MIDWAY FAULT DIAGNOSTIC SYSTEM AND ELECTRIC POWER STEERING DEVICE EQUIPPED WITH SAME

Title:

MIDWAY FAULT DIAGNOSTIC SYSTEM AND ELECTRIC POWER STEERING DEVICE EQUIPPED WITH SAME

Document Type and Number:

WIPO Patent Application WO/2015/076173

Kind Code:

A1

Abstract:

[Problem] To provide a midway fault diagnostic system having improved reliability and a high-performance electric power steering device equipped with this system, wherein midway faults are detected and unanticipated system failures can be suppressed either by setting a midway fault diagnostic threshold below a conventional fault threshold in addition to setting the conventional fault threshold, or by setting a midway fault diagnostic threshold in detection resolution units. [Solution] A fault diagnostic system comprising a fail counter for calculating a normal distribution from the average value and standard deviation of measured values during normal operation of an electric device, setting at least one fault threshold as a diagnostic threshold of the measured values, measuring the rotation or time duration of measured values exceeding the fault threshold, and confirming faults diagnosed in a normal manner; wherein the midway fault diagnostic threshold is set between the average value and the fault threshold, the fail counter measures the rotation or time duration during which the measured values exceed the midway fault diagnostic threshold, and a counted number or a time duration for faults confirmed by the fail counter is set so that a false fault probability of normal diagnosis and a false fault probability of midway fault diagnosis are the same.

Inventors:

GOTO HIROKI (JP)

Application Number:

PCT/JP2014/080042

Publication Date:

May 28, 2015

Filing Date:

November 13, 2014

Export Citation:

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Assignee:

NSK LTD (JP)

International Classes:

B62D6/00; B62D5/04; G05B23/02

Foreign References:

JP2004090683A	2004-03-25
JP2006143359A	2006-06-08
JP2011079350A	2011-04-21
JP2004301568A	2004-10-28
JP2011189788A	2011-09-29
JP2012220485A	2012-11-12
JP2012220485A	2012-10-02

Other References: