U.S. patent application number 16/600170 was filed with the patent office on 2020-02-13 for engine degradation management via multi-engine mechanical power control.
The applicant listed for this patent is Bell Helicopter Textron Inc., Rolls-Royce North American Technologies, Inc.. Invention is credited to Douglas Boyd, Brian Tucker.
Application Number | 20200047907 16/600170 |
Document ID | / |
Family ID | 60242843 |
Filed Date | 2020-02-13 |
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United States Patent
Application |
20200047907 |
Kind Code |
A1 |
Boyd; Douglas ; et
al. |
February 13, 2020 |
ENGINE DEGRADATION MANAGEMENT VIA MULTI-ENGINE MECHANICAL POWER
CONTROL
Abstract
A multi-engine power system is described that includes at least
a first engine and a second engine configured to jointly provided
mechanical power to the multi-engine power system. The multi-engine
power system further includes a controller configured to estimate a
deterioration factor of the first engine. The controller is further
configured to adjust, based on the deterioration factor of the
first engine, a first amount of mechanical power being provided by
the first engine to increase a service time of the first engine,
and adjust, based on the first amount of mechanical power being
provided by the first engine, a second amount of mechanical power
being provided by the second engine to compensate for the
adjustment to the first amount of mechanical power.
Inventors: |
Boyd; Douglas;
(Indianapolis, IN) ; Tucker; Brian; (Fort Worth,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rolls-Royce North American Technologies, Inc.
Bell Helicopter Textron Inc. |
Indianapolis
Fort Worth |
IN
TX |
US
US |
|
|
Family ID: |
60242843 |
Appl. No.: |
16/600170 |
Filed: |
October 11, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15586136 |
May 3, 2017 |
10442544 |
|
|
16600170 |
|
|
|
|
62333747 |
May 9, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D 2045/0085 20130101;
B64D 31/06 20130101 |
International
Class: |
B64D 31/06 20060101
B64D031/06 |
Claims
1. An engine controller comprising: at least one processor; and a
memory storing instructions that, when executed, cause the at least
one processor to: monitor one or more operating parameters of each
of a first engine and a second engine from two or more engines that
are configured to jointly provide mechanical power to a
multi-engine power system; estimate a deterioration factor of the
first engine based on the one or more operating parameters of the
first engine, wherein the first engine is configured to supply
mechanical power to a first propulsor or a first generator;
estimate a deterioration factor of the second engine based on the
one or more operating parameters of the second engine, wherein the
second engine is configured to supply mechanical power to a second
propulsor or a second generator, different from the first propulsor
or the first generator; adjust, based on the deterioration factor
of the first engine, a first amount of mechanical power being
provided by the first engine to extend a service time of the first
engine; and adjust, based on the deterioration factor of the second
engine, a second amount of mechanical power being provided by the
second engine to at least partially compensate for the adjustment
to the first amount of mechanical power.
2. The engine controller of claim 1, wherein the one or more
operating parameters of the first engine includes at least one of a
temperature of the first engine, a fuel consumption of the first
engine, or a shaft speed of the first engine, and wherein the one
or more operating parameters of the second engine includes at least
one of a temperature of the second engine, a fuel consumption of
the second engine, or a shaft speed of the second engine.
3. The engine controller of claim 1, wherein the instructions, when
executed, further cause the at least one processor to: estimate the
deterioration factor of the first engine using a model that equates
the one or more operating parameters of the first engine at the
first amount of mechanical power to the deterioration factor of the
first engine; and estimate the deterioration factor of the second
engine using a model that equates the one or more operating
parameters of the second engine at the second amount of mechanical
power to the deterioration factor of the second engine.
4. The engine controller of claim 1, wherein the instructions, when
executed, further cause the at least one processor to: adjust the
first amount of mechanical power being provided by the first engine
to adjust a rate of change of the deterioration factor of the first
engine; adjust the second amount of mechanical power being provided
by the second engine to adjust a rate of change of the
deterioration factor of the second engine.
5. The engine controller of claim 4, wherein the instructions, when
executed, further cause the at least one processor to: adjust the
first amount of mechanical power being provided by the first engine
to decrease the rate of change of the deterioration factor of the
first engine to extend the service time of the first engine; and
adjust the second amount of mechanical power being provided by the
second engine to increase the rate of change of the deterioration
factor of the second engine to shorten a service time of the second
engine.
6. The engine controller of claim 5, wherein the instructions, when
executed, further cause the at least one processor to: determine
that the rate of change of the deterioration factor of the first
engine is greater than the rate of change of the deterioration
factor of the second engine; in response to determining that the
rate of change of the deterioration factor of the first engine is
greater than the rate of change of the deterioration factor of the
second engine, adjusting the first amount of mechanical power being
provided by the first engine and the second amount of mechanical
power being provided by the second engine.
7. The engine controller of claim 1, wherein the deterioration
factor of the first engine corresponds to a percentage of a total
amount of degradation of the first engine, and wherein the
deterioration factor of the second engine corresponds to a
percentage of a total amount of degradation of the second
engine.
8. A method comprising: monitoring, by a controller of two or more
engines that are configured to jointly provide mechanical power to
a multi-engine power system, one or more operating parameters of
each of a first engine and a second engine of the two or more
engines: estimating, by the controller, a deterioration factor of
the first engine based on the one or more operating parameters of
the first engine, wherein the first engine is configured to supply
mechanical power to a first propulsor or a first generator;
estimating, by the controller a deterioration factor of the second
engine based on the one or more operating parameters of the second
engine, wherein the second engine is configured to supply
mechanical power to a second propulsor or a second generator,
different from the first propulsor or the first generator;
adjusting, by the controller and based on the deterioration factor
of the first engine, a first amount of mechanical power being
provided by the first engine to extend a service time of the first
engine; and adjusting, by the controller and based on the
deterioration factor of the second engine, a second amount of
mechanical power being provided by the second engine to at least
partially compensate for the adjustment to the first amount of
mechanical power.
9. The method of claim 8, wherein the one or more operating
parameters of the first engine includes at least one of a
temperature of the first engine, a fuel consumption of the first
engine, or a shaft speed of the first engine, and wherein the one
or more operating parameters of the second engine includes at least
one of a temperature of the second engine, a fuel consumption of
the second engine, or a shaft speed of the second engine.
10. The method of claim 8, further comprising: estimating, by the
controller, the deterioration factor of the first engine using a
model that equates the one or more operating parameters of the
first engine at the first amount of mechanical power to the
deterioration factor of the first engine; and estimating, by the
controller, the deterioration factor of the second engine using a
model that equates the one or more operating parameters of the
second engine at the second amount of mechanical power to the
deterioration factor of the second engine.
11. The method of claim 8, further comprising: adjusting, by the
controller, the first amount of mechanical power being provided by
the first engine to adjust a rate of change of the deterioration
factor of the first engine; and adjusting, by the controller, the
second amount of mechanical power being provided by the second
engine to adjust a rate of change of the deterioration factor of
the second engine.
12. The method of claim 11, further comprising: adjusting, by the
controller, the first amount of mechanical power being provided by
the first engine to decrease the rate of change of the
deterioration factor of the first engine to extend the service time
of the first engine; and adjusting, by the controller, the second
amount of mechanical power being provided by the second engine to
increase the rate of change of the deterioration factor of the
second engine to shorten a service time of the second engine.
13. The method of claim 8, wherein the deterioration factor of the
first engine corresponds to a percentage of a total amount of
degradation of the first engine, and wherein the deterioration
factor of the second engine corresponds to a percentage of a total
amount of degradation of the second engine.
14. A multi-engine power system comprising: at least a first engine
and a second engine configured to jointly provide mechanical power
to the multi-engine power system; and a controller configured to:
monitor one or more operating parameters of each of the first
engine and the second engine; estimate a deterioration factor of
the first engine based on the one or more operating parameters of
the first engine, wherein the first engine is configured to supply
mechanical power to a first propulsor or a first generator;
estimate a deterioration factor of the second engine based on the
one or more operating parameters of the second engine, wherein the
second engine is configured to supply mechanical power to a second
propulsor or a second generator, different from the first propulsor
or the first generator; adjust, based on the deterioration factor
of the first engine, a first amount of mechanical power being
provided by the first engine to extend a service time of the first
engine; and adjust, based on the deterioration factor of the second
engine, a second amount of mechanical power being provided by the
second engine to at least partially compensate for the adjustment
to the first amount of mechanical power.
15. The multi-engine power system of claim 14, wherein the one or
more operating parameters of the first engine includes at least one
of a temperature of the first engine, a fuel consumption of the
first engine, or a shaft speed of the first engine, and wherein the
one or more operating parameters of the second engine includes at
least one of a temperature of the second engine, a fuel consumption
of the second engine, or a shaft speed of the second engine.
16. The multi-engine power system of claim 14, wherein the
controller is configured to: estimate the deterioration factor of
the first engine using a model that equates the one or more
operating parameters of the first engine at the first amount of
mechanical power to the deterioration factor of the first engine;
and estimate the deterioration factor of the second engine using a
model that equates the one or more operating parameters of the
second engine at the second amount of mechanical power to the
deterioration factor of the second engine.
17. The multi-engine power system of claim 14, wherein the
controller is configured to: adjust the first amount of mechanical
power being provided by the first engine to adjust a rate of change
of the deterioration factor of the first engine; and adjust the
second amount of mechanical power being provided by the second
engine to adjust a rate of change of the deterioration factor of
the second engine.
18. The multi-engine power system of claim 17, wherein the
controller is configured to: adjust the first amount of mechanical
power being provided by the first engine to decrease the rate of
change of the deterioration factor of the first engine to extend
the service time of the first engine; and adjust the second amount
of mechanical power being provided by the second engine to increase
the rate of change of the deterioration factor of the second engine
to shorten a service time of the second engine.
19. The multi-engine power system of claim 14, wherein the
deterioration factor of the first engine corresponds to a
percentage of a total amount of degradation of the first engine,
and wherein the deterioration factor of the second engine
corresponds to a percentage of a total amount of degradation of the
second engine.
20. The multi-engine power system of claim 14, wherein the first
and second engines are tilt-rotor engines of a tilt-rotor aircraft.
Description
[0001] This application is a continuation of U.S. application Ser.
No. 15/586,136 filed May 3, 2017, which claims the benefit of U.S.
Provisional Application Ser. No. 62/333,747 filed May 9, 2016, both
of which are incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The disclosure relates to techniques for mechanical power
management in multi-engine systems.
BACKGROUND
[0003] Some systems rely on multiple engines for producing
mechanical power. For example, many aircraft (e.g., fixed-wing,
rotorcraft, tilt-rotorcraft, etc.) rely on two or more engines to
produce thrust. Mechanical deterioration and operational stresses
endured by mechanical components of an engine may cause performance
of that engine to degrade over time. Even if a multi-engine system
commands each engine to provide approximately the same amount of
mechanical power, each engine is inherently unique and may degrade
at a different rate.
[0004] Eventually an engine may degrade to its respective
end-of-life. Although other engines of the system may still possess
useful life, a system may need to be taken offline each time a
degraded engine needs to be serviced, overhauled, or replaced. To
avoid having to take an entire system offline each time a single
engine needs overhauling or replacing, a multi-engine system may
replace all the engines while the system is offline, potentially
wasting the useful life left in the other engines that do not
necessarily need replacing.
SUMMARY
[0005] In one example, the disclosure is directed to an engine
controller that includes at least one processor, and a memory
storing instructions. The instructions, when executed, cause the at
least one processor to: estimate a deterioration factor of a first
engine from two or more engines that are configured to jointly
provide mechanical power to a multi-engine power system, adjust,
based on the deterioration factor of the first engine, a first
amount of mechanical power being provided by the first engine to
extend a service time of the first engine, and adjust, based on the
first amount of mechanical power being provided by the first
engine, a second amount of mechanical power being provided by a
second engine from the two or more engines to compensate for the
adjustment to the first amount of mechanical power.
[0006] In another example, the disclosure is directed to a method
that includes estimating, by a controller of two or more engines of
a multi-engine power system, a deterioration factor of a first
engine from two or more engines that are configured to jointly
provide mechanical power required by the multi-engine power system,
and adjusting, by the controller, based on the deterioration factor
of the first engine, a first amount of mechanical power being
provided by the first engine to increase a service time of the
first engine. The method further includes adjusting, by the
controller, based on the first amount of mechanical power being
provided by the first engine, a second amount of mechanical power
being provided by a second engine from the two or more engines to
compensate for the adjustment to the first amount of mechanical
power.
[0007] In yet another example, the disclosure is directed to a
multi-engine power system that includes at least a first engine and
a second engine configured to jointly provided mechanical power to
the multi-engine power system, and a controller. The controller is
configured to: estimate a deterioration factor of the first engine,
adjust, based on the deterioration factor of the first engine, a
first amount of mechanical power being provided by the first engine
to increase a service time of the first engine, and adjust, based
on the first amount of mechanical power being provided by the first
engine, a second amount of mechanical power being provided by the
second engine to compensate for the adjustment to the first amount
of mechanical power.
[0008] The details of one or more examples are set forth in the
accompanying drawings and the description below. Other features,
objects, and advantages of the disclosure will be apparent from the
description and drawings, and from the claims.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a conceptual diagram illustrating an example
multi-engine system configured to independently adjust the
mechanical power being provided by multiple engines to balance the
respective degradation levels of each of the engines, in accordance
with one or more aspects of the present disclosure.
[0010] FIG. 2 is a flow chart illustrating example operations
performed by an example controller configured to individually
adjust the mechanical power being provided by multiple engines to
balance the respective degradation levels of each of the engines,
in accordance with one or more aspects of the present
disclosure.
[0011] FIG. 3 is a conceptual diagram illustrating degradation
rates of two different engines of an example multi-engine system
that is configured to independently adjust the mechanical power
being provided by multiple engines to balance the respective
degradation levels of each of the engines, in accordance with one
or more aspects of the present disclosure.
DETAILED DESCRIPTION
[0012] In general, techniques and circuits of this disclosure may
enable an engine controller to individually adjust the mechanical
power being provided by two or more engines of a multi-engine
system to adjust the degradation rate of at least one of the
engines while meeting mechanical power requirements of the system.
For example, a multi-engine system, such as an aircraft, may rely
on mechanical power provided by two or more engines (e.g., turbine
engines, piston engines, etc.) to provide thrust, to be converted
to electrical power, or the like. An example controller of the
multi-engine system may dynamically manage the mechanical power
output from each of the two or more engines not only to meet the
mechanical power requirements of the system, but also to directly
affect deterioration of mechanical components of, and therefore
degradation in performance of, at least one of the engines. In
other words, unlike other multi-engine system controllers that
manage engine output primarily to satisfy electrical or mechanical
power requirements of the system, the example controller described
herein also considers engine degradation when determining how much
mechanical power to extract from each engine at any given time.
[0013] For instance, the example controller may request different
amounts of mechanical power from two different engines depending on
the degradation levels of the two engines. The controller may keep
the total power produced by the two engines the same, while
commanding the better preforming (or less deteriorated) engine of
the two to produce more power and commanding the worse performing
(or more deteriorated) engine of the two to produce less power. The
power differential between the two engines may depend on the
difference in degradation between them.
[0014] In this way, the example controller may vary mechanical
power produced by at least one engine in the system as a way to
manage the relative deterioration and degradation of each engine in
the system, extend the service time or even end-of-life of a more
deteriorated engine, or cause multiple engines to degrade a
different rates so as to be ready for service at approximately the
same time. In addition, since a better performing engine (e.g., an
engine that produces more mechanical power for similar degradation
rate) typically consumes less fuel than a worse performing engine,
a multi-engine system that relies on an example controller
described herein may experience better overall fuel flow since the
example controller may cause the better performing engine to
produce more of the mechanical power. As such, a multi-engine
system that relies on the example controller may experience less
down time, have a greater maintenance-free operating period,
potentially consume less fuel, and therefore, cost less to operate
and maintain as compared to other systems.
[0015] FIG. 1 is a conceptual diagram illustrating an example
multi-engine system 100 configured to adjust the mechanical power
being provided by multiple engines to balance the respective
degradation levels of each of the engines, in accordance with one
or more aspects of the present disclosure. Multi-engine system 100
(also referred to simply as "system 100") represents any
multi-engine system relies on two or more engines for mechanical
power. For ease of description, system 100 is described primarily
as being part of an aircraft, such as a fixed-wing aircraft,
rotor-craft, tilt-rotor craft or any other type of aircraft.
However, many other examples of system 100 exist. For example,
system 100 may be part of a mechanical power system of a marine
craft, space craft, or other vehicle, a power plant for driving
generators for powering a power grid or other electrical system, or
any other type of mechanical power system that relies on the
mechanical output from multiple engines to perform work.
[0016] System 100 includes engines 102A-102N (collectively "engines
102"), mechanical shafts 108A-108N (collectively "shafts 108"), one
or more loads 106, and controller 112. Controller 112 is
communicatively coupled to some or all of components 102, 106, and
108 via communication link 118. In other examples, system 100 may
include additional or fewer components than those shown including a
single communication link 118 or multiple, communication links
communicatively coupling controller 112 to the various components
of system 100.
[0017] Loads 106 represent any number of components (e.g.,
mechanical or electrical) that rely on mechanical power produced by
a multi-engine power system such as system 100. For example, when
system 100 is part of an aircraft, load 106 may include any
quantity electrical machines (e.g., alternators, generators, or
other electrical machines) for powering lighting components,
avionics components, pumps, communication systems, computer
systems, display systems, cabin comfort systems, or any other
electrical component or subsystem of the aircraft. Load 106 may
include any quantity of mechanical propulsion components (e.g.,
shafts, propellers, gearboxes, or other mechanical components) that
rely on mechanical power from a multiple engines to perform work.
As one example, loads 106 are shown in FIG. 1 as propellers,
however loads 106 may include any type of and any quantity of
mechanical load that derives mechanical power from one or more
engines such as engines 102.
[0018] Loads 106 are shown in FIG. 1 as being mechanically coupled
to engines 102 via mechanical shafts 108. When engine 102A is
running, engine 102A may output mechanical power to loads 106 by
spinning mechanical shaft 108A. Similarly, when engine 102N is
running, engine 102N may output mechanical power to loads 106 by
spinning mechanical shaft 108N.
[0019] Each of engines 102 represents any mechanical power source
that is configured to produce mechanical power. In some examples,
engines 102 may produce mechanical power for loads 106, for
instance, for providing thrust or power for one or more propellers,
fans, fuel pumps, hydraulic pumps and other equipment associated
with load 106. As shown in FIG. 1, each of engines 102 may be
mechanically coupled to a propeller or fan (e.g., a propulsor) for
producing thrust. Examples of engines 102 include gas turbine
engines, internal combustion engines, such as piston or rotary
engines, or any other type of engine that mechanically drives one
or more mechanical shafts 108. The mechanical output from each of
engines 102 can be individually controlled by controller 112. For
example, controller 112 may control the throttle of engine 102A to
control the speed at which engine 102A spins mechanical shaft 108A
independently of the throttle setting controller 112 commands to
engine 102N to control the speed with which engine 102N spins
mechanical shaft 108N.
[0020] In some examples, for instance, on a multi-engine aircraft,
each engine 102 may include multiple shafts 108. For example, in
examples in which engine 102 are gas turbine engines, often times
each of engines 102 may have two shafts, a high pressure shaft and
a low pressure shaft. Load 106 may be coupled to one or both shafts
108 to receive mechanical power being produced by engines 102.
[0021] In any case, by load 106 consuming mechanical power from
engines 102, load 106 is extracting mechanical power from the
thermodynamic cycles of engines 102. This mechanical power
extraction by load 106 will affect the thermodynamic cycle of each
of engines 102 thereby impacting fuel consumption, operating
temperatures, and pressures in each of engines 102.
[0022] Each of engines 102 may be at a different stage in its
respective service time or life cycle when that engine is installed
in system 100. For example, engine 102N may be been installed in
system 100 as a new engine, hours, months or even years before
engine 102A is installed as a new engine in system 100. Therefore,
when engine 102A is installed in system 100, engine 102A may
inherently have a longer remaining operating life as compared to
engine 102N since engine 102N was installed and ran for some time
prior to engine 102A being installed. Or in some examples, engines
102A and 102N may be installed as new engines in system 100 at the
same time, but engine 102N may incur damage or experience a failure
condition (e.g., during combat, training, or in an accident) and as
a result, have a shorter respective service time or life cycle as
compared to engine 102A that did not incur damage or experience the
failure condition.
[0023] Even if each of engines 102 are at the same stage in their
respective service times or operating life cycles when installed in
system 100, and each of engines 102 has similar power and torque
ratings, each of engines 102 is unique and the respective
performance of each may degrade at different rates over time. For
example, due to variations in manufacturing conditions, operating
conditions, environmental conditions, and other factors, the
mechanical components of engine 102A may deteriorate faster than
the mechanical components of engine 102N. Engine 102A may therefore
be required to work harder (e.g., run faster, hotter, etc.) during
its life to produce the same amount of mechanical power as engine
102N. Eventually, over time, even if both engines 102A and 102N are
controlled so as to produce the same or similar amounts of
mechanical power, engines 102A and 102N may reach their respective
end of life or service time, at different points in time. For
example, engine 102A may degrade or deteriorate more quickly than
engine 102N and need to be maintained, overhauled, and/or replaced
before engine 102N needs similar servicing.
[0024] In general, controller 112 may control the amount of
mechanical power being produced by each of engines 102 for use by
load 106 and the rest of system 100. Controller 112 may adjust the
mechanical power being provided by engines 102 to manage the rate
of degradation of at least one of engines 102 while meeting
mechanical power requirements of system 100.
[0025] Controller 112 is shown in FIG. 1 as being operationally
coupled to each of components 102, 106, and 108 via communication
link 118, which may be one or more wired or wireless communication
links. In some examples, controller 112 may be operationally
coupled to a subset of components 102, 106, and 108. Controller 112
may exchange information across communication link 118 between
components 102, 106, and 108, and any other components of system
100 to cause engines 102 to distribute, and refrain from
distributing, mechanical power to load 106. In some instances,
controller 112 may communicate via communication link 118 with
other control modules of system 100 (not shown in FIG. 1), such as
respective engine control modules associated with engines 102, to
vary or manage the mechanical power being produced for load
106.
[0026] Controller 112 may comprise any suitable arrangement of
hardware, software, firmware, or any combination thereof, to
perform the techniques attributed to controller 112 herein.
Examples of controller 12 include any one or more microprocessors,
digital signal processors (DSPs), application specific integrated
circuits (ASICs), field programmable gate arrays (FPGAs), or any
other equivalent integrated or discrete logic circuitry, as well as
any combinations of such components. When controller 121 includes
software or firmware, controller 112 further includes any necessary
hardware for storing and executing the software or firmware, such
as one or more processors or processing units.
[0027] In general, a processing unit may include one or more
microprocessors, DSPs, ASICs, FPGAs, or any other equivalent
integrated or discrete logic circuitry, as well as any combinations
of such components. Although not shown in FIG. 1, controller 112
may include a memory configured to store data. The memory may
include any volatile or non-volatile media, such as a random access
memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM),
electrically erasable programmable ROM (EEPROM), flash memory, and
the like. In some examples, the memory may be external to
controller 112 (e.g., may be external to a package in which
controller 112 is housed).
[0028] While controller 112 may coordinate mechanical power
production and degradation of engines 102 to meet overall
performance requirements (e.g., total electrical, mechanical,
and/or thrust power) of system 100, controller 112 may also control
engines 102 to coordinate deterioration or degradation in
performance of engines 102 as a way to coordinate the respective
service life of each of engines 102. For example, controller 112
may control engines 102 to ensure a total amount of thrust or
particular fuel consumption is being provided by engines 102 while
at the same time request a different amount of power from each of
engines 102 depending on their respective degradation levels. For
instance, controller 112 may request less power from a more
degraded engine 102 and to compensate in the total system level
reduction in power, controller 112 may request more power from a
lightly degraded engine 102. By controlling engines 102 based on
the respective deterioration levels of each of engines 102,
controller 112 may coordinate the respective service times of
engines 102.
[0029] As used herein, the term "service time" of an engine
corresponds to any milestone in the life cycle of an engine at
which it may be desirable to replace, perform maintenance,
overhaul, repair, or otherwise service the engine. For example, the
service time of an engine may correspond to the end-of-life of the
engine or a maintenance milestone of the engine.
[0030] The service time of an engine may depend on a variety of
factors, including variations in: manufacturing conditions of the
engine and components thereof (e.g., variations in quality,
humidity, materials, etc.), operating stresses (e.g., throttle
settings, torque settings, operating temperatures, acceleration
loads, other stresses, etc.) environmental conditions (e.g.,
altitude variations, external temperature variations, humidity
variations, etc.) and other factors (e.g., bird strikes, combat
related damage, civilian accidents, maintenance or operator error,
etc.).
[0031] The service time of an engine may occur naturally (e.g.,
through regular use) or occur suddenly (e.g., after a failure
event) and may change over time. For instance, the service time of
an engine that was previously set to occur at some future time may
change and correspond to an earlier time (e.g., due to stressing
the engine, bird strike, combat event, accident, etc.). In some
examples, the service time of an engine that was previously set to
occur at some future time may change and become immediate,
corresponding to a current time (e.g., due to a catastrophic
failure event from combat, accident, over-stressing, other failure
condition).
[0032] Controller 112 may operate with an objective of managing
deterioration levels of engines 102 such that each of engines 102
reaches a respective service time at approximately the same time.
For example, controller 112 may extract mechanical power from each
engine 102 differently, as needed, to decrease the rate of
degradation of the most degraded engine 102 (less electrical power
extraction) while increasing the rate of degradation of the least
degraded engines 102 (more electrical power extraction). By
adjusting mechanical power extraction from engines 102 based on
deterioration levels of engines 102, controller 112 may minimize
the frequency with which system 100 goes down for engine
maintenance and in some examples, may extend the amount of time
between engine service times. In addition, by extracting more
mechanical power from a less deteriorated engine 102 to compensate
for a reduction in mechanical output from a greater deteriorated
engine 102, controller 112 may cause system 100 to have an overall
reduced amount of fuel flow. As such, the example multi-engine
system may experience less down time for engine maintenance and
cost less to maintain as compared to other systems.
[0033] FIG. 2 is a flow chart illustrating example operations
performed by an example controller configured to adjust the
mechanical power being provided by multiple engines to balance the
respective degradation levels of each of the engines, in accordance
with one or more aspects of the present disclosure. FIG. 2 is
described in the context of the components of system 100 of FIG. 1,
although the technique of FIG. 2 may be implemented by other
systems including additional or fewer components. Controller 112
may perform additional or fewer operations than those shown in FIG.
2 and may perform the operations shown in FIG. 2 in any order.
[0034] As shown in FIG. 2, in accordance with techniques of this
disclosure, controller 112 may estimate a deterioration factor of a
first engine and a deterioration factor of a second engine from two
or more engines that are configured to jointly provide mechanical
power to a multi-engine power system (200). For example, controller
112 may communicate via link 118 with load 106 and the various
other systems and subsystems associated with system 100 to
determine the total mechanical power required from engines 102.
Controller 112 may determine the total mechanical power to be
provided to load 106 and system 100 so that controller 112 can
cause engines 102 to jointly provide sufficient mechanical power to
system 100.
[0035] While controller 112 causes engines 102 to jointly provide
mechanical power that is sufficient to power load 106, controller
112 may monitor one or more operating parameters associated with
each of engines 102 in order to estimate respective deterioration
factors associated with each of engines 102. For example,
controller 112 may monitor operating temperatures, fuel consumption
rates, shaft speeds, hours of usage, pressures, amounts of
electrical and mechanical output, and other operating parameters
associated with engines 102 to obtain information about the
respective degradation levels of each of engines 102 in order to
quantify an amount of remaining useful life associated with each of
engines 102.
[0036] Controller 112 may measure the one or more respective
operating parameters associated with engines 102 over prior time
durations (e.g., one or more minutes, hours, and/or days of prior
operation) and input the measured operating parameters into a model
for estimating, predicting, or projecting the amount of degradation
of each of engines 102 or the amount of useful life left in each of
engines 102 until its next service time. For example, controller
112 may rely on a model that is built from prior engine data
collected over time for a particular one of engines 102, or from
other, similar engines. The model may project the current
performance of a particular engine onto a degradation glide slope
that the model uses to estimate an end-of-life, or other service
time of that particular engine. The model may determine a
deterioration factor (e.g., a percentage, a score, etc.) that
indicates an amount of degradation or amount of operating life that
has been used up by a particular one of engines 102, before that
particular one of engines 102 will fail, need replacing, or
otherwise need servicing. Controller 112 may rely on look up
tables, functions, or other modules (in addition to or instead of a
model) to determine the deterioration factor of a particular one of
engines 102.
[0037] Unlike other engine balancing control systems, the example
multi-engine system may rely on averaging techniques and/or trends
analysis in the deterioration data to determine the best mechanical
power output to extract from each engine at various times. In
addition, unlike other engine balancing control systems, the
example multi-engine system may perform engine-life management
optimization rather than engine-limit avoidance. In other words,
rather than simply control engines to avoid exceeding their
mechanical power limits, the example multi-engine system may
perform trend analysis of engine data to control when and how fast
an engine reaches the end of its useful life.
[0038] Although primarily described herein as indicating an
engine's amount (e.g., percentage) of degradation or an amount of
spent or consumed useful life, a deterioration factor in some
examples could instead indicate an amount of life that is left in
an engine. In cases where the deterioration factor indicates an
engine's amount of degradation or amount of spent or consumed
useful life, reducing mechanical output from that engine may reduce
the rate of increase of the deterioration factor of the engine.
Whereas, in cases where the deterioration factor indicates and
engine's remaining useful life, reducing mechanical output from
that engine may reduce the rate of decrease of the deterioration
factor of the engine.
[0039] Controller 112 may input one or more operational parameters
of engines 102A into the model, and in response, the model may
output a deterioration factor of engines 102A. Similarly,
controller 112 may input one or more operational parameters of
engines 102N into the model, and in response, the model may output
a deterioration factor of engines 102N. For instance, the model may
output a deterioration factor of engine 102A that corresponds to a
percentage of a total amount of degradation of engine 102A before
engine 102A requires servicing or a total amount of degradation of
engine 102A since engine 102A was last serviced. Similarly, the
model may output a deterioration factor of engine 102N that
corresponds to a percentage of a total amount of degradation of
engine 102N before engine 102N requires servicing or a total amount
of degradation of engine 102N since engine 102N was last
serviced.
[0040] Controller 112 may rely on various sensors embedded within
engines 102 and other parts of system 100 to determine the
deterioration factor of each of engines 102. For example,
controller 112 may communicate with speedometers, tachometers,
accelerometers, thermometers, pressure sensors, and the like to
determine whether the performance of each of engines 102 has
degraded, and if so, by how much.
[0041] In some examples, the model relied on by controller 112 may
equate turbine temperature at a certain power to a deterioration
factor. For instance, if the temperature of engine 102A is higher
than expected for a certain commanded output, the model may
determine that by running hot, engine 102A is degraded. The level
of temperature increase over expected may be proportional to the
amount of degradation of the engine.
[0042] Controller 112 may measure variations in fuel flow to
achieve certain power as indicators of a deterioration factor of
one of engines 102. For example, controller 112 may determine that
a higher than expected rate of fuel burn for a particular power
setting indicates that a particular engine 102 is more degraded
than a different engine that burns less fuel for the same
particular power setting.
[0043] Similar to temperature and fuel flow, controller 112 may
determine a deterioration factor of any one of engines 102 based on
shaft speed of that particular one of engines 102 to achieve
certain power output. For example, controller 112 may determine
that a higher than expected shaft speed of shaft 108A for a
particular power setting indicates that engine 102A is more
degraded than engine 102N which spins shaft 108N at a lower shaft
speed for the same particular power setting.
[0044] Controller 112 may determine a differential between the
deterioration factor of the first engine and the deterioration
factor of the second engine (210). For example, controller 112 may
refrain from balancing the service times of two or more engines 102
if the deterioration factors are too far apart (e.g., the
difference in deterioration factors exceeds a threshold) and only
coordinate the service times if the deterioration factors are
somewhat similar (e.g., the difference in deterioration factors is
less than the threshold).
[0045] Controller 112 may determine whether the differential
exceeds a threshold (220). For instance, controller 112 may refrain
from coordinating service times if engine 102A is greatly
deteriorated (e.g., having degraded by 80% and having only 20%
remaining life) and engine 102N is less deteriorated (e.g., having
degraded by only 10% and still having 90% remaining life) causing
the differential between deterioration factors of engines 102A and
102N to be high (e.g., approximately 70%). On the other hand, if
engine 102A is somewhat deteriorated (e.g., having degraded 50% and
having 50% remaining life), and engine 102N is less deteriorated
(e.g., having degraded 80% and only having 20% remaining life),
causing the differential between deterioration factors of engines
102A and 102N to be approximately 30%, controller 112 may
coordinate services times of engines 102A and 102N.
[0046] Responsive to determining that the differential exceeds a
threshold (220, YES path), controller 112 may refrain from
adjusting the first amount of mechanical power being provided by
the first engine. For example, controller 112 may avoid adjusting
the mechanical power being provided by engines 102A and 102N to
balance service times if the difference in deterioration factors is
too great (e.g., greater than 50%).
[0047] Conversely, controller 112 may adjust the first amount of
mechanical power being provided by the first engine (230) in
response to determining that the differential does not exceed the
threshold (220, NO path) and may adjust, based on the first amount
of mechanical power being provided by the first engine, a second
amount of mechanical power being provided by the second engine to
compensate for the adjustment to the first amount of mechanical
power (240). For example, controller 112 may decrease the amount of
mechanical power being provided by engine 102A to decrease a rate
of change in the deterioration factor of engine 102A (e.g., to
extend the service life of engine 102A) or may increase the amount
of mechanical power being provided by engine 102A to increase a
rate of change in the deterioration factor of the engine 102A
(e.g., to shorten the service life of engine 102A). In any case,
whether controller 112 increases or decreases the power output from
engine 102A, controller 112 may adjust the power output of engine
102N to compensate for the adjustment to 102A such that system 100
continues to receive the required amount of mechanical power form
engines 102. In other words, if controller 112 decreases the power
output from engine 102A by some amount, controller 112 may increase
the power output from engine 102N by a similar amount.
[0048] In some examples, controller 112 may adjust the amount of
mechanical power being provided by engine 102A in response to
determining a rate of change in the deterioration factor of engine
102A exceeds a rate of change in a deterioration factor of engine
102N. Said differently, controller 112 may perform operations
200-240 in response to determining that engine 102A may be
deteriorating faster than engine 102N which causes the
deterioration factor of engine 102A to increase more rapidly than
deterioration factor of engine 102N. For example, while controller
112 may estimate the deterioration factors of engines 102A and 102N
to be approximately 50%, controller 112 may determine that the
deterioration factor of engine 102A suddenly increases to 90%
(e.g., after suffering from catastrophic component failure, combat
damage, bird strike, or experiencing some other failure condition)
while the deterioration factor of engine 102N only increases
slightly above 50%. Controller 112 may determine that the sudden
change in deterioration of one engine but not the other requires
management to extend the service life of all of engines 102.
[0049] While the above example has been described from the
perspective of engine 102A, similar operations may be performed
against engine 102N or any other one of engines 102. For example,
controller 112 may adjust the amount of mechanical power being
provided by engine 102A in response to detecting a change in the
deterioration factor of engine 102N. For instance, while controller
112 may estimate the deterioration factors of engines 102A and 102N
to be approximately 50%, controller 112 may determine that the
deterioration factor of engine 102N suddenly increases to 90% while
the deterioration factor of engine 102A continues to remain at
approximately 50%.
[0050] Although in some examples, controller 112 may adjust
mechanical output from engines 102 to extend the service life of
one or more of engines 102, in other instances, controller 112 may
deliberately burn up or shorten the service time of one of engines
102 (e.g., a good engine) to match the service life of that engine
102 with a badly deteriorated engine 102. For example, system 100
may experience a failure condition (e.g., due to damage from
combat, damage from a bird strike, or some other failure condition)
causing engine 102A to change from having a deterioration factor of
50% to having a deterioration factor of 90%. To prevent engine 102A
from deteriorating further, controller 112 may dramatically
increase the power being commanded from engine 102N to cause the
deterioration factor of engine 102N to catch-up with the
deterioration factor of engine 102A. While holding, or at least
minimizing the increase in the deterioration factor of engine 102A
beyond 90%, controller 112 may control the power output from engine
102N to cause the deterioration factor of engine 102N to increase
from 50% to 90% even though engine 102N did not experience the
failure condition that engine 102A experienced.
[0051] FIG. 3 is a conceptual diagram illustrating degradation
rates of two different engines of an example multi-engine system
that is configured to adjust the mechanical power being provided by
multiple engines to balance the respective degradation levels of
each of the engines, in accordance with one or more aspects of the
present disclosure. FIG. 3 is described below in the context of
system 100 of FIG. 1 as well as operations 200-240 of FIG. 2.
[0052] FIG. 3 includes degradation glide slopes 300A and 300B of
engine 102A and degradation glide slopes 302A and 302B of engine
102N. As shown in FIG. 3, both engines 102A and 102N are "100%
healthy" at time t0 or at least at the same degradation level. At
time t0, controller 112 may determine that both engines 102A and
102N have approximately the same, respective deterioration factors
that correspond to approximately 0% indicating that neither of
engines 102A or 102N has degraded. In some cases, engines 102A and
102N may be newly installed engines of system 100, newly
overhauled, etc.
[0053] In any case, during operational use, engine 102N may degrade
faster than engine 102A. For example, as illustrated by a
comparison between degradation glide slopes 300A and 302A between
times t0 and t1, either due to manufacturing differences or other
characteristics that make engine 102A unique from engine 102N,
engine 102N may degrade faster than engine 102A causing the
deterioration factor of engine 102A to increase at a faster rate
than the rate of increase of the deterioration factor of engine
102N. At time t1, controller 112 may estimate that engine 102A has
a deterioration factor of 50% whereas engine 102N has a
deterioration factor of 70% and if left unchecked, engine 102N will
degrade to a 100% deterioration factor at time t2 and engine 102A
will degrade to a 100% deterioration factor at time t4.
[0054] Rather than continue to cause engines 102A and 102N to
evenly split the power required by system 100, controller 112 may
alter its mechanical power control scheme associated with engines
102 to compensate for the differences in degradation glide slopes
300A and 302A, and to coordinate the service times of engines 102A
and 102N. For example, controller 112 may increase the amount of
mechanical power being extracted from engine 102A so as to increase
the rate at which the deterioration factor of engine 102A
increases, thereby causing engine 102A to degrade faster and
according to degradation glideslope 300B. Controller 112 may
decrease the amount of mechanical power being extracted from engine
102N so as to cause engine 102N to degrade slower and according to
degradation glideslope 302B thereby decreasing the rate at which
the deterioration factor of engine 102N increases. In this way,
controller 112 may cause engines 102A and 102N to continue to
satisfy the mechanical power needs of system 100 while causing
engines 102A and 102N to reach their respective service times at
approximately the same time (e.g., at time t3).
[0055] In one or more examples, the operations described may be
implemented in hardware, software, firmware, or any combination
thereof. If implemented in software, the operations may be stored
on or transmitted over, as one or more instructions or code, a
computer-readable medium and executed by a hardware-based
processing unit. Computer-readable media may include
computer-readable storage media, which corresponds to a tangible
medium such as data storage media, or communication media including
any medium that facilitates transfer of a computer program from one
place to another, e.g., according to a communication protocol. In
this manner, computer-readable media generally may correspond to
(1) tangible computer-readable storage media, which is
non-transitory or (2) a communication medium such as a signal or
carrier wave. Data storage media may be any available media that
can be accessed by one or more computers or one or more processors
to retrieve instructions, code and/or data structures for
implementation of the techniques described in this disclosure. A
computer program product may include a computer-readable
medium.
[0056] By way of example, and not limitation, such
computer-readable storage media can comprise RAM, ROM, EEPROM,
CD-ROM or other optical disk storage, magnetic disk storage, or
other magnetic storage devices, flash memory, or any other medium
that can be used to store desired program code in the form of
instructions or data structures and that can be accessed by a
computer. Also, any connection is properly termed a
computer-readable medium. For example, if instructions are
transmitted from a website, server, or other remote source using a
coaxial cable, fiber optic cable, twisted pair, digital subscriber
line (DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
DSL, or wireless technologies such as infrared, radio, and
microwave are included in the definition of medium. It should be
understood, however, that computer-readable storage media and data
storage media do not include connections, carrier waves, signals,
or other transient media, but are instead directed to
non-transient, tangible storage media. Disk and disc, as used
herein, includes compact disc (CD), laser disc, optical disc,
digital versatile disc (DVD), floppy disk and Blu-ray disc, where
disks usually reproduce data magnetically, while discs reproduce
data optically with lasers. Combinations of the above should also
be included within the scope of computer-readable media.
[0057] Instructions may be executed by one or more processors, such
as one or more DSPs, general purpose microprocessors, ASICs, FPGAs,
or other equivalent integrated or discrete logic circuitry.
Accordingly, the term "processor," as used herein may refer to any
of the foregoing structure or any other structure suitable for
implementation of the techniques described herein. In addition, in
some aspects, the functionality described herein may be provided
within dedicated hardware and/or software modules. Also, the
techniques could be fully implemented in one or more circuits or
logic elements.
[0058] The techniques of this disclosure may be implemented in a
wide variety of devices or apparatuses, including a processor, an
integrated circuit (IC) or a set of ICs (e.g., a chip set). Various
components, modules, or units are described in this disclosure to
emphasize functional aspects of devices configured to perform the
disclosed techniques, but do not necessarily require realization by
different hardware units. Rather, as described above, various units
may be combined in a hardware unit or provided by a collection of
interoperative hardware units, including one or more processors as
described above, in conjunction with suitable software and/or
firmware.
[0059] Various examples have been described. These and other
examples are within the scope of the following claims.
* * * * *