Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Vehicle diagnosis or maintenance indication
Reexamination Certificate
1999-09-28
2001-04-17
Cuchlinski, Jr., William A. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Vehicle diagnosis or maintenance indication
C701S029000, C701S030000, C701S045000, C244S00100R, 36, 36
Reexamination Certificate
active
06219597
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for aiding the maintenance of a complex system, as well as a device for implementing this process.
2. Description of the Related Art
Within the context of the present invention, the expression complex system is understood to mean a system comprising a plurality of components, especially electronic, mechanical and hydraulic components, exhibiting numerous interconnections. Complex systems of this type exist in a great variety of fields of activity, such as for example in industry, in the automobile sector or in aviation.
For the maintenance of a complex system of this kind, in particular an aircraft such as a helicopter, in the simplest cases a maintenance plan is formed which catalogs the potential failures of said complex system and describes the refurbishment procedures suitable for the situation encountered. This known approach has a major drawback due to the unforeseen and unforeseeable nature of the moment of the failure so that it is often completely inadvisable, or even impossible, to implement it, for safety reasons.
By way of illustration, with regard, for example, to the lubricating of the engine of a vehicle, this known approach presupposes that the oil is neither changed nor checked, but that the consequences of the loss of lubrication are awaited in order to carry out a maintenance action, which is of course absurd.
To remedy this drawback, another known maintenance procedure advocates the use of a concept of preventive maintenance, which in its simplest version consists in periodically exchanging or overhauling parts or elements of the complex system. In the aforesaid exemplary illustration, this approach consists in carrying out drainage at regular time intervals, for example every three months (a period which is presumed to be sufficient in order for the oil for example of an optimally running automobile to be degraded). The drawback of this maintenance procedure relates to the operational constraints (availability, cost) related thereto, since the maintenance is performed prior to failure, usually on parts which are still serviceable.
It will be noted that another known procedure advocates that the state of the parts be monitored directly, this entailing drawbacks due to the quality of the observation criteria, to their representativity, to the constraint imposed on the user of the complex system and to the risks of errors.
In practice, the constructor of the complex system or the maintenance operator seeks, among the various possible maintenance options, the best compromise between the risk of an unforeseen failure, and one which is therefore penalizing in respect of safety or availability, and prior maintenance, which is therefore expensive and constraining.
However, this compromise generally entails a maintenance deadline which is very much ahead of the optimal deadline and, usually, the changed parts are still in a satisfactory state of serviceability when they are replaced.
Accordingly, for parts such as the settings for the blades of a helicopter, for example, for which any maintenance error is proscribed for obvious safety reasons, the margins regarding the timescales for changing parts are considerable and/or the maintenance regarding the monitoring of the state of the parts is very unwieldy.
SUMMARY OF THE INVENTION
The object of the present invention is to remedy these drawbacks according to the present invention a process for aiding the maintenance of a complex system which makes it possible to carry out maintenance actions at reduced cost and reduced monitoring, whilst preserving safety.
To this end, according to the invention, a process for aiding the maintenance of a complex system, especially an aircraft, is noteworthy in that the following actions are carried out iteratively and automatically:
a) during the operation of said complex system, monitoring data representative of the actual operation of at least one element of said complex system are determined and recorded iteratively;
b) at least one damage level representative of the actual damage to said element is determined from said recorded monitoring data and with the aid of degradation models;
c) on the basis of this damage level at least maintenance deadlines are updated for said element; and
d) these maintenance deadlines are signaled to an operator of said complex system.
Thus, by virtue of the invention, the maintenance deadlines or the maintenance plan are automatically adapted to the actual state (of damage) of the complex system and/or of its elements, during the operation of said complex system, thus making it possible to define maintenance actions which are optimal in particular as regards availability, cost and safety.
To this end, it will be noted that:
the process in accordance with the invention makes it possible to refine the diagnosis relating to the damage to the parts or elements of the complex system and hence to limit the margins with regard to the dismantling or repair criteria, so as to ensure the safety and availability of the complex system. This reduction in the margins makes it possible to defer the maintenance works and hence to limit, over a given period, the cost of maintenance; and
the knowledge of the actual damage to the complex system makes it possible to anticipate the failures and thereby permits preventive maintenance which limits the cases of unprogrammed dismantling, which are the most penalizing with regard to the operational availability of the system.
Moreover, the early and reliable prediction of failures, which is thus achieved, allows economic planning of maintenance.
Advantageously, in step a) at least some of the following information is determined and recorded as monitoring data:
information characterizing levels of use of said complex system;
information characterizing levels of loading;
health information;
information relating to the behavior of said element or of said complex system; and
information relating to alarms or instructions generated by said complex system.
Furthermore, advantageously:
in step b), at least one of the following models is used as degradation models:
a model for determining limits of operation of said element of the complex system; and
a behavioral model of said element; and/or
in step c), the maintenance deadlines are determined from:
the damage level determined in step b);
a damage threshold for said element; and
a damage rate for said element; and/or
in step c), a projected timetable of maintenance actions to be carried out on said complex system is generated; and/or
in step c), auxiliary maintenance information is also determined, and in step d), this auxiliary maintenance information, in particular damage curves and tie-ups with maintenance manuals, is signaled to said operator.
Additionally, in order to optimize the maintenance actions, advantageously, in step a), said monitoring data are determined arbitrarily in such a way as to be able to carry out simulations.
Moreover, advantageously, at least the conditions of use of said complex system and data occurring during the implementation of the process are recorded, thus making it possible to exploit the experience acquired by implementing said process. The information thus recorded benefits in particular the user of said complex system in order to provide him with a better knowledge of said complex system and/or of the elements thereof, as well as the impact of the operational conditions on this complex system or these elements.
Furthermore, to improve the accuracy of the processings, advantageously, complementary information is used to refine:
in step b), said damage level; and
in step c), the information determined on the basis of said damage level.
Moreover, according to the invention, at least data occurring during the implementation of steps a) and b) of said process are recorded in such a way as to be able to retrieve them, thus making it possible to obtain an accurate picture regarding the actual state of the complex system.
Furthermore, in particular so that
Cuchlinski Jr. William A.
Eurocopter
Stevens Davis Miller & Mosher LLP
To Tuan
LandOfFree
Process and device for aiding the maintenance of a complex... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and device for aiding the maintenance of a complex..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and device for aiding the maintenance of a complex... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2552356