Patent Application
20100036540
1. Field
The present disclosure relates generally to managing systems and in particular, to managing power systems. Still more particularly, the present disclosure relates to a method, apparatus, and program code for reducing a total life cycle cost for a system containing a set of mechanical, electrical, and other components that provide power generation, conversion, distribution, and usage.
2. Background
With an aircraft, the cost of the aircraft is one part of the total life cycle cost. Other costs include maintenance costs, energy usage costs, and costs to replace and/or repair systems and components. Further, another cost may be the availability of the aircraft. A cost is present in terms of lost revenue when an aircraft is in maintenance or otherwise unavailable.
Health monitoring systems have been implemented in aircraft to monitor various systems, such as, for example, electrical power generation systems, braking systems, engine systems, and other systems. With a capability of monitoring the different systems, fault detection and isolation may be performed more quickly. Further, health monitoring systems also may provide a capability to predict when faults or less than optimal performance of a system may occur. With this type of information, maintenance planning may be improved.
Further, different control systems in an aircraft are designed to achieve or reach various performance metrics. For example, control systems may be used to ensure that performance levels are reached by the different systems in an aircraft. More particularly, control systems may be used to ensure that electric actuators in an aircraft reach specified speed and accuracy performance levels. Additionally, these controllers also may be programmed and designed to reduce energy usage. These and other efforts are made to reduce the total life cycle cost of aircraft.
In one advantageous embodiment, an apparatus comprises a power source, a set of primary loads, a set of life extension loads, and a controller. The power source is capable of supplying power and the set of primary loads is capable of being operated using the power. The set of life extension loads is capable of being operated using the power and capable of extending a life of the set of primary loads. The controller is capable of controlling an operation of the set of primary loads and the set of life extension loads based on performance, energy use, and life to reduce a total cost.
In another advantageous embodiment, an apparatus comprises a load and a controller. The controller is capable of controlling an operation of the load based on performance, energy use, and life time to reduce a total cost of the load.
In yet another advantageous embodiment, a method is present for operating a set of loads. The method is capable of monitoring a set of parameters and energy use for the set of loads; identifying a remaining life for the set of loads; and changing at least one of performance and energy use for the set of loads to reduce a total cost for the set of loads based on a policy.
The features, functions, and advantages can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments in which further details can be seen with reference to the following description and drawings.
The novel features believed characteristic of the advantageous embodiments are set forth in the appended claims. The advantageous embodiments, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an advantageous embodiment of the present disclosure when read in conjunction with the accompanying drawings, wherein:
Referring more particularly to the drawings, embodiments of the disclosure may be described in the context of the aircraft manufacturing and service method 100 as shown in
During production, component and subassembly manufacturing 106 and system integration 108 of aircraft 200 in
Each of the processes of aircraft manufacturing and service method 100 may be performed or carried out by a system integrator, a third party, and/or an operator. In these examples, the operator may be a customer. For the purposes of this description, a system integrator may include, without limitation, any number of aircraft manufacturers and major-system subcontractors; a third party may include, without limitation, any number of venders, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
With reference now to
Apparatus and methods embodied herein may be employed during any one or more of the stages of aircraft manufacturing and service method 100 in
Also, one or more apparatus embodiments, method embodiments, or a combination thereof may be utilized during production stages, such as component and subassembly manufacturing 106 and system integration 108 in
The different advantageous embodiments recognize and take into account that currently available management systems are capable of only managing the performance and/or power usage of a system. The different advantageous embodiments recognize that these types of systems are not capable of controlling loads in a manner that extends the life of the entire system.
The different advantageous embodiments recognize that extending the life of a system does not necessarily involve reaching performance metrics and/or reducing energy usage costs. The different advantageous embodiments recognize that the total life cycle costs include both energy costs to operate a system and repair costs to repair and/or replace the system. The different advantageous embodiments recognize and take into account that currently used systems are not capable of reducing total costs.
Thus, the different advantageous embodiments provide a method and apparatus for managing loads in a system to reduce the total costs of the system. The management of the loads may include managing subsystems that contain power sources and loads. In one advantageous embodiment, an apparatus has a power source capable of supplying power, a set of primary loads, a set of life extension loads, and a controller. A set as used herein refers to one or more items. For example, a set of primary loads is one or more primary loads.
The controller is capable of controlling the operation of the set of power sources, primary loads and the set of life extension loads based on performance, energy use, and life to reduce a total cost. The performance is the manner in which the different sources or loads may perform. The energy may be provided by different power sources and usage may be the energy used by the different loads. The life in these examples is the life of the different loads. In other words, the life is how long a particular load may last. The life of a power source or load may vary depending on the performance metric set for the particular load.
With reference now to
In these examples, life extension load system 302 contains set of life extension loads 310, while primary load system 304 contains set of primary loads 312. A life extension load within set of life extension loads 310 is associated with a primary load within set of primary loads 312. In these examples, a load is a device that uses hydraulic, pneumatic, mechanical, electrical, or other types of power. Loads also may be referred to in conjunction with their power source. For example, loads that use electrical power may be referred to as electrical loads.
A life extension load is associated with a primary load when the life extension load provides a capability to extend the life of the primary load. Set of life extension loads 310 may comprise, for example, at least one of a liquid cooling system, a ram air cooling system, an extended cooling system, a vibration control device, an acoustic control device, a power filtering unit, a fluid filtering unit, a lubrication unit, and some other suitable device.
As used herein, the phrase “at least one of” when used with a list of items means that different combinations of one or more of the items may be used and only one of each item in the list may be needed. For example, “at least one of item A, item B, and item C” may include, for example, without limitation, item A or item A and item B. This example also may include item A, item B, and item C or item B and item C.
In other examples, “at least one of” may be, for example, without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or other suitable combinations.
Set of primary loads 312 in these examples may comprise at least one of a hydraulic system, avionics, a landing gear system, an engine, a brake system, an environmental control system, an in-flight entertainment system, a navigation system, and some other suitable device. Life extension load system 302 and primary load system 304 are powered by power source system 306. Power source system 306 supplies power 314 to life extension load system 302 and supplies power 316 to primary load system 304.
Power source system 306 supplies power to loads. Power source system 306 may take various forms. For example, power source system 306 may be a generator, an engine, a battery, a fuel cell, an electronic power supply, or some other suitable source of power. Power source system 306 may vary power 314 and power 316 supplied to different loads within life extension load system 302 and/or primary load system 304. The variance of power supplied is controlled by controller 308. In these examples, operational control 318 may send control signal 332 to power source system 306 to vary power 314 and/or power 316 as needed.
In these examples, power source system 306 may be a power source or may be multiple power sources that provide power. Power source system 306 may contain heterogeneous or homogeneous power sources depending on the particular implementation. Reduction of power to a load may be associated with extension of the life of the load. In a like manner, reduction of power from a power source may be associated with extension of the life of the power source.
Further, in some advantageous embodiments, some primary loads may have more than one life extension load associated with the primary load. Also, a life extension load within set of life extension loads 310 also may be associated with power source system 306.
Further, operational control 318 and controller 308 may send control signals 320 to life extension load system 302 and control signals 322 to primary load system 304. Control signals 320 and 322 change the manner in which different loads operate. Control signals 320 and 322 may be used to change the performance and/or energy usage of the different loads within life extension load system 302 and primary load system 304. Operational control 318 is a software process and makes these changes based on data received from life extension load system 302 and primary load system 304. This data may be identified using sensors 324 and sensors 326.
Sensors 324 monitor set of life extension loads 310 within life extension load system 302, while sensors 326 monitor set of primary loads 312 within primary load system 304. Sensors 324 may generate data, such as energy use data 328 and parameters 330. Sensors 326 may generate data, such as energy use data 332 and parameters 334. This data is sent back to controller 308.
The data from sensors 324 and 326 is used by life extension estimator 336 in conjunction with models 338 to identify the remaining life for a particular load within life extension load system 302 and/or primary load system 304. Life extension estimator 336 also is implemented as a software process in these examples. Models 338 contain models of the different loads within life extension load system 302 and primary load system 304. These models may be used to identify life remaining for a particular load based on energy usage and/or parameters returned for the particular load. Models 338 also may include models for identifying the total costs of operating loads.
Models 338 contain information needed to estimate the life of a power source or load based on various parameters that are present during operation of the load. The life of a load is how long the load will last until a replacement of the load is needed. For example, a capacitor in a motor drive system may have an expected life based on the core temperature of the capacitor and the voltage under which the capacitor operates.
As a result, the life expectancy of the motor drive system based on the capacitor may be calculated in response to parameters such as the core temperature and the voltage. With this example, the parameters received from sensors 324 and/or sensors 326 may include a core temperature and a voltage for a capacitor.
A model for the capacitor may be used to identify the remaining life with these parameters. In these examples, a capacitor manufacturer may specify the capacitor life as a function of the capacitor core temperature and applied voltage; the core temperature may be further identified as a function of the amplitude and frequency of the ripple current, Equivalent Series Resistance (ESR), and of the ambient operating temperature of the capacitor. This type of information is available and/or can be derived for many types of sources or loads under specified operating conditions.
Further, this type of information may be empirical data gathered from operation of a load. In these different illustrative examples, the models may be linear or non-linear models, or combinations thereof, depending on the particular implementation. These types of models may be obtained for various sources or loads. For example, the life of a generator, fuel cell, motorized pump, a vehicle, a computer, or some other device may be modeled for use in models 338.
Based on the amount of life remaining, operational control 318 may send control signals 320 and/or control signals 322 to change the rate at which the life remaining for the load is reduced and/or used. This change may be performed to reduce the overall costs of a primary load. This cost also may include the cost for the life extension load associated with the primary load. The generation of these control signals may be performed using policy 340.
Policy 340 is a set of rules and/or parameters used to generate control signals 320 and control signals 322. Models 338 may contain information used to apply policy 340 in generating control signals 320 and control signals 322. For example, a model may be present to identify an optimal operation point to minimize the total cost to operate a load. Further, policy 340 may apply a criteria for performance and/or energy use to a model within models 338 in generating control signals 320 and control signals 322.
Policy 340 may provide tools to balance the performance, energy use, and life of a particular load or set of loads. The policy may specify balancing these types of parameters for a single load, a primary load and an associated life extension load, or an entire grouping of loads within system management environment 300. In these examples, policy 340 may be used to reduce a total cost for one or more loads within life extension load system 302 and primary load system 304. In other examples for aircraft operations, the policy may include cost factors for schedule delay, in-flight diversions, loss of capability to meet extended over water operations, and loss of automatic landing capability.
The reduction of the total cost may be performed with parameters set for performance and energy use. For example, a certain minimal level of performance may be required. The different advantageous embodiments may increase the energy use to meet the performance and to increase the life of a particular device, which may be a power source or load. By increasing the life, the total cost of the particular device may be reduced even though the energy use is increased. This total cost may be reduced because of a reduction in replacement costs and/or maintenance costs when increased energy use is applied.
In one example, a life extension load may be a cooling unit associated with a primary load in the form of an in-flight entertainment system. By maintaining the in-flight entertainment system at a particular temperature, the life of the in-flight entertainment system may be increased even though the energy consumption is increased. As a result, the total cost of the in-flight entertainment system may be reduced even though extra energy may be consumed by the cooling system associated with the in-flight entertainment system.
In this example, by maintaining the in-flight entertainment system at the particular temperature, the life of the cooling unit may be decreased. The cost of replacing and/or maintaining the cooling unit may be small when compared to maintenance and/or replacement costs for the in-flight entertainment system. As a result, this type of operation may result in a lower total cost even though the cooling unit may be replaced more often.
In other advantageous embodiments, a primary load may not have a life extension load associated with it. In this case, the performance of the primary load may be reduced to the required level and/or a cooling system integral to the primary load may be activated more often to increase the life of the primary load.
In these examples, policy 340 is directed towards reducing the total or lifetime cost of a load or a set of loads. The total costs may include the costs of the device itself, maintenance costs for the load, and/or costs for operating the load.
In reference now to
In this example, the X axis represents the pump flow rate, while the Y axis represents the cost to pump one cubic meter of fluid. Line 402 in graph 400 represents the equipment cost while line 404 represents the energy cost. Line 406 represents the total cost. The equipment cost represented in line 402 includes replacement costs for the equipment as well as maintenance costs. The total cost represented in line 406 represents a combination of the energy cost and/or the equipment cost.
Line 404 is initially high because of low motor efficiency at low speeds. Further, line 402 also is initially high because of component deterioration under minimal use. Both lines 402 and 404 then decrease sharply with a small increase in the pump flow rate until the lines reach minimal cost values. As the pump flow rate continues to increase, both lines 402 and 404 then also continue to increase steadily. The energy cost increases as the pump flow rate increases in this example, because of high motor power that is needed for the high flow rate.
Further, at the higher pump flow rate, accelerated depletion of motor winding life may occur as the motor temperature increases. As can be seen in this example, an optimal total cost in line 406 may be seen at point 408. Lines 402 and 404 may be balanced to minimize the total cost to operate the motorized pump in line 406 by balancing energy costs and equipment costs. Of course, if a certain performance level such as a desired pump flow rate is required, the total cost may increase. Graph 400 is an example of information that may be found within models 338 for different loads.
With reference now to
The cooling pump flow rate for a cooling pump in the vehicle is shown on axis 504. Axis 506 represents the vehicle speed. The cooling flow pump rate in axis 504 is for a motorized pump, which is an example of a life extension load in this example. The vehicle speed in axis 506 represents the operation of a primary load such as an engine.
As can be seen in this example, low vehicle speeds may result in inefficient energy use and low equipment utilization. As a result, the total cost may be high. High vehicle speeds result in a loss of efficiency and faster equipment wear.
In this example, graph 500 shows that a high cooling pump flow rate increases the lifetime of the engine but may increase energy usage and decrease the lifetime of the motorized pump. Point 508 represents an optimal operating point for both the cooling pump flow rate and the vehicle speed with respect to the total cost of driving the vehicle. Of course, performance parameters, such as the minimum or maximum allowable vehicle speed, may dictate a less than optimal operating point depending on the particular implementation. The selection of point 508 may be made using policy 340 in
With reference now to
In this depicted example, controller 602 may control the generation of power by power sources similar to 604, 606, 608, and 610. These power sources may be power generators and/or energy storage devices. These power sources generate power that may be placed onto aircraft power bus 611. Remote power distribution units 612, 614, 616 and 618 also are connected to aircraft power bus 611. Controller 602 also may control the distribution of power by these remote power distribution units. These remote power distribution units distribute power from aircraft power bus 611 to electrical loads 620, 622, 624 and 626.
Controller 602 controls the generation and distribution of power to these various loads in these examples. The control signals sent to the power sources and/or remote power distribution units may be such to control the operation of loads 620, 622, 624 and 626 in a manner that reduces the total cost to operate these loads. This total cost may be a total cost for an individual load or for the loads as a group.
For example, in reducing the overall costs for loads 620, 622, 624 and 626 as a group, controller 602 may increase the total cost to run one of the electrical loads such that the overall total costs may be reduced. If a load within these loads is nearing the end of life and a maintenance operation is scheduled to occur, that particular load may be operated at a higher level such that the life of that load decreases more quickly such that the load may be replaced during the next maintenance operation.
With this type of operation, the power supplied to other loads may be reduced to increase the life of the other loads such that those loads may last longer. In these examples, if power is supplied to another power source, that power source may also be considered a load in the different advantageous embodiments. This type of selection may be made when a maintenance operation is scheduled. If the cost of maintenance to replace one load more quickly results in an increase in life of the other loads, the total cost for the loads as a whole may be reduced. Of course, in other examples, controller 602 also may control the operation of the loads in addition to or in place of the power supplied to the loads.
With reference now to
In this example, controller 702 may control the generation of power by various power sources such as main generator 704, power source 706, power source 708, and power source 710. Controller 702 may be implemented using a controller such as, for example, controller 308 in
Additionally, sensors 726 may provide data that may be sent back through remote power distribution units 714 and 716 in these examples. Sensors 726 provide signals from switches or devices to turn loads on and off. Sensors 726 also may generate data such as, for example, identifying temperature in the winding of a generator or a motor, temperature in a motor drive, vibration from a fuselage of an aircraft, or other suitable sources. This data may be used to control loads 724.
Power distribution point 712 also may supply power directly to various components such as, for example, energy management unit 728, aircraft system 730, and aircraft system 732. Energy management unit 728 may control the availability of power sources such as, for example, power source 706, 708, and 710. For example, sensors 726 may provide energy use and parameters from loads 724. These aircraft systems may be, for example, an in-flight entertainment system, avionics, a navigation unit, or some other suitable device or system.
Controller 702 also may control the operation of various components within aircraft system management environment 700. Control signals may be sent to loads through data bus 740. Data such as energy use and parameters also may be sent on data bus 740. For example, controller 702 may control the operation of energy management unit 728, aircraft system 730, aircraft system 732, smart load 734, smart load 736, and smart sensor 738.
Controller 702 also may manage the operation of loads 724, the generation of power by main generator 704, power source 706, power source 708, and power source 710, and the distribution of power by power distribution point 712, remote distribution unit 714, remote distribution unit 716, remote distribution unit 718, remote distribution unit 720, and remote distribution unit 722.
With reference now to
In this illustrative example, controller 802 includes life and maintenance control 816, shared information 818, and supply and load control 820. Life and maintenance control 816 may control the operation of loads 804, 806, and 808. Life and maintenance control 816 may generate commands to these loads to meet various performance constraints, as well as to form operations that may optimize the life. In optimizing life and energy operations, various performance constraints or loads 804, 806, and 808, are taken into account by life and maintenance control 816.
Supply and load control 820 sends commands to sources 810, 812, and 814 to supply power to loads 804, 806, and 808. These commands may connect or disconnect these power sources as well as turn on or off these power sources based on performance and energy constraints. For example, supply and load control 820 may turn off power if power is not needed and restore power when more power is needed by loads 804, 806, and 808.
Shared information 818 is information that may be supplied by life and maintenance control 816 to supply and load control 820, and/or from supply and load control 820 to life and maintenance control 816 to meet various constraints.
The generation of commands in these examples may be based on various inputs. In these examples, the inputs include, for example, without limitation, schedule of life of systems and/or time to next overhaul 822, schedule of current loads and status 824, and schedule of power supplies and current status 826.
With reference now to
The process begins while monitoring a set of parameters and energy use for a set of loads (operation 900). The parameters and energy use may be identified using sensors associated with the loads. Energy use also may be identified based on knowing the amount of power sent to the set of loads. The parameters and energy use may be identified for each load individually as well as for the set of loads as a group.
The process then identifies remaining life for the set of loads (operation 902). The process then compares the parameters, energy use, and/or remaining life with a policy (operation 904). The policy may include a set of rules in which the parameters, energy use, and/or life may be compared with a model. In these examples, the model may be a model for the total cost of operating a load. In these examples, a model may be present for each load within the set of loads. Further, a model also may be present for the set of loads as a whole.
Next, a determination is made as to whether performance and/or energy use should be changed for the set of loads (operation 906). This change may be for one or more loads within the set of loads. If a change should be made, control signals are sent to the set of loads (operation 908). The process then returns to operation 900 as described above. If a change is not to be made, the process proceeds directly back to operation 900.
Thus, the different advantageous embodiments provide a method and apparatus for operating loads. The different advantageous embodiments may include processes and a controller that are capable of controlling the operations of a set of loads. This set of loads may include a primary load as well as a life extension load that is associated with the primary load. The life extension load is capable of operating to extend the life of the primary load. The controller controls the operation of the loads based on performance, energy use, and life to reduce a total cost of operating the loads.
The different advantageous embodiments can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment containing both hardware and software elements. Some embodiments are implemented in software, which includes forms, such as, for example, without limitation, firmware, resident software, and microcode.
Furthermore, the different embodiments can take the form of a computer program product accessible from a computer usable or computer readable medium providing program code for use by or in connection with a computer or any device or system that executes instructions. For the purposes of this disclosure, a computer usable or computer readable medium can generally be any tangible apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The computer usable or computer readable medium can be, for example, without limitation, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium. Non limiting examples of a computer readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk, and an optical disk. Optical disks may include compact disk—read only memory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.
Further, a computer usable or computer readable medium may contain or store a computer readable or usable program code such that when the computer readable or usable program code is executed on a computer, the execution of this computer readable or usable program code causes the computer to transmit another computer readable or usable program code over a communications link. This communications link may use a medium that is, for example, without limitation, physical or wireless.
A data processing system suitable for storing and/or executing computer readable or computer usable program code will include one or more processors coupled directly or indirectly to memory elements through a communications fabric, such as a system bus. The memory elements may include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some computer readable or computer usable program code to reduce the number of times code may be retrieved from bulk storage during execution of the code.
Input/output or I/O devices can be coupled to the system either directly or through intervening I/O controllers. These devices may include, for example, without limitation, keyboards, touch screen displays, and pointing devices. Different communications adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Non-limiting examples, such as modems and network adapters, are just a few of the currently available types of communications adapters.
The description of the different advantageous embodiments has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Further, different advantageous embodiments may provide different advantages as compared to other advantageous embodiments. The embodiment or embodiments selected are chosen and described in order to best explain the principles of the embodiments, the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
