a number or a time of said measured values exceeding said failure threshold:
-
wherein said intermittent failure diagnostic system sets an intermittent failure diagnostic threshold for an intermittent failure diagnosis between said mean value and said failure threshold, and said fail-counter measures a number or a time that said measured values exceed said intermittent failure diagnostic threshold; and wherein said intermittent failure diagnostic system sets a counting value or a time to failure-settle 2 on said fail-counter so as to coincide a permissible value on a false-failure probability of said ordinary diagnosis with a permissible value on a false-failure probability of said intermittent failure diagnosis, wherein assuming that a counting value of said fail-counter to failure-settle 1 on said ordinary diagnosis is n, a counting value of said fail-counter to failure-settle 2 is N, a permissible value on a false-failure probability of said ordinary diagnosis is PFn and a permissible value on a false-failure probability of said intermittent failure diagnosis is PTN, a relation
N=(n*log PF)/(log PT)is established. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification